JP4695351B2 - Wireless communication system and road-to-vehicle communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the probability that a roadside machine and an on-vehicle device perform miscommunication outside a communication area, when a communication antenna is mounted onto a ceiling wall or a roof, as in indoor or basement parking lots and drive-throughs in restaurants. <P>SOLUTION: A communication antenna system is provided which starts to emit transmission radio waves within a communication area to start to communicate with the on-vehicle device, and lowers the transmission power value or stops emitting the transmission radio waves according to the communication termination with the on-vehicle device. The transmission output of the communication antenna system is &le;4 dBm and the reception sensitivity is &ge;-55 dBm. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

The present invention relates to a wireless communication system and a road-to-vehicle communication method for performing wireless communication with a vehicle-mounted wireless device (vehicle-mounted device) mounted on a vehicle. The present invention also relates to a communication antenna, an in-vehicle device, and an IC card used in the wireless communication system.
In particular, the DSRC (Dedicated Short Range Communication) system that performs wireless communication between a wireless device (roadside device) on the roadside and the vehicle-mounted device in a limited communication area within the vehicle's roadway (hereinafter referred to as a roadway). It is suitable for use in wireless communication.

As a wireless communication system using the DSRC system, an automatic toll collection (ETC) system has been put into practical use.
In the conventional ETC system, the radio wave transmitted from the roadside device may be reflected on the road surface, the body of the car, the roof of the toll booth, the land, or the like. At this time, before the second succeeding vehicle passes the vehicle detector and enters the communication area, the wireless communication between the vehicle-mounted device and the roadside machine is started, and the first vehicle passing through the communication area Is a non-ETC vehicle (a vehicle that cannot receive automatic tolls because it does not have an on-board device or does not work), the non-ETC vehicle is converted to an ETC vehicle (automatic toll collection is possible) Vehicle).

  To prevent such misidentification, immediately after the vehicle entering the lane passes the first vehicle detector, the license plate information is acquired by the license plate recognition device, and the vehicle license plate is communicated with the vehicle-mounted device. By acquiring the information, compare both the acquired license plate information, and if the license plate information matches by comparison, it is determined that the vehicle can accept automatic fee collection. If the license plate information does not match, automatic fee collection is possible. A system for determining an impossible vehicle has been devised. In this system, it is possible to quickly specify whether an approaching vehicle is an ETC vehicle even under a situation where radio wave reflection occurs (see Patent Document 1).

JP 2002-329222 A

  In addition, in order to prevent non-ETC cars and ETC cars from being misidentified due to radio wave reflections, by attaching radio wave absorbers to various structures such as toll booths and gantry to reduce the arrival of radio waves from adjacent lanes, It is also known that multipath due to radio waves coming directly from a roadside antenna and radio waves coming indirectly by reflection of a roof can be prevented, and erroneous determination between ETC vehicles and non-ETC vehicles can be prevented (see Patent Document 2).

JP 2001-134895 A

  When using DSRC wireless communication in indoor parking lots, covered gas stations, underground parking lots, etc., ceilings that make up metal walls are installed on the inside of the parking lots and gas station roofs, or buildings Due to the large number of structures such as support columns and pipes, multiple reflections and unnecessary reflections of radio waves occur between the road surface, ceiling, and structures in the parking lot. Due to the influence of multiple reflections and unnecessary reflections, the communication between the roadside device placed on the traffic road and the vehicle-mounted device is performed outside the regular communication area set for communication, and the probability of erroneous communication is high. There was a problem of becoming.

  For example, a registered vehicle that is permitted to use a designated indoor parking lot so that it can freely enter and leave the parking lot without stopping once before the ticketing machine at the parking lot through communication between the on-board device and the roadside machine ( It is assumed that the use registration vehicle enters and exits the designated indoor parking lot. In this case, while the usage registration vehicle passes through the regular communication area, the roadside device may communicate with the vehicle-mounted device of another usage registration vehicle (outside area registration vehicle) that exists outside the communication area. At this time, the license plate information of the out-of-area use registration vehicle acquired by communication with the vehicle-mounted device is compared with the license plate information of the use registration vehicle in the communication area acquired by the license plate recognition device. As a result of the comparison, the registered vehicle is judged as an unregistered vehicle due to the discrepancy in the license plate information, stopped by the stop rod of the breaker, and temporarily stopped in front of the ticketing machine, allowing free access to the parking lot Limited. Therefore, there is a problem that even a use registration vehicle that has been registered correctly is erroneously determined as an unregistered vehicle.

  In addition, when installing a communication antenna for a roadside unit under the ceiling of an indoor parking lot or an underground parking lot, the height of the antenna is less than that of a toll gate roof or gantry due to ceiling height restrictions. Lower. For this reason, the electric field intensity of the radio wave transmitted from the roadside device to the communication area is increased, and an area having a high electric field intensity is generated outside the communication area due to radio wave reflection on the road surface. This further increases the probability that the roadside device and the vehicle-mounted device miscommunicate.

  Furthermore, when installing a radio wave absorber in an indoor parking lot in order to prevent erroneous communication between the roadside machine and the vehicle-mounted device, the radio wave absorber is placed over a wide area on the ceiling around the antenna that constitutes the roadside machine. There is a problem that it is necessary to wear, and the cost of installing the radio wave absorber is high. Therefore, it has been desired to reduce the cost due to the mounting of the radio wave absorber.

  The present invention has been made to solve such a problem, and is directly or indirectly on a ceiling wall surface or a roof, such as an indoor or underground parking lot, a covered gas station, or a drive-through of a restaurant. An object of the present invention is to obtain a wireless communication system that reduces erroneous communication between a roadside device having a communication antenna installed directly under a ceiling wall surface or a roof and a vehicle-mounted device of the vehicle.

The wireless communication system according to the present invention starts communication by starting emission of transmission radio waves in the communication area with the vehicle-mounted device, and stops emission of transmission radio waves according to the end of communication with the vehicle-mounted device, or A communication antenna is provided that stops the emission of transmission radio waves within a predetermined time from the start of transmission radio wave emission.
The communication antenna may have a transmission output of 4 dBm or less and a reception sensitivity of −55 dBm or more.

A vehicle detector that detects the passage of the vehicle within a communication area with the vehicle-mounted device; and a reception power level that is within a first predetermined distance from the vehicle detector toward the near side in the vehicle traveling direction. The received power level of the vehicle-mounted device has an on-vehicle device at a second predetermined distance or longer than the first predetermined distance from the vehicle detector toward the front side in the vehicle traveling direction. A communication antenna having a transmission power characteristic that is lower than the reception sensitivity of the receiver, and the communication antenna starts communication when a vehicle passage is detected by the vehicle detector. After the start of the transmission, the emission of the transmission radio wave is stopped according to the end of the communication with the vehicle-mounted device, or the emission of the transmission radio wave is stopped within a predetermined time from the start of the emission of the transmission radio wave.
The first predetermined distance may be set to 1.5 m to 3 m, and the second predetermined distance may be set to 3 m to 5 m.

  Furthermore, a vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector, and specification of the vehicle-mounted device transmitted from the vehicle-mounted device according to vehicle passage detection by the vehicle detector A communication control device for acquiring information, a database for storing the specific information of the on-vehicle device and the number information, a specific information of the on-vehicle device acquired by the communication control device, and a specific information of the on-vehicle device stored in the database And outputs an opening / closing signal for opening / closing the circuit breaker when the result of comparison is the same, and comparing the number identified by the vehicle number reader with the number stored in the database. An information processing apparatus that outputs an opening / closing signal for opening / closing the circuit breaker when the results coincide with each other may be provided.

  According to the present invention, it is possible to reduce the probability of erroneous communication between the roadside device and the vehicle-mounted device outside the normal communication region due to radio wave reflection between the ceiling wall surface and the road surface.

  In addition, it is possible to reduce a probability that a legitimate use registered vehicle is erroneously determined as a use unregistered vehicle.

Embodiment 1 FIG.
1 is a perspective view showing a configuration of a wireless communication system according to Embodiment 1 of the present invention.
In FIG. 1, a vehicle 1 travels in a traveling direction of the vehicle 1 from an entrance of an indoor parking lot (hereinafter referred to as a parking lot) toward a parking area (not shown) and passes through a passage 3 provided in an entrance gate 100. Then enter the parking area. The vehicle 1 has an in-vehicle device 10 mounted on a dashboard in the vehicle near the windshield (window). Usually, the vehicle-mounted device 10 has a height of 1 m to 1.5 m from the ground contact surface of the tire within a range of 0.5 m to less than 2 m in the longitudinal direction of the vehicle from the tip position of the vehicle nose (between the front bumper tip and the windshield). It is installed in the range.

  In the entrance gate 100, islands 2 a and 2 b are arranged across the traffic path 3 so as to form the traffic path 3 of the vehicle 1. The width of the traffic path 3 is about 3.5 m. A desired desired communication area 4 is formed on the traffic path 3 between the islands 2a and 2b. In the figure, for convenience of explanation, the communication area 4 is shown as a substantially rectangular area virtually surrounded by a solid flat curve, but the actual communication area is formed by radially enclosing a trapezoidal area. Complicated shape is made. The islands 2a and 2b and the traffic path 3 constitute a traveling lane of the vehicle. A loop coil for detecting a magnetic field change due to the passage of the vehicle body (metal body) of the vehicle 1 is embedded under the road surface around the communication area 4 on the passage 3.

An optical receiver 5a is installed on the island 2a, and an optical transmitter 5b is installed on the island 2b. The optical receiver 5a and the optical transmitter 5b constitute a vehicle detector 50. The vehicle number reading device 6 is installed on the island 2a. The vehicle number reading device 66b is installed on the island 2b. The vehicle number reading device 6 and the vehicle number reading device 66b each identify a number stamped on the number plate. The ticket issuing machine 7 is installed between the vehicle detector 50 and the vehicle number reading device 6 on the island 2a. The circuit breaker 8 is provided on the island 2 a adjacent to the vehicle number reading device 6. The circuit breaker 8 is provided with a stop rod 9 that can be opened and closed, and the stop rod 9 is raised or lowered.
In this embodiment, the vehicle number reading device 6 and the vehicle number reading device 66b are installed on the islands 2a and 2b on both sides of the passage 3, respectively. As a result, even if the vehicle 1 travels to the left or right in the traffic path 3, the number plate of the vehicle 1 can be reliably identified by each vehicle number reading device.

  The islands 2a and 2b are not necessarily required, and can guide the vehicle so that vehicles entering and leaving the parking lot can sequentially pass through the communication area 4, the vehicle detector 50, and the stop rod 9 installation positions. If so, it may be a fence or a lane displayed simply on the road surface.

  The communication antenna device 11 constitutes a roadside device together with the communication control device 12. The communication antenna device 11 is supported by a hanging tool 21 and is suspended from the ceiling 20 of the parking lot. Of course, in addition to hanging from the ceiling 20, an antenna may be attached to the upper part of a pole erected under the ceiling, and it goes without saying that there are various methods for installing the communication antenna device 11. For simplification of illustration, only a part of the ceiling 20 is shown in the figure. The communication control device 12 is disposed near the entrance gate 100. The mounting angle of the radiation surface of the communication antenna device 11 with respect to the horizontal plane (in other words, the mounting angle of the transmission radio wave 30 output from the communication antenna device 11 with respect to the vertical axis) θ is set to approximately 48 degrees. Has been.

FIG. 2 is a diagram illustrating the configuration of the communication antenna device 11 according to the first embodiment (FIG. 2A) and the configuration of the vehicle-mounted device (FIG. 2B).
In FIG. 2A showing the configuration of the communication antenna device 11, the communication antenna device 11 includes a transmission / reception antenna 111 and a transceiver 110. The transceiver 110 includes a transmission / reception level adjustment unit 112, a transmission / reception distributor 113, a transmitter 114, and a receiver 115.

  The transmission / reception antenna 111 is composed of a planar array antenna in which a plurality of antenna elements (radiating conductors) are arranged on a plane to constitute an antenna array. The transmission / reception antenna 111 is a directional antenna having desired gain characteristics, and operates as a transmission / reception antenna. In order to simplify the explanation, the input end (feeding point) side for inputting the transmission power when the transmission / reception antenna 111 is operated as a transmission antenna is called the antenna input end 111b, and the transmission power is transmitted to the space as a transmission radio wave. The radiating output end (antenna element) side is referred to as an antenna output end 111a. When the transmission / reception antenna 111 is operated as a receiving antenna, the antenna output end 111a is an input side of a received radio wave, and the antenna input end 111b is an output side of a reception signal received by an antenna element. The transmission / reception antenna 111 radiates the transmission power of the modulated RF signal (transmission output) output from the transceiver 110 with a desired antenna gain from the antenna output end 111a as a transmission radio wave. In addition, a reception radio wave input to the antenna element of the transmission / reception antenna 111 is received, and an RF signal (reception signal) is output from the antenna input end 111 b to the transceiver 110.

  The transmitter 114 receives a transmission signal from the communication control device 12 and performs power amplification and frequency modulation. The transmission output from the transmitter 114 is output to the transmission / reception level adjustment unit 112 via the transmission / reception distributor 113, and the transmission signal subjected to level conversion is output to the transmission / reception antenna 111. Also, the transmission / reception level adjustment unit 112 performs level conversion on the received signal received and input by the transmission / reception antenna 111, and outputs the level-converted signal to the transmission / reception distributor 113. The receiver 115 receives the output signal of the transmission / reception distributor 113, performs frequency demodulation and power amplification, and outputs a signal to the communication control device 12. The transmission / reception level adjustment unit 112 is configured by, for example, a variable attenuator (attenuator), and the reception sensitivity of the reception signal output from the transmission / reception antenna 111 (the electric field strength level of input power at which the receiver receives and reacts to the reception signal). Then, the level is adjusted to be equal to or higher than a predetermined reception sensitivity setting value (the electric field strength level of the minimum input power at which the receiver receives and reacts to the received signal). Further, the transmission signal output from the transmission / reception distributor 113 is attenuated to a predetermined magnitude.

FIG. 2B is a diagram illustrating a configuration of the vehicle-mounted device 10.
In the figure, the vehicle-mounted device 10 includes a transmission / reception antenna 120, a transmission / reception device 121, a communication controller 122, a memory 123, and an IC card reader / writer 124. The transmission / reception antenna 120 is composed of an omnidirectional antenna.

The IC card reader / writer 124 mounts (inserts) or removes (removes) a separate IC card 125. The IC card 125 is stored in an internal memory (not shown) such as identification information (card ID information) of the IC card 125, license plate information of a private vehicle, identification information of the vehicle-mounted device (vehicle ID information), and data for fee settlement. Stores information. That is, the vehicle ID information and the card ID information are associated in advance in the card information. When the IC card 125 is attached to the IC card reader / writer 124, the card information of the IC card 125 and the storage information of the vehicle-mounted device 10 are exchanged between the IC card 125 and the IC card reader / writer 124. . At this time, the IC card 125 transmits card information (or vehicle ID information) to the vehicle-mounted device 10. The vehicle-mounted device 10 transmits the vehicle ID information of the vehicle-mounted device 10 transmitted from the IC card 125 to the communication controller 122. The vehicle-mounted device 10 is such that the vehicle ID information in the card ID information of the IC card 125 matches the vehicle ID information stored in advance in the vehicle-mounted device 10 based on the received card information from the IC card 125. Check if there is a mismatch. If it is confirmed as a result of the match confirmation, it is determined that the card ID of the IC card 125 and the vehicle ID information of the vehicle-mounted device 10 are associated in advance.
The IC card 125 may be a non-contact type IC card configured with a resin card with a built-in nonvolatile memory and a wireless communication chip. In this case, the IC card 125 may be placed over the IC card reader / writer 124 or placed around the IC card reader / writer 124.

  The transmission / reception antenna 120 communicates with the communication antenna device 11 of the roadside unit. A reception signal received by the transmission / reception antenna 120 is sent to the transceiver 121. Based on this received signal, the transmitter / receiver 121 includes reception information such as a communication start request (polling request), a communication permission notification, an ID transmission request, and a communication disconnection request included in the signal transmitted from the communication antenna device 11. Take out. Based on the reception information output from the transceiver 121, the communication controller 122 performs communication processing such as communication activation, ID return, and amplification operation start of the transceiver 121. The memory 123 stores the aforementioned vehicle ID information as unique information for specifying the vehicle in advance. Since the vehicle-mounted device and the vehicle are associated one-to-one, the vehicle ID information includes the vehicle number, the serial number of the vehicle-mounted device, and the like (this will be described later). When the communication controller 122 acquires an ID transmission request from the received information, the communication controller 122 starts communication activation, reads the stored vehicle ID information with reference to the memory 123, and transmits the read vehicle ID information to the communication controller 122. . The communication controller 122 sends the received vehicle ID information to the transceiver 121 and starts the amplification operation of the transceiver 121. The transceiver 121 transmits a transmission signal including vehicle ID information to the transmission / reception antenna 120 (returns an ID). The transmission / reception antenna 120 radiates a signal received from the transceiver 121 as a transmission radio wave.

  In general, in a conventional ETC system that is currently in operation, the downlink radio communication frequency from the roadside device side to the vehicle-mounted device is 5.795 GHz or 5.805 GHz, and the uplink wireless communication frequency from the vehicle-mounted device to the roadside device side. The communication frequency is 5.835 GHz or 5.845 GHz, and the ASK modulation method is used. The antenna gain of the transmission / reception antenna in the communication antenna device is 12.7 dBi. In addition, the radio wave specifications are set so that the transmission output of the transmitter in the communication antenna device is 10 dBm (10 mW) or less and the reception sensitivity of the receiver is −65 dBm or more (reception sensitivity setting value is −65 dBm). .

  The reception sensitivity of the transmitter / receiver of the in-vehicle device 10 is −63 dBm to −57 dBm in consideration of manufacturing variation, and is approximately −60.5 dBm. The transmission output of the transceiver 121 of the vehicle-mounted device 10 is 10 dBm (10 mW), and the transmission output is about 11.8 dBm at the maximum considering the output fluctuation of ± 50%. In addition, the antenna gain of the transmitting / receiving antenna 120 in the vehicle-mounted device is approximately 0 to 3 dBi. Therefore, the transmission output from the transmission / reception antenna 120 of the vehicle-mounted device is 7 dBm to 14.8 dBm in consideration of manufacturing variations.

  In the DSRC system for indoor parking lots according to the first embodiment, the wireless communication frequencies of the transmitter 114 and the receiver 115 of the communication antenna device 11 and the transmitter / receiver 121 of the vehicle-mounted device 10 are defined in, for example, Table 1. Use the frequency (utilization frequency) in appropriate combination. If necessary, different frequencies may be used between adjacent entrance gates or exit gates. For example, the downlink from the communication antenna device 11 to the vehicle-mounted device 10 uses 5.795 GHz or 5.805 GHz, and the uplink from the vehicle-mounted device 10 to the communication antenna device 11 uses 5.835 GHz or 5.845 GHz. A modulation method for wireless communication uses ASK modulation, and a code format uses a split phase code format.

  The antenna gain of the transmission / reception antenna 111 is 12.7 dBi. The transmission output Ak at the antenna input end 111b of the transmission / reception antenna 111 is set to 4 dBm or less, preferably 2 dBm, and set to be smaller than the output 10 dBm of the transceiver of the vehicle-mounted device 10. Set the radio wave specifications so that the reception sensitivity Bk at the antenna input terminal 111b is −55 dBm or more (reception sensitivity setting value is −55 dBm), preferably −52 dBm or more (reception sensitivity setting value is −52 dBm). Yes.

  Specifically, by providing a transmission / reception level adjustment unit 112 between the transmission / reception antenna 111 and the transmission / reception distributor 113, the transmission output is attenuated and the reception sensitivity is lowered. In the following description, the circuit line loss such as the power loss of the transmission / reception distributor 113 and the power loss of the transmission line between the transmission / reception antenna 111, the transmitter 114, and the receiver 115 is ignored. Note that the vehicle-mounted device 10 according to the first embodiment has the same communication characteristics as those used in the conventional ETC system.

  In the first embodiment, for example, the transmission output A2 output from the output end of the transmitter 114 via the transmission / reception distributor 113 is preferably attenuated by 2 dBm by the transmission / reception level adjustment unit 112. Accordingly, for example, the transmission output Ak is preferably set to 2 dBm at the antenna side terminal (antenna input end 111b) of the transmission / reception level adjustment unit 112. Since the antenna gain is 12.7 dBi, the transmission output A1 is about 15 dBm on the antenna output end 111a side in front of the antenna (vertical plane or horizontal plane angle 0 °).

  Further, by setting the reception sensitivity B2 at the input end of the receiver to, for example, −54 dBm or more and providing the transmission / reception level adjustment unit 112, the sensitivity Bk at the antenna side terminal of the transmission / reception level adjustment unit 112 is set to, for example, −52 dBm or more. It is preferable to set. Since the antenna gain of the transmission / reception antenna 111 is 12.7 dBi, the reception sensitivity B1 on the antenna output end side of the transmission / reception antenna 111 is about −65 dBm or more.

  Note that the transmission / reception level adjustment unit 112 has an automatic gain adjustment function, and automatically adjusts the reception sensitivity at the input end of the receiver to be B2 = −54 dBm or more (reception sensitivity setting value B2 = −54 dBm). To do. In the following description, the transmission output of the communication antenna device 11 is represented by Ak = 2 dBm, and the reception sensitivity of the communication antenna device 11 is represented by Bk = −52 dBm or more (reception sensitivity setting value Bk = −52 dBm). Of course, the transmission / reception distributor 113 may be directly connected to the transmission / reception antenna 111 without providing the transmission / reception level adjustment unit 112. In that case, the transmission output of the transmitter 114 is set to Ak = 2 dBm, and the reception sensitivity of the receiver 115 is set to Bk = −52 dBm or more (reception sensitivity setting value Bk = −52 dBm).

Next, transmission characteristics of the communication antenna device 11 will be described.
FIG. 3 is a diagram illustrating an example of multiple reflection of transmission radio waves radiated from the communication antenna device 11. FIG. 3A is a diagram showing a state of reflection of radio waves before the vehicle 1 enters the communication area 4, and FIG. 3B is a state of reflection of radio waves after the vehicle 1 enters the communication area 4. FIG. 3A and 3B, a desired communication area for performing wireless communication between the communication antenna device 11 and the vehicle-mounted device 10 is illustrated as a communication area 4.

  The communication area 4 has a height that takes into account the installation height of the vehicle-mounted device 10 in the vehicle 1, where Hc is the height from the road surface of the traffic path 3 and L is the length of the area in the traveling direction of the vehicle 1. It is preferable to set Hc to be approximately 1 m to 1.5 m and length L to be approximately 2 m to 3.5 m. More preferably, the length L is set to about 3 m.

  The width W of the communication area 4 in the direction perpendicular to the traveling direction of the vehicle 1 is also preferably set to be approximately 2 m to 3 m, and more preferably is set to approximately 2.5 m. Is preferred. For example, since the width of the vehicle 1 is 1.8 m, considering the width of the roadway, when the vehicle 1 passes through the center of the roadway 3, the distance between the vehicle 1 and the island 2a or 2b is 0.85m. Become. Since the driver of the vehicle 1 travels at an interval of 0.3 m to 0.5 m from the island 2a or 2b so as to avoid contact with the island 2a or 2b, the width of the communication area 4 is set to 2.5 m. Then, this communication area 4 can substantially cover the traffic area of the vehicle 1.

  In the conventional ETC system, the size of the communication area is set to 4 m long × 3 m wide.

