JP2005210214A - Communication unit and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-vehicle communication unit capable of acquiring traffic jam information at an early stage. <P>SOLUTION: When traffic jam continues from vehicle M to vehicle A, traffic jam information of the head vehicle M in a dynamic address AD001 at the head of traffic jam, traffic jam information of the head vehicle I in second dynamic address AD002, and traffic jam information of the head vehicle E in third dynamic address AD003 are acquired. More specifically, traffic jam information is inquired by transmitting data to a destination having a previous dynamic address, and the head vehicle in that dynamic address sends back traffic jam information preferentially. Upon attaining traffic jam information, the vehicle A sums the length 20 m of three forward dynamic addresses AD001, AD002 and AD003 where traffic is jamming thus determining traffic jam of 60 m. Since each jamming vehicle grasps jam occurrence time information of the head vehicle in each dynamic address, traffic jam time can be determined from the time difference between the time information of its own vehicle and the time information corresponding to the head address. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication device for communicating information between vehicles.

  As a conventional technique for obtaining information related to traffic jams, for example, there is a technique for obtaining information via roadside fixed stations (see, for example, Patent Document 1). There is a technique (for example, refer to Patent Document 2) that transmits a current speed, a traveling direction, and a speed of a vehicle to a center and generates a traffic information database in the traffic information center. However, in the case of a method of collecting traffic information by generating information on the traffic information center and providing it in this way, the time from information collection to data distribution becomes relatively long, and traffic congestion information There is a problem with accuracy.

On the other hand, if information is exchanged between vehicles that are a source of traffic jams, that is, communication between vehicles is performed, there is a possibility that the problem of data distribution delay that occurs in the above-described method of collecting information in the traffic information center may be solved. In addition, in order to acquire traffic information regardless of infrastructure at any location, it is suitable to collect information by inter-vehicle communication. For example, a technology for transmitting information determined by the driver by inter-vehicle communication (for example, patents) Reference 3). In the case of communication between vehicles, in the case of a communication system using light or a radio wave of a relatively high frequency, it is often limited to communication at a relatively short distance. Therefore, it is necessary to relay short-distance communications in order to communicate with a vehicle (not an adjacent vehicle) several hundred meters away with several vehicles between itself and to collect traffic information. A relay system for this purpose has already been proposed (see, for example, Patent Document 4).
This system is a type of system that detects the speed and position information of vehicles forming a train of vehicles through inter-vehicle communication using a relay function and detects traffic jams, but performs sequential relay operations between adjacent vehicles. It is. Information can be shared by each vehicle by communication between adjacent vehicles (here, meanings adjacent to each other with respect to the vehicle traveling direction).
Japanese Patent Laid-Open No. 9-180094 JP 2001-118190 A JP 2002-183889 A JP-A-4-297000

  However, when there are a lot of congested vehicles, the communication traffic becomes very large by performing the above-described sequential relay operation, and the response time becomes very large. In that case, it becomes impossible to obtain information at an early stage, the merit of acquiring information by the inter-vehicle communication method is reduced, and a problem arises in terms of accuracy of traffic jam information.

  Accordingly, an object of the present invention is to solve the above-described problems and provide an inter-vehicle communication device that can acquire traffic jam information at an early stage.

  The communication device of the present invention is mounted on a vehicle and can communicate information between vehicles, and includes an address data storage means, a communication means, a current position specifying means, a traffic jam information storage means, and a control means. I have.

  Shared address data is stored in the address data storage means. This shared address data is an address set so that each of the continuous areas divided along the road on the map can identify the area. It is constructed by associating with a dynamic address. Specifically, the region may be set separately from any starting point. For example, it is conceivable that the starting point is a point where a vehicle such as a traffic light or a tollgate may stop. A specific example of the length (along the road) of the area corresponding to the dynamic address is 20 m, for example. Of course, various lengths can be adopted. However, if the length is too short, the effectiveness is reduced. Therefore, it is necessary to set the length so that at least two vehicles can exist at the same time. For example, if the area is 20 m long, there can be about four vehicles that are stopped due to traffic jams.

  Further, since it is necessary to be able to perform wireless communication with the communication device 1 existing in the area corresponding to the adjacent dynamic address, the communication area of the communication unit is set so as to be able to do so. Yes. In this case, it is conceivable to adopt a so-called narrow area wireless communication system as a communication system.

The control means includes a traffic condition determination means, a traffic information storage control means, an inquiry control means, and a reply control means.
The congestion state determination means determines that the vehicle is in a traffic congestion state from the behavior of the vehicle. For example, it can be determined that the traffic congestion state is present when the same dynamic address exists for a predetermined time or longer. The predetermined time may be a fixed value, but is set based on, for example, the time during which the vehicle must stop at a traffic signal that exists ahead of the current position specified by the current position specifying means. You may do it. That is, since the time that the vehicle must be stopped varies depending on the traffic light, it can be estimated that a traffic jam has occurred when the vehicle exists at the same dynamic address for the time required for the stop + α. In that case, the idea of including the stop required time for every traffic light in the map data for navigation can be considered. Of course, you may determine by another method. For example, it is determined that the traffic is congested if the low speed running state continues for a predetermined time as judged from the legal speed. In any case, since the determination is made from the behavior of the vehicle on which the communication device is mounted, it can be determined whether or not the traffic is in real time. That is, a time lag unlike the conventional method based on external information is unlikely to occur.

Then, the traffic jam information storage control means stores the traffic jam information related to the own vehicle in the traffic jam information storage means when it is judged by the traffic jam status judgment means that the traffic is in a traffic jam state.
The inquiry control means transmits the following transmission data via the communication means when it is determined that the traffic is congested. In other words, a dynamic address corresponding to the current position is included as a transmission-side dynamic address, and a dynamic address adjacent to the traveling direction of the vehicle is included as a destination address, and exists in an area corresponding to the adjacent dynamic address. This is transmission data for inquiring traffic jam information stored in another communication device.

