JP2007081499A - Vehicle radio communication apparatus and vehicle radio communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring forward a start time of radio communication between an in-vehicle radio apparatus and a subsequent road-side radio apparatus. <P>SOLUTION: An information storage device 2 stores the position of a road-side radio apparatus and an assigned radio frequency in advance. A controller 3 estimates the road-side radio apparatus by which the in-vehicle radio apparatus subsequently performs radio transmission on the basis of the vehicle position detected by a GPS sensor 1 and data stored in the information storage device 2, and specifies the radio frequency assigned to the estimated road-side radio apparatus on the basis of the data stored in the information storage device 2. A communication apparatus 4 uses the radio frequency specified by the controller 3 to try radio communication with the road-side radio apparatus estimated to subsequently perform radio communication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicular radio communication apparatus and a vehicular radio communication method for performing radio communication with a roadside radio apparatus.

  A system that performs wireless communication between a roadside wireless device and a vehicle-mounted wireless device by using a radio frequency assigned to each roadside wireless device is known. In this system, information on radio frequencies used by one or more roadside wireless device candidates that can be wirelessly communicated next by a vehicle-mounted wireless device performing wireless communication is transmitted from the roadside wireless device to the vehicle-mounted wireless device. A technique for searching for and setting the next radio frequency based on the received radio frequency information is known (see Patent Document 1). According to this technique, the time required for switching the radio frequency can be shortened.

JP 2003-244061 A

  However, the conventional technology has a problem that it takes time to switch the radio frequency when there are a plurality of roadside wireless device candidates that the in-vehicle wireless device can communicate with next time.

  The vehicle wireless communication device and the vehicle wireless communication method according to the present invention store in advance information on the position of the roadside wireless device and the radio frequency assigned to the roadside wireless device, the position of the vehicle, and When the roadside wireless device that performs the next wireless communication is estimated based on the information on the position of each roadside wireless device that is stored in advance, and the next wireless communication is performed based on the information of the wireless frequency that is stored in advance The radio frequency allocated to the estimated roadside radio apparatus is specified, and the radio communication with the roadside radio apparatus estimated to perform the next radio communication is attempted using the specified radio frequency. .

  According to the vehicle wireless communication device and the vehicle wireless communication method of the present invention, it is estimated that the next wireless communication is performed using the radio frequency assigned to the roadside wireless device estimated to perform the next wireless communication. Since the wireless communication with the roadside wireless device is attempted, the wireless communication with the roadside wireless device that performs the next wireless communication can be quickly started.

-First embodiment-
FIG. 1 is a diagram illustrating a configuration of a vehicle wireless communication device according to the first embodiment. The vehicle radio communication apparatus according to the first embodiment includes a GPS sensor 1, an information storage device 2, a controller 3, a communication apparatus 4, and a communication antenna 5, and is installed on the road side. Wireless communication with In order to prevent radio wave interference between adjacent roadside radio apparatuses, different radio frequencies are assigned to each roadside radio apparatus.

  The GPS sensor 1 receives a radio wave transmitted from a GPS satellite (not shown) and detects the current position of the vehicle. The information storage device 2 is, for example, a hard disk drive (HDD), and stores various types of information regarding a plurality of roadside wireless devices. Various information on the roadside wireless device includes information such as the position (latitude and longitude) of the roadside wireless device, the radio frequency assigned to the roadside wireless device, the transmission output, the antenna orientation, and the antenna height. It is.

  The communication device 4 exchanges various information by performing wireless communication with the roadside wireless device via the communication antenna 5. Information acquired from the roadside apparatus via wireless communication includes, for example, traffic information.

  Based on the vehicle position detected by the GPS sensor 1 and various information on the roadside wireless device stored in the information storage device 2, the controller 3 estimates the roadside wireless device that performs wireless communication next time and estimates The radio frequency assigned to the roadside radio device is identified. Next, the roadside wireless device that performs wireless communication detects the position of the vehicle a plurality of times at different timings, detects the traveling direction of the vehicle, and estimates by detecting the roadside wireless device that exists in the traveling direction of the vehicle. can do. The communication device 4 attempts to perform wireless communication with the roadside wireless communication estimated to perform wireless communication next using the specified wireless frequency.

  FIG. 2 is a diagram for explaining a method in which a vehicle wireless communication device mounted on a moving vehicle performs wireless communication with roadside wireless communication. In FIG. 2, the positions of the vehicle wireless communication devices mounted on the moving vehicle are indicated by 10A, 10B, and 10C. As described above, the controller 3 performs the next wireless communication 50 based on the vehicle position detected by the GPS sensor 1 and various information of the roadside wireless device stored in the information storage device 2. And the radio frequency assigned to the estimated roadside apparatus 50 is specified.