  FIG. 3A shows a communication area 40 (non-standard) outside the communication area 4 when a reflected wave 31 of the transmission radio wave 30 is generated between the ceiling 20 (canopy) of the parking lot and the road surface of the traffic path 3. (Communication area) is schematically shown.

  In FIG. 3B, the reflected wave 31 of the transmission radio wave 30 is generated between the ceiling 20 of the parking lot and the road surface of the traffic path 3, and the reflected wave 31 b is generated between the vehicle body of the vehicle 1 and the communication area 4. It schematically shows that a communicable area 41 is generated outside the network. The communicable area 41 here is, for example, approximately 1 m in the traveling direction of the vehicle 1, and is communicable area compared to the communicable area 40 when the vehicle 1 is not present in the communication area 4. The length of is shortened.

  This is because the phase is inverted when the transmission radio wave of the communication antenna device 11 is reflected by the metal vehicle body of the vehicle 1, so that the reflected wave 31 from the road surface 3 and the reflected wave 31 b from the vehicle 1 are generated. This is because the size of the communicable area 41 becomes smaller than the communicable area 40 by canceling out in phase.

  Further, in this case, the electric field intensity of the radio wave received by the vehicle-mounted device 10 is further weakened due to the loss of the radio wave in the windshield (window) of the vehicle 1, and in the communicable region 41, In the meantime, the probability that road-to-vehicle communication (details will be described later) is not established is further increased.

  For this reason, the vehicle detector 50 for detecting the passage of the vehicle 1 is installed in the communication area, and the emission of the transmission radio wave from the communication antenna device 11 is started only when the vehicle 1 passes through the communication area 4. And perform road-to-vehicle communication. The communication antenna device 11 radiates the transmission radio wave after a predetermined transmission time T elapses after radiating the transmission radio wave or when communication is completed. Thereby, the probability that erroneous communication occurs between the vehicle-mounted device of another vehicle existing outside the communication region and the communication antenna device 11 can be reduced.

FIG. 3C is a diagram schematically showing the electric field strength distribution 501 of the transmission radio wave of the transmission antenna device 11. In the figure, in the communicable area 41, it is shown that erroneous communication occurs when the electric field strength of the transmission radio wave is equal to or higher than the reception sensitivity setting value Bw of the vehicle-mounted device 10.
In the following description, by appropriately adjusting the transmission power and the reception sensitivity of the transmission antenna device 11, it is possible to avoid erroneous communication without depending on the variation in the transmission output or reception sensitivity (or reception sensitivity setting value) of the vehicle-mounted device. The fact that the probability of occurrence can be further reduced will be described.

First, the relationship between the transmission characteristics of the communication antenna device 11 and the communication area will be described.
FIG. 4A is a diagram schematically showing the relationship between the vehicle 1 entering the desired communication area 4 of the communication antenna device 11 and the following vehicle 1 b of the vehicle 1. FIG. 4B is a diagram showing the electric field strength distribution (solid line 51) of the transmission radio wave from the communication antenna device 11 corresponding to each position in the vehicle traveling direction, corresponding to FIG. 4A.

  In the figure, a vehicle 1 and a vehicle 1b are equipped with a vehicle-mounted device 10 and a vehicle-mounted device 10b, respectively. The vehicle detector 50 is disposed at a position that is separated from the antenna center position P0 of the communication antenna device 11 by a distance L3 in the horizontal direction toward the front side in the vehicle traveling direction. The communication area 4 is located at a position separated from the position P2 of the vehicle detector 50 by a distance L1 (first distance) on the front side in the vehicle traveling direction. Let P3.

  A position away from the front side end P3 by a distance L in the vehicle traveling direction is defined as a traveling direction side end (or traveling direction front end) P1 of the communication area 4. The distance from the position P2 of the vehicle detector 50 to the traveling direction side end is L-L1. In addition, an area between a position P4 that is separated from the position P2 of the vehicle detector 50 by a distance L2 (second distance) on the front side in the vehicle traveling direction and a front end P3 of the communication area 4 is a gray zone 43. And The gray zone 43 is an area where communication may be established outside the communication area when the vehicle-mounted device 10 exists. A region closer to the front side of the vehicle traveling direction than the distance L2 from the vehicle detector 50 is defined as a non-communication region 44. In the non-communication area 44, even if the vehicle-mounted device 10 exists, road-to-vehicle communication between the vehicle-mounted device 10 and the communication antenna device 11 is not performed. The distance L <b> 2 indicates the distance from the vehicle detector 50 to the vicinity of the end of the non-communication area 44. The level increasing portion 48 indicates a portion where the electric field strength of the transmission radio wave is high around the succeeding vehicle 1b in the gray zone 43 outside the communication area.

FIG. 5 is a diagram illustrating a relationship between the vehicle-mounted devices 10 and 10b of the vehicle 1 and the succeeding vehicle 1b, and the distance L1 and the distance L2. FIG. 5A shows a state in which the vehicle 1 has reached the vehicle detector 50, and FIG. 5B shows a state in which the vehicle 1 has traveled in the communication area 4 after reaching the vehicle detector 50. In the figure, an area surrounded by a dotted line indicates the communication area 4.
In general, considering that the maximum nose length of the vehicle 1 (the length from the vehicle to the windshield) is 1.5 m and the onboard mounting position is less than 0.5 m, as shown in FIG. The distance L1 of 1 is set to 1.5 m or more, preferably 2 m. As a result, when a vehicle having a long nose reaches the vehicle detector 50, the position of the vehicle-mounted device 10 exists in the communication area 4. For this reason, after the vehicle detector 50 detects the vehicle 1, the delay time until the vehicle-mounted device 10 and the communication antenna device 11 start communication is a short time delay equal to or shorter than the minimum required communication time Tm (= 200 ms). can do.

  In general, considering that the vehicle length CL is 3.8 m or less, the shortest inter-vehicle distance Cd is 0.5 m, and the shortest vehicle-mounted device mounting position Ct from the nose of the vehicle 1 is 0.5 m, the distance L2 is set to CL + Cd + Ct. It is good to set it to be larger than (= 4.8 m). The distance L2 is preferably set to about 5 m, for example. Accordingly, as shown in FIG. 5A, when the vehicle 1 reaches the vehicle detector 50, the vehicle-mounted device 10b cannot physically reach the communication area side from the distance L2, and the following vehicle The vehicle-mounted device 10b 1b exists in the non-communication area 44 outside the communication area of the communication antenna device 11.

  The predetermined transmission time T from when the communication antenna device 11 starts to radiate radio waves to when it stops radiating without communicating with the vehicle-mounted device is set to 0.5 seconds or less. Is preferred. For example, in a parking lot, the speed of a vehicle passing through a narrow entrance / exit gate (especially a road width of 3.5 m between islands 2a and 2b) is 15 km / h or less. In the meantime, the vehicle 1 travels between 2 m and 2.5 m. In FIG. 5B, the distance L6 from the vehicle detector 50 to the vehicle-mounted device 10b of the succeeding vehicle 1b when the transmission time T has elapsed since the vehicle 1 reached the vehicle detector 50 is the distance L6 = L2−. 0.5 s × 15 km / h = 2.5 m to 3 m (> L1). At this time, the position reaches the position P6 in FIG. Therefore, the vehicle-mounted device 10b of the succeeding vehicle 1b exists between the position P6 and the position P4 of the gray zone 43 outside the communication area.

  In the first embodiment, the transmission output Ak of the communication antenna device 11 is reduced, and the electric field strength of the transmission radio wave outside the communication area 44 is the reception sensitivity Bw1 (reception sensitivity setting value = −60. 5 dBm) or less. For example, as shown in FIG. 4B, by reducing the transmission power characteristic of the communication antenna device 11 from the dotted line 52 to the solid line 51, the vehicle-mounted device 10 transmits the transmission signal of the communication antenna device 11 outside the communication area 44. Set to not receive. This also reduces the maximum power level of the level increasing section 48, and can suppress the communicable area existing in the gray zone 43.

  Furthermore, since the vehicle-mounted device 10 is installed in the vehicle, the radio wave incident on the vehicle through the windshield actually has a radio wave propagation loss of about 5 dB including the loss due to the windshield. In consideration of this loss, when the reception sensitivity of the vehicle-mounted device 10 is approximately converted outside (around the vehicle) around the windshield, the reception sensitivity setting value Bw2 (= −55.4 dBm) is substantially exceeded. This substantial reception sensitivity setting value Bw2 is the minimum reception level that the vehicle-mounted device 10 can receive. Further, as can be seen from FIG. 4B, in the gray zone 43, the minimum reception level of the vehicle-mounted device 10 has a sufficient margin Bm (≧ 3 dB) with respect to the electric field strength of the level increasing unit 48. Incorrect communication in the gray zone 43 can be reduced.

  Note that the region where the electric field intensity of the transmission radio wave of the communication antenna device 11 is equal to or higher than the reception sensitivity setting value Bw2 of the vehicle-mounted device 10 includes, for example, the position P5 in the gray zone 43 in FIG. An area outside the area 4 is included. At the boundary positions P1 (travel direction side end) and P3 (front end) of the communication area 4, the electric field strength Pwk of the transmission radio wave is −52 dBm, and the substantial reception sensitivity outside the vehicle of the vehicle-mounted device 10 is. It is higher than the set value Bw2.

  FIG. 6 is an actual measurement value showing an example of the electric field strength distribution of the transmission radio wave from the communication antenna device 11. As shown in the figure, the communication antenna device 11 is set so that the electric field strength in the desired communication area is equal to or higher than the reception sensitivity -55.4 dBm of the vehicle-mounted device 10 (reception sensitivity setting value Bw2 = -55.4 dBm). Has been. At a position away from the position of the vehicle detector 50 by the second distance L2 or more, the electric field strength is less than −55 dBm and is out of the communication area. In addition, the electric field strength at the level increasing portion 48 is also less than −55 dBm and is out of the communication area. The position P5 at which the electric field strength is −55 dBm is between the position P3 and the position P6 of the vehicle detector 50. Therefore, when the vehicle 1 arrives at the vehicle detector 50, the vehicle-mounted device 10b of the subsequent vehicle 1b is located outside the communication region of the communication region 4 and the vehicle-mounted device 10b is a communication antenna device. The power level received from the 11 transmission radio waves is smaller than the substantial reception sensitivity of the vehicle-mounted device 10b.

FIG. 7 is a diagram illustrating an example of radiation characteristics of the communication antenna device 11, and FIG. 7A illustrates transmission power characteristics with respect to the antenna main axis ((1) horizontal plane direction (elevation angle direction), (2). FIG. 7B shows the received power characteristics ((1) horizontal plane direction, (2) vertical plane direction).
FIG. 8 is a diagram illustrating a geometric arrangement relationship between the transmission / reception antenna 111 of the communication antenna device 11 and the vertical plane of the communication area. In the figure, the installation height H of the transmission / reception antenna 111 is 3 m, the mounting angle θ is 48 °, the distance L is 3 m, the distance L1 is 2 m, the distance L2 is 5 m, and the distance L3 is 2 m. The electric field strength of the transmission radio wave 30 from the communication antenna device 11 received by the vehicle-mounted device 10 can also be estimated based on FIGS. 7 and 8 and the following equations (1) and (2).

Next, reception characteristics of the communication antenna device 11 will be described.
FIG. 9A is a diagram showing the relationship between the vehicle 1 entering the desired communication area 4 of the communication antenna device 11 and the following vehicle 1b of the vehicle 1, and FIG. It is the figure which showed the receiving characteristic of the antenna apparatus 11 for communication corresponding to a). In the figure, a solid line 53 indicates the received power distribution of the radio wave transmitted from the vehicle-mounted device 10 and incident on the communication antenna device 11, the vertical axis indicates the received power level, and the horizontal axis indicates the position in the vehicle traveling direction. Yes. In the figure, the relationship among the vehicle 1, the following vehicle 1b, the distances L, L1, L2, and the positions P1, P2, P3, P4, P5, P6 is the same as that in FIG.

  As described above with reference to FIG. 2, the communication antenna device 11 according to this embodiment reduces the sensitivity of the reception beam of the communication antenna device 11 in the communication region 4 and increases the reception sensitivity to −55 dBm or more (reception The sensitivity level is adjusted so that the sensitivity setting value Bw2 = −55 dBm), and preferably −52 dBm or more (reception sensitivity setting value Bk = −52 dBm). For this reason, even if the transmission radio wave from the vehicle-mounted device 10 forms the level increasing portion 45 that is a region where the electric field strength is high (maximum) outside the communication region, the sensitivity of the received wave of the communication antenna device 11 is high. Since it is low, it is difficult to receive the transmission wave from the vehicle-mounted device 10 (the transmission wave from the vehicle-mounted device 10 is difficult to hear).

  For example, the input level (converted to the antenna input end) of the receiver 115 of the transmitting antenna device 11 at the level raising unit 45 is the transmission output from the vehicle-mounted device 10b of the following vehicle 1b = 11.8 dBm (considering + 50% variation) The antenna directivity gain of the vehicle-mounted device 10b = 3 dBi, the directivity gain of the roadside device = 12.7 dBi, the gain reduction amount of the communication antenna device 11 near the position P4 = 16 dBm, and the radio wave propagation loss including the loss due to the windshield. When calculated as 5 dBm and radio wave propagation loss = 63 dBm, the input level Bw1 of the receiver 115 is 11.8 + 3 + 12.7-16-5-63 = −56.5 dBm (<reception sensitivity setting value Bw2 = −55.4 dBm). . Further, since the reception sensitivity setting value Bk is sufficiently higher than the receiver input level Bw2 of the transmission signal from the vehicle-mounted device 10b, the communication antenna apparatus 11 can be used even if the level increasing unit 45 in which the receiver input level becomes high exists. And erroneous communication between the vehicle-mounted device 10b can be eliminated. Moreover, as above-mentioned, when the onboard equipment 10 exists in the position P5 in a figure, the reception level of the received signal received with the transmitter / receiver 121 of the onboard equipment 10 becomes more than the receiving sensitivity of the onboard equipment 10, and the onboard equipment 10 Receives a transmission signal from the communication antenna device 11 and makes a response such as an ID response. However, the communication antenna device 11 according to this embodiment receives signals from the vehicle-mounted device 10 at the end (position P3) of the communication area 4 when the vehicle-mounted device 10 has the maximum level of transmission output (= 11.8 dBm). The reception sensitivity of the communication antenna device 11 is adjusted so that the power level of the signal substantially matches the reception sensitivity setting value Bk (= −52 dBm). Therefore, even when the vehicle-mounted device 10 exists between the position P5 and the position P3 in the figure, the communication antenna device 11 does not receive the transmission signal from the vehicle-mounted device 10.

  In general, the transmission radio wave output from the vehicle equipped with the vehicle-mounted device has a transmission output level for each vehicle-mounted device due to individual differences of the vehicle-mounted device itself or individual differences such as the windshield and mounting position of the vehicle equipped with the vehicle-mounted device. It varies. For this reason, the received power level of the radio wave transmitted from the vehicle-mounted device 10 and incident on the communication antenna device 11 varies for each vehicle-mounted device, and the received power distribution of the radio wave incident on the communication antenna device 11 is shown in the figure. As indicated by a solid line 53 to a dotted line 58, the distance changes in the range of P up and down. In the communication antenna 11 according to this embodiment, when the vehicle-mounted device 10 has the maximum level of transmission output (= 11.8 dBm), the power level of the received signal from the vehicle-mounted device 10 at the end of the communication area 4 is approximately The reception sensitivity of the communication antenna device 11 is adjusted to match the sensitivity setting value of the reception sensitivity Bk. Therefore, even if the transmission output level fluctuates for each vehicle-mounted device, the transmission radio wave transmitted from the vehicle-mounted device 10b of the succeeding vehicle 1b is not received in the external region (non-communication region and gray zone) of the communication region 4. Absent.

  FIG. 10 is a diagram showing the relationship between the antenna installation height H and the antenna mounting angle θ. As shown in the figure, it is necessary to increase the antenna attachment angle θ as the antenna installation height decreases. Since the antenna installation height is 2 m to 3.5 m in an indoor parking lot, the antenna mounting angle θ is preferably set to 50 ° to 45 °. For example, when the antenna installation height is 3 m, the antenna mounting angle θ is set to 48 °.

FIG. 11 is a diagram illustrating the relationship between the position of the vehicle-mounted device and the antenna mounting angle of the communication antenna device 11.
FIG. 11A shows an example in which the vehicle detector 50 is disposed near the end on the near side of the communication area, the antenna installation height is 3 m, and the antenna mounting angle is set to 23 °. In this case, the length of the communication area in the vehicle traveling direction is 2.5 m and the width of the communication area in the road width direction is 2 m, and a communication area having a sufficient size cannot be obtained in the road width direction.

  In this example, after the vehicle detector 50 detects the front end of the vehicle 1, a vehicle entry signal is received from the vehicle detector 50, and radio waves are radiated from the communication antenna device 11. Depending on the vehicle, the mounting position of the vehicle-mounted device 10 is about 1.5 m from the front end of the vehicle 1. For this reason, when the radio wave is radiated from the communication antenna device 11, the vehicle-mounted device 10 of the vehicle 1 exists outside the communication area. As the vehicle 1 travels, the vehicle-mounted device 10 enters the communication area and starts road-to-vehicle communication. At this time, depending on the approach speed of the vehicle (for example, 10 km / h to 15 km / h), the time for starting road-to-vehicle communication is 300 to 400 ms after the vehicle 1 is detected by the vehicle detector 50, and 500 ms There are cases where road-to-vehicle communication does not end normally during the communication time.

  FIG. 11B shows a case where the vehicle detector 50 is arranged in the vicinity of 1 m from the traveling direction side end of the communication area, the antenna installation height is 3 m, and the antenna mounting angle is set to 48 °. In this case, the length of the communication area in the vehicle traveling direction is 3 m, and the width of the communication area in the road width direction is 2.5 m, so that the communication area 4 having a sufficient size in the road width direction can be obtained.

  Moreover, even if the mounting position of the vehicle-mounted device 10 is 2 m from the front end of the vehicle 1, the vehicle-mounted device 10 exists in the communication area when the vehicle detector 50 detects the vehicle 1, and Communication begins immediately. Therefore, it is possible to start communication between the vehicle-mounted device 10 and the communication antenna device 11 within a required time Tm = 200 ms or less required for one communication. Note that increasing the mounting angle of the communication antenna device 11 will slightly increase the electric field strength due to multiple reflections that occur between the road surface and the ceiling. As described above, the transmission output and the reception sensitivity are adjusted. By doing so, the problem of miscommunication associated with a local increase in electric field strength due to multiple reflection of the communication antenna device 11 is solved.

  When the mounting position of the vehicle-mounted device 10 is 0.5 m from the front end of the vehicle 1, the vehicle-mounted device 10 exists in the communication area 4 when the vehicle detector 50 detects the vehicle 1. Road vehicle communication will be started immediately. At this time, the distance between the position of the vehicle-mounted device 10 and the traveling direction end of the communication region 4 is 1.5 m. When the approach speed of the vehicle 1 is 15 km / h, a communication time of at least 300 ms can be obtained. Therefore, road-vehicle communication can be performed in a time required for one communication Tm = 200 ms or more.

  FIG. 12 is a block diagram showing the connection relationship of each component device of the wireless communication system according to this embodiment, which operates as follows.

  In the figure, when the vehicle 1 passes between the optical transmitter 5b and the optical receiver 5a, the output light of the optical transmitter 5b is blocked and the output light of the optical receiver 5a is not received by the optical transmitter 5b. By detecting this, the vehicle detector 50 detects whether the vehicle 1 is passing. When the vehicle detector 50 detects the vehicle 1, it sends a processing start signal S <b> 1 to the communication control device 12. At the same time, the processing start signal S1 is output also to the vehicle number reading device 6 and the vehicle number reading device 66b.

  The loop coil 13 a is embedded under the surface of the road surface 3 so as to be in contact with the front end of the communication region 4 in the vehicle traveling direction (or the traveling direction side end). The circuit breaker 8 is installed such that the stop rod 9 is disposed at a position 4 m away from the front end of the communication area 4 in the vehicle traveling direction. The loop coil 13 b is disposed so as to be positioned in front of the restraining rod 9 in the traveling direction of the vehicle 1. An information processing apparatus 14 is installed in the parking lot management room 550. In addition, the substantially square hatching area in the figure indicates the communication area 4.

  The communication control device 12 is activated immediately in response to the reception of the processing start signal S1, and controls the communication antenna device 11 to start emitting transmission radio waves. Further, the vehicle number reading device 6 is immediately activated in response to the reception of the processing start signal S1. The vehicle number reading device 6 is an internal camera that captures an image including a license plate of a vehicle passing through the communication area 4. The vehicle number reading device 6 performs image processing on the captured image, extracts a license plate image, and binarizes it. The vehicle number reading device 6 individually cuts out each number stamped on the number plate of the vehicle from the binarized license plate image, and all of the number cut out or a part of the number that can identify the vehicle. Is identified. At this time, the processing time Tn from when the vehicle number reader 6 is activated until the number is identified is 0.7 seconds to 0.8 seconds. The number information (S2) identified by the vehicle number reading device 6 is sent from the vehicle number reading device 6 to the information processing device 14.

  Similarly, the vehicle number reading device 66b is activated immediately in response to the reception of the processing start signal S1, photographs the license plate of the vehicle passing through the communication area 4, and identifies the number of the license plate. The number information S200 identified by the vehicle number reading device 66b is sent from the vehicle number reading device 66b to the information processing device 14. The information processing device 14 performs internal signal processing using the number information S2 from the vehicle number reading device 6 or the number information S200 from the vehicle number reading device 66b, whichever is output earlier. Therefore, in the following description, for the sake of simplification, description of the operation of the vehicle number reading device 66b and the processing operation of the number information S200 output from the vehicle number reading device 66b will be omitted. The number information S2 will be described.

  The vehicle detector 50 is disposed at a position advanced 2 m forward from the rear end of the communication area 4 in the vehicle traveling direction (or the front end in the traveling direction). As described above, the vehicle 5 is provided with the vehicle-mounted device 10 within 2 m from the nose (front bumper tip), and the vehicle 5 enters the communication area 4 when the vehicle 5 reaches the vehicle detector 50. Can do. The transmission radio wave radiated from the communication antenna device 11 is received by the vehicle-mounted device 10 of the vehicle 1 that passes through the communication area. As a result, a communication transaction is started, and a communication link establishment execution process described later is started between the communication antenna device 11 and the vehicle-mounted device 10. When the communication link is established, road-to-vehicle communication is executed between the communication antenna device 11 and the vehicle-mounted device 10, and vehicle ID information is transmitted from the vehicle-mounted device 10. After vehicle ID information is transmitted from the vehicle-mounted device 10 to the communication antenna device 11, the communication is disconnected. The communication antenna device 11 receives the transmitted ID information from the vehicle-mounted device 10. The vehicle ID information received and demodulated by the communication antenna device 11 is transmitted to the communication control device 12, converted into digital information, and output as vehicle ID information (S3).

  When the vehicle 1 reaches above the loop coil 13 a and the loop coil 13 a detects the passage of the vehicle 1, the loop coil 13 a sends a vehicle entry signal S 6 to the ticket issuing machine 7. When the ticket issuing machine 7 receives the vehicle approach signal S6, it sets a built-in bit memory (not shown) to the ON state (logical 1). At the same time, the ticket issuing machine 7 sends a gate opening / closing permission signal S4 to the information processing apparatus 14. Further, when the vehicle 1 reaches above the loop coil 13 b and the loop coil 13 b detects the passage of the vehicle 1, the loop coil 13 b immediately outputs a gate closing signal S 7 to the ticket issuing machine 7. The gate closing signal S7 resets the bit memory of the ticket issuing machine 7 to the OFF state (logical 0).