  On the other hand, when transmission data including a dynamic address corresponding to the current position as a transmission destination address is received from another communication device, the reply control means transmits the following reply data via the communication means. To do. That is, the reply data includes the traffic information stored in the traffic information storage means and includes the transmission-side dynamic address included in the transmission data as a reply destination address.

  Then, when the reply data including the dynamic address corresponding to the current position as the reply destination address is received from another communication device, the traffic jam information storage control means displays the traffic jam information included in the reply data as the traffic jam information storage means. Remember me. In this way, the traffic information obtained from other communication devices existing in the area corresponding to the dynamic address adjacent in the traveling direction is also stored in the traffic information storing means, so that it is adjacent in the direction opposite to the traveling direction. The reply data sent by the reply control means when there is an inquiry about traffic jam information from another communication device that exists in the area corresponding to the dynamic address includes the traffic address information related to the host vehicle along with the traffic address adjacent in the traveling direction. Congestion information relating to a vehicle on which another communication device existing in the corresponding area is mounted is also included. Therefore, by repeating such data communication between the communication devices existing in the area corresponding to the adjacent dynamic address, it exists in any area of the dynamic address group in which the congestion occurs. Even if it is a communication apparatus, the traffic information ahead can be acquired from the vehicle in which the own apparatus is mounted.

  Thus, according to the communication apparatus of the present invention, information can be acquired in real time by a so-called inter-vehicle communication system. In addition, data communication using skillful dynamic addresses is performed. That is, in a format in which sequential relay communication is performed as in a conventional inter-vehicle communication device, when there are a large number of conventional vehicles, communication traffic becomes very large and response time becomes very large. In that case, information cannot be obtained at an early stage, and the merit of the inter-vehicle communication method is diminished. On the other hand, in the case of the present invention, information communication is performed in units of dynamic addresses. An area corresponding to the dynamic address is an area where a plurality of vehicles can exist simultaneously. Therefore, for example, assuming that 100 vehicles form a traffic jam queue and there are 4 vehicles each in an area corresponding to 25 dynamic addresses, 100 adjacent vehicles as in the conventional case. When successive relay communication is performed by a communication device mounted on a vehicle, communication traffic increases. However, if relay communication is performed in units of dynamic addresses, sequential relay communication between 25 dynamic addresses is sufficient. As a result, the data communication traffic is greatly reduced and the response time is shortened, so that traffic jam information can be acquired early.

Moreover, you may make it determine traffic jam content based on the traffic jam information acquired in this way. In this case, the traffic jam content may be a traffic jam distance or a traffic jam time, for example.
Among these, the traffic jam distance can be determined as follows. That is, the address data storage means stores the length of the area corresponding to the dynamic address along the road in association with the dynamic address. Then, based on the traffic jam information, the length of the area corresponding to the dynamic address where the traffic jam occurs is read from the address data storage means, and the traffic jam distance is determined by accumulating the length as necessary. . “Accumulated as necessary” is also assumed that there is only traffic information of one dynamic address, so if there is traffic information of two or more dynamic addresses, It means to accumulate the length. For example, it is also possible to include the length information of the dynamic address (corresponding to) corresponding to the traffic jam information itself and calculate the traffic jam distance based on the information.

  On the other hand, the traffic jam time can be determined as follows. For example, the time (congestion time) at which the traffic condition determination means determines that the traffic is in the traffic condition is included in the traffic information. Since the congestion time becomes slower as the communication device mounted on the following vehicle becomes, the congestion time corresponding to the communication device of the vehicle in the area corresponding to the head address of the congestion column and the congestion time corresponding to the communication device of the own vehicle By calculating the difference, it is possible to predict the time required to pass through the congestion queue. In addition, if all the congestion times corresponding to the communication devices of the vehicles in the area corresponding to each dynamic address existing ahead are obtained, it is possible to grasp information on where and where the congestion has occurred at which dynamic address. . This point will be described in detail later with reference to FIGS.

  In addition, since a plurality of vehicles can simultaneously exist in the area corresponding to the dynamic address, there is a possibility that a plurality of communication terminals that can be information communication targets exist simultaneously in the area corresponding to the same dynamic address. In that case, a plurality of communication devices will receive transmission data for inquiring traffic jam information. If these multiple communication devices send reply data, respectively, the same traffic jam information will be duplicated, so there will be a need to organize information by deleting unnecessary data. . Therefore, it is preferable not to receive such unnecessary data itself. From this point of view, even if there are a plurality of communication devices in the area corresponding to the dynamic address, only one of the communication devices is present. It is recommended to send reply data. Specifically, the following measures can be considered.

  In other words, the following device is applied to the reply control means. In other words, after the transmission permission start time determined based on the moving distance after entering the dynamic address, the dynamic address corresponding to the area where the data and the vehicle in which the transmission priority has been acquired and the vehicle is present. Priority acquisition data including the address as the transmission destination address is made transmittable. When priority acquisition data including a dynamic address corresponding to the current position as a transmission destination address is received from another communication device, transmission of priority acquisition data and reply data is not executed. On the other hand, when the priority acquisition data can be transmitted, the reply data is transmitted. In this way, only the communication device that has been able to transmit the priority acquisition data can transmit the response data, and otherwise does not transmit the response data.

  In addition, if you want to make sure that only one vehicle transmits the priority acquisition data, the communication device installed in the vehicle that can exist simultaneously in the dynamic address with respect to the transmission permission start time starts the same transmission permission at the same time. What is necessary is just to determine so that it may not be assigned to time. Also, if you want the priority acquisition data to be transmitted only by the leading vehicle in the dynamic address, the transmission permission start time will occur earlier as the movement distance from entering the dynamic address becomes longer. Just decide.