  From the transmission output data of the roadside apparatus 50 stored in the information storage device 2, the communication range T1 of the roadside apparatus 50 is obtained. A range T2 that is a predetermined distance wider than the communication range T1 is set as a communication start range by the communication device 4. The communication range T1 and the communication start range T2 may be obtained by the controller 3 based on the estimated transmission output data of the roadside apparatus after estimating the roadside apparatus 50 that performs the next wireless communication, or obtained in advance. Alternatively, the information may be stored in the information storage device 2.

  Based on the vehicle position detected by the GPS sensor 1, the controller 3 determines whether or not the vehicle equipped with the vehicle wireless communication device is within the communication start range T2, and determines that the vehicle is within the communication start range T2. Then, wireless communication with the roadside wireless device 50 is attempted by the communication device 4 using the specified wireless frequency. For example, when there is a response from the roadside apparatus 50 to the inquiry from the communication apparatus 4, wireless communication for exchanging information with the roadside apparatus 50 is started.

  FIG. 3 is a flowchart showing the contents of processing performed by the vehicular wireless communication apparatus according to the first embodiment. When the vehicle is activated and the power of the vehicle wireless communication device is turned on, the controller 3 starts the process of step S10. In step S10, the vehicle position information detected by the GPS sensor 1 is acquired, and the process proceeds to step S20.

  In step S20, based on the vehicle position acquired in step S10 and the information on the roadside wireless device stored in the information storage device 2, the roadside wireless device that performs the next wireless communication is estimated, and the estimated roadside wireless Identify the radio frequency assigned to the device. Further, the communication start range T2 is obtained based on the identified transmission output of the roadside apparatus.

  In step S30 following step S20, based on the vehicle position detected by the GPS sensor 1, it is determined whether or not the vehicle has entered the communication start range T2 of the specified roadside apparatus. If it is determined that the vehicle has not entered the communication start range T2, the process returns to step S10. If it is determined that the vehicle has entered, the process proceeds to step S40. In step S40, the communication device 4 attempts wireless communication with the estimated roadside wireless device using the wireless frequency specified in step S20. As described above, an inquiry for wireless communication is made to the roadside wireless device, and when there is a response from the roadside wireless device, wireless communication for exchanging information is started.

  According to the vehicular radio communication apparatus in the first embodiment, information on the positions of a plurality of roadside radio apparatuses and radio frequencies assigned to these roadside radio apparatuses is stored in advance and stored in advance. Based on the current information and the current position of the vehicle, the roadside radio device that performs the next wireless communication is estimated, the radio frequency of the estimated roadside radio device is specified, and the specified radio frequency is used. A wireless communication with a roadside wireless device that performs wireless communication is attempted. As a result, it is possible to quickly start wireless communication with the roadside wireless device that performs the next wireless communication. Moreover, since more communication time can be ensured by starting the wireless communication earlier, it is possible to download information with a large communication capacity.

  Further, according to the vehicle wireless communication device in the first embodiment, when entering a range that is a predetermined distance away from the communication range of the roadside wireless device estimated to perform wireless communication next, the estimated roadside wireless device and Since wireless communication is attempted, wireless communication can be started immediately.

-Second Embodiment-
In the vehicular wireless communication apparatus according to the first embodiment, information on positions of a plurality of roadside radio apparatuses and radio frequencies assigned to the roadside radio apparatuses is stored in advance. Based on the information and the current position of the vehicle, the roadside radio device that performs the next radio communication is estimated, the radio frequency of the estimated roadside radio device is specified, and using the specified radio frequency, Tried to communicate wirelessly. In the vehicle radio communication apparatus according to the second embodiment, the orientation of the communication antenna 5 is further adjusted as the vehicle moves.

  FIG. 4 is a diagram for explaining a method of adjusting the direction of the communication antenna 5 as the vehicle moves. When the vehicle enters the communication start range T2 of the roadside apparatus 50, wireless communication with the roadside apparatus 50 is attempted using the radio frequency specified in advance. When the wireless connection with the roadside apparatus 50 is successful, the direction of the communication antenna 5 is adjusted so that the directivity of the communication antenna 5 matches the direction of the roadside apparatus 50 according to the movement of the vehicle. In FIG. 4, the directivity directions of the communication antennas according to the vehicle positions 10D to 10H are indicated by arrows 11D to 11H, respectively.