  When the road-vehicle communication between the communication antenna device 11 and the vehicle-mounted device 10 is completed, vehicle ID information (S3) is sent from the communication control device 12 to the information processing device 14. The information processing apparatus 14 is desirably provided in the management room 550. Of course, the information processing apparatus 14 can also be set in a separate location such as another adjacent parking lot or a building adjacent to the parking lot. In this case, the connection between the communication control device 12 and each device such as the information processing device 14 and the vehicle number reading device 6 may be connected through a dedicated network line or a public network line. The information processing device 14 performs a coincidence comparison (ID comparison) between the vehicle ID information S3 transmitted from the communication control device 12 and the vehicle ID information that is specific information registered in advance. Further, the information processing device 14 performs a coincidence comparison (number comparison) between the number information S2 transmitted from the vehicle number reading device 6 and the number information that is pre-registered specific information. The information processing apparatus 14 receives the gate opening / closing permission signal S4 from the ticket issuing machine 7 when the loop coil 13a has transmitted the vehicle entry signal S6.

  When the information processing device 14 has received the gate opening / closing permission signal S4 from the ticketing machine 7, the ticket processing is performed when the ID comparison result is the same or the number comparison result is the same. A control command (S8) is sent to the machine 7. If both the ID comparison result and the number comparison result do not match, a control command (S9) is sent to the ticket issuing machine 7. On the other hand, when the information processing device 14 has not received the gate opening / closing permission signal S4 from the ticketing machine 7, that is, when the vehicle 1 does not reach the loop coil 13a and the vehicle entry signal S6 is not output. Regardless of the result of the comparison of the number information, the information processing apparatus 14 stops sending the control command S8 or S9 until the gate opening / closing permission signal S4 is received.

  When the ticket issuing machine 7 receives the control command S8 from the information processing device 14, it sends the control command S5 to the circuit breaker 8. When receiving the control command S5 from the ticket issuing machine 7, the breaker 8 releases the restraint of the vehicle and opens / closes the restraining rod 9. Further, when the ticket issuing machine 7 receives the control command S9 from the information processing apparatus 14, the ticket issuing machine 7 executes a ticket issuing process operation.

  Thus, when the vehicle ID information S3 of the vehicle-mounted device 10 matches the vehicle ID information registered in advance, or when the number information S2 of the vehicle 1 matches the number information registered in advance, the control from the ticket issuing machine 7 is performed. In response to reception of the command S5, the circuit breaker 8 jumps up the stop rod 9, and the gate is automatically opened (the vehicle 1 can enter the parking area). At this time, the bit memory of the circuit breaker 8 is set to the ON state. Accordingly, when the vehicle 1 passes through the entrance gate 100, the vehicle 1 can enter the parking area in a non-stop manner without stopping once before the ticket issuing machine 7 in the entrance gate.

  Further, when the vehicle ID information S3 of the vehicle-mounted device 10 does not match the vehicle ID information registered in advance, and the number information S2 of the vehicle 1 does not match the number information registered in advance, the control command of the ticket issuing machine 7 Ticketing processing is executed in response to the reception of S9. For example, the ticket-issuing machine 7 announces to use a parking lot use ticket (parking ticket) issued to the driver of the vehicle 1. When the driver takes out the parking ticket issued by the ticket issuing machine 7, the ticket issuing machine 7 sends a control command S <b> 5 to the circuit breaker 8. The breaker 8 jumps up the stop rod 9 in response to receiving the control command S5, and the gate is automatically opened. Accordingly, the vehicle 1 can enter the parking area while the driver of the vehicle 1 has the parking ticket issued by the ticket issuing machine 7. At this time, the bit memory of the circuit breaker 8 is set to the ON state.

  Next, in a state where the stop rod 9 is opened, the vehicle 1 passes the side of the breaker 8 and reaches above the loop coil 13b, and a gate closing signal S7 is sent from the loop coil 13b to the ticket issuing machine 7. When sent out, the ticket issuing machine 7 sends a gate closing signal S52 to the circuit breaker 8. When the circuit breaker 8 receives the gate closing signal S52, the circuit breaker 8 operates so as to close the stop rod 9, and the stop rod 9 that has been flipped down descends horizontally, and the bit memory of the breaker 8 Is reset to the OFF state.

FIG. 13 is a diagram illustrating a configuration of the information processing apparatus 14. The information processing apparatus 14 includes a comparator 141, a database 142, and a controller 143. The vehicle number reading device 6 sends the number information S2 to the comparator 141 of the information processing device 14. The communication control device 12 sends the vehicle ID information S3 to the comparator 141 of the information processing device 14.
When the vehicle ID information S3 of the vehicle-mounted device 10 matches the vehicle ID information registered in advance, or the number information S2 of the vehicle 1 matches the number information registered in advance, the information processing apparatus 14 Vehicle ID information corresponding to S3 or number information S2 is transmitted to a management center (not shown) through a dedicated line or public line (not shown).

A user of a parking lot equipped with the wireless communication system uses a parking lot (use parking lot) to be used when making a parking lot use contract with a system administrator as a user of the wireless communication system. In the registration application form, the license plate number information, the vehicle ID information stored in the vehicle-mounted device, and the usage period information are entered and registered as usage registration information. When the driver makes a use registration application, the use vehicle described in the use registration application is registered as a use-registered vehicle (use registration vehicle). Vehicles that are not registered for use are referred to as unregistered vehicles.
In addition, when making a use contract that allows use of a plurality of parking lots arranged in wide areas in different places, information for identifying available parking lots (for example, parking lot ID) is used as parking lot information. Register in the registration information.
In the database 142, the usage registration information described in advance in the above-mentioned usage registration application form is registered and stored for all usage registration vehicles. The database 142 registers various information such as vehicle ID information, number information, usage period information, and usage parking lot information as usage registration information for each usage registration vehicle, and constitutes a relational database. Yes.

  When the user of the wireless communication system makes a use registration application, the user sets the above-described use period information and simultaneously pays a use fee to the system administrator in accordance with the use period. In this case, for example, the usage contract may be a monthly usage contract or an annual usage contract, and a fee corresponding to the usage period is paid in advance.

  Alternatively, the usage period may be automatically updated, and the usage fee may be paid after delivery. In this case, the usage period information stored in the database 142 may be updated every fixed period. Of course, it goes without saying that the system administrator obtains the consent of the user before the use period is updated.

Or you may use the form which uses a vehicle ID information transmitted to a management center, and settles a usage fee by postpay.
In this case, according to the user registration application, the management center stores the vehicle ID information and the card ID information in a management database (not shown) in association with each other, and stores the card ID information of the IC card 125 and the vehicle onboard device 10. The vehicle ID information is associated in advance. After the usage contract for the IC card 125, the management center stores the card information and the credit number in association with each other in the management database, and associates the card information of the personal IC card 125 with the credit card credit number in advance. . Alternatively, the management center may store the credit card credit number and the vehicle ID information directly in a one-to-one correspondence in advance in the management database. Since the card ID of the IC card 125 is associated with the vehicle ID information of the vehicle onboard 10 when the IC card 125 is mounted on the car onboard 10, the vehicle onboard The ten vehicle ID information and the credit number of the credit card are associated one-to-one.

  As a result, the management center searches the management database, and searches the credit number stored in the management database in association with the vehicle ID information based on the vehicle ID information transmitted from the information processing apparatus 14. The management center charges the credit company in association with the retrieved credit number and the parking lot usage fee to be charged to the parking lot user. The credit company pays the usage fee for the parking lot that is charged to the management center. At the same time, it is possible to settle the payment for the parking lot using a payment method such as automatic bank withdrawal or issuance of bills to the credit card contractor. Therefore, it becomes possible to make a payment for the parking lot usage fee to the parking lot user by charging the credit card at the end of the month.

  In addition, about the calculation method of the usage fee of the parking lot which should be charged to the user of a parking lot, concrete description is abbreviate | omitted here. For example, vehicle ID information may be transmitted between the vehicle-mounted device and the communication antenna device at the exit gate. Based on the vehicle ID information transmitted from the vehicle-mounted device, the information processing device calculates the difference between the time when the vehicle exits from the exit gate and the time when the vehicle enters the entrance gate. Calculate the usage fee. The information processing apparatus transmits the calculated parking lot usage fee to the management center in association with the vehicle ID information. The management center may charge the credit company for the transmitted parking fee.

Next, the ID comparison process of the vehicle ID information S3 and the number information S2 number comparison process in the information processing apparatus 14 will be described.
The database 142 searches for the use registration information stored based on the vehicle ID information S3 using the vehicle ID information S3 as a key, and corresponds to the vehicle ID information S3 included in the use registration information (matches). ) Get vehicle ID information. In this case, the database 142 outputs data coincidence information N3 indicating that the vehicle ID information S2 is legitimate vehicle ID information that is registered in the database 142 and permitted to use the use parking lot. On the other hand, if there is no vehicle ID information corresponding to the vehicle ID information S3 in the stored usage registration information as a result of the search of the database 142, the database 142 permits the vehicle ID information S3 to use the usage parking lot. The data mismatch information NN3 indicating that it has not been output is output.

  Further, the database 142 searches for usage registration information stored based on the number information S2 using the number information S2 as a key, thereby corresponding to (matching) the number information S2 included in the usage registration information. Number information can be acquired. In this case, the database 142 outputs data matching information N2 indicating that the number information S2 is stored in the database 142 and is the number information of a regular vehicle permitted to use the used parking lot. On the other hand, if the number information corresponding to the number information S2 does not exist in the stored use registration information as a result of the search of the database 142, the number information N2 in the database 142 is not permitted to use the use parking lot. The data mismatch information NN2 indicating that this is output.

  As the vehicle ID information, it is preferable to use a combination of a header code and a serial code that is different for each vehicle-mounted device and configured by “header code + serial code”. As the header code, it is convenient to use a unique number indicating that the vehicle-mounted device is properly sold and can use a specific service.

  For example, a different unique number is assigned as a header code for each service provider (organization) that provides a parking lot use service that allows non-stop traffic at the entrance and exit of a parking lot. As a result, the header code can be used as authentication information at the time of link establishment by storing the header code information in advance in the communication control devices 12 of all service providing parking lots that belong to the same organization. .

  For example, if there are 10 service providers, the header code may be composed of 4-bit data (0000 to 1111). The vehicle-mounted device 10 mixes the header code in the response signal C2 and transmits it. As a result, the communication control device 12 compares the header code extracted from the received response signal C2 with which of the 10 preset header codes corresponds, so that the vehicle-mounted device 10 is a legitimate user. Can be authenticated. Of course, it goes without saying that more reliable authentication can be performed by adding encryption processing to header code recognition. The serial code can be converted to 16-bit data (0 to F) if it is expected that the number of on-vehicle devices registered for use to receive service from the same service provider will be 10,000. What is necessary is just to comprise. For example, the vehicle ID information may be configured with 20-bit data of 00000 to 1111F.

  When receiving the vehicle ID information S3 from the communication control device 12, the comparator 141 searches the database 142 based on the vehicle ID information S3. If the vehicle ID information corresponding to the received vehicle ID information S3 is registered in the database 142 as a result of the search, the comparator 141 to the controller 143 responds to the reception of the data match information N3 output from the database 142. A match signal S11 is transmitted. If the vehicle ID information corresponding to the received vehicle ID information S3 is not registered in the database 142 as a result of the search, the vehicle ID information S3 is received in response to the reception of the data mismatch information NN3 output from the database 142. It is determined that it is unregistered (or unregistered ID), and the mismatch signal S10a is transmitted from the comparator 141 to the controller 143.

  Further, when the comparator 141 receives the number information S2 from the vehicle number reading device 6, the comparator 141 searches the database 142 based on the number information S2. If the number information corresponding to the received number information S2 is registered in the database 142 as a result of the search, the comparator 141 sends the data to the controller 143 in response to the reception of the data match information N2 output from the database 142. The coincidence signal S11 is transmitted. As a result of the search, if the number information corresponding to the received number information S2 is not registered in the database 142, the number information S2 is not registered in response to the reception of the data mismatch information NN2 output from the database 142. (Or unregistered ID), and the comparator 141 transmits a mismatch signal S10b to the controller 143.

  Therefore, when the comparator 141 receives the number information S2 pre-registered in the database 142 from the vehicle number reading device 6 or the vehicle ID information S3 pre-registered in the database 142 from the communication control device 12, the comparator 141 matches. The signal S11 is output. Further, when the comparator 141 receives the number information S2 that is not pre-registered in the database 142 from the vehicle number reading device 6, the comparator 141 outputs a mismatch signal S10a. When the comparator 141 receives vehicle ID information S3 that is not pre-registered in the database 142 from the communication control device 12, the comparator 141 outputs a mismatch signal S10b.

  Upon receiving the coincidence signal S11 from the comparator 141, the controller 143 sends a control command S8 to the ticket issuing machine 7. When the controller 143 receives the mismatch signal S10a from the comparator 141 and receives the mismatch signal S10b from the comparator 141, the controller 143 sends a control command S9 to the ticket issuing machine 7. The controller 143 temporarily stores setting information corresponding to the mismatch signal S10a and the mismatch signal S10b received from the comparator 141 in an internal memory (not shown). As a result, even if the reception timings of the mismatch signal S10a and the mismatch signal S10b are shifted, the control command S9 is issued only when the mismatch signals S10a and S10b are received by referring to the setting information stored in the internal memory. It can be sent out.

  FIG. 14 is a time chart showing operation timings of the vehicle detector 50, the vehicle number reading device 6, and the communication control device 12. As shown in FIG. 14A, when the processing start signal S1 is output from the vehicle detector 50, as shown in FIG. 14B, the vehicle number reading device 6 starts operation (operation ON), After approximately 0.7 to 0.8 seconds, the number information S2 is output to complete the operation (operation OFF). When the processing start signal S1 is output from the vehicle detector 50, as shown in FIG. 14C, the communication control device 12 activates the communication antenna device 11 (operation ON), and the communication antenna device. A transmission wave is output from 11, and road-to-vehicle communication is started. The vehicle control unit 12 outputs the vehicle ID information S3 within 0.2 seconds to 0.5 seconds or less from the time when the communication antenna device 11 is activated, and the road-to-vehicle communication ends. At the same time, the communication control device 12 stops outputting the transmission radio wave from the communication antenna device 11. The communication control device 12 performs time-out processing so that no transmission radio wave is output from the communication antenna device 11 even if a predetermined transmission time T (for example, 0.5 seconds) is exceeded. In the time-out process, for example, a timer is started when output of a transmission radio wave from the communication antenna device 11 is started. The timer operates to stop the output of radio waves from the communication antenna device 11 when road-to-vehicle communication is not started even after a predetermined time has elapsed from the timer activation time. At the same time, the setting information stored in the internal memory of the comparator 141 is reset.

  Even when the vehicle 1 enters the communication area at a speed of 25 km / h, the distance that the vehicle 1 travels within 0.5 seconds after the vehicle detector 50 detects the tip of the vehicle 1 is approximately Since it is 3.5 m and the vehicle length of the general vehicle is about 4 m, the vehicle body of the vehicle 1 exists in the communication area 4 while road-to-vehicle communication is being executed.

  FIG. 14D is a diagram illustrating a communication transaction between the vehicle-mounted device 1 and the roadside device. When the vehicle-mounted device 10 receives a polling signal C1 that is a transmission radio wave radiated from the communication antenna device 11, execution of link establishment between the communication antenna device 11 and the vehicle-mounted device 10 is started. First, the vehicle-mounted device 10 transmits the polling signal C <b> 1 received by the transceiver 121 to the communication controller 122. The communication controller 122 compares the polling signal C1 with the unique word stored in the memory 123 in advance. If the polling signal C1 matches the unique word as a result of the comparison, the communication controller 122 outputs a response signal C2 from the transceiver 121 to the communication antenna device 11. Thereby, a communication link between the communication antenna device 11 and the vehicle-mounted device 10 is established, and road-to-vehicle communication is started. The link establishment is completed within approximately 0.1 seconds from the time when the communication antenna device 11 is activated. If the link establishment is not completed within the predetermined transmission time T, the transmission radio wave output from the communication antenna device 11 is stopped as described above.

Next, when the link establishment is completed, ID acquisition is performed between the vehicle-mounted device 10 and the communication antenna device 11. First, the ID request signal C3 is output from the communication antenna device 11 to the vehicle-mounted device 10 (ID transmission request). When receiving the ID request signal C3 from the communication antenna device 11, the vehicle-mounted device 10 returns vehicle ID information C4 to the communication antenna device 11 (ID return). In order to prevent erroneous communication, a majority process is executed in which an ID acquisition process including an ID transmission request and an ID return is executed at least twice a predetermined number of times. For example, the ID acquisition process is preferably executed three times. In this case, vehicle ID information is transmitted from the vehicle-mounted device 10 to the communication antenna device 11 three times. The communication control device 12 compares the received vehicle ID information with each other, and outputs the vehicle ID information having the largest number of matches, that is, the largest number of receptions, to the comparator 141 as the vehicle ID information S3. The ID acquisition process takes approximately 0.1 seconds per time. In addition, when all the vehicle ID information obtained by the predetermined number of ID acquisitions is different from each other, the vehicle ID information acquired first is output to the comparator 141 as the vehicle ID information S3.
By performing the majority process in this way, it is possible to further suppress the influence of interference caused by road-to-vehicle communication between the adjacent communication antenna device and the vehicle-mounted device.

Next, after transmitting the ID request signal C3 from the communication antenna device 11 to the vehicle-mounted device 10 a predetermined number of times and then receiving the vehicle-mounted ID information C4 at least once, the communication antenna device 11 disconnects communication with the vehicle-mounted device 10. Send request C5. When the on-vehicle device 10 receives the communication disconnection request C5 from the communication antenna device 11, the on-vehicle device 10 transmits a communication disconnection acknowledgment signal C6 indicating that the road-to-vehicle communication disconnection processing execution operation has been started to the communication antenna device 11. To do. At the same time, the communication is disconnected (communication disconnection), such as turning off the power supply to the power amplifier constituting the transmitter and disconnecting the power supply of the transmission radio wave. The communication disconnection process takes approximately 0.1 seconds per time. After the communication disconnection process is performed, the communication antenna device 11 stops emitting the transmission radio wave.
Note that while the passing vehicle did not pass the vehicle detector 50 and the vehicle detector 50 still detected the passing vehicle (during the ON state), the communication antenna device 11 stopped emitting the transmission radio wave. Even after that, during the period, the communication antenna device 11 stops emitting the next transmission radio wave. When the passing vehicle passes through the vehicle detector 50 and the output of the vehicle detector 50 is turned off, the transmission antenna device 11 stops releasing the transmission radio wave, and the on-board device of the following vehicle So that the communication antenna device 11 is in a standby state.

  When the processing time Tn from when the communication antenna device 11 is activated until the vehicle ID information is acquired is longer than 0.5 seconds, the stop rod 9 of the circuit breaker 8 is passed after the vehicle 1 passes the vehicle detector 50. It takes longer time to open. In this case, while the vehicle 1 communicates with the roadside machine, there is a harmful effect that the vehicle 1 has to stop once before the stop rod 9. For example, when the vehicle 1 enters the communication area 4 at a speed of 10 km / h, the vehicle 1 travels about 1.5 m by determining that the vehicle can pass after 0.5 seconds. Since the distance between the vehicle detector 50 and the stop rod 9 is 5 m, the vehicle 1 travels to a position 3.5 m before the stop rod 9 during this time. If the distance is shorter than this, the driver will psychologically brake, which will prevent him from passing through the gate non-stop.

  Since the loop coil 13a is disposed at a position 1.5 m away from the vehicle detector 50, the loop coil 13a enters the vehicle 1 around the ticket issuing machine while the vehicle 1 is in the communication area 4. Is detected, a vehicle approach signal S6 is output, and the stop rod 9 enters an open / close standby state.

FIG. 15 shows an operation flowchart of the radio communication system according to this embodiment.
Although details of the operation are as described above, in the figure, after the wireless communication system is activated, the vehicle detector 50 detects whether or not the vehicle 1 has passed (step S101). When the vehicle detector 50 detects the vehicle 1, the transmission start operation of the communication antenna device 11 in the roadside device is executed (step S102). At the same time, after the vehicle number reading device 6 starts to execute a vehicle number reading operation (step S103), the vehicle number reading device 6 executes a vehicle number identification process (step S104). The vehicle number reading device 6 outputs the identified number information S2 to the information processing device 14 (step S105).

  A transmission radio wave is emitted from the communication antenna device 11, and a communication connection request (polling) is transmitted from the roadside device to the vehicle-mounted device 10 (step S110). As a result of the communication connection request from the roadside device to the vehicle-mounted device 10, when there is a response to polling from the vehicle-mounted device 10 (step S111), road-to-vehicle communication between the roadside device and the vehicle-mounted device 10 is started. Next, an ID transmission request is output from the roadside device to the vehicle-mounted device 10 (step S112), and the vehicle-mounted device 10 transmits vehicle ID information S3 to the roadside device (step S113). The communication control device 12 of the roadside machine determines whether or not the communication antenna device 11 has received the vehicle ID information S3 transmitted from the vehicle-mounted device 10 (step S114). Inter-vehicle communication ends. Further, the communication control device 12 outputs the vehicle ID information S3 to the information processing device 14 (step S115). If there is no response to the polling with respect to the vehicle-mounted device 10 for a predetermined time T, the information processing device 14 determines that the vehicle is not a vehicle equipped with the vehicle-mounted device (is a non-ETC vehicle) (S1110), and the ticketing machine 7 A control command S9 is output so as to activate the.

  The information processing apparatus 14 searches the database and compares whether the vehicle ID information S3 and the number information S2 match the vehicle ID information or the number information registered in advance (step S116). As a result of the comparison, when at least one of the vehicle ID information S3 and the number information S2 matches the vehicle ID information or the number information pre-registered in the database, the control command S8 is output to the breaker 8 to output the breaker 8 is operated to open the stop rod 9 (step S117). As a result of comparison, if neither the vehicle ID information S3 nor the number information S2 matches the vehicle ID information or the number information registered in advance in the database, a control command S9 is output to the ticket issuing machine 7. Then, the ticket issuing machine 7 is operated to issue a ticket (step S118), and the stop rod 9 is opened in the same manner as in step S117 described above. The information processing apparatus 14 searches the database 142, and if the vehicle ID information S3 does not match the pre-registered vehicle ID information S3, the vehicle ID information is an unregistered ID (or a use unregistered vehicle). The control command S9 is output so that the ticket issuing machine 7 is operated.

By processing in this way, the probability of misjudging a registered vehicle as a non-registered vehicle can be made extremely small. Even though it is a registered vehicle, it is temporarily stopped at the entrance gate and turned into a checkout machine. The probability of making direct payments can be reduced.
For example, when the identification number number identification probability by the vehicle number reading device 6 is 95% and the probability that communication between the vehicle-mounted device 10 and the communication antenna device 10 of the roadside device is normally performed is 99%, a parking lot The probability of erroneously determining that the vehicle 1 entering the gate is a use registered vehicle can be reduced to 0.05%. That is, even if the communication antenna device 10 cannot acquire the vehicle ID information from the vehicle-mounted device 1 with a probability of 1%, the vehicle number reading device 6 identifies the vehicle number information with a probability of 95%. It can be determined with a probability of 99.95% that the vehicle is passing the entrance gate. Accordingly, it is possible to accurately determine that 9995 vehicles are registered usage vehicles per 10,000 vehicles. For this reason, it is possible to further prevent a decrease in the use service such that the use registration vehicle temporarily stops to wait for ticketing at the gate of the parking lot.