  By the way, for the communication device existing in the area corresponding to the first dynamic address of the traffic jam column, from the communication apparatus existing in the area corresponding to the dynamic address ahead (that is, the dynamic address adjacent in the vehicle traveling direction). There is no need to get traffic information. This is because the traffic jam information itself does not exist and the traffic jam information cannot be obtained. Therefore, in order to prevent such a meaningless operation from being executed, the following measures may be taken. In other words, if the head address determination means does not receive a response as a result of the inquiry by the inquiry control means, it is determined that the dynamic address corresponding to the own device is the first dynamic address in the traffic jam column. The inquiry control means inquires about the traffic jam information unless the dynamic address corresponding to the current position specified by the current position specifying means changes when the start address determining means determines that it is the first dynamic address. Therefore, the transmission of the transmission data is not executed.

  In addition, when the control means in the communication apparatus described above is realized by a computer, it can be provided as a program executed by the computer. Such a program is recorded on a computer-readable recording medium such as a flexible disk, a magneto-optical disk, a CD-ROM, a hard disk, a ROM, or a RAM, and is loaded into a computer for execution as necessary. The function as the control means can be realized by loading and executing the program.

Embodiments to which the present invention is applied will be described below with reference to the drawings. The embodiments of the present invention are not limited to the following examples, and can take various forms as long as they belong to the technical scope of the present invention.
[Description of communication device]
FIG. 1 is a block diagram illustrating a schematic configuration of a communication apparatus 1 according to the embodiment.

  The communication device 1 of the present embodiment is a communication device that is mounted on a vehicle and also has a car navigation function. As shown in FIG. 1, the communication device 1 includes a position detector 21 that detects the current position of the vehicle, an operation switch group 22 for inputting various instructions from the user, and various instructions similar to the operation switch group 22. Remote control terminal (hereinafter referred to as remote control) 23a, remote control sensor 23b for inputting a signal from remote control 23a, external information input / output device 24, and external recording in which map data and various information are recorded A map data input device 25 for inputting map data and the like from a medium; a display device 26 for performing various displays such as a map display screen and a TV screen; a voice output device 27 for outputting various guide voices; Hard disk 28 for storing various data, wireless communication device 30, position detector 21, operation switch group 22, remote controller 23a, external information described above. Various processes are executed in accordance with input from the input / output device 24, the map data input device 25, and the hard disk 28, and the position detector 21, operation switch group 22, remote control sensor 23b, external information input / output device 24, map data input device. 25, a display device 26, an audio output device 27, a hard disk 28, and a control circuit 29 for controlling the wireless communication device 30.

  The position detector 21 receives a radio wave transmitted from an artificial satellite for GPS (Global Positioning System) via a GPS antenna and is added to the vehicle and a GPS receiver 21a that detects the position, direction, speed, and the like of the vehicle. A gyroscope 21b for detecting the magnitude of the rotational motion, a distance sensor 21c for detecting the distance traveled from the longitudinal acceleration of the vehicle, and the like, and a geomagnetic sensor 21d for detecting the traveling direction from the geomagnetism are provided. Yes. Each of the sensors 21a to 21d has an error having a different property, and is configured to be used while complementing each other. Depending on the accuracy, a part of the sensors described above may be used, or a steering rotation sensor, a wheel sensor of each rolling wheel, or the like may be used.

  As the operation switch group 22, a touch panel installed on the display screen, mechanical key switches provided around the display device 26, and the like are used. Note that the touch panel and the display device 26 are laminated and integrated, and there are various types of touch panels such as a pressure-sensitive method, an electromagnetic induction method, a capacitance method, or a combination of these methods. Also good.

  The external information input / output device 24 is for inputting information from various information collecting devices and the like. For example, an FM broadcast signal received via a radio antenna (not shown) or a VICS (Vehicle arranged near the road) Information and Communication System) Inputs radio wave beacon signals and optical beacon signals received from fixed stations for services. Further, for example, information from various in-vehicle devices such as a sensor for detecting the presence or absence of rain and a sensor for detecting the road surface condition can be input.

  The map data input device 25 includes various kinds of data including road data as network data, map data such as so-called map matching data for improving the accuracy of position identification, mark data indicating facilities, guidance images and audio data, and the like. A device for inputting data. As a recording medium for these data, a CD-ROM, DVD, hard disk, memory, memory card, or the like can be used.

  The display device 26 is a color display device, such as a liquid crystal display, a plasma display, or a CRT, any of which may be used. The display screen of the display device 26 includes a mark indicating the current location identified from the current position of the vehicle detected by the position detector 21 and the map data input from the map data input device 25, a guidance route to the destination, and a name. Additional data such as landmarks and various facility marks can be displayed in an overlapping manner. Also, facility guides can be displayed. The voice output device 27 can output facility guidance and various guidance voices input from the map data input device 25, and information reading voices obtained via the external information input / output device 24.

The hard disk 28 stores shared address data 28a. This shared address data will be described in detail later.
The wireless communication device 30 is for performing vehicle-to-vehicle communication, and performs wireless communication with the communication device 1 (the wireless communication device 30) mounted on another vehicle. As a communication method, for example, it is conceivable to adopt a wireless communication method mainly in a narrow area such as DSRC, BlueTooth (registered trademark), wireless LAN, UWB, and millimeter wave communication. In addition, since the communication area required in this radio | wireless communication apparatus 30 is determined by the relationship with the dynamic address mentioned later, it demonstrates together in the description of the dynamic address.

  The control circuit 29 is configured around a well-known microcomputer comprising a CPU, ROM, RAM, I / O and a bus line connecting these components, and the position is determined based on a program stored in the ROM or the like. Based on each detection signal from the detector 21, the current position of the vehicle is calculated as a set of coordinates and traveling directions, the map near the current position read via the map data input device 25, the operation switch group 22, the remote controller 23a, etc. Based on the map display processing for displaying a map or the like in the range instructed by the operation on the display device 26 or the point data stored in the map data input device 25, the destination and the destination are determined according to the operation of the operation switch group 22 or the remote controller 23a. Route guidance process that performs route guidance by selecting a facility and automatically calculating the optimal route from the current position to the destination Do. A technique such as the Dijkstra method is known as a technique for automatically setting an optimum route in this way. Also, the control circuit 29 can exchange information with the communication device 1 (the wireless communication device 30) mounted on another vehicle via the wireless communication device 30.