  Next, when estimating the roadside wireless device 50 that performs wireless communication, the controller 3a detects the position of the vehicle detected by the GPS sensor 1, the position (latitude and longitude) of the roadside wireless device 50 stored in the information storage device 2, Based on the direction and height of the antenna of the roadside apparatus 50, the direction of the antenna of the roadside apparatus 50 with respect to the communication antenna 5 is calculated. Subsequently, the angle of the communication antenna 5 is adjusted so that the directivity of the communication antenna 5 matches the calculated antenna direction of the roadside apparatus 50.

  According to the vehicular radio communication apparatus in the second embodiment, wireless communication with the roadside radio apparatus that performs radio communication next can be quickly performed in the same manner as the vehicular radio communication apparatus in the first embodiment. Since the direction of the communication antenna 5 is adjusted so that the directivity of the communication antenna 5 matches the direction of the roadside apparatus, the communication state can be maintained in a good state.

-Third embodiment-
FIG. 5 is a diagram illustrating a configuration of a vehicle wireless communication device according to the third embodiment. The vehicle wireless communication apparatus according to the third embodiment includes a vehicle speed sensor 7 that detects the speed of the vehicle in addition to the configuration of the vehicle wireless communication apparatus according to the first embodiment shown in FIG.

  FIG. 6 is a diagram for explaining a situation in which wireless communication is performed between the vehicle wireless communication device mounted on the moving vehicle and the roadside wireless devices 51 to 53. When the vehicle travels in the direction of the arrow Y1, the vehicle wireless communication device performs wireless communication in the order of the roadside wireless device 51 → 52 → 53. Here, when the speed of the vehicle is high, after the wireless communication with the roadside wireless device 51 is finished, the wireless communication with the roadside wireless device 52 may be attempted while passing through the communication range T52 of the roadside wireless device 52. There is sex.

  In the vehicular wireless communication apparatus according to the third embodiment, wireless communication is performed next based on a communication range of a roadside wireless apparatus that performs wireless communication next and a communication range of a roadside wireless apparatus that performs wireless communication next. When it is determined that sufficient wireless communication cannot be performed with the roadside wireless device that performs communication, wireless communication is attempted with the next roadside wireless device without performing wireless communication with the next roadside wireless device. In the example shown in FIG. 6, after leaving the communication range T51 of the roadside wireless device 51 and before performing sufficient wireless communication with the roadside wireless device 52, it is determined that the vehicle enters the communication range T53 of the roadside wireless device 53. The wireless communication with the roadside wireless device 53 is attempted without performing wireless communication with the roadside wireless device 52.

  FIG. 7 is a diagram for explaining a method for determining whether or not sufficient communication can be performed with the next roadside apparatus. The distances of the communication ranges T51 to T53 of the roadside apparatuses 51 to 53 in the traveling direction Y1 of the vehicle are d1 to d3, respectively. Further, a distance in a range where the communication ranges T52 and T53 overlap is assumed to be d4. Accordingly, the distance of the communication range T52 that does not overlap with the communication range T53 is d2-d4.

  After leaving the communication range T51, the time required to enter the next communication range T53 is, in the case of FIG. 7, the time required to travel in a range that does not overlap the communication range T53 in the next communication range T52. If the vehicle speed detected by the vehicle speed sensor 7 coincides with V1, it becomes (d2-d4) / V1. If the traveling time is shorter than the predetermined time T1, it is determined that sufficient communication with the roadside apparatus 52 cannot be performed. That is, if {(d2-d4) / V1} <T1 holds, wireless communication with the next roadside wireless device 53 is attempted without performing wireless communication with the roadside wireless device 52. In this case, when the vehicle enters the communication start range of the roadside wireless device 53, wireless communication with the roadside wireless device 53 is attempted using the radio frequency assigned to the roadside wireless device 53.

  FIG. 8 is a flowchart showing the contents of processing performed by the vehicle wireless communication apparatus in the third embodiment. Steps in which the same processing as that in the flowchart shown in FIG. 3 is performed are denoted by the same reference numerals, and detailed description thereof is omitted. When the vehicle exits from the communication range of the roadside apparatus that performs wireless communication, the controller 3b starts the process of step S10. In step S10, the vehicle position information detected by the GPS sensor 1 is acquired, and the process proceeds to step S100.

  In step S100, based on the vehicle position acquired in step S10 and the roadside wireless device information stored in the information storage device 2, the roadside wireless device that performs wireless communication next, and the next wireless communication. The roadside wireless device that performs is estimated. Next, when a roadside