  Further, the communication control device 12 transmits the acquisition information (vehicle ID information) to the information processing device 14 earlier than the acquisition information (number information) of the vehicle number reading device 6. At this time, the probability that the communication between the vehicle-mounted device 10 and the roadside device is normally performed and the vehicle ID information can be accurately acquired is higher than the probability that the vehicle number reading device 6 reads the number information correctly. For this reason, the passing vehicle of the entrance gate 100 can be identified more reliably than the case where the number information is obtained by the vehicle number reading device 6 alone.

  As described above, according to the first embodiment, the output sensitivity of the transmission radio wave radiated from the communication antenna device 11 of the roadside device is suppressed to 4 dBm or less, preferably 2 dBm, and the reception sensitivity of the communication antenna device 11 of the roadside device is reduced. Is reduced to −55 dBm or more, the communicable area generated outside the normal communication area 4 can be suppressed, and erroneous communication between the vehicle-mounted device 10 of the vehicle 1 passing through the communication area and the roadside device can be prevented. Occurrence can be suppressed. In addition, the occurrence of road-to-vehicle communication outside the communication area can be suppressed.

  Furthermore, in response to detection of the vehicle entering the communication area 4, after starting the transmission of the transmission radio wave from the communication antenna device 11 of the roadside machine, after the communication between the roadside machine and the vehicle-mounted device 10, the communication antenna 4 By stopping the emission of the transmission radio wave, the communication time between the roadside device and the vehicle-mounted device 10 can be limited within a specified time, and the occurrence of erroneous communication between the roadside device and the vehicle-mounted device 10 can be further suppressed.

  In particular, when the vehicle-mounted device 10 enters the communication area 4, the vehicle detector 50 detects the position of the front end of the vehicle 1 or the position of the front of the vehicle, and starts emission of transmission radio waves in response to the detection. Then, communication can be performed only when the vehicle passes around the communication area by stopping the emission of the transmission radio wave after the communication ends. In this case, the size of the communicable area generated outside the regular communication area 4 can be further reduced by the interference action between the reflection from the vehicle and the road surface reflection. This also leads to a reduction in transmission power loss.

  For example, as shown in FIG. 4, after the vehicle 1 is detected by the vehicle detector 50, the vehicle 1 is passing through the communication area 4 until the communication between the vehicle-mounted device 10 and the roadside device is completed. Therefore, the electric field strength is suppressed in the region 43 having a high electric field strength outside the communication region generated in the course of the following vehicle 1b.

  Of course, a method other than the transmission radio wave control may be used in which the emission of the transmission radio wave is started after the vehicle detector 50 detects the position specifying portion and then the transmission radio wave is stopped after the communication is completed. For example, in the communication area, in response to detection of the position specifying portion by the vehicle detector 50, the power value of the transmission radio wave of the communication antenna device 11 is increased to a predetermined value or more that can be received and responded to by the vehicle onboard device 10. Then, after the end of road-to-vehicle communication, the power control of the transmission radio wave may be performed so that the power value of the transmission radio wave of the communication antenna device 11 is reduced to a predetermined value or less at a level at which the vehicle mounter 10 cannot receive and respond. Needless to say.

  As another form, the roadside machine is compared by comparing the number information corresponding to the vehicle ID information acquired by communication between the roadside machine and the vehicle-mounted device 10 with the number information identified by the vehicle number reading device 6. Misjudgment of a use registration vehicle accompanying miscommunication with the vehicle-mounted device 10 (for example, judging that a use registration vehicle is a use unregistered vehicle, or judging that an unused registration vehicle is a use registration vehicle Alternatively, it is possible to take a form that suppresses the occurrence of the use registration vehicle passing through the gate as another use registration vehicle.

  In such other forms, for example, when the identification number number identification probability by the vehicle number reading device 6 is 95%, and the probability that the communication between the vehicle-mounted device 10 and the roadside device is normally performed is 99%, Since the use registration vehicle that enters the entrance / exit gate of the parking lot can be determined more accurately as the use registration vehicle, the probability of erroneous determination can be reduced to 0.05%. Therefore, it is possible to more reliably prevent a vehicle that is not registered for use from using a parking lot without paying a parking fee.

  Moreover, even if the transmission power and reception sensitivity of the vehicle-mounted device 10 vary, the occurrence of erroneous communication between the vehicle and the roadside device can be suppressed. The communication area 4 is set to a size of 3 m × 2.5 m, but the size of the communication area varies within a range of 2 m × 2 m to less than 3 m × 3 m due to variations in the characteristics of the vehicle-mounted equipment. There is. Even if such a variation occurs, it is possible to suppress erroneous determination of the use registered vehicle due to erroneous communication between the roadside device and the vehicle-mounted device 10.

  Therefore, according to this embodiment, the cost due to the installation of the radio wave absorber is suppressed, and the radio wave reflection between the ceiling wall surface and the road surface causes erroneous communication between the roadside device and the vehicle-mounted device outside the normal communication area. It is possible to reduce the probability of occurrence.

  Further, it is possible to reduce misjudgment between a use-registered vehicle and an unregistered vehicle due to erroneous communication between the roadside device and the vehicle-mounted device outside the regular communication area.

  Although the above description in this embodiment has been described by taking a wireless communication system installed at an entrance gate to an indoor or underground parking lot as an example, it is needless to say that the present invention is not limited to this case. For example, it may be a wireless communication system installed at an exit gate, a drive-through entrance of a restaurant, or a gas station. Of course, when applying to the exit gate, it goes without saying that a settlement machine is provided in place of the ticket issuing machine, and the driver performs the settlement process to pay the fee displayed on the settlement machine by inserting the parking ticket. . In addition, when installing at a drive-through entrance of a restaurant or at a gas station etc., a ceiling wall or roof is provided above the communication area for paying charges, directly or indirectly under the ceiling or roof. Needless to say, when a communication antenna is attached to the wireless communication system, the wireless communication system exhibits an effect of preventing erroneous communication and erroneous determination.

As described above, the radio communication system according to this embodiment starts the transmission radio wave in the communication area with the vehicle-mounted device, starts communication, and transmits the radio wave according to the end of the communication with the vehicle-mounted device. Or a communication antenna device for stopping transmission radio wave transmission within a predetermined time from the start of transmission radio wave transmission, wherein the communication antenna device has a transmission output of 4 dBm or less and a reception sensitivity. By setting the value to −55 dBm or more, it is possible to reduce the probability of erroneous communication between the roadside device and the vehicle-mounted device outside the normal communication region due to radio wave reflection between the ceiling wall surface and the road surface.
In addition, it is possible to obtain an effect that the probability of erroneously determining a legitimate use registered vehicle as a use unregistered vehicle can be reduced.

  In this case, the vehicle detector that detects the passage of the vehicle within the communication area with the vehicle-mounted device, and the transmission of the transmission radio wave is started in response to detection of the vehicle by the vehicle detector, and then communication with the vehicle-mounted device is started. Then, the emission of the transmission radio wave is stopped at the end of the communication, or if the communication with the vehicle-mounted device is not started within a predetermined time from the start of the emission of the transmission radio wave, the emission of the transmission radio wave is stopped. A communication antenna may be provided.

A vehicle detector that detects the passage of the vehicle within a communication area with the vehicle-mounted device; and a reception power level that is within a first predetermined distance from the vehicle detector toward the near side in the vehicle traveling direction. The received power level of the vehicle-mounted device has an on-vehicle device at a second predetermined distance or longer than the first predetermined distance from the vehicle detector toward the front side in the vehicle traveling direction. A communication antenna device having a transmission power characteristic that is equal to or lower than the reception sensitivity of the transmitter, and the communication antenna device starts emitting a transmission radio wave in response to detection of passage of the vehicle by the vehicle detector. After the communication is started, the emission of the transmission radio wave is stopped according to the end of the communication with the vehicle-mounted device, or the emission of the transmission radio wave is stopped within a predetermined time from the start of the emission of the transmission radio wave. 1 predetermined distance is A .5m to 3m, the second predetermined distance may be 3m to 5 m.
Furthermore, the first predetermined distance may be about 2 m, and the second predetermined distance may be about 5 m.

In addition, a vehicle detector that detects the passage of the vehicle within a communication area with the vehicle-mounted device, and a reception power level that is greater than or equal to a predetermined reception sensitivity within a first predetermined distance from the vehicle detector in front of the vehicle traveling direction. And a communication antenna apparatus having a reception characteristic in which a reception power level is equal to or lower than the reception sensitivity at a second predetermined distance longer than the first predetermined distance from the vehicle detector to the front side in the vehicle traveling direction. The communication antenna device starts transmission of radio waves in response to detection of vehicle passage by the vehicle detector and starts communication, and then transmits in response to termination of communication with the vehicle-mounted device. The radio wave emission may be stopped, or the radio wave emission may be stopped when the communication is not started within a predetermined time from the start of transmission radio wave emission, and the predetermined time may be set to 0.5 seconds or less.
Furthermore, the radio communication system may be configured such that the electric field strength of the transmission radio wave is −55 dBm or more in the vicinity of the first predetermined distance on the near side in the vehicle traveling direction in the communication area.

  A vehicle detector for detecting the passage of the vehicle in the communication area with the vehicle-mounted device; and a communication antenna device having a non-communication area at a predetermined distance or more from the vehicle detector in the vehicle traveling direction. The communication antenna device starts radiating transmission radio waves in response to detection of vehicle passage by the vehicle detector and starts communication, and then radiates transmission radio waves in response to termination of communication with the vehicle-mounted device. Stop the transmission of the transmission radio wave within a predetermined time from the start of the emission of the transmission radio wave, and after the vehicle passing the vehicle detector passes the vehicle detector, You may set within the time when the succeeding vehicle reaches the predetermined distance.

  In addition, a vehicle detector that detects the passage of the vehicle within the communication area with the vehicle-mounted device, and starts emission of a transmission radio wave in response to detection of the vehicle passage by the vehicle detector, and communication with the vehicle-mounted device is started. A communication antenna device that stops emission of transmission radio waves in response to the end of communication with the vehicle-mounted device, or stops emission of transmission radio waves within a predetermined time from the start of transmission radio wave transmission. The communication antenna device has a communication area within 2.5 m from the vehicle detector toward the front side of the vehicle traveling direction, and within 1.5 m from the vehicle detector toward the vehicle traveling direction. A communication area may be included in the range.

  In addition, the vehicle detector that detects the passage of the vehicle within the communication area with the vehicle-mounted device, and the transmission of the transmission radio wave is started in response to the vehicle passage detection by the vehicle detector, and the communication with the vehicle-mounted device is started. After that, when the communication with the vehicle-mounted device is terminated, the transmission radio wave is stopped, or the transmission radio wave is stopped when the communication is not started within 0.5 seconds from the start of the transmission radio wave emission. The communication antenna device has a transmission output of 4 dBm or less, a reception sensitivity of −55 dBm or more, an antenna angle with respect to the vertical axis of 45 ° to 50 °, and a high height of 2 m to 4 m. You may install it.

  Furthermore, after the communication antenna device starts emitting the transmission radio wave and then stops emitting the transmission radio wave, the communication antenna device emits the next transmission radio wave while the vehicle detector detects the presence of the passing vehicle. You may stop.

Further, a vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector, and a vehicle-mounted device via the communication antenna device according to vehicle passage detection by the vehicle detector. A communication control device that acquires the specific information of the on-vehicle device transmitted from the database, a database that stores the specific information of the on-vehicle device and the number information, the specific information of the on-vehicle device acquired by the communication control device, and the database Compared with the stored specific information of the vehicle-mounted device, and outputs an opening / closing signal for opening / closing the circuit breaker when the comparison results in coincidence, and the number identified by the vehicle number reader and stored in the database An information processing device that compares the number and outputs an opening / closing signal for opening / closing the circuit breaker when the comparison results in a match may be provided.
Furthermore, a vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector, and a vehicle-mounted device via the communication antenna device according to vehicle passage detection by the vehicle detector. The communication control device for acquiring the specific information of the on-vehicle device transmitted from the database, the database for storing the specific information of the on-vehicle device and the number information, the specific information of the on-vehicle device acquired by the communication control device, the vehicle number An information processing device that outputs a signal for releasing the vehicle restraint may be provided based on the number identified by the reading device and the stored information in the database.

  Alternatively, in response to detection of vehicle passage by the vehicle detector, a communication control device that acquires onboard device specific information transmitted from the onboard device via the communication antenna device, and the onboard device specific information are stored. And an information processing device for determining whether the vehicle is a use registration vehicle based on the onboard device specific information acquired by the communication control device and the onboard device specific information stored in the database May be provided.

  Of course, in response to detection of vehicle passage by the vehicle detector, communication with the vehicle-mounted device is started, and the roadside device that acquires the specific information of the vehicle-mounted device transmitted from the vehicle-mounted device, and the vehicle detector passes through the vehicle detector. Information for outputting a signal for opening and closing the circuit breaker based on the number acquired from the vehicle number reading device for identifying the number of the license plate according to the detection of the number and the onboard device specific information acquired by the roadside device The roadside device may be configured such that the transmission output from the communication antenna device is 4 dBm or less and the reception sensitivity is -55 dBm or more.

  Furthermore, a vehicle detector for detecting the passage of the vehicle within a communication area with the vehicle-mounted device, and a vehicle number for identifying the number of the license plate according to detection of the vehicle by the vehicle detector and outputting the identified number When communication with the vehicle-mounted device is not started after starting radio wave emission in response to detection of the vehicle by the reading device and the vehicle detector, the number of the license plate is output from the vehicle number reading device. A communication antenna that stops emission of the transmission radio wave.

Embodiment 2. FIG.
FIG. 16 is a diagram showing a configuration of a wireless communication system according to the second embodiment of the present invention.
In the figure, the vehicle 1 entering the entrance of the parking lot enters the parking area 90 through the passage 3 of the entrance gate 100. Further, when the vehicle 101 in the parking area 90 exits from the exit gate 100b of the parking lot, the vehicle 101 passes through the passage 3b and goes out of the parking lot (outside) through the exit gate 100b.

  The vehicle 1 has an in-vehicle device 10 mounted on a dashboard near the windshield inside the vehicle. The vehicle 101 has an in-vehicle device 10b mounted on a dashboard near the windshield inside the vehicle. The traffic path 3 is disposed so as to be sandwiched between the islands 2a and 2b, and the traffic path 3b is disposed so as to be sandwiched between the islands 2b and 2c. A communication area 4 is formed on the traffic path 3, and a communication area 4b is formed on the traffic path 3b. The islands 2a, 2b and the traffic path 3 constitute a travel lane of the entrance vehicle, and the islands 2b, 2c and the traffic path 3b constitute a travel lane of the exit vehicle.

  An optical receiver 5a is installed on the island 2a, and an optical transmitter 5b is installed on the end of the parking lot entrance on the island 2b. The optical receiver 5a and the optical transmitter 5b are used as vehicles. A detector 50 is configured. A vehicle number reading device 6 for identifying the number stamped on the number plate is installed on the island 2a. The vehicle number reading device 6 may be provided on both sides of the traffic path 3 as in the example of the first embodiment. The ticket issuing machine 7 is installed between the vehicle detector 50 and the vehicle number reading device 6 on the island 2a. The circuit breaker 8 is provided on the island 2a adjacent to the vehicle number reading device 6, and the circuit breaker 8 is provided with a stop rod 9 that can be opened and closed. As shown in FIG. 2, the communication antenna device 11 includes a transmission / reception antenna 111, a transmitter 114, and a receiver 115, and forms a roadside device together with the communication control device 210. The communication antenna device 11 is installed above the vicinity of the front end of the communication area 4 in the vehicle traveling direction and below the ceiling of the parking lot. The mounting angle of the radiation surface of the communication antenna device 11 is set to about 48 degrees. The communication control device 210 is disposed near the entrance gate 100. Below the road surface of the traffic path 3, a loop coil 13 a is embedded near the front end of the communication area 4 in the vehicle traveling direction, and a loop coil 13 b is embedded near the circuit breaker 8.

  An optical receiver 500a is installed on the island 2c, and an optical transmitter 500b is installed on the end of the parking area on the island 2b. The optical receiver 500a and the optical transmitter 500b A vehicle detector 500 is configured. A vehicle number reading device 6b for identifying the number stamped on the license plate is installed on the island 2c. The vehicle number reading device 6b may be provided on both sides of the traffic path 3b as in the example of the first embodiment. The settlement machine 7b is installed between the vehicle detector 500 and the vehicle number reading device 6b on the island 2c. The circuit breaker 8b is provided on the island 2c adjacent to the vehicle number reading device 6b, and the circuit breaker 8b is provided with a stop rod 9b that can be opened and closed. The communication antenna device 11b includes a transmission / reception antenna 111, a transmitter 114, and a receiver 115, and constitutes a roadside device together with the communication control device 210. The communication antenna device 11b is installed above the vicinity of the front end of the communication area 4b in the vehicle traveling direction and below the ceiling of the parking lot. Below the road surface of the traffic path 3b, a loop coil 130a is embedded near the rear end of the communication area 4b in the vehicle traveling direction, and a loop coil 130b is embedded near the circuit breaker 8b.

  An information processing apparatus 140 is installed in a management room 550 provided in the parking area 90. Each device (communication control device 210, vehicle detectors 50 and 500, vehicle number reading devices 6 and 6b, ticket issuing machines 7 and 7b, breakers 8 and 8b) is connected to a data bus 60 laid in the parking lot. Yes.

  Note that components having the same reference numerals as those shown in FIG. 12 of the first embodiment are equivalent in configuration and operation. Further, the communication antenna device 11b, the vehicle detector 500, the vehicle number reading device 6b, the settlement machine 7b, and the breaker 8b are the communication antenna device 11, the vehicle detector 50, the vehicle number reading device 6, and the ticket issuing machine 7, respectively. , And the same equivalent as the circuit breaker 8. Therefore, the characteristics of the communication antenna device 11b and the communication area 4b, the arrangement intervals of the communication area 4b, the vehicle detector 500, the circuit breaker 8b, and the traffic path 3b, and the like are described in FIGS. 1 to 15 of the first embodiment. The communication antenna device 11 and the characteristics of the communication area 4, and the communication area 4, the vehicle detector 50, the circuit breaker 8, and the traffic path 3 are equivalent.

Next, the operation of each device in the entrance gate 100 will be described.
When the vehicle 1 entering the entrance gate 100 passes between the optical transmitter 5b and the optical receiver 5a, the vehicle detector 50 detects whether the vehicle 1 has passed. When the vehicle detector 50 detects the vehicle 1, it sends a processing start signal S <b> 1 to the communication control device 210 and the vehicle number reading device 6 via the data bus 60.

  The communication control device 210 is activated immediately in response to the reception of the processing start signal S1, and controls the communication antenna device 11 to start emitting transmission radio waves. The vehicle number reading device 6 is activated immediately in response to the reception of the processing start signal S <b> 1 and identifies the number of the vehicle passing through the communication area 4. The number information (S2) identified by the vehicle number reading device 6 is sent from the vehicle number reading device 6 to the information processing device 140 via the data bus 60.

  The transmission radio wave radiated from the communication antenna device 11 is received by the vehicle-mounted device 10 of the vehicle 1 that passes through the communication area. Thereby, a communication link is established between the communication antenna device 11 and the vehicle-mounted device 10, and road-to-vehicle communication is started. The vehicle-mounted device 10 transmits the vehicle ID information (S3) to the communication antenna device 11.

  When the vehicle 1 reaches the loop coil 13a, the loop coil 13a sends a vehicle entry signal S6 to the ticket issuing machine 7. Upon receiving the vehicle entry signal S6, the ticket issuing machine 7 sends a gate opening / closing permission signal S4 to the information processing apparatus 140 via the data bus 60. When the vehicle 1 reaches the loop coil 13b, the loop coil 13b outputs a gate closing signal S7 to the ticket issuing machine 7 via the data bus 60.

  When the road-to-vehicle communication between the communication antenna device 11 and the vehicle-mounted device 10 is completed, the vehicle ID information (S3) received by the communication antenna device 11 is sent to the communication control device 210. In addition, the communication control device 210 sends the vehicle ID information (S3) received from the communication antenna device 11 to the information processing device 140. In the information processing apparatus 140, vehicle ID information corresponding to each use registration vehicle is preset, and this setting information V is stored in a database. The information processing device 140 searches the database based on the vehicle ID information S3 transmitted from the communication control device 210, and performs a coincidence comparison (vehicle ID comparison) between the vehicle ID information S3 and the setting information V. As a result of the search, when the vehicle ID information S3 is stored in the database, it is determined that the vehicle ID information S3 matches the setting information V stored in the database, and when the vehicle ID information S3 is not stored in the database. The vehicle ID information S3 is determined to be inconsistent with the setting information stored in the database.

  In the information processing apparatus 140, number information corresponding to each use registration vehicle is set in advance, and this setting information W is stored in a database. The information processing device 140 searches the database based on the number information S2 transmitted from the vehicle number reading device 6, and performs a coincidence comparison (number comparison) between the number information S2 and the setting information W. As a result of the search, if the number information S2 is stored in the database, it is determined that the number information S2 matches the setting information W stored in the database, and if the number information S2 is not stored in the database, the number information It is determined that S2 does not match the setting information W stored in the database.

  If the information processing device 140 has received the gate opening / closing permission signal S4 from the ticketing machine 7 and the vehicle ID comparison or the number comparison results match, the ticketing machine 7 is connected via the data bus 60. Control command (S8). If the results of vehicle ID comparison and number comparison do not match, a control command (S9) is sent to the ticket issuing machine 7. On the other hand, if the information processing device 140 has not received the gate opening / closing permission signal S4 from the ticket issuing machine 7, the information processing device 140 is in a period until the gate opening / closing permission signal S4 is received regardless of the result of the vehicle ID comparison or the number comparison. The sending of the control command (S8 or S9) to the ticket issuing machine 7 is stopped.

  When the ticket issuing machine 7 receives the control command S8 from the information processing device 140 via the data bus 60, the ticket issuing machine 7 sends the control command S5 to the circuit breaker 8 via the data bus 60. When receiving the control command S5 from the ticket issuing machine 7, the circuit breaker 8 starts the opening / closing operation of the stop rod 9. Accordingly, when the vehicle 1 passes through the entrance gate 100, the vehicle 1 can enter the parking area in a non-stop manner without stopping once before the ticket issuing machine 7 in the entrance gate.

  When the ticket issuing machine 7 receives the control command S9 from the information processing apparatus 140 via the data bus 60, the ticket issuing machine 7 performs the operation of the ticket issuing process. For example, the ticket-issuing machine 7 announces to use a parking lot use ticket (parking ticket) issued to the driver of the vehicle 1. When the driver takes out the parking ticket issued by the ticket issuing machine 7, the ticket issuing machine 7 sends a control command S <b> 5 to the circuit breaker 8. In response to the reception of the control command S5, the breaker 8 jumps the stop rod 9 and the gate is automatically opened.

  Further, the vehicle 1 passes by the side of the circuit breaker 8 with the stop rod 9 opened, reaches the upper side of the loop coil 13b, and a gate closing signal S7 is sent from the loop coil 13b to the ticket issuing machine 7. Then, the ticket issuing machine 7 sends a gate closing signal S52 to the circuit breaker 8 via the data bus 60. When the breaker 8 receives the gate closing signal S52, the breaker 8 operates to lower the stop rod 9 and close the inlet gate 100.