[Description of shared address data]
Next, the shared address data 28a will be described.
The shared address data 28a is configured by associating each continuous area divided along the road on the map with a dynamic address that is an address set so that the area can be specified. . In the present embodiment, it is assumed that traffic jam information of the road on which the vehicle is traveling is acquired. Therefore, the “road” in this case is considered to be a different road if the traveling direction of the traffic jam is different. Therefore, a continuous area divided along the roads on the up lane side and the down lane side is set. Moreover, although the length along the road of this area | region can also be fixed (for example, 20 m), it is good also as variable according to a road shape. For example, when there is a road that is bent in an L shape, if the length of the region is fixed, the bent portion may be set as an L-shaped region. Of course, such a setting may be realized, but since it has a road width in a straight line so as not to be L-shaped, it is preferably set as a substantially rectangular area in terms of data processing. This is because the rectangular shape can be specified by, for example, the latitude and longitude of four corners.

  Therefore, in such a case, the length of the area may be adjusted flexibly. For example, even if the normal length is 20 m, the L-shaped corner may be set to extend to the corner. It is done. That is, the length of the region is exceptionally 35 m (an example only). Even if it does in this way, there is no special problem and the merit that it can set in a substantially rectangular area as mentioned above is acquired.

  As for the length of the area, for example, the above-mentioned 20 m is an example, and various lengths can be adopted. However, since the effectiveness is reduced if it is too short, the length is such that at least two vehicles can exist. It is necessary to keep. For example, if the area is 20 meters long, there can be about 4 vehicles that are stopped due to traffic jams, so if you communicate only with the leading vehicle, for example, you can skip the other 3 vehicles. And overall communication traffic is reduced. This point will be described later with a specific example.

  For example, if the dynamic addresses are numbered so that adjacent dynamic addresses are serial numbers, it is easy to determine the positional relationship of each dynamic address with respect to other dynamic addresses. Can be judged.

  Therefore, as illustrated in FIG. 2, the shared address data 28a including the dynamic address, the area specifying information (for example, latitude and longitude) corresponding to the dynamic address, and the length of the dynamic address is stored in the hard disk 28. Become. Note that the “dynamic address length” here means the length along the road in the area corresponding to the dynamic address, but in the following explanation, the “dynamic address” is appropriately used. The length of "."

  The length of this dynamic address is used for calculating the traffic jam distance. As illustrated by the rabbit and the turtle in FIG. 2, a dynamic address AD1235... And a dynamic address 1234... Exist in front of the rabbit, and congestion occurs at the two dynamic addresses. To do. In this case, 35 + 20 = 55 (m) obtained by adding the lengths of the two dynamic addresses can be calculated as the congestion distance at the position where the rabbit is present.

  It has been described that the communication area required in the wireless communication device 30 is determined in relation to the dynamic address. This means that it is necessary to be able to perform wireless communication with the communication device 1 existing in the area corresponding to the adjacent dynamic address, and thus it is set to a communication area in which such a communication is possible. That is, communication is performed between the vehicle communication device 1 existing at the end of the area corresponding to one dynamic address and the vehicle communication device 1 existing at the forefront of the area corresponding to the other dynamic address. Need to be realized. Specifically, the longest of the combinations of the lengths of two adjacent dynamic addresses is assumed. For example, if the combination of 20 m and 35 m is the longest, if the intersection dynamic address is set in an area 50 m from the intersection for each road, the wireless communication device 30 having a communication area with a radius of about 55 m is used. If there is, it is possible. Of course, directivity may be given in the longitudinal direction of the vehicle.

[Description of Operation of Communication Device 1]
First, an outline of the operation will be described. In the communication apparatus 1 according to the present embodiment, by using the shared address data, the vehicle-to-vehicle communication is performed to acquire the traffic jam information, and the traffic jam distance is calculated. The outline will be described with reference to FIGS.

  In FIG. 3, it is assumed that the place where the traffic signal exists is between the dynamic address AD000 and the dynamic address AD001, and the dynamic address AD002 is adjacent to the dynamic address AD001 in the direction opposite to the traveling direction of the vehicle. The description will be made assuming that the address AD003 and the dynamic address AD004 are adjacent to each other. Consider a traffic jam situation where three dynamic addresses AD001 to AD003 connected to a traffic light each have four vehicles and a total of 12 vehicles. In addition, in FIG. 3, they are shown by the figure of a turtle. An example in which the vehicle attached to the tail of the traffic jam calculates the traffic jam distance will be described. Note that the vehicle attached to the tail end of the traffic jam is indicated by a rabbit in FIG. Moreover, in FIG. 3, the vehicle shown by the figure of a rabbit is set to A, and the 12 vehicles lined up from there to a traffic signal are shown by B-M in order. FIG. 3 shows the traffic information of each vehicle when a traffic jam occurs from the vehicle M and the vehicle A is connected.

  First, what kind of traffic jam information the communication device 1 mounted on each vehicle has will be described. The absolute time at the time of traffic jam is stored (saved) for the vehicles J, K, L, and M of the head group existing at the dynamic address AD001 to which the vehicle M at the traffic jam belongs. The absolute time during this traffic jam will be described. It is determined that the traffic is congested when it exists in the area corresponding to the same dynamic address for a predetermined time or longer (hereinafter referred to as “existing for the same dynamic address for a predetermined time or longer”, which means the same). Then, the absolute time at the time of the determination is defined as “absolute time at traffic jam”. The absolute time can be calculated based on time information included in a GPS signal received by the GPS receiver 21a, for example. For example, if it is possible to receive a GPS signal every 30 seconds based on timekeeping with a real time clock (RTC) (not shown), it is possible to update the time information received every time it is received, so that it is almost accurate. Time (absolute time) can be calculated.

  It is considered that a state in which the same dynamic address exists for a predetermined time or longer sequentially occurs from the leading vehicle in the traffic jam. In the case of FIG. 3, the absolute times when the vehicles M, L, K, and J are congested are 0:01, 0:02, 0:03, and 0:04 (in this embodiment, the unit is minutes). Similarly for the subsequent vehicles I, H, G, F, E, D, C, B, and A, the absolute times at the time of congestion are 0:05, 0:06, 0:07, 0:08, respectively. 0:09, 0:10, 0:11, 0:12, 0:13. However, for vehicles belonging to the dynamic addresses after the first dynamic address AD001, information on the first vehicle at the front dynamic address (absolute time at the time of traffic jam) is also stored. For example, four vehicles F, G, H, and I belonging to the dynamic address AD002 that is the second most distant from the traffic light store the absolute time 0:01 that is information of the leading vehicle M of the previous dynamic address AD001. ing. Then, the four vehicles B, C, D and E belonging to the dynamic address AD003 which is the third furthest from the traffic light store the absolute time 0:01 which is information of the leading vehicle M of the previous dynamic address AD001. In addition, absolute time 0:05, which is information of the leading vehicle I of the immediately preceding dynamic address AD002, is stored. Then, the vehicle A (indicated by the rabbit) belonging to the dynamic address AD004 that is the fourth furthest from the traffic light is the absolute time 0:01, which is the information of the leading vehicle M of the previous dynamic address AD001, The absolute time 0:05 which is information of the leading vehicle I of the dynamic address AD002 and the absolute time 0:09 which is information of E which is the leading vehicle of the previous dynamic address AD003 are also stored. Become.

  The reason why the information on the leading vehicle is transmitted to the vehicle existing at the rear dynamic address even though there are multiple vehicles at each dynamic address is shown in a predetermined map (see FIG. 2 or FIG. 3). This is because only the leading vehicle has a priority for data transmission on the basis of the map shown in FIG.

  The vehicle A that has obtained the traffic jam information in this manner grasps that the traffic jam has occurred at the three dynamic addresses AD001, AD002, and AD003 ahead, and the length data of each dynamic address is 20 m respectively. Since it is known, it can be determined that the jam is 60 m in the present embodiment by adding them. On the other hand, the traffic jam time can be calculated from the difference between the absolute time information (in this case 0:01) corresponding to the obtained head address and the absolute time information of the own vehicle (vehicle A) (in this case 0:13). Specifically, it can be determined that 0: 13-0: 01 = 0: 12 (minutes).

  Next, FIG. 4 shows the traffic jam information of each vehicle when the vehicle M leaves the traffic jam and the vehicle L becomes the head of the traffic jam. Note that the vehicles A, E, and I move forward one by one in order, so that the dynamic addresses themselves have moved forward one by one. Since the leading vehicle of the dynamic address AD001 is L, the leading vehicle of the dynamic address AD002 is H, and the leading vehicle of the dynamic address AD003 is D, the vehicles E, F, and G belonging to the second dynamic address AD002. , H stores absolute time 0:02, which is information of the leading vehicle L of the previous dynamic address AD001, and the vehicles A, B, C, D belonging to the third dynamic address AD003 are stored. The absolute time 0:02 which is the information of the first vehicle L of the previous dynamic address AD001 and the absolute time 0:06 which is the information of the first vehicle H of the previous dynamic address AD002 are also stored. Yes. In addition to these, the vehicle AA of the dynamic address AD004 further stores absolute time 0:10 which is information of the leading vehicle D of the dynamic address AD003.

Then, the process performed in the communication apparatus 1 in the case of performing such operation | movement is demonstrated with reference to the flowchart of FIGS.
The flowchart of FIG. 5 shows the processing when obtaining or updating the traffic jam information. When the process starts, first, the latitude and longitude of the current position of the vehicle is calculated based on information from the position detector 21 (see FIG. 1), and the own device 1 exists by referring to the shared address data 28a in the hard disk 28. The dynamic address corresponding to the area to be checked is confirmed (S10). Then, it is determined whether or not the area corresponding to the same dynamic address exists for a predetermined time or longer (hereinafter referred to as “existing for the same dynamic address for a predetermined time or longer”, which means the same). S20) If the same dynamic address does not exist for a predetermined time or longer (S20: NO), the process returns to S10. If the same dynamic address exists for a predetermined time or longer (S20: YES), the absolute time at that time is set. Save (in RAM or the like) (S30).

  Then, the traffic jam information is obtained from the dynamic address one ahead (S40). At the time of acquisition, as shown in FIG. 8 (b), the dynamic address (forward dynamic address) positioned one forward (along the traveling direction of the road) of the dynamic address confirmed in S10 is transmitted. Communication is performed in a data format including the dynamic address and transmission time on the side. The communication apparatus 1 that has received such data executes processing as shown in the flowchart of FIG.

Here, the process shown in the flowchart of FIG. 6 will be described. This is a process executed by the communication device 1 when called from behind.
First, based on the information from the position detector 21 (see FIG. 1), the current position of the own vehicle is calculated, and the dynamic address corresponding to the area where the own apparatus 1 exists with reference to the shared address data 28a in the hard disk 28. Is confirmed (S310). Then, it is determined whether a call interrupt has occurred (S320). Specifically, it is called only when data having the same dynamic address as that of the vehicle confirmed in S310 is received as the “forward dynamic address” shown in (1) of FIG. 8B. It is determined that an interrupt has occurred.

  If a call interrupt has not occurred (S320: NO), the process returns to S310. If a call interrupt has occurred (S320: YES), the approach distance to the dynamic address confirmed in S310 is confirmed (S320: NO). S330). Since the position of the end of the dynamic address is known, the approach distance can be easily calculated if the current position is known.