Next, the operation of each device in the exit gate 100b will be described.
When the vehicle 1 entering the exit gate 100b passes between the optical transmitter 500b and the optical receiver 500a, the vehicle detector 500 detects whether the vehicle 101 is passing. When the vehicle detector 500 detects the vehicle 101, it sends a processing start signal S1b to the communication control device 210 and the vehicle number reading device 6b via the data bus 60.

  The communication control device 210 is activated immediately in response to the reception of the processing start signal S1b, and controls the communication antenna device 11b to start radiating transmission radio waves. The vehicle number reading device 6b is activated immediately upon receiving the processing start signal S1b, and identifies the number of the vehicle passing through the communication area 4b. The number information (S2b) identified by the vehicle number reading device 6b is sent from the vehicle number reading device 6 to the information processing device 140 via the data bus 60.

  The transmission radio wave radiated from the communication antenna device 11b is received by the vehicle-mounted device 10b of the vehicle 101 passing through the communication area. As a result, a communication link is established between the communication antenna device 11b and the vehicle-mounted device 10b, and road-to-vehicle communication is started. The onboard equipment 10b transmits vehicle ID information (S3b) with respect to the communication antenna apparatus 11b.

  When the vehicle 101 reaches the loop coil 130a, the loop coil 130a sends a vehicle approach signal S6b to the settlement machine 7b. When the payment machine 7b receives the vehicle entry signal S6b, it sends a gate opening / closing permission signal S4b to the information processing apparatus 140 via the data bus 60. When the vehicle 1 reaches the loop coil 130b, the loop coil 130b outputs a gate closing signal S7b to the ticket issuing machine 7b via the data bus 60.

  When the road-to-vehicle communication between the communication antenna device 11b and the vehicle-mounted device 10b is completed, the vehicle ID information (S3b) received by the communication antenna device 11b is sent to the communication control device 210. In addition, the communication control device 210 sends the vehicle ID information (S3b) received from the communication antenna device 11b to the information processing device 140. In the information processing apparatus 140, vehicle ID information corresponding to each use registration vehicle is set in advance, and this setting information VV is stored in a database. The information processing device 140 searches the database based on the vehicle ID information S3b transmitted from the communication control device 210, and performs a coincidence comparison (vehicle ID comparison) between the vehicle ID information S3b and the setting information VV. As a result of the search, when the vehicle ID information S3 is stored in the database, it is determined that the vehicle ID information S3 matches the setting information VV stored in the database, and when the vehicle ID information S3 is not stored in the database. The vehicle ID information S3 is determined to be inconsistent with the setting information VV stored in the database.

  In the information processing apparatus 140, number information corresponding to each use registration vehicle is set in advance, and this setting information WW is stored in a database. The information processing device 140 searches the database based on the number information S2 transmitted from the vehicle number reading device 6b, and performs a coincidence comparison (number comparison) between the number information S2b and the setting information WW. As a result of the search, if the number information S2b is stored in the database, it is determined that the number information S2b matches the setting information WW stored in the database, and if the number information S2b is not stored in the database, the number information It is determined that S2 does not match the setting information WW stored in the database.

  If the information processing device 140 has received the gate opening / closing permission signal S4b from the settlement machine 7b and the vehicle ID comparison or number comparison results are the same, the settlement apparatus 7b is connected via the data bus 60. A control command (S8b) is sent out. If the results of the vehicle ID comparison and the number comparison do not match, a control command (S9b) is sent to the settlement machine 7b. On the other hand, when the information processing apparatus 140 has not received the gate opening / closing permission signal S4b from the settlement machine 7b, the information processing apparatus 140 is in a period until the gate opening / closing permission signal S4b is received regardless of the result of vehicle ID comparison or number comparison. The sending of the control command (S8b or S9b) to the settlement machine 7b is stopped.

  When the settlement machine 7b receives the control command S8b from the information processing device 140 via the data bus 60, the settlement machine 7b sends the control command S5b to the circuit breaker 8b via the data bus 60. When the breaker 8b receives the control command S5b from the settlement machine 7b via the data bus 60, the breaker 8b starts to open and close the stop rod 9b. As a result, when the vehicle 101 passes through the exit gate 100b, the vehicle 101 can go out of the parking lot non-stop without stopping once before the settlement machine 7b in the exit gate.

  When the settlement machine 7b receives the control command S9b from the information processing apparatus 140 via the data bus 60, the settlement machine 7b executes the settlement process. For example, when the driver of the vehicle 101 inserts a parking lot use ticket (parking ticket) from a ticket insertion slot (not shown), the settlement machine 7b displays a settlement fee on a display (not shown), and by voice from a speaker (not shown). Announce settlement. When the driver pays the settlement fee of the settlement machine 7b from a fee payment port (money insertion port) (not shown), the settlement machine 7b sends a control command S5b to the circuit breaker 8b. In response to the reception of the control command S5b, the breaker 8b jumps up the stop rod 9b and the exit gate is automatically opened.

Of course, the settlement machine 7b may perform settlement processing by inserting the IC card 125. For example, even if the information processing apparatus 14 erroneously determines that the use registered vehicle is an unregistered vehicle, the driver takes out the IC card 125 inserted in the vehicle-mounted device, and illustrates the settlement machine 7b. The checkout machine 7b determines whether the vehicle mounted with the vehicle-mounted device is a use registration vehicle based on the stored information read from the internal memory of the IC card 125. It ’s fine.
In this case, card information such as vehicle ID information, information indicating that the vehicle mounted with the vehicle-mounted device is a use registration vehicle, or card ID information of the IC card may be recorded in the internal memory of the IC card 125. . The checkout machine 7b pre-registers the card information corresponding to each use registration vehicle in the internal memory for each use registration vehicle. The checkout machine 7b reads the card information of the IC card 125 and compares it with the card information pre-registered in the internal memory. If the result of the comparison is that they match, the settlement machine 7b sends a control command S5b to the circuit breaker 8b, so that the registration vehicle can use the exit gate 100b without paying (injecting) the usage fee on the spot. Can pass through.

  Further, the vehicle 101 passes the side of the circuit breaker 8b with the stop rod 9b opened, reaches the upper part of the loop coil 130b, and a gate closing signal S7b is sent from the loop coil 130b to the settlement machine 7b. Then, the checkout machine 7b sends a gate closing signal S52b to the circuit breaker 8b via the data bus 60. When the breaker 8b receives the gate closing signal S52b, the breaker 8b operates to lower the stop rod 9b and close the outlet gate 100b.

  FIG. 17 is a diagram illustrating a configuration of the information processing apparatus 140. The information processing apparatus 140 includes a comparator 141, a comparator 141b, a database 142, a controller 143, and a controller 143b. The communication control device 210 includes an entrance communication control unit 12a and an exit communication control unit 12b, and the entrance communication control unit 12a and the exit communication control unit 12b each have the same configuration as the communication control device 12.

  At the entrance gate 100, the vehicle number reading device 6 sends the number information S2 to the comparator 141 of the information processing device 140. In addition, the entrance communication control unit 12a of the communication control device 210 sends the vehicle ID information S3 to the comparator 141 of the information processing device 140. At the exit gate 100b, the vehicle number reading device 6b sends the number information S2b to the comparator 141b of the information processing device 140. Further, the exit communication control unit 12b of the communication control device 210 sends the vehicle ID information S3b to the comparator 141b of the information processing device 140.

In the database 142, usage registration information such as number plate number information and vehicle ID information is pre-registered in advance. Further, the database 142 stores vehicle ID information (incoming vehicle ID information) of vehicles in storage that have already entered the parking lot after passing through the entrance gate 100 and have not been released from the parking lot. Yes. The incoming vehicle ID information includes number information corresponding to the vehicle ID information.
The vehicle ID information whose usage registration period has passed is configured to be deleted from the database 142. Thereby, by using the vehicle ID of the vehicle that has exceeded the usage period, it can be prevented that the vehicle is erroneously determined to be a usage registered vehicle.

When the comparator 141 corresponding to the entrance gate 100 receives the vehicle ID information S3, the comparator 141 accesses the stored data in the database 142 and searches for the incoming vehicle ID information including the vehicle ID information S3. As a result of this database search, if there is incoming vehicle ID information including vehicle ID information S3, match information MY is received from database 142. Accordingly, the comparator 141 determines that the vehicle ID information S3 is transmitted from the exit gate 100b, and transmits a mismatch signal S10 to the controller 143.
Note that the vehicle number reading device 6 may have already stored the vehicle ID information in the database 142 by transmitting the number information S2 to the information processing device 140 first. In this case, while the vehicle-mounted device 10 and the communication antenna device 11 perform road-to-vehicle communication, the storage vehicle ID storage flag described later is set in advance, so the comparator 141 searches the stored data in the database 142. Without determining whether there is the vehicle ID information. Therefore, in this case, the mismatch signal S10 is not output.

On the other hand, as a result of the database search, if there is no incoming vehicle ID information including the vehicle ID information S3, the mismatch information MN is received from the database 142. Accordingly, the comparator 141 determines that the vehicle ID information S3 is transmitted from the entrance gate 100. In this case, the comparator 141 accesses the data stored in the database 142 and searches whether vehicle ID information that matches the vehicle ID information S3 is pre-registered. If there is pre-registered vehicle ID information that matches the vehicle ID information S3 as a result of this database search, the comparator 141 receives the data match information N3 from the database 142 and sends a match signal to the controller 143. S11 is transmitted. The comparator 141 outputs the coincidence signal S11 to the controller 143 and at the same time stores the vehicle ID information S3 in the database 142 as the incoming vehicle ID information. At this time, referring to the usage registration information pre-registered in the database 142 based on the vehicle ID information S3, the number information corresponding to the vehicle ID information S3 is read from the referenced usage registration information, and the read number information and the vehicle Both ID information S3 is included and stored in warehousing vehicle ID information. At the same time, a storage vehicle ID storage flag indicating that storage vehicle ID information corresponding to the vehicle ID information S3 is stored is set. The storage vehicle ID storage flag is held in a memory (not shown) until the output signal of the vehicle detector 50 switches from the ON state to the OFF state (for at least 0.9 seconds), and the output signal of the vehicle detector 50 is stored. Is deleted when the state is switched from the OFF state to the ON state.
If there is no pre-registered vehicle ID information that matches the vehicle ID information S3 as a result of the database search, the comparator 141 receives data mismatch information NN3 from the database 142.

Further, when the comparator 141 receives the number information S2 from the vehicle number reading device 6, the comparator 141 accesses the stored data in the database 142 and searches the warehousing vehicle ID information including the number information S2. As a result of this database search, if there is incoming vehicle ID information including the number information S2, whether the incoming vehicle ID information exists in the database 142 as abnormal storage information due to a system malfunction or the vehicle number reading device 6 is judged to have an operation error, and a mismatch signal S10 is transmitted to the controller 143.
Note that the vehicle ID information corresponding to the number information S2 is transmitted to the information processing device 140 first by communication between the vehicle-mounted device 10 and the communication antenna device 11, so that the warehousing vehicle ID information is already registered in the database 142. May have been. In this case, since the storage vehicle ID storage flag described above is set in advance while the vehicle number reading device 6 is in the ON state, the comparator 141 does not search the stored data in the database 142 and stores the storage vehicle ID information. Does not determine the presence or absence of. Therefore, in this case, the mismatch signal S10 is not output.

On the other hand, when the warehousing vehicle ID information including the number information S2 does not exist, the comparator 141 accesses the stored data of the database 142 to check whether the number information that matches the number information S2 is registered in advance. Search for. As a result of this database search, if there is pre-registered number information that matches the number information S2, the comparator 141 receives the data match information N2 from the database 142 and sends a match signal S11 to the controller 143. Send. The comparator 141 outputs the coincidence signal S11 to the controller 143 and at the same time stores the number information S2 in the database 142 as incoming vehicle ID information.
At this time, based on the number information S2, the use registration information pre-registered in the database 142 is referred to, the vehicle ID information corresponding to the number information S2 is read from the referenced use registration information, and the read vehicle ID information is read out. Is included in the incoming vehicle ID information and stored. At the same time, an incoming vehicle ID storage flag indicating that the incoming vehicle ID information corresponding to the number information S2 has been stored is set. The storage vehicle ID storage flag is held in a memory (not shown) until the output signal of the vehicle detector 50 switches from the ON state to the OFF state (for at least 0.9 seconds), and the output signal of the vehicle detector 50 is stored. Is deleted when the state is switched from the OFF state to the ON state.
If there is no pre-registered number information that matches the number information S2 as a result of the database search, the comparator 141 receives data mismatch information NN2 from the database 142.

  When the comparator 141 receives both the data mismatch information NN2 and the data mismatch information NN3 from the database 142, the comparator 141 determines that the vehicle ID information is unregistered (or unregistered ID), and the comparator 141 controls the controller 143. A mismatch signal S10 is transmitted.

  Upon receiving the coincidence signal S11 from the comparator 141, the controller 143 sends a control command S8 to the ticket issuing machine 7. Further, when the controller 143 receives the mismatch signal S10 from the comparator 141, the controller 143 sends a control command S9 to the ticket issuing machine 7.

Next, when the comparator 141b corresponding to the exit gate 100b receives the vehicle ID information S3b, the comparator 141b accesses the stored data in the database 142 and searches for the incoming vehicle ID information including the vehicle ID information S3b. As a result of this database search, when there is no incoming vehicle ID information including the vehicle ID information S3b, the mismatch information MMN is received from the database 142. As a result, it is determined that the vehicle ID information is not registered for use or the vehicle ID information S3b is transmitted from the entrance gate 100, and a mismatch signal S10b is transmitted to the controller 143b. .
In some cases, the vehicle number reading device 6b transmits the number information S2b to the information processing device 140 first, so that the warehousing vehicle ID information in the database 142 has already been deleted. In this case, while the vehicle-mounted device 10b and the communication antenna device 11b are performing road-to-vehicle communication, the output vehicle ID storage flag to be described later is preset, so the comparator 141 searches the stored data in the database 142. The presence / absence of the incoming vehicle ID information is not determined. Therefore, in this case, the mismatch signal S10b is not output.

On the other hand, when there is an incoming vehicle ID including the vehicle ID information S3b, the matching information MMY is received from the database 142. The comparator 141b determines that the vehicle ID information S3b is transmitted from the exit gate 100b. In this case, the comparator 141b outputs the coincidence signal S11b to the controller 143b, and at the same time deletes the incoming vehicle ID information from the database 142b. At the same time, a delivery vehicle ID storage flag indicating that the entry vehicle ID information corresponding to the vehicle ID information S3b has been deleted is raised. The outgoing vehicle ID storage flag is held in a memory (not shown) until the output signal of the vehicle detector 50b switches from the ON state to the OFF state (for at least 0.9 seconds), and the output signal of the vehicle detector 50b. Is deleted when the state is switched from the OFF state to the ON state.
At this time, the data stored in the database 142 may be accessed to search for whether vehicle ID information that matches the vehicle ID information S3b has been pre-registered. If there is pre-registered vehicle ID information that matches the vehicle ID information S3b as a result of this database search, the comparator 141b receives the data match information N3b from the database 142, and the communication control device 210 operates normally. Judge that you are doing. Further, as a result of the database search, when there is no pre-registered vehicle ID information that matches the vehicle ID information S3b, the comparator 141b receives the data mismatch information NN3b from the database 142, and the communication control device 210 Judge that it is not operating normally.

Further, when the vehicle number reading device 6b receives the number information S2b, it accesses the data stored in the database 142 and searches for the incoming vehicle ID information including the number information S2b. As a result of this database search, when there is no warehousing vehicle ID information including the number information S2b, it is determined that the vehicle ID information is a vehicle that is not registered for use, and a mismatch signal S10b is sent to the controller 143b. Send. However, in this case, there is a possibility that the inbound vehicle ID information is not normally stored in the database 142 due to a system malfunction or there is an operation error in the vehicle number reading device 6 itself.
In addition, the vehicle ID information corresponding to the number information S2b is first transmitted to the information processing device 140 by communication between the vehicle-mounted device 10b and the communication antenna device 11b, so that the entrant vehicle ID information in the database 142 has already been deleted. May have been. In this case, since the above-described outgoing vehicle ID storage flag is already set while the vehicle number reading device 6b is in the ON state, the comparator 141 does not search the stored data in the database 142, and stores the incoming vehicle ID information. Does not judge existence. Therefore, in this case, the mismatch signal S10b is not output.

On the other hand, when the entering vehicle ID information including the number information S <b> 2 b exists, the comparator 141 b receives the matching information MMY from the database 142. In this case, the comparator 141b outputs the coincidence signal S11b to the controller 143b, and at the same time deletes the incoming vehicle ID information from the database 142b. At the same time, a delivery vehicle ID storage flag indicating that the entry vehicle ID information corresponding to the number information S2b has been deleted is raised. The outgoing vehicle ID storage flag is held in a memory (not shown) until the output signal of the vehicle detector 50 is switched from the ON state to the OFF state (for at least 0.9 seconds). Is deleted when the state is switched from the OFF state to the ON state.
At this time, the data stored in the database 142 may be accessed to search whether or not the number information that matches the number information S2b is pre-registered. As a result of this database search, when there is pre-registered number information that matches the number information S2b, the comparator 141b receives the data match information N2b from the database 142, and the vehicle number reading device 6b is normally sent from the vehicle. It is determined that the number information is read (confirms that the operation function is normal). If there is no pre-registered number information that matches the number information S2b as a result of the database search, the comparator 141b receives the data mismatch information NN2b from the database 142, and the vehicle number reading device 6b From this, it is determined that the number information has not been read normally (recognizing that there is a malfunction in the operation).

  Further, when the comparator 141b receives both the data mismatch information NN3b and the data mismatch information NN2b from the database 142, the comparator 141b may transmit the mismatch signal S10b to the controller 143b. good. In this case, it is determined that the incoming vehicle ID information is not normally stored in the database 142 due to a system malfunction, or that there is a possibility that the in-vehicle device 10 has some injustice.

  When receiving the coincidence signal S11b from the comparator 141b, the controller 143b sends a control command S8b to the settlement machine 7b. Further, when receiving the mismatch signal S10b from the comparator 141b, the controller 143b sends a control command S9b to the settlement machine 7b.

  Since the second embodiment is configured as described above, in addition to the effects obtained by the first embodiment, the vehicle ID of the vehicle already in the parking lot, the roadside device, and the vehicle-mounted device Comparison is made with the vehicle ID obtained by communication. This further reduces the probability of misjudging legitimate use-registered vehicles and non-use-registered vehicles by communicating with vehicles exiting at the entrance gate or communicating with vehicles entering the exit gate. can do. Therefore, the vehicle can pass through the gate without being temporarily stopped at the entrance or exit gate due to an erroneous determination, and the occurrence of a malfunction in which the use registration vehicle pays a fee can be further reduced.

  Even if the registration vehicle stops before the settlement machine and performs the settlement process, the driver inserts the IC card inserted in the vehicle-mounted device into the IC card insertion slot of the settlement machine 7b, The checkout machine 7b may determine whether or not the vehicle mounted with the vehicle-mounted device is a use registration vehicle. In this case, it is possible to pass through the exit gate without paying the usage fee to the settlement machine 7b. For this reason, when registering as a registration vehicle for use, it is possible to prevent a confusion such as paying a charge twice even though the use charge is paid in advance or after delivery.

  As described above, according to this embodiment, the vehicle detector that detects the passage of the vehicle within the communication area with the vehicle-mounted device, and the emission of the transmission radio wave according to the vehicle passage detection by the vehicle detector are started. After starting communication with the on-board device, stop the transmission of the transmission radio wave according to the end of the communication with the on-vehicle device, or stop the transmission radio wave emission within a predetermined time from the start of the transmission radio wave emission An on-vehicle device, a communication control device for acquiring on-vehicle device specific information transmitted from the on-vehicle device via the communication antenna in response to vehicle passage detection by the vehicle detector, and the on-vehicle device specific information in advance And a database for storing the in-vehicle device specific information acquired by the communication control device, the in-vehicle device specific information acquired by the communication control device, and the storage information of the database Communicating with a vehicle exiting at the entrance gate or communicating with a vehicle entering at the exit gate by providing an information processing device that outputs a signal for releasing the restraint of the vehicle based on the coincidence comparison Thus, the probability of erroneously determining a regular use registered vehicle and a use unregistered vehicle can be further reduced.

  Further, the information processing apparatus includes a vehicle number reading device that identifies a number of a license plate according to vehicle passage detection by a vehicle detector, and a database that stores vehicle number information in advance. The signal for releasing the vehicle restraint may be output based on the coincidence comparison between the on-vehicle device specific information acquired in step 1 and the number identified by the vehicle number reading device and the stored information in the database. .

  Of course, in the first and second communication areas with the vehicle-mounted device, the first and second vehicle detectors for detecting the passage of the vehicle, respectively, and the detection of the passage of each vehicle by the respective vehicle detectors, respectively. After starting to radiate the transmission radio wave and starting communication with the on-board unit, either stop radiating the transmission radio wave according to the end of communication with the on-board unit, or within a predetermined time from the start of emission of the transmission radio wave First and second communication antennas that respectively stop transmission radio waves when communication with the vehicle-mounted device is not started, and the first and second communication antennas detect the passage of each vehicle by the vehicle detectors. A communication control device that acquires specific information of each vehicle-mounted device transmitted from each vehicle-mounted device via the two communication antennas; and the vehicle-mounted vehicle obtained from the first communication antenna acquired by the communication control device Store specific information A signal for releasing the restraint of the vehicle based on a coincidence comparison between the database and the in-vehicle device specific information obtained from the second communication antenna obtained by the communication control device and the stored information in the database It goes without saying that an information processing device that outputs the information may be provided.

Embodiment 3 FIG.
FIG. 18 is a perspective view showing a configuration of a wireless communication system according to Embodiment 3 of the present invention.
In FIG. 18, the vehicle 1 travels in the traveling direction of the vehicle 1 from the entrance of the indoor parking lot (hereinafter referred to as a parking lot) toward the parking area (not shown) and passes through the passage 3 of the entrance gate 100. A state of entering 100 is shown. In the vehicle 1, the vehicle-mounted device 10 is mounted on a dashboard near the in-vehicle windshield (window). In the entrance gate 100, islands 2 a and 2 b are arranged so as to form the traffic path 3 of the vehicle with the traffic path 3 interposed therebetween. The width of the traffic path 3 is about 3.5 m. A regular communication area 4 is formed on the traffic path 3 between the islands 2a and 2b. In the figure, the communication area 4 is indicated by a substantially square area virtually surrounded by a solid flat curve. ing. The islands 2a and 2b and the traffic path 3 constitute a traveling lane of the vehicle. A loop coil for detecting a magnetic field change due to the passage of the vehicle body (metal body) of the vehicle is embedded under the road surface around the communication area 4 of the passage 3.

  An optical receiver 5a is installed on the island 2a, and an optical transmitter 5b is installed on the island 2b, and the optical receiver 5a and the optical transmitter 5b constitute a vehicle detector 50. A vehicle number reader 6 for identifying the number stamped on the license plate is installed on the island 2a. The ticket issuing machine 7 is installed between the vehicle detector 50 and the vehicle number reading device 6 on the island 2a. The circuit breaker 8 is provided on the island 2a adjacent to the vehicle number reading device 6, and the circuit breaker 8 is provided so that it can be opened and closed by raising or lowering the stop rod 9.