  Then, the information transmission map is confirmed (S340). This information transmission map is map data for determining the information transmission order as shown in FIG. 2, and when there are a plurality of vehicles, that is, a plurality of communication devices 1, within the same dynamic address, Used to select one communication device 1 from Specifically, this is a contrivance for selecting the communication device 1 mounted on the vehicle that exists at the head in the area corresponding to the dynamic address. This information transmission map shows the relationship between the dynamic address approach distance and the transmission start interval, and in this embodiment, the longer the approach distance is, the faster the transmission start time is set, that is, transmission is possible with priority. Is set to Specifically, for example, as the approach distance becomes longer from 5 m → 10 m → 15 m → 20 m, the communication start interval becomes shorter as 4 seconds → 3 seconds → 2 seconds → 1 second. Note that the transmission priority may be advanced instead of the transmission start time.

  In the next step S350, it is determined whether or not the priority acquisition data format has been received. This determines whether or not the other communication apparatus 1 that has acquired the priority has received the priority acquisition data format in the process of S370 described later. If the priority acquisition data format is received here (S350: YES), the other communication device 1 has acquired the transmission right, so that the own device 1 has no transmission right and returns to S310.

  On the other hand, when the priority acquisition data format has not been received (S350: NO), confirmation of priority acquisition is performed (S360). This is based on the information transmission map confirmed in S340, and it is confirmed whether or not the priority has been acquired based on whether or not the transmission start time has come. If the acquisition of priority has not been confirmed (S350: NO), the process returns to S330. If the acquisition of priority has been confirmed (S350: YES), the process proceeds to S370 and the priority acquisition data format is changed. Send. As shown in (2) of FIG. 8 (b), this priority acquisition data format includes the own vehicle dynamic address and a transmission impossible signal. The transmission time in the data format on the information request side shown in 1) is used.

  Thereafter, traffic jam information is prepared (S380), and communication is started (S390). The traffic jam information in S380 is the dynamic address of the own vehicle and the absolute time of traffic jam start (that is, the time saved in S30 of FIG. 5). Regarding the communication in S390, as shown in (3) of FIG. 8B, the transmission side dynamic address and the transmission time in the data format on the information requesting side shown in (1) of FIG. 8B, S380 It is a data format that includes traffic information prepared in.

  In this way, the traffic jam information is obtained from one dynamic address ahead (S40 in FIG. 5), and at the same time, if there is no response, that is, if the traffic jam information itself cannot be obtained, it is determined that it is the head address. When there is a response, that is, when traffic jam information is obtained, it is determined that the address is a subsequent address. Thereafter, the acquired traffic information is accumulated and saved (S50). As described with reference to FIGS. 3 and 4, the vehicle at the head address stores only its own vehicle information (absolute time and address), and the vehicle at the subsequent address has a dynamic one ahead in addition to its own vehicle information. The information held by the first car in the address is also saved.

  Then, traffic congestion detour determination is performed (S60). This congestion detour determination is shown as a separate routine in FIG. 5. When the congestion detour determination starts, the congestion distance is calculated (S210), and the congestion time is calculated (S220).

  Then, the calculated traffic time is notified to the driver (S230). The notification may be notification by voice through the voice output device 27, display through the display device 26, or notification using both of them. In addition, a detour route etc. can be considered as information other than the traffic jam time notified to the driver in S230. For example, if the traffic time is expected to be longer than a predetermined time, it is determined whether or not there is a detour route connecting the front of the traffic jam portion and the current position using, for example, a navigation function (based on map data) If there is, the driver may be notified of the detour route via the display device 26.

  After the traffic congestion detour determination in S60, it is determined whether or not the dynamic address has advanced by one (S70). It waits until the dynamic address advances by one, and if it advances by one (S70: YES), it is determined whether or not the head address has been lost (S80). When the vehicle exits from the first dynamic address (AD001) in the traffic jam column and moves forward to the front dynamic address (AD000) as in the vehicle M shown in FIG. 4 (S80: YES), the processing after S90 is performed. Return to S10 without executing. On the other hand, for example, the second dynamic address (AD002) from the second dynamic address (AD002) as in the vehicle I shown in FIG. 4 or the second from the third dynamic address (AD003) as in the vehicle E. Or when moving forward from the fourth dynamic address (AD004) to the third dynamic address (AD003) as in vehicle A (S80: NO), the process proceeds to S90. .

  In S90, the traffic jam information is obtained from one forward dynamic address, and in S100, the obtained traffic jam information is accumulated and stored. Since the processing contents of S90 and S100 are the same as those of S40 and S50, respectively, description thereof will be omitted. In subsequent S110, a request for obtaining information of the dynamic address one forward is transmitted to the previous dynamic address (that is, one dynamic address behind). In obtaining this, as shown in (1) of FIG. 8 (a), a dynamic address (rear dynamic address) located one rearward along the traveling direction of the road, a dynamic address on the transmission side, and transmission Communication is performed in a data format including time. The communication apparatus 1 that has received such data executes processing as shown in the flowchart of FIG.

  Here, the processing shown in the flowchart of FIG. 7 will be described. This is a process executed by the communication device 1 when called from the front. In the following description, in order to facilitate understanding, the vehicle I that has advanced to the head address in FIG. 4 executes a call in the process of S110 in FIG. 5, and the second dynamic address in response to the call. The contents executed by the communication device 1 mounted on the vehicle in the AD002 will be described by exemplifying as appropriate.

  First, based on information from the position detector 21 (see FIG. 1), the latitude and longitude of the current position of the vehicle is calculated, and the shared address data 28a in the hard disk 28 is referenced to correspond to the area where the own device 1 exists. The dynamic address is confirmed (S410). Then, it is determined whether a call interrupt has occurred (S420). As described above, the vehicle I that has advanced to the head address in FIG. 4 makes a call in a data format as shown in (1) of FIG. Since the rear address in this case is the second dynamic address AD002, the rear address in the data format shown in 8 (a) (1) is AD002, and the communication mounted on the vehicles F, G, and H in FIG. In the apparatus 1, since it is the same as the dynamic address of the own vehicle confirmed in S410, an affirmative determination is made in S420, that is, it is determined that a call interruption has occurred.

  Although the vehicle E in FIG. 4 is shown to exist at the second dynamic address AD002, in reality, there is a transition state between the state of FIG. 3 and the state of FIG. That is, in a state where the vehicle M has exited the traffic jam, the vehicle L has become the head of the traffic jam, and the vehicle I has advanced from the second dynamic address AD002 to the first dynamic address AD001, the vehicle E is not necessarily the second dynamic address. It does not always exist at the address AD002. Normally, in a traffic jam train, the vehicle moves forward one by one while passing the timing, so when the vehicle I moves from the second dynamic address AD002 to the first dynamic address AD001, the third dynamic address is still present. It is highly probable that it exists in AD003, and it is considered that after a while, the process proceeds to the second dynamic address AD002. Similarly, regarding the vehicle A, the vehicle I advances from the second dynamic address AD002 to the first dynamic address AD001, and then the vehicle E advances from the third dynamic address AD003 to the second dynamic address AD002. Later, it is considered that the vehicle A proceeds from the fourth dynamic address AD004 to the third dynamic address AD003. Therefore, it is considered that the timing at which an affirmative determination is made that the dynamic address has advanced by one in the processing at S70 in FIG. 5 is normally shifted in the order of vehicle I → vehicle E → vehicle A.

  Returning to the description of FIG. 7, if a call interrupt has not occurred (S420: NO), the process returns to S410. If a call interrupt has occurred (S420: YES), the dynamic address confirmed in S410 is returned to. The approach distance is confirmed (S430).

  Then, the information transmission map is confirmed (S440), waits until the transmission time determined by the information transmission map (S450: NO), and when the transmission time is reached (S450: YES), the forward dynamic address is transmitted ( S460), communication is started (S470). The forward dynamic address in S460 means “transmission side dynamic address of (1) in FIG. 8A” as shown in the data format of (2) in FIG. 8A. . At the same time, as shown in (2) of FIG. 8 (a), the data is transmitted in a data format including the content of requesting the rear dynamic address (that is, the dynamic address of the own vehicle) and traffic jam information.

  When such a traffic information request is issued to the first dynamic address by the vehicles F, G, and H (the vehicle E also enters the vehicle) in the second dynamic address, The communication device 1 mounted on the vehicle L present at the head will respond to the response. The data format in this case is shown in (3) of FIG. 8A, and the transmission time and traffic jam information are included in the backward dynamic address (in this case, the second dynamic address AD002). Therefore, when the traffic information from the vehicle L is obtained and accumulated and stored, as shown in FIG. 4, the traffic at the head address stored by the vehicles F, G, and H (applicable if the vehicle E has also entered) is stored. The information is information about the vehicle L, and the absolute time at the time of traffic jam is also 0:02. In the above specific example, the vehicle I that has advanced to the top address in FIG. 4 executes a call in the process of S110 in FIG. 5, and is mounted on the vehicle in the second dynamic address AD002 in response to the call. In this case, the vehicle E that has advanced to the second dynamic address in FIG. 4 executes a call in the process of S110 in FIG. The same applies to the case where the communication device 1 mounted on the vehicle in the target address AD003 executes and the case of the subsequent dynamic addresses.

  Although the processing up to S110 in FIG. 5 has been described, a traffic congestion detour determination is performed thereafter (S120). Since the traffic congestion bypass determination in S120 is the same as the processing content in S60, the description thereof is omitted.

  In this embodiment, the position detector 21 corresponds to “current position specifying means”, and the hard disk 28 corresponds to “address data storage means” and “congestion information storage means”. The control circuit 29 corresponds to “control means”, and the wireless communication device 30 corresponds to “communication means”.

[Effects of communication device 1 of implementation]
(A) As described above, according to the communication device 1 of the present embodiment, in addition to being able to acquire information in real time by the inter-vehicle communication method, by performing data communication skillfully using a dynamic address, The response time can be expected to be greatly reduced as compared with a conventional type in which relay communication is performed sequentially between adjacent vehicles as in a conventional inter-vehicle communication device. In other words, in the conventional method, when there are very many vehicles, the communication traffic becomes very large and the response time becomes very large, and it becomes impossible to obtain information at an early stage, and the merit of the inter-vehicle communication method has diminished. . On the other hand, in the case of the communication apparatus 1 of the present embodiment, information communication is performed in units of dynamic addresses, but the area corresponding to this dynamic address has a plurality of vehicles simultaneously (specifically, at least at least). 4 units) This is an area that can exist. Therefore, for example, assuming that 100 vehicles form a traffic jam queue and there are 4 vehicles each in an area corresponding to 25 dynamic addresses, 100 adjacent vehicles as in the conventional case. When successive relay communication is performed by a communication device mounted on a vehicle, communication traffic increases. However, if relay communication is performed in units of dynamic addresses, sequential relay communication between 25 dynamic addresses is sufficient. As a result, the data communication traffic is greatly reduced and the response time is shortened, so that traffic jam information can be acquired early.

  (B) In the case of the communication device 1 of the present embodiment, when there are a plurality of communication devices 1 in the area corresponding to the same dynamic address, the information transmission of FIG. 2 (or FIGS. 3 and 4) is performed. As shown in the map, the longer the approach distance to the dynamic address, the faster the start of communication, that is, it is set so that it can be transmitted preferentially, so in the area corresponding to the same dynamic address It is possible to avoid returning similar traffic information from a plurality of communication devices 1. In the case of the present embodiment, since it is returned only from the communication device 1 mounted on the leading vehicle in the dynamic address, the congestion distance can be calculated more accurately.