  The communication antenna 11 constitutes a roadside machine together with the communication control device 12. The communication antenna 11 is supported by a hanging tool 21 and is suspended from the ceiling 20 of the parking lot. Of course, in addition to hanging from the ceiling 20, the antenna may be attached to the top of a pole upright under the ceiling, and it goes without saying that there are various methods for installing the communication antenna 11. For simplification of illustration, only a part of the ceiling 20 is shown in the figure. The communication control device 12 is disposed near the entrance gate 100. The mounting angle of the radiation surface of the communication antenna 11 is set to approximately 23 degrees.

  FIG. 19 is a diagram illustrating a configuration of the communication antenna 11. In the figure, the communication antenna 11 includes a transmission / reception antenna 111 and a transceiver 110. The transceiver 110 includes a transmission / reception level adjustment unit 112, a transmission / reception distributor 113, a transmitter 114, and a receiver 115. The transmission / reception antenna 111 has directivity, and radiates an RF signal output from the transmitter / receiver 110 to the space as a transmission radio wave with a desired antenna gain, or a reception radio wave input to the antenna terminal of the transmission / reception antenna 111. And outputs an RF signal to the transceiver 110. The transmitter 114 receives a transmission signal from the communication control device 12 and performs power amplification and frequency modulation. The modulated signal output from the transmitter 114 is transmitted to the transmission / reception level adjustment unit 112 via the transmission / reception distributor 113, and the transmission signal subjected to level conversion is output to the transmission / reception antenna 111. Also, the transmission / reception level adjustment unit 112 performs level conversion on the RF signal received and input by the transmission / reception antenna 111 and outputs the level-converted signal to the transmission / reception distributor 113. The receiver 115 receives the output signal of the transmission / reception distributor 113, performs frequency demodulation and power amplification, and outputs a signal to the communication control device 12. The transmission / reception level adjustment unit 112 is configured by, for example, a variable attenuator (attenuator), and performs level adjustment so that the reception sensitivity of the reception signal output from the transmission / reception antenna 111 is set to a predetermined value or less. Further, the transmission signal output from the transmission / reception distributor 113 is attenuated to a predetermined magnitude.

  Generally, in a conventional ETC system that is currently in practical use, the radio communication frequency of the transceiver is 5.795 GHz or 5.805 GHz, and the antenna gain of the transmission / reception antenna is 12.7 dBi. The radio wave specifications are set so that the transmission output of the transmitter in the communication antenna is 4 dBm (3.5 mW) and the reception sensitivity of the antenna input terminal is −65 dBm.

  In the DSRC system for indoor parking lots according to the third embodiment, the radio communication frequency of the transceiver 110 is 5.795 GHz or 5.805 GHz, and the antenna gain of the transmission / reception antenna 111 is 12.7 dBi. In addition, radio wave specifications are set so that the transmission output of the communication antenna 11 in the roadside unit is 0 dBm or less, preferably −2 dBm (0.63 mW), and the reception sensitivity is −60 dBm or less, preferably −60 dBm. ing. Specifically, by providing a transmission / reception level adjustment unit 112 between the transmission / reception antenna 111 and the transmission / reception distributor 113, the transmission output is attenuated and the reception sensitivity is lowered. In the communication antenna of the conventional ETC system, the transmission / reception level adjustment unit 112 used in the third embodiment does not exist.

For example, the transmission / reception level adjustment unit 112 attenuates 6 dBm so that the transmission output A2 output from the output end of the transmitter 114 via the transmission / reception distributor 113 is attenuated from 4 dBm in the case of the ETC system to −2 dBm. Since the antenna gain is 12.7 dBi, the transmission output A1 is about 11 dB at the antenna output end in front of the antenna (vertical plane or horizontal plane angle 0 °).
Also, the reception sensitivity B2 at the input end of the receiver is set to -53 dBm, and by providing the transmission / reception level adjustment unit 112, the sensitivity at the input end of the transmission / reception level adjustment unit 112 is attenuated to -47 dBm. Accordingly, since the antenna gain of the transmission / reception antenna 111 is 12.7 dBi, the reception sensitivity Bk at the antenna input end of the transmission / reception antenna 111 is about −60 dBm. Note that the transmission / reception level adjustment unit 112 has an automatic gain adjustment function, and adjusts the reception sensitivity B2 at the input end of the receiver to be −53 dBm.

  In addition, the communication antenna of the vehicle-mounted device 10 that communicates with the roadside device is configured by an omnidirectional antenna, and is configured to radiate a radio wave with a transmission output of 10 dBm (10 mW), for example.

Here, the transmission characteristics of the communication antenna 11 will be described.
FIG. 20 is a diagram illustrating an example of multiple reflection of transmission radio waves radiated from the communication antenna 11, and FIG. 20A is a diagram illustrating a reflection state of radio waves before the vehicle 1 enters the communication area 4. FIG. 20 (b) is a diagram showing a reflected state of radio waves after the vehicle 1 has entered the communication area 4. 20A and 20B, the communication area 4 for performing wireless communication between the communication antenna 11 and the vehicle-mounted device 10 is a traffic path 3 in consideration of the installation height of the vehicle-mounted device 10 in the vehicle 1. At a height of approximately 1 m from the road surface, the length of the region in the traveling direction of the vehicle 1 is preferably set to be not less than 2 m and less than 3 m, more preferably approximately 2.5 m. Is preferable. The width of the communication area 4 in the direction perpendicular to the traveling direction of the vehicle 1 is also preferably set to be 2 m or more and less than 3 m, and more preferably set to be approximately 2.5 m. Is preferred. For example, when the width of the vehicle 1 is 1.8 m and the width of the roadway is taken into consideration, when the vehicle 1 passes through the center of the roadway 3, the distance between the vehicle 1 and the island 2a or 2b is 0.85m. Become. Since the driver of the vehicle 1 travels at a distance of 0.3 m to 0.5 m from the island 2a or 2b so as to avoid contact with the island 2a or 2b, the width of the communication area 4 is set to 2.5 m. Then, the communication area 4 can sufficiently cover the traffic area of the vehicle 1 sufficiently.
In the conventional ETC system, the size of the communication area is set to 4.5 m long × 3.5 m wide.

  In FIG. 20A, a reflected wave 31 of the transmission radio wave 30 is generated between the ceiling 20 of the parking lot and the road surface of the traffic path 3, so that a communicable area 40 (non-standard communication area) is formed outside the communication area 4. ) Has occurred. The communicable area 40 here has a length of about 5 m in the traveling direction of the vehicle 1.

  On the other hand, in FIG. 20B, a reflected wave 31 of the transmission radio wave 30 is generated between the ceiling 20 of the parking lot and the road surface of the traffic path 3, and a reflected wave 31 b is generated between the vehicle 1 and the vehicle body. A communicable area 41 is generated outside the communication area 4. Here, the communicable area 41 has a length of about 1 m in the traveling direction of the vehicle 1, and the length of the communicable area is shorter than when the vehicle 1 does not exist in the communication area 4. ing. This is because the phase is reversed when the transmission radio wave of the communication antenna 11 is reflected by the metal body of the vehicle 1, so that the reflected wave 31 from the road surface 3 and the reflected wave 31 b from the vehicle 1 are This is because the size of the communicable area 41 becomes smaller than the communicable area 40 by canceling out in phase. In this case, the electric field intensity of the radio wave received by the vehicle-mounted device 10 is weakened due to the loss of the radio wave in the windshield (window) of the vehicle 1, and in this communicable region 41, between the vehicle-mounted device 10 and the communication antenna 11. The probability that no road-to-vehicle communication (details will be described later) is not established is extremely high. For this reason, by performing road-to-vehicle communication only when the vehicle 1 passes through the communication area 4, erroneous communication between the vehicle on which the other vehicle-mounted device existing outside the communication area is mounted and the communication antenna 11 is performed. Can be reduced.

  FIG. 21A shows a relationship between the vehicle 1 entering the communication area 4 of the communication antenna 11 and the following vehicle 1b of the vehicle 1, and FIG. 21B corresponds to FIG. It is the figure which showed the electric field strength distribution (solid line 51) of the transmission radio wave from the antenna 11 for communication. Here, the vehicle 1 and the vehicle 1b are equipped with the vehicle-mounted devices 10 and 10b, respectively. A region 43 indicates a region where the electric field strength is high in the vicinity of the vehicle 1b in front of the vehicle 1 in the approach direction outside the communication region. FIG. 21B shows the electric field strength of a radio wave incident on the vehicle for convenience, as the electric field strength of a transmission radio wave radiated from the communication antenna 11.

  FIG. 22 is a diagram showing an example of the radiation characteristics of the communication antenna 11, and FIG. 22 (a) shows transmission power characteristics ((1) horizontal plane direction, (2) vertical plane direction), FIG. 22 (b). Indicates received power characteristics ((1) horizontal plane direction, (2) vertical plane direction), respectively.

  FIG. 23 is a diagram showing a geometric arrangement of the communication antenna 11. The electric field strength of the transmission radio wave 30 from the communication antenna 11 in the vehicle at points P1 to P3 in FIG. 23 can be calculated based on the same figure and the following equations (3) to (7). .

  As shown in FIG. 21 (b), the electric field strength of the transmission radio wave 30 of the communication antenna 11 at the center of the communication area 4 (around the point P2 in FIG. 23) is -49.7 dBm when the transmission output is -2 dBm. It is as follows. In the figure, if the minimum reception level at the antenna input end of the vehicle-mounted device 10 is −60 dBm or more, the electric field strength in the region 43 where the electric field strength is high (maximum) outside the communication region is The minimum reception level is −60 dBm or less (shown in FIG. 21B). In this case, road-to-vehicle communication between the communication antenna 11 and the vehicle-mounted device 10 is not caused. In FIG. 21B, a dotted line 52 in FIG. 21B indicates the transmission power characteristic of the communication antenna 11 of the vehicle-mounted device 10 of a general ETC system, and is −60 dBm, which is the minimum reception level of the vehicle-mounted device 10. As described above, the communicable area 48 outside the communication area exists. As described above, it is possible to increase the probability that road-to-vehicle communication is not established in the region 43 where the electric field strength is high. Incidentally, when the antenna output of the transmission radio wave of the communication antenna 11 is 4 dBm, the electric field strength around the center of the communication area 4 is −43.7 dBm.

Next, the reception characteristics of the communication antenna 11 will be described.
FIG. 24 is a diagram illustrating reception characteristics of the communication antenna 11. In the figure, the solid line 53 indicates the received power distribution of the radio wave transmitted from the vehicle-mounted device 10 and incident on the communication antenna 11, the vertical axis indicates the received power, and the horizontal axis indicates the position in the vehicle traveling direction. Moreover, the fluctuation | variation of the received power in the boundary line in the communication area 47 of the communication antenna of the conventional ETC system and the onboard equipment 10 is illustrated by hatching.

  In the conventional ETC system, when the vehicle-mounted device 10 is located in the communication area 47, the reception sensitivity at the antenna input end of the communication antenna 11 is set to be −65 dBm or more. Generally, the transmission radio wave output from a vehicle equipped with an on-board device has a transmission output level for each on-board device due to the individual difference of the on-vehicle device itself or individual differences such as the windshield and mounting position of the vehicle equipped with the on-vehicle device. It varies. This transmission output level varies in the range of 10 dBm ± 3 dBm. For this reason, the received power level of the radio wave transmitted from the vehicle-mounted device 10 and incident on the communication antenna 11 varies for each vehicle-mounted device, and the received power distribution of the radio wave incident on the communication antenna 11 is indicated by a solid line 53 in the figure. It changes in the range of P up and down like the dotted lines above and below. Accordingly, in the conventional ETC, the reception power at the input end of the communication antenna 11 at the boundary line of the communication region 47 fluctuates in the range B (−75 dBm to −65 dBm) in the figure, as if reception is performed. The behavior is such that the sensitivity varies from -75 dBm to -65 dBm. On the other hand, as shown in the figure, in the region 45 where the reception sensitivity of the communication antenna is high (maximum) outside the communication region with the vehicle-mounted device 10, the reception power of the communication antenna 11 exceeds -75 dBm. In this case, erroneous communication is performed between the vehicle-mounted device 10 located outside the communication area and the communication antenna.

  However, the communication antenna 11 according to this embodiment is provided with the transmission / reception level adjustment unit 112 as described above with reference to FIG. Thereby, compared with the conventional ETC system, the sensitivity of the reception beam of the communication antenna 11 in the communication area 4 is lowered, and the reception sensitivity is adjusted so as to be −60 dB or more, preferably −60 dB. is doing. For this reason, even if the transmission radio wave from the vehicle-mounted device 10 forms the region 45 where the electric field strength is high (maximum) outside the communication region, the sensitivity of the received wave of the communication antenna 11 is low. It is difficult to receive the transmission wave from the vehicle (the transmission wave from the vehicle-mounted device 10 is difficult to hear), and it is possible to increase the probability that road-to-vehicle communication in the region 45 is not established.

FIG. 25 is a block diagram showing the connection relationship of each component device of the wireless communication system according to this embodiment, which operates as follows.
In the figure, when the vehicle 1 passes between the optical transmitter 5b and the optical receiver 5a, the output light of the optical transmitter 5b is blocked and the output light of the optical receiver 5a is not received by the optical transmitter 5b. By detecting this, the vehicle detector 50 detects whether the vehicle 1 is passing. When the vehicle detector 50 detects the vehicle 1, it sends a processing start signal S <b> 1 to the communication control device 12. At the same time, a process start signal S1 is output to the vehicle number reading device 6.

  The loop coil 13 a is embedded below the surface of the road surface 3 so as to be in contact with the front end of the communication region 4 in the traveling direction. The circuit breaker 8 is installed such that the stop rod 9 is disposed at a position 3 m away from the front end of the communication area 4 in the vehicle traveling direction. The loop coil 13 b is disposed so as to be positioned in front of the restraining rod 9 in the traveling direction of the vehicle 1. An information processing apparatus 14 is installed in the parking lot management room 50. In addition, the substantially square hatching area in the figure indicates the communication area 4.

  The communication control device 12 is activated immediately in response to the reception of the processing start signal S1, and controls the communication antenna 11 to start radiating transmission radio waves. The vehicle number reading device 6 is activated immediately in response to the reception of the processing start signal S1, photographs the license plate of the vehicle passing through the communication area 4 with a camera installed therein, and marks the license plate. Identifies the assigned number. At this time, the processing time Tn from when the vehicle number reader 6 is activated until the number is identified is 0.5 seconds or less. The number information (S2) identified by the vehicle number reading device 6 is sent from the vehicle number reading device 6 to the information processing device 14.

  The vehicle detector 50 is disposed at a position advanced 0.5 m forward from the rear end of the communication area 4 in the vehicle traveling direction. In general, the dashboard of the vehicle 5 is provided within 0.5 m from the front end (front bumper), and the vehicle 5 can enter the communication area 4 when the vehicle 5 reaches the vehicle detector 50. The transmission radio wave radiated from the communication antenna 11 is received by the vehicle-mounted device 10 of the vehicle 1 that passes through the communication area. As a result, execution of link establishment, which will be described later, is started between the communication antenna 11 and the vehicle-mounted device 10, and when the link is established, road-to-vehicle communication is performed. Unique information (vehicle ID information) for specifying the vehicle is transmitted. Since the vehicle-mounted device and the vehicle are associated one-to-one, a vehicle number, a serial number of the vehicle-mounted device, or the like is used as the vehicle ID information (this will be described later). The vehicle ID information received and demodulated by the communication antenna 11 is transmitted to the communication control device 12, converted into digital information, and output as vehicle ID information (S3).

  When the vehicle 1 reaches above the loop coil 13 a and the loop coil 13 a detects the passage of the vehicle 1, the loop coil 13 a sends a vehicle entry signal S 6 to the ticket issuing machine 7. When the ticket issuing machine 7 receives the vehicle approach signal S6, it sets a built-in bit memory (not shown) to the ON state (logical 1). At the same time, the ticket issuing machine 7 sends a gate opening / closing permission signal S4 to the information processing apparatus 14. When the vehicle 1 reaches above the loop coil 13 b and the loop coil 13 b detects the passage of the vehicle 1, the loop coil 13 b outputs a gate closing signal S 7 to the ticket issuing machine 7. The gate closing signal S7 resets the bit memory of the ticket issuing machine 7 to the OFF state (logical 0).

  When the road-to-vehicle communication between the communication antenna 11 and the vehicle-mounted device 10 is completed, vehicle ID information (S3) is sent from the communication control device 12 to the information processing device 14. The information processing apparatus 14 is disposed in the management room 50. In the information processing apparatus 14, vehicle number information (N2) corresponding to the vehicle ID information is set in advance, and this setting information is stored in a database (142) described later with reference to FIG. The information processing device 14 acquires the number information N2 from the database (142) based on the vehicle ID information S3 transmitted from the communication control device 12, and is transmitted from the acquired number information N2 and the vehicle number reading device 6. A coincidence comparison with the number information S2 is executed.

  When the information processing device 14 has received the gate opening / closing permission signal S4 from the ticketing machine 7, that is, when the loop coil 13a has transmitted the vehicle entry signal S6, the number information (N2 and S2) matches. As a result of the comparison, if they match, a control command (S8) is sent to the ticket issuing machine 7. If the number information matches and does not match, a control command (S9) is sent to the ticket issuing machine 7. On the other hand, when the information processing device 14 has not received the gate opening / closing permission signal S4 from the ticketing machine 7, that is, when the vehicle 1 does not reach the loop coil 13a and the vehicle entry signal S6 is not output. Regardless of the result of the coincidence comparison of the number information, the information processing apparatus 14 stops sending the control command S8 or S9 until the gate opening / closing permission signal S4 is received.

  When the ticket issuing machine 7 receives the control command S8 from the information processing device 14, it sends the control command S5 to the circuit breaker 8. When receiving the control command S5 from the ticket issuing machine 7, the breaker 8 releases the restraint of the vehicle and opens / closes the restraining rod 9. In addition, when the ticket issuing machine 7 receives the control command S9 from the information processing apparatus 14, the ticket issuing machine 7 performs the operation of the ticket issuing process.

  Thereby, when the number of the vehicle 1 coincides with the number corresponding to the vehicle ID of the vehicle-mounted device 10, the circuit breaker 8 jumps up the stop rod 9 in response to reception of the control command S8 of the ticket issuing machine 7, The gate is automatically opened (the vehicle 1 can enter the parking area). At this time, the bit memory of the circuit breaker 8 is set to the ON state. Accordingly, when the vehicle 1 passes through the entrance gate 100, the vehicle 1 can enter the parking area in a non-stop manner without stopping once before the ticket issuing machine 7 in the entrance gate.

  When the number of the vehicle 1 does not match the number corresponding to the vehicle ID of the vehicle-mounted device 10, the ticket issuing process is executed in response to the reception of the control command S <b> 9 of the ticket issuing machine 7. For example, the ticket issuing machine 7 announces to the driver of the vehicle 1 to take a parking lot use ticket (parking ticket) issued. When the driver takes out the parking ticket issued by the ticket issuing machine 7, the ticket issuing machine 7 sends a control command S <b> 5 to the circuit breaker 8. In response to the reception of the control command S5, the breaker 8 jumps up the stop rod 9 and the gate is automatically opened. As a result, the vehicle 1 can enter the parking area while the driver of the vehicle 1 has the parking ticket issued by the ticket issuing machine 7. At this time, the bit memory of the circuit breaker 8 is set to the ON state.

  Next, in a state where the stop rod 9 is opened, the vehicle 1 passes the side of the breaker 8 and reaches above the loop coil 13b, and a gate closing signal S7 is sent from the loop coil 13b to the ticket issuing machine 7. When sent out, the ticket issuing machine 7 sends a gate closing signal S52 to the circuit breaker 8. When the breaker 8 receives the gate closing signal S52, the breaker 8 operates so as to close the stop rod 9, and the jumped stop rod 9 is lowered to become horizontal, and the bit memory of the breaker 8 is turned on. Is reset to the OFF state.

  FIG. 26 is a diagram illustrating a configuration of the information processing apparatus 14. The information processing apparatus 14 includes a comparator 141, a database 142, and a controller 143. The vehicle number reading device 6 sends number information S <b> 2 to the comparator 141 of the information processing device 14. The communication control device 12 sends the vehicle ID information S3 to the comparator 141 of the information processing device 14.

When a parking lot user makes a parking lot usage agreement with the system administrator as a user of the wireless communication system in the parking lot to be used, the license registration number form contains the license plate number information, Vehicle ID information (use registration information) and use period information stored in the vehicle-mounted device are described and registered as use registration information. When the driver applies for use registration, the use vehicle described in the use registration application is registered as a use-registered vehicle (use registration vehicle). A vehicle that is not registered for use is referred to as a non-use registered vehicle.
In the database 142, usage registration information described in advance in the usage registration application is registered and stored. When the user of the wireless communication system makes a use registration application, the user sets the above-described use period information and simultaneously pays a use fee to the system administrator in accordance with the use period. In this case, for example, the usage contract may be a monthly usage contract or an annual usage contract, and a fee corresponding to the usage period is paid in advance. Alternatively, the usage period may be automatically updated, and the usage fee may be paid after delivery. In this case, the usage period information stored in the database 142 may be updated every fixed period. Of course, it goes without saying that the system administrator obtains the consent of the user before the use period is updated.

  When the comparator 141 receives the vehicle ID information S3, the comparator 141 refers to the database 142 and acquires the number information (N2) corresponding to the vehicle ID information S3 from the stored use registration information. At this time, if the number information (N2) corresponding to the vehicle ID information S3 cannot be acquired as a result of referring to the database 142, it is determined that the vehicle ID information is unregistered (or unregistered ID), and the comparator 141 is obtained. Transmits a mismatch signal S10 to the controller 143.

  Further, the comparator 141 compares the number information S2 and the number information N2, and outputs a coincidence signal S11 to the controller 143 when the comparison results in a match. Upon receiving the coincidence signal S11 from the comparator 141, the controller 143 sends a control command S8 to the ticket issuing machine 7. Further, the comparator 141 compares the number information S2 and the number information N2, and outputs a mismatch signal S10 to the controller 143 when the comparison results in a mismatch. Upon receiving the mismatch signal S10 from the comparator 141, the controller 143 sends a control command S9 to the ticket issuing machine 7.

  FIG. 27 is a time chart showing operation timings of the vehicle detector 50, the vehicle number reading device 6, and the communication control device 12. As shown in FIG. 27A, when the processing start signal S1 is output from the vehicle detector 50, as shown in FIG. 27B, the vehicle number reading device 6 starts operation (operation ON), After about 0.5 seconds, the number information S2 is output to complete the operation (operation OFF). When the processing start signal S1 is output from the vehicle detector 50, the communication control device 12 activates the communication antenna 11 (operation ON) as shown in FIG. A transmission wave is output and road-to-vehicle communication is started. The vehicle ID information S3 is output from the communication control device 12 within 0.2 seconds to 0.5 seconds from the activation of the communication antenna 11, and the road-vehicle communication ends. At the same time, the communication control device 12 stops outputting the transmission radio wave from the communication antenna 11. The communication control device 12 performs time-out processing so that a transmission radio wave is not output from the communication antenna 11 even if a predetermined time (for example, 0.5 seconds) is exceeded. The time-out process operates, for example, to start a timer at the start of output of radio waves from the communication antenna 11 and to stop output of radio waves from the communication antenna 11 after a predetermined time has elapsed from the timer startup time.