[Others]
(1) In the above embodiment, the vehicle is mainly assumed to be in a slow state or completely stopped. However, on a highway or the like, for example, traveling at about 30 to 40 km / h It can be considered as a target of traffic jams. Therefore, the determination of the traffic congestion state may be performed by the fact that the traveling state below the predetermined speed has continued for a predetermined time. In that case, the length of the area corresponding to the dynamic address may be increased to some extent, for example, at a level of 100 m or 200 m.

  (2) In the above embodiment, the current vehicle position is specified based on data detected by the position detector 210 including a gyroscope and a GPS receiver. However, in order to specify the current position, such a position detector 21 is not necessarily required. For example, it is possible to specify the current position based on position information obtained from a roadside beacon or the like. Further, the current location may be specified by the position specifying function of the mobile phone 31.

It is a block diagram which shows schematic structure of the communication apparatus of an Example. It is explanatory drawing which shows the outline | summary of a shared address data, the mechanism of calculation of traffic jam distance, etc. It is explanatory drawing which shows the outline | summary of operation | movement of the communication apparatus of an Example. It is explanatory drawing which shows the outline | summary of operation | movement of the communication apparatus of an Example. It is a flowchart which shows the traffic information acquisition / update process performed with the communication apparatus of an Example. It is a flowchart which shows the traffic information provision process performed when the communication apparatus of an Example is called from back. It is a flowchart which shows the traffic information provision process performed when the communication apparatus of an Example is called from the front. It is explanatory drawing of a data format.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Communication apparatus, 21 ... Position detector, 21a ... GPS receiver, 21b ... Gyroscope, 21c ... Distance sensor, 21d ... Geomagnetic sensor, 22 ... Operation switch group, 23a ... Remote control, 23b ... Remote control sensor, 24 ... External Information input / output device, 25 ... map data input device, 26 ... display device, 27 ... audio output device, 28 ... hard disk, 28a ... shared address data, 29 ... control circuit, 30 ... wireless communication device.

Claims (8)

A communication device mounted on a vehicle and capable of mutually communicating information between vehicles,
Consecutive areas divided along the road on the map, each of which can have multiple vehicles at the same time, is configured by associating a dynamic address that is an address set so that the area can be specified Address data storage means for storing the shared address data,
A communication unit having a communication area capable of wireless communication with a communication device existing in an area corresponding to another adjacent dynamic address when the area exists in an area corresponding to an arbitrary dynamic address;
Current position specifying means for specifying the current position;
Traffic information storage means for storing traffic information, control means for executing various controls,
With
The control means includes
A traffic condition determination means for determining that the vehicle is in a traffic jam state from the behavior of the host vehicle;
When it is determined that the traffic condition is determined by the traffic condition determination means, the traffic information related to the vehicle is stored in the traffic information storage means, and the traffic condition information is determined by the traffic condition determination means. In this case, the dynamic address corresponding to the current position specified by the current position specifying means is included as a transmission-side dynamic address, and a dynamic address adjacent to the traveling direction of the vehicle is included as a destination address. Inquiry control means for sending transmission data for inquiring traffic jam information stored in other communication devices existing in the area corresponding to the dynamic address to be transmitted through the communication means;
When the transmission data including the dynamic address corresponding to the current position specified by the current position specifying unit as the destination address is received from another communication device via the communication unit, the congestion Reply control means for transmitting the reply data including the traffic side information stored in the information storage means and the sending side dynamic address contained in the transmission data as a reply destination address via the communication means;
Have
When the reply data including the dynamic address corresponding to the current position specified by the current position specifying means as the reply destination address is received from another communication device via the communication means, the congestion information storage The control unit causes the traffic jam information storage unit to store the traffic jam information included in the reply data. The communication device according to claim 1,
The control means includes
The communication apparatus further comprises traffic content determination means for determining the traffic content based on the traffic information stored in the traffic information storage means. The communication device according to claim 2,
The address data storage means stores the length along the road of the area corresponding to the dynamic address in association with the dynamic address,
The traffic content determination means reads out the length of the area corresponding to the dynamic address where the traffic congestion is based on the traffic information from the address data storage means, and accumulates the length as necessary. A communication device characterized by determining a traffic jam distance. In the communication apparatus in any one of Claims 1-3,
The reply control means includes
After the transmission permission start time determined based on the travel distance after entering the dynamic address, data indicating that the transmission priority has been acquired and the dynamic address corresponding to the area where the host vehicle exists It is possible to send the priority acquisition data including the destination address,
When the priority acquisition data including the dynamic address corresponding to the current position specified by the current position specifying means as the destination address is received from another communication device, the priority acquisition data and the A communication apparatus, wherein transmission of reply data is not executed, and transmission of the reply data is executed when the priority acquisition data can be transmitted. The communication device according to claim 4, wherein
The transmission apparatus is characterized in that the transmission permission start time is determined so that communication apparatuses mounted on a vehicle that can exist simultaneously in the dynamic address are not simultaneously assigned to the same transmission permission start time. The communication device according to claim 4 or 5,
The transmission apparatus is characterized in that the transmission permission start time is determined so as to occur earlier as the moving distance after entering the dynamic address is longer. In the communication apparatus in any one of Claims 1-6,
The control means further includes start address determination means for determining that the dynamic address corresponding to the own apparatus is the first dynamic address of the traffic jam sequence when there is no response as a result of the inquiry by the inquiry control means. Have
In the case where the inquiry control means determines that the head dynamic address is the head dynamic address by the head address determination means, the traffic congestion is determined as long as the dynamic address corresponding to the current position specified by the current position specifying means does not change. A communication apparatus characterized by not transmitting transmission data for inquiring information.   The program for functioning a computer as the said control means in the communication apparatus in any one of Claims 1-7.