  When the vehicle 1 enters the communication area at a speed of 25 km / h, the distance traveled by the vehicle 1 within 0.5 seconds after the vehicle detector 50 detects the tip of the vehicle 1 is about 3.5 m. In addition, since the vehicle length of a general vehicle is about 4 m, the vehicle body of the vehicle 1 exists in the communication area 4 while road-to-vehicle communication is being executed.

  FIG.27 (d) is a figure which shows the communication transaction of the onboard equipment 1 and a roadside machine. When the on-vehicle device 10 receives a polling signal C1 that is a transmission radio wave radiated from the communication antenna 11, execution of link establishment between the communication antenna 11 and the on-vehicle device 10 is started. First, the response signal C <b> 2 is output from the vehicle-mounted device 10 to the communication antenna 11. As a result, a communication link between the communication antenna 11 and the vehicle-mounted device 10 is established, and road-to-vehicle communication is started. Next, the ID request signal C3 is output from the communication antenna 11 to the vehicle-mounted device 10. When receiving the ID request signal C3 from the communication antenna 11, the vehicle-mounted device 10 transmits the vehicle-mounted ID information C4 to the communication antenna 11. When receiving the in-vehicle ID information C4, the communication antenna 11 transmits a communication disconnection request C5 to the in-vehicle device 10. When receiving the communication disconnection request C <b> 5 from the communication antenna 11, the vehicle-mounted device 10 transmits a communication disconnection acknowledge signal C <b> 6 indicating that the road-to-vehicle communication disconnection processing execution operation has been started to the communication antenna 11. At the same time, the communication is cut off, such as turning off the power supply to the power amplifier constituting the transmitter and cutting off the power supply of the transmission radio wave.

  If the processing time Tn from the start of the vehicle number reading device 6 until the number is identified becomes longer than 0.5 seconds, the stop rod 9 of the circuit breaker 8 is passed after the vehicle 1 passes the vehicle detector 50. As a result, it takes a long time until the vehicle 1 is opened, and the vehicle 1 communicates with the roadside machine, but there is a problem that the vehicle 1 must stop before the stop rod 9. For example, when the vehicle 1 enters the communication area 4 at a speed of 10 km / h, the vehicle 1 travels about 3.5 m by determining that the vehicle can pass after 0.5 seconds. Since the distance between the vehicle detector 50 and the stop rod 9 is 5 m, the vehicle 1 travels to a position 3.5 m before the stop rod 9 during this time. However, if the distance becomes shorter than this, the driver will psychologically brake, which will prevent him from passing the gate non-stop. Further, since the loop coil 13a is disposed at a position 1.5 m away from the vehicle detector 50, the loop coil 13a detects the entry of the vehicle 1 to the periphery of the ticket issuing machine during this time, and the vehicle entry signal S6 is output. Then, the stop rod 9 enters the open / close standby state.

In this embodiment, as the vehicle ID information, a combination of a header code and a serial code that is different for each vehicle-mounted device and configured by “header code + serial code” may be used. As the header code, it is convenient to use a unique number indicating that the vehicle-mounted device is properly sold and can use a specific service.
For example, a different unique number is assigned as a header code for each service provider (organization) that provides a parking lot use service that allows non-stop traffic at the entrance and exit of a parking lot. As a result, the header code can be used as authentication information at the time of link establishment by storing the header code information in advance in the communication control devices 12 of all service providing parking lots that belong to the same organization. .
For example, if there are 10 service providers, the header code may be composed of 4-bit data (0000 to 1111). The vehicle-mounted device 10 mixes the header code in the response signal C2 and transmits it. As a result, the communication control device 12 compares the header code extracted from the received response signal C2 with which of the 10 preset header codes corresponds, so that the vehicle-mounted device 10 is a legitimate user. Can be authenticated. Of course, it goes without saying that more reliable authentication can be performed by adding encryption processing to header code recognition. The serial code can be converted to 16-bit data (0 to F) if it is expected that the number of on-vehicle devices registered for use to receive service from the same service provider will be 10,000. What is necessary is just to comprise. For example, the vehicle ID information may be configured with 20-bit data of 00000 to 1111F.

FIG. 28 shows an operation flowchart of the radio communication system according to this embodiment.
Although details of the operation are as described above, in the figure, after the wireless communication system is activated, the vehicle detector 50 detects whether or not the vehicle 1 has passed (step S101). When the vehicle detector 50 detects the vehicle 1, the transmission start operation of the communication antenna 11 in the roadside device is executed (step S102). At the same time, after the vehicle number reading device 6 starts to execute a vehicle number reading operation (step S103), the vehicle number reading device 6 executes a vehicle number identification process (step S104). The vehicle number reading device 6 outputs the identified number information S2 to the information processing device 14 (step S105).

  In addition, a transmission radio wave is emitted from the communication antenna 11, and a communication connection request (polling) is transmitted from the roadside unit to the vehicle-mounted device 10 (step S110). As a result of the communication connection request from the roadside device to the vehicle-mounted device 10, when there is a response to polling from the vehicle-mounted device 10 (step S111), road-to-vehicle communication between the roadside device and the vehicle-mounted device 10 is started. Next, an ID transmission request is output from the roadside device to the vehicle-mounted device 10 (step S112), and the vehicle-mounted device 10 transmits vehicle ID information to the roadside device (step S113). The communication control device 12 of the roadside machine determines whether or not the communication antenna 11 has received the vehicle ID information transmitted from the vehicle-mounted device 10 (step S114). If the vehicle ID information is received, the road-to-vehicle communication is performed. finish. Further, the information processing apparatus 14 refers to the database 142 and acquires the number information N2 of the vehicle 1 corresponding to the vehicle ID information (step S115). The information processing device 14 compares the number information S2 and the number information N2 (step S116), and if they match, the information processing device 14 outputs a control command S8 to the breaker 8 to operate the breaker 8 and the stop rod 9 Is opened (step S117). If they do not match as a result of the comparison, a control command S9 is output to the ticketing machine 7, the ticketing machine 7 is operated to perform the ticketing process (step S118), and then the above-mentioned step S117 is reached. If the information processing apparatus 14 cannot acquire the number information N2 of the vehicle 1 corresponding to the vehicle ID information S3 with reference to the database 142, the vehicle ID information is an unregistered ID (or a use unregistered vehicle). The control command S9 is output so that the ticket issuing machine 7 is operated.

  As described above, according to the third embodiment, the output of the transmission radio wave radiated from the communication antenna 11 of the roadside unit is suppressed to 0 dBm or less, more preferably −2 dBm, and the reception of the communication antenna 11 of the roadside unit is received. By reducing the sensitivity to -60 dBm or more, the size of the communicable area generated outside the regular communication area 4 can be reduced, and the vehicle-mounted device 10 of the vehicle 1 passing through the communication area and the roadside machine The occurrence of erroneous communication can be suppressed. In addition, the number of communicable areas can be further reduced.

  Furthermore, in response to the detection of the vehicle entering the communication area 4, after the transmission of the transmission radio wave is started from the communication antenna 11 of the roadside machine, the transmission from the communication antenna is performed after the communication between the roadside machine and the vehicle-mounted device 10 is completed. By stopping the emission of radio waves, the communication time between the roadside device and the vehicle-mounted device 10 can be limited within a specified time, and the occurrence of erroneous communication between the roadside device and the vehicle-mounted device 10 can be further suppressed.

  In particular, when the vehicle-mounted device 10 enters the communication area 4, the vehicle detector 50 detects the position of the front end of the vehicle 1 or the position of the front of the vehicle, and starts emission of transmission radio waves in response to the detection. Then, communication can be performed only when the vehicle passes around the communication area by stopping the emission of the transmission radio wave after the communication ends. In this case, the size of the communicable area generated outside the regular communication area 4 can be further reduced by the interference action between the reflection from the vehicle and the road surface reflection. This also leads to a reduction in transmission power loss.

  For example, as shown in FIG. 21, after the vehicle 1 is detected by the vehicle detector 50, the vehicle 1 is passing through the communication area 4 until the communication between the vehicle-mounted device 10 and the roadside device is completed. Therefore, the electric field strength is suppressed in the region 43 having a high electric field strength outside the communication region generated in the course of the following vehicle 1b.

  Of course, a method other than the transmission radio wave control may be used in which the emission of the transmission radio wave is started after the vehicle detector 50 detects the position specifying portion and then the transmission radio wave is stopped after the communication is completed. For example, in the communication area, in response to detection of the position specifying portion by the vehicle detector 50, the power value of the transmission radio wave of the communication antenna 11 is increased to a predetermined value or more at a level at which the vehicle mounter 10 can receive and respond. After that, after the road-to-vehicle communication is completed, the power control of the transmission radio wave may be performed so that the power value of the transmission radio wave of the communication antenna 11 is reduced to a predetermined value or less at a level where the vehicle onboard device 10 cannot receive and respond. Needless to say.

  Further, by comparing the number information corresponding to the vehicle ID information acquired by communication between the roadside device and the vehicle-mounted device 10 with the number information identified by the vehicle number reading device 6, the roadside device and the vehicle-mounted device 10 are compared. Misjudgment of registered vehicle associated with miscommunication (e.g., it is determined that the registered vehicle is a non-used registered vehicle, or the unused registered vehicle is determined to be a registered registered vehicle, or the gate is Occurrence of the use registration vehicle being passed as another use registration vehicle can be suppressed.

  For example, if the number information identification establishment by the vehicle number reading device 6 is 95% and the establishment in which communication between the vehicle-mounted device 10 and the roadside device is normally performed is 99%, the vehicle entering the gate of the parking lot The probability of erroneously determining that 1 is not a registered use vehicle permitted to pass through the gate non-stop can be reduced to 0.05%. As a result, it is possible to prevent the use service vehicle from being lowered such that the use registration vehicle temporarily stops to wait for ticketing at the parking lot gate. It should be noted that the establishment that the vehicle ID information can be accurately acquired by the normal communication between the vehicle-mounted device 10 and the roadside device is higher than the establishment that the vehicle number reading device 6 reads the number information correctly. For this reason, the passing vehicle of the entrance gate 100 can be identified more reliably than the case where the number information is obtained by the vehicle number reading device 6 alone.

  Moreover, even if the transmission power and reception sensitivity of the vehicle-mounted device 10 vary, the occurrence of erroneous communication between the vehicle and the roadside device can be suppressed. The communication area 4 is set to a size of 2.5 m × 2.5 m, but the size of the communication area is, for example, in the range of 2 m × 2 m to less than 3 m × 3 m due to variations in the characteristics of the vehicle-mounted equipment. May vary. Even if such a variation occurs, it is possible to suppress erroneous determination of the use registered vehicle due to erroneous communication between the roadside device and the vehicle-mounted device 10.

  Therefore, according to this embodiment, the cost due to the installation of the radio wave absorber is suppressed, and the radio wave reflection between the ceiling wall surface and the road surface causes erroneous communication between the roadside device and the vehicle-mounted device outside the normal communication area. It is possible to reduce the probability of occurrence.

  Further, it is possible to reduce misjudgment between a use-registered vehicle and an unregistered vehicle due to erroneous communication between the roadside device and the vehicle-mounted device outside the regular communication area.

  Although the above description in this embodiment has been described by taking a wireless communication system installed at an entrance gate to an indoor or underground parking lot as an example, it is needless to say that the present invention is not limited to this case. For example, it may be a wireless communication system installed at an exit gate, a drive-through entrance of a restaurant, or a gas station. Of course, when applied to the exit gate, it goes without saying that a settlement machine is provided instead of the ticketing machine, and the driver performs a settlement process to pay the fee displayed on the settlement machine by inserting a parking ticket. . In addition, when installing at a drive-through entrance of a restaurant or at a gas station etc., a ceiling wall or roof is provided above the communication area for paying charges, directly or indirectly under the ceiling or roof. Needless to say, when a communication antenna is attached to the wireless communication system, the wireless communication system exhibits an effect of preventing erroneous communication and erroneous determination.

Embodiment 4 FIG.
FIG. 28 is a diagram showing a configuration of a wireless communication system according to the fourth embodiment of the present invention.
In the figure, the vehicle 1 entering the entrance of the parking lot enters the parking area 90 through the passage 3 of the entrance gate 100. Further, when the vehicle 101 in the parking area 90 enters the exit gate 100b of the parking lot, the vehicle 101 passes through the passage 3b and goes out of the parking lot (outside) through the exit gate 100b.

  The vehicle 1 has an in-vehicle device 10 mounted on a dashboard near the windshield inside the vehicle. The vehicle 101 has an in-vehicle device 10b mounted on a dashboard near the windshield inside the vehicle. The traffic path 3 is disposed so as to be sandwiched between the islands 2a and 2b, and the traffic path 3b is disposed so as to be sandwiched between the islands 2b and 2c. A communication area 4 is formed on the traffic path 3, and a communication area 4b is formed on the traffic path 3b. The islands 2a, 2b and the traffic path 3 constitute a travel lane of the entrance vehicle, and the islands 2b, 2c and the traffic path 3b constitute a travel lane of the exit vehicle.

  An optical receiver 5a is installed on the island 2a, and an optical transmitter 5b is installed on the end of the parking lot entrance on the island 2b. The optical receiver 5a and the optical transmitter 5b are used as vehicles. A detector 50 is configured. On the island 2a, a vehicle number reading device 6 for identifying the number stamped on the number plate is installed. The ticket issuing machine 7 is installed between the vehicle detector 50 and the vehicle number reading device 6 on the island 2a. The circuit breaker 8 is provided on the island 2a adjacent to the vehicle number reading device 6, and the circuit breaker 8 is provided with a stop rod 9 that can be opened and closed. As shown in FIG. 19, the communication antenna 11 includes a transmission / reception antenna and a transmitter / receiver, and forms a roadside unit together with the communication control device 210. The communication antenna 11 is installed above the vicinity of the front end of the communication area 4 in the vehicle traveling direction and under the ceiling of the parking lot. The mounting angle of the radiation surface of the communication antenna 11 is set to about 23 degrees. The communication control device 210 is disposed near the entrance gate 100. Below the road surface of the traffic path 3, a loop coil 13 a is embedded near the rear end of the communication area 4 in the vehicle traveling direction, and a loop coil 13 b is embedded near the circuit breaker 8.

  An optical receiver 500a is installed on the island 2c, and an optical transmitter 500b is installed on the end of the parking area on the island 2b. The optical receiver 500a and the optical transmitter 500b A vehicle detector 500 is configured. A vehicle number reading device 6b for identifying the number stamped on the number plate is installed on the island 2c. The settlement machine 7b is installed between the vehicle detector 500 and the vehicle number reading device 6b on the island 2c. The circuit breaker 8b is provided on the island 2c adjacent to the vehicle number reading device 6b, and the circuit breaker 8b is provided with a stop rod 9b that can be opened and closed. The communication antenna 11b includes a transmission / reception antenna and a transmitter / receiver, and forms a roadside unit together with the communication control device 12b. The communication antenna 11b is installed under the ceiling of the parking lot above the front end of the communication area 4b in the vehicle traveling direction. Below the road surface of the traffic path 3b, a loop coil 130a is embedded near the rear end of the communication area 4b in the vehicle traveling direction, and a loop coil 130b is embedded near the circuit breaker 8b.

  An information processing apparatus 140 is installed in the management room 50 provided in the parking area 90. Each device (communication control device 210, vehicle detectors 50 and 500, vehicle number reading devices 6 and 6b, ticket issuing machines 7 and 7b, breakers 8 and 8b) is connected to a data bus 60 laid in the parking lot. Yes.

  Note that components having the same reference numerals as those shown in FIG. 24 of the third embodiment are equivalent in configuration and operation. Further, the communication antenna 11b, the vehicle detector 500, the vehicle number reading device 6b, the checkout machine 7b, and the breaker 8b are respectively the communication antenna 11, the vehicle detector 50, the vehicle number reading device 6, the ticketing machine 7, and This is equivalent to the circuit breaker 8. Therefore, the characteristics of the communication antenna 11b and the communication area 4b, and the arrangement interval between the communication area 4b and the vehicle detector 500, the circuit breaker 8b, and the traffic path 3b are described in FIGS. 18 to 28 of the third embodiment. The characteristics of the communication antenna 11 and the communication area 4, and the communication area 4, the vehicle detector 50, the circuit breaker 8, and the traffic path 3 are equivalent.

Next, the operation of each device in the entrance gate 100 will be described.
When the vehicle 1 entering the entrance gate 100 passes between the optical transmitter 5b and the optical receiver 5a, the vehicle detector 50 detects whether the vehicle 1 is passing. When the vehicle detector 50 detects the vehicle 1, it sends a processing start signal S <b> 1 to the communication control device 210 and the vehicle number reading device 6 through the data bus 60.

  The communication control device 210 is activated immediately in response to the reception of the processing start signal S1, and controls the communication antenna 11 to start radiating transmission radio waves. The vehicle number reading device 6 is activated immediately in response to the reception of the processing start signal S <b> 1 and identifies the number of the vehicle passing through the communication area 4. The number information (S2) identified by the vehicle number reading device 6 is sent from the vehicle number reading device 6 to the information processing device 140 via the data bus 60.

  The transmission radio wave radiated from the communication antenna 11 is received by the vehicle-mounted device 10 of the vehicle 1 that passes through the communication area. Thereby, a communication link is established between the communication antenna 11 and the vehicle-mounted device 10, and road-to-vehicle communication is started. The onboard equipment 10 transmits vehicle ID information (S3) with respect to the antenna 11 for communication.

  When the vehicle 1 reaches the loop coil 13a, the loop coil 13a sends a vehicle entry signal S6 to the ticket issuing machine 7. Upon receiving the vehicle entry signal S6, the ticket issuing machine 7 sends a gate opening / closing permission signal S4 to the information processing apparatus 140 via the data bus 60. When the vehicle 1 reaches the loop coil 13b, the loop coil 13b outputs a gate closing signal S7 to the ticket issuing machine 7 via the data bus 60.

  When the road-to-vehicle communication between the communication antenna 11 and the vehicle-mounted device 10 is completed, vehicle ID information (S3) is sent from the communication control device 210 to the information processing device 140. In the information processing apparatus 140, vehicle number information (N2) corresponding to the vehicle ID information is preset, and this setting information is stored in a database. The information processing device 140 acquires the number information N2 from the database based on the vehicle ID information S3 transmitted from the communication control device 210, and the number information S2 transmitted from the acquired number information N2 and the vehicle number reading device 6. Perform a match comparison with.

  If the information processing apparatus 140 has received the gate opening / closing permission signal S4 from the ticketing machine 7, it sends a control command (S8) to the ticketing machine 7 via the data bus 60. If the number information matches and does not match, a control command (S9) is sent to the ticket issuing machine 7. On the other hand, if the information processing device 140 has not received the gate opening / closing permission signal S4 from the ticketing machine 7, the gate information until the gate opening / closing permission signal S4 is received regardless of the result of the coincidence comparison of the number information. The sending of the control command (S8 or S9) to the ticket issuing machine 7 is stopped.

  When the ticket issuing machine 7 receives the control command S8 from the information processing device 140 via the data bus 60, the ticket issuing machine 7 sends the control command S5 to the circuit breaker 8 via the data bus 60. When receiving the control command S5 from the ticket issuing machine 7, the circuit breaker 8 opens and closes the stop rod 9. Accordingly, when the vehicle 1 passes through the entrance gate 100, the vehicle 1 can enter the parking area in a non-stop manner without stopping once before the ticket issuing machine 7 in the entrance gate.

  Further, when the ticket issuing machine 7 receives the control command S9 from the information processing apparatus 140 via the data bus 60, the ticket issuing machine 7 executes the operation of the ticket issuing process. For example, the ticket issuing machine 7 announces to the driver of the vehicle 1 to take a parking lot use ticket (parking ticket) issued. When the driver takes out the parking ticket issued by the ticket issuing machine 7, the ticket issuing machine 7 sends a control command S <b> 5 to the circuit breaker 8. In response to the reception of the control command S5, the breaker 8 jumps the stop rod 9 and the gate is automatically opened.

  Further, the vehicle 1 passes by the side of the circuit breaker 8 with the stop rod 9 opened, reaches the upper side of the loop coil 13b, and a gate closing signal S7 is sent from the loop coil 13b to the ticket issuing machine 7. Then, the ticket issuing machine 7 sends a gate closing signal S52 to the circuit breaker 8 via the data bus 60. When the breaker 8 receives the gate closing signal S52, the breaker 8 operates to lower the stop rod 9 and close the inlet gate 100.

Next, the operation of each device in the exit gate 100b will be described.
When the vehicle 1 entering the exit gate 100b passes between the optical transmitter 500b and the optical receiver 500a, the vehicle detector 500 detects whether the vehicle 101 is passing. When the vehicle detector 500 detects the vehicle 101, it sends a processing start signal S1b to the communication control device 210 and the vehicle number reading device 6b via the data bus 60. The communication control device 210 is activated immediately in response to the reception of the processing start signal S1b, and controls the communication antenna 11b to start radiating transmission radio waves. The vehicle number reading device 6b is activated immediately in response to the reception of the processing start signal S1b, and identifies the number of the vehicle passing through the communication area 4b. The number information (S2b) identified by the vehicle number reading device 6b is sent from the vehicle number reading device 6 to the information processing device 140 via the data bus 60.

  The transmission radio wave radiated from the communication antenna 11b is received by the vehicle-mounted device 10b of the vehicle 101 passing through the communication area. Thereby, a communication link is established between the communication antenna 11b and the vehicle-mounted device 10b, and road-to-vehicle communication is started. The on-vehicle device 10b transmits vehicle ID information (S3b) to the communication antenna 11b.

  When the vehicle 101 reaches the loop coil 130a, the loop coil 130a sends a vehicle approach signal S6b to the settlement machine 7b. When the payment machine 7b receives the vehicle entry signal S6b, it sends a gate opening / closing permission signal S4b to the information processing apparatus 140 via the data bus 60. When the vehicle 1 reaches the loop coil 13b, the loop coil 13b outputs a gate closing signal S7b to the ticket issuing machine 7b via the data bus 60.

  When the road-to-vehicle communication between the communication antenna 11b and the vehicle-mounted device 10b is completed, vehicle ID information (S3b) is sent from the communication control device 210 to the information processing device 140. In the information processing apparatus 140, vehicle number information (N2b) corresponding to the vehicle ID information is set in advance, and this setting information is stored in a database. The information processing device 140 acquires the number information N2b from the database based on the vehicle ID information S3b transmitted from the communication control device 210, and the number information S2b transmitted from the acquired number information N2b and the vehicle number reading device 6b. Perform a match comparison with.

  When the information processing apparatus 140 has received the gate opening / closing permission signal S4b from the settlement machine 7b, the information processing apparatus 140 sends a control command (S8b) to the settlement machine 7b via the data bus 60. Further, if the number information coincides as a result of the comparison, a control command (S9b) is sent to the settlement machine 7b. On the other hand, when the information processing device 140 has not received the gate opening / closing permission signal S4b from the settlement machine 7b, the information processing device 140 does not receive the gate opening / closing permission signal S4b regardless of the result of the coincidence comparison of the number information. The sending of the control command (S8b or S9b) to the settlement machine 7b is stopped.

  When the settlement machine 7b receives the control command S8b from the information processing device 140 via the data bus 60, the settlement machine 7b sends the control command S5b to the circuit breaker 8b via the data bus 60. When receiving the control command S5b from the settlement machine 7b via the data bus 60, the circuit breaker 8b opens and closes the stop rod 9b. As a result, when the vehicle 101 passes through the exit gate 100b, the vehicle 101 can go out of the parking lot non-stop without stopping once before the settlement machine 7b in the exit gate.

  Further, when the settlement machine 7b receives the control command S9b from the information processing apparatus 140 via the data bus 60, the settlement machine 7b executes the settlement process. For example, when the driver of the vehicle 101 inserts a parking lot use ticket (parking ticket) from a ticket insertion slot (not shown), the settlement machine 7b displays a settlement fee on a display (not shown) and voices from a speaker (not shown). Announce settlement. When the driver pays the settlement fee of the settlement machine 7b from a fee payment port (money insertion port) (not shown), the settlement machine 7b sends a control command S5b to the circuit breaker 8b. In response to the reception of the control command S5b, the breaker 8b jumps up the stop rod 9b and the exit gate is automatically opened. Note that the settlement machine 7b may perform settlement processing by inserting an IC card. For example, even if the information processing apparatus 14 erroneously determines that the use registration vehicle is an unregistered vehicle, the driver takes out the IC card with the memory inserted in the vehicle-mounted device, and sets the checkout machine 7b. The checkout machine 7b may be configured to determine whether the vehicle mounted with the vehicle-mounted device is a use registration vehicle based on the stored information in the memory of the IC card. . At this time, when the vehicle ID information is stored in the memory of the IC card and the fact that the vehicle equipped with the vehicle-mounted device is a use registration vehicle is stored in the memory of the IC card, the use registration vehicle is displayed on the spot. It is possible to pass through the exit gate 100b without paying a fee.

  Further, the vehicle 101 passes the side of the circuit breaker 8b with the stop rod 9b opened, reaches the upper part of the loop coil 130b, and a gate closing signal S7b is sent from the loop coil 130b to the settlement machine 7b. Then, the checkout machine 7b sends a gate closing signal S52b to the circuit breaker 8b via the data bus 60. When the breaker 8b receives the gate closing signal S52b, the breaker 8b operates to lower the stop rod 9b and close the outlet gate 100b.

  FIG. 29 is a diagram illustrating a configuration of the information processing apparatus 140. The information processing apparatus 140 includes a comparator 141, a comparator 141b, a database 142, a controller 143, and a controller 143b.

  At the entrance gate 100, the vehicle number reading device 6 sends the number information S2 to the comparator 141 of the information processing device 140. In addition, the entrance communication control unit 12a of the communication control device 210 sends the vehicle ID information S3 to the comparator 141 of the information processing device 140. At the exit gate 100b, the vehicle number reading device 6b sends the number information S2b to the comparator 141b of the information processing device 140. Further, the exit communication control unit 12b of the communication control device 210 sends the vehicle ID information S3b to the comparator 141b of the information processing device 140.

In the database 142, usage registration information such as license plate numbers and vehicle ID information is registered in advance. In addition, the database 142 stores vehicle ID information (incoming vehicle ID) of vehicles in storage that have already entered the parking lot through the entrance gate 100 and have not been released from the parking lot. .
The vehicle ID information whose usage registration period has passed is configured to be deleted from the database 142. Thereby, by using the vehicle ID of the vehicle that has exceeded the usage period, it can be prevented that the vehicle is erroneously determined to be a usage registered vehicle.

  When the comparator 141 corresponding to the entrance gate 100 receives the vehicle ID information S3, the comparator 141 accesses the stored data in the database 142 and searches for the incoming vehicle ID (N3) that matches the vehicle ID information S3. As a result of this database search, if there is an incoming vehicle ID (N3) that matches the vehicle ID information S3, it is determined that the vehicle ID information S3 is transmitted from the exit gate 100b, and the controller 143 is informed. A mismatch signal S10 is transmitted.

  On the other hand, if there is no incoming vehicle ID that matches the vehicle ID information S3, the comparator 141 refers to the database 142 and acquires the number information (N2) corresponding to the vehicle ID information S3. At this time, when the number information (N2) corresponding to the vehicle ID information S3 cannot be acquired as a result of referring to the database 142, it is determined that the vehicle ID information is unregistered (or unregistered ID), and the comparator 141 sends a mismatch signal S10 to the controller 143.

  Further, when the comparator 141 obtains the number information (N2) corresponding to the vehicle ID information S3 from the database 142, the comparator 141 performs a comparison between the number information S2 and the number information N2, and when both are matched as a result of the comparison. The coincidence signal S11 is output to the controller 143. At the same time, the comparator 141 stores the vehicle ID information S3 in the database 142 as the warehousing vehicle ID. On the other hand, the comparator 141 compares the number information S2 and the number information N2, and outputs a mismatch signal S10 to the controller 143 when the comparison results in a mismatch.

  Upon receiving the coincidence signal S11 from the comparator 141, the controller 143 sends a control command S8 to the ticket issuing machine 7. Further, when the controller 143 receives the mismatch signal S10 from the comparator 141, the controller 143 sends a control command S9 to the ticket issuing machine 7.

  Next, when the comparator 141b corresponding to the exit gate 100b receives the vehicle ID information S3b, the comparator 141b accesses the stored data in the database 142 and searches for the outgoing vehicle ID (N3b) that matches the vehicle ID information S3b. As a result of this database search, if there is no outgoing vehicle ID that matches the vehicle ID information S3b, it is determined that the vehicle ID information S3b is transmitted from the entrance gate 100 and does not match the controller 143b. Signal S10b is transmitted.

  On the other hand, when there is a leaving vehicle ID that matches the vehicle ID information S3b, the comparator 141b refers to the database 142 and acquires the number information (N2b) corresponding to the vehicle ID information S3b. At this time, if the number information (N2b) corresponding to the vehicle ID information S3b cannot be acquired as a result of referring to the database 142, it is determined that the vehicle ID information is unregistered (or unregistered ID), and the comparator A mismatch signal S10b is transmitted from 141b to the controller 143b.

  Further, when the comparator 141b obtains the number information (N2b) corresponding to the vehicle ID information S3b from the database 142, the comparator 141b performs a comparison between the number information S2b and the number information N2b. The coincidence signal S11b is output to the controller 143b. At the same time, the comparator 141b stores the vehicle ID information S3b in the database 142b as the outgoing vehicle ID. On the other hand, the comparator 141b compares the number information S2b and the number information N2b, and outputs a mismatch signal S10b to the controller 143b when the comparison results in a mismatch.

  When receiving the coincidence signal S11b from the comparator 141b, the controller 143b sends a control command S8b to the settlement machine 7b. Further, when receiving the mismatch signal S10b from the comparator 141b, the controller 143b sends a control command S9b to the settlement machine 7b.

  Since the fourth embodiment is configured as described above, in addition to the effects obtained by the third embodiment, the vehicle ID of the vehicle already in the parking lot, the roadside device, and the vehicle-mounted device Comparison is made with the vehicle ID obtained by communication. In this way, the establishment of misjudging a legitimate use registered vehicle and a use unregistered vehicle by communicating with a vehicle leaving at the entrance gate or communicating with a vehicle entering at the exit gate, Can be reduced. As a result, the vehicle can pass through the gate without stopping once at the entrance or exit gate due to an erroneous determination, and the occurrence of a malfunction in which the usage registration vehicle pays a fee can be reduced.

  Even if the registration vehicle stops before the settlement machine and performs the settlement process, the driver inserts the IC card inserted in the vehicle-mounted device into the IC card insertion slot of the settlement machine 7b, The checkout machine 7b may determine whether or not the vehicle mounted with the vehicle-mounted device is a use registration vehicle. In this case, it is possible to pass through the exit gate without paying the usage fee to the settlement machine 7b. For this reason, when registering as a registration vehicle for use, it is possible to prevent a confusion such as paying a charge twice even though the use charge is paid in advance or after delivery.

1 is a perspective view showing a configuration of a wireless communication system according to Embodiment 1 of the present invention. It is a figure explaining the structure (FIG.2 (a)) of a communication antenna of the radio | wireless communications system by Embodiment 1 of this invention, and the structure (FIG.2 (b)) of onboard equipment. It is a figure explaining the electromagnetic wave reflection of the radio | wireless communications system by Embodiment 1 of this invention. It is a figure which shows the electric field strength distribution of the transmission radio wave of the antenna for communication by Embodiment 1 of this invention. It is a figure which shows the positional relationship of the communication area and vehicle of the communication antenna by Embodiment 1 of this invention. It is a figure which shows the transmission characteristic of the antenna for communication by Embodiment 1 of this invention. It is a figure which shows the antenna characteristic of the antenna for communication by Embodiment 1 of this invention. It is a figure which shows the geometric relationship between the communication area | region of an antenna for communication by Embodiment 1 of this invention, and an antenna electromagnetic wave axis. It is a figure which shows distribution of the receiving sensitivity of the antenna for communication by Embodiment 1 of this invention. It is a figure which shows the relationship between the installation height and attachment angle of the communication antenna by Embodiment 1 of this invention. It is a figure which shows the relationship between the antenna characteristic of the antenna for communication by Embodiment 1 of this invention, and an antenna attachment angle. It is a figure which shows the connection structure of the component apparatus of the radio | wireless communications system by Embodiment 1 of this invention. It is a figure which shows the structure of the information processing apparatus by Embodiment 1 of this invention. It is a figure which shows the operation | movement time chart of the component apparatus by Embodiment 1 of this invention. It is a flowchart of the radio | wireless communications system by Embodiment 1 of this invention. It is a figure which shows the structure of the radio | wireless communications system by Embodiment 2 of this invention. It is a block diagram of the information processing apparatus by Embodiment 2 of this invention. It is a perspective view which shows the structure of the radio | wireless communications system by Embodiment 3 of this invention. It is a figure explaining the structure of the antenna for communication of the radio | wireless communications system by Embodiment 3 of this invention. It is a figure explaining the electromagnetic wave reflection of the radio | wireless communications system by Embodiment 3 of this invention. It is a figure which shows the electric field strength distribution of the transmission radio wave of the antenna for communication by Embodiment 3 of this invention. It is a figure which shows the transmission and reception characteristics of the antenna for communication by Embodiment 3 of this invention. The figure used for calculation of the electric field strength of the antenna for communication by Embodiment 3 of this invention is shown. It is a figure which shows distribution of the receiving sensitivity of the antenna for communication by Embodiment 3 of this invention. It is a figure which shows the connection structure of the component apparatus of the radio | wireless communications system by Embodiment 3 of this invention. It is a figure which shows the structure of the information processing apparatus by Embodiment 3 of this invention. It is a figure which shows the operation | movement time chart of the component apparatus by Embodiment 3 of this invention. It is a flowchart of the radio | wireless communications system by Embodiment 3 of this invention. It is a figure which shows the structure of the radio | wireless communications system by Embodiment 4 of this invention. It is a block diagram of the information processing apparatus by Embodiment 4 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle, 4, 4b Communication area | region, 6, 6b Vehicle number reading apparatus, 7 Ticket issuing machine, 7b Settlement machine, 8, 8b Breaker, 9, 9b Stop rod, 10, 10b Onboard equipment, 11, 11b Communication antenna apparatus , 12 Communication control device, 14 Information processing device, 50,500 Vehicle detector, 125 IC card, 140 Information processing device, 210 Communication control device.

Claims (26)

In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
A vehicle detector that is installed indoors and detects a vehicle present in a communication area;
The transmission power characteristic installed on the ceiling and having a reception power level of the vehicle-mounted device within a first predetermined distance from the vehicle detector toward the near side in the vehicle traveling direction is equal to or higher than a predetermined reception sensitivity, and Transmission power characteristics such that the reception power level of the vehicle-mounted device is equal to or lower than the reception sensitivity of the vehicle-mounted device at a second predetermined distance longer than the first predetermined distance from the vehicle detector toward the near side in the vehicle traveling direction. A communication antenna having
The communication antenna starts transmission radio waves in response to detection of a vehicle by the vehicle detector, and then transmits the transmission radio waves after a predetermined time elapses from the end of communication with the vehicle-mounted device or the start of transmission radio waves. While stopping the radiation,
The first predetermined distance is 1.5 m to 3 m, the second predetermined distance is 3 m to 5 m,
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
A wireless communication system. The wireless communication system according to claim 1, wherein the first predetermined distance is 2 m, and the second predetermined distance is 5 m . In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
A vehicle detector that is installed indoors and detects a vehicle present in a communication area;
Within the first predetermined distance from the vehicle detector, which is installed on the ceiling and within the vehicle traveling direction, the reception power level of the vehicle-mounted device is equal to or higher than a predetermined reception sensitivity, and the vehicle detector is in front of the vehicle traveling direction. A communication antenna having a transmission power characteristic in which the reception power level of the vehicle-mounted device is equal to or lower than the reception sensitivity at a second predetermined distance longer than the first predetermined distance on the side;
The communication antenna starts transmission radio waves in response to detection of a vehicle by the vehicle detector, and then transmits the transmission radio waves after a predetermined time elapses from the end of communication with the vehicle-mounted device or the start of transmission radio waves. While stopping the radiation,
The predetermined time is 0.5 seconds or less,
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
The wireless communication system according to claim 1 . 2. The radio communication system according to claim 1, wherein an electric field intensity of a transmission radio wave is −55 dBm or more in the vicinity of the first predetermined distance on the near side in the vehicle traveling direction in the communication area. The wireless communication system according to claim 3 . 2. The predetermined time is set within a time for a vehicle passing through the vehicle detector to reach the predetermined distance after a vehicle passing through the vehicle detector. Item 4. The wireless communication system according to any one of Items 3 to 3 . The communication area of the communication antenna is within a range of 2.5 m from the vehicle detector toward the front side of the vehicle traveling direction to within 1.5 m from the vehicle detector toward the vehicle traveling direction. The wireless communication system according to any one of claims 1 to 3, further comprising: The communication antenna stops emission of the next transmission radio wave while the vehicle detector detects the presence of a passing vehicle after stopping the emission of the transmission radio wave after starting the emission of the transmission radio wave. The wireless communication system according to any one of claims 1 to 6 . A vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector;
A communication control device that acquires specific information of the vehicle-mounted device transmitted from the vehicle-mounted device via the communication antenna in response to vehicle passage detection by the vehicle detector;
A database for storing the specific information of the vehicle-mounted device and the number;
Compare the onboard device specific information acquired by the communication control device with the onboard device specific information stored in the database, and output an open / close signal to open and close the circuit breaker when the result of the comparison is matched,
An information processing device that compares a number identified by the vehicle number reading device with a number stored in the database, and outputs an opening / closing signal for opening / closing the circuit breaker when the comparison results in a match;
The wireless communication system according to any one of claims 1 to 6, further comprising: A vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector;
A communication control device that acquires specific information of the vehicle-mounted device transmitted from the vehicle-mounted device via the communication antenna in response to vehicle passage detection by the vehicle detector;
A database for storing the specific information of the vehicle-mounted device and the number;
An information processing device that outputs a signal for releasing the vehicle restraint based on the onboard device specific information acquired by the communication control device, the number identified by the vehicle number reading device, and the stored information of the database When
The wireless communication system according to any one of claims 1 to 6, further comprising: A communication control device that acquires specific information of the vehicle-mounted device transmitted from the vehicle-mounted device via the communication antenna in response to vehicle passage detection by the vehicle detector;
A database for storing the specific information of the in-vehicle device;
An information processing apparatus for determining whether or not the vehicle is a use-registered vehicle, based on the onboard device specific information acquired by the communication control device and the onboard device specific information stored in the database;
The wireless communication system according to any one of claims 1 to 6, further comprising: In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
In response to detection of the vehicle by the vehicle detector installed indoors, a roadside device that starts communication with the vehicle-mounted device and acquires specific information of the vehicle-mounted device transmitted from the vehicle-mounted device,
In order to open and close the circuit breaker based on the number acquired from the vehicle number reading device for identifying the number of the license plate according to the detection of the vehicle by the vehicle detector, and the onboard device specific information acquired by the roadside device An information processing device that outputs a signal of
With
The roadside machine has a transmission output from a communication antenna installed on the ceiling of 4 dBm or less, a reception sensitivity of -55 dBm or more, and the communication antenna is installed at a height of 2 m to 4 m,
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
The wireless communication system according to claim 1 . The road-to-vehicle communication method which transmits the specific information of onboard equipment between the radio | wireless communications system in any one of the said Claim 1 thru | or 11, and onboard equipment. In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
A vehicle detector that is installed indoors and detects a vehicle present in a communication area;
Emission of transmission radio waves is started in response to vehicle detection by the vehicle detector installed on the ceiling, and transmission radio waves are emitted after a predetermined time has elapsed from the end of communication with the vehicle-mounted device or the start of emission of the transmission radio waves. A communication antenna to stop
A communication control device for acquiring onboard device specific information transmitted from the onboard device via the communication antenna in response to detection of the vehicle by the vehicle detector;
A database that stores in-vehicle device specific information in advance, and stores in-vehicle device specific information acquired by the communication control device;
Information for comparing the in-vehicle device specific information corresponding to the number determined by the vehicle number reading device with the in-vehicle device specific information acquired by the communication control device, and opening and closing the circuit breaker if they match With processing equipment
The wireless communication system according to claim 1, further comprising: A vehicle number reading device for identifying the number of a license plate according to vehicle passage detection by the vehicle detector;
A database for storing vehicle number information in advance,
The information processing device releases the vehicle restraint based on the comparison between the on-vehicle device specific information acquired by the communication control device and the number identified by the vehicle number reading device and the stored information in the database. 14. The wireless communication system according to claim 13, wherein a signal for performing the operation is output. In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
First and second vehicle detectors that are installed indoors and detect vehicles in first and second communication areas with the vehicle-mounted device, respectively,
2. The communication antenna according to claim 1, wherein the communication antenna is installed on each of the ceilings, and starts to radiate a transmission radio wave in response to detection of each vehicle by the first and second vehicle detectors. First and second communication antennas that respectively stop transmission radio waves after a predetermined time has elapsed from the end of the communication or the start of transmission radio waves,
Communication for acquiring specific information of each vehicle-mounted device transmitted from each vehicle-mounted device via the first and second communication antennas in response to detection of each vehicle by the first and second vehicle detectors. A control device;
A database for storing on-vehicle device specific information obtained from the first communication antenna, acquired by the communication control device corresponding to the number determined by the vehicle number reading device;
Information processing that opens and closes the circuit breaker when there is a match based on a match comparison between the in-vehicle device specific information obtained from the second communication antenna acquired by the communication control device and the stored information in the database Equipment and
The wireless communication system according to claim 1, further comprising: Installed on the ceiling, and starting transmission radio waves in response to vehicle detection by the vehicle detector, then transmitting radio waves after a predetermined time has elapsed since the end of communication with the vehicle-mounted device or the start of transmission radio waves A communication antenna that stops radiation,
The wireless communication system according to any one of claims 13 to 15, further comprising: The wireless communication system according to claim 16, wherein the communication antenna terminates the communication after acquiring communication information with the vehicle-mounted device after starting communication with the vehicle-mounted device. A vehicle number reading device for identifying the number of a license plate in response to detection of a vehicle by the vehicle detector and outputting the identified number;
If communication with the vehicle-mounted device is not started after the transmission of the transmission radio wave is started in response to detection of the vehicle by the vehicle detector installed on the ceiling, the number of the license plate is obtained from the vehicle number reading device. A communication antenna that stops emission of the transmission radio wave before being output;
The wireless communication system according to claim 15, further comprising: In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
It is installed on the ceiling and increases the value of transmission power within the communication area or starts the transmission radio wave to start communication with the vehicle-mounted device, and the value of transmission power according to the end of communication with the vehicle-mounted device Equipped with a communication antenna that lowers or stops the transmission of radio waves,
The communication antenna has a transmission output of 0 dBm or less, a reception sensitivity of -60 dBm or more, and is installed at a height of 2 m to 4 m.
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
The wireless communication system according to claim 1 . In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
A vehicle detector that is installed indoors and detects a vehicle present in a communication area;
In response to detection of the vehicle by the vehicle detector, the transmission power is increased or the transmission radio wave is started to be emitted, and communication with the vehicle-mounted device is started. With a communication antenna that lowers the value of transmission power or stops emission of transmission radio waves according to the end of communication,
The communication antenna has a transmission output of 0 dBm or less, a reception sensitivity of -60 dBm or more, and is installed at a height of 2 m to 4 m.
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
The wireless communication system according to claim 1 . 21. The wireless communication system according to claim 20, wherein a communication area between the communication antenna and the vehicle-mounted device has a length in a vehicle passage direction of 2 m or more and less than 3 m . A vehicle number reading device for determining the number of a license plate in accordance with vehicle passage detection by the vehicle detector;
A communication control device for acquiring specific information of the vehicle-mounted device transmitted from the vehicle-mounted device in response to vehicle passage detection by the vehicle detector;
The onboard device specific information corresponding to the number determined by the vehicle number reading device is compared with the onboard device specific information acquired by the communication control device. An information processing device that outputs a signal for canceling
The wireless communication system according to claim 20 or 21, further comprising: A vehicle number reading device for determining the number of a license plate in accordance with vehicle passage detection by the vehicle detector;
A communication control device for acquiring specific information of the vehicle-mounted device transmitted from the vehicle-mounted device in response to vehicle passage detection by the vehicle detector;
The onboard device specific information corresponding to the number determined by the vehicle number reading device is compared with the onboard device specific information acquired by the communication control device, and the circuit breaker is opened and closed when they match. An information processing device;
The wireless communication system according to claim 20 or 21, further comprising: A vehicle number reading device for determining the number of a license plate in accordance with vehicle passage detection by the vehicle detector;
A communication control device for acquiring specific information of the vehicle-mounted device transmitted from the vehicle-mounted device in response to vehicle passage detection by the vehicle detector;
The vehicle-use registration vehicle compares the on-vehicle device specific information corresponding to the number determined by the vehicle number reading device with the on-vehicle device specific information acquired by the communication control device, and the vehicle is registered based on the comparison result. An information processing device for determining whether or not,
The wireless communication system according to claim 20 or 21, further comprising: In a radio wave environment where radio waves are reflected multiple times between the indoor ceiling and the road surface or vehicle,
In response to detection of the vehicle by the vehicle detector installed indoors, a roadside device that starts communication with the vehicle-mounted device and acquires specific information of the vehicle-mounted device transmitted from the vehicle-mounted device,
From the vehicle number reading device that determines the number of the license plate according to the detection of the vehicle by the vehicle detector, the specific information of the in-vehicle device corresponding to the number determined by the device is acquired, and the specific information of the on-vehicle device and the An information processing device that compares the coincidence with the specific information of the vehicle-mounted device acquired by the roadside device, and outputs a signal for opening and closing the circuit breaker when they coincide with each other,
With
The roadside machine has a transmission output from a communication antenna installed on the ceiling of 0 dBm or less, a reception sensitivity of -60 dBm or more, and the communication antenna is installed at a height of 2 m to 4 m,
The electric field intensity of the transmission radio wave radiated from the communication antenna is maximum in the communication area and outside the communication area, and the electric field intensity of the transmission radio wave that is maximum outside the communication area is smaller than the reception sensitivity of the in-vehicle device,
The power level of the received signal that the communication antenna receives from the vehicle-mounted device is maximum within the communication area and outside the communication area, and the reception sensitivity of the communication antenna is higher than the power level of the received signal that is maximum outside the communication area. large,
The wireless communication system according to claim 1 . The roadside device decreases the radiation level of the transmission radio wave after increasing the radiation level of the transmission radio wave according to the vehicle passage detection by the vehicle detector and before acquiring the number information from the vehicle number reader. 26. The wireless communication system according to claim 25 .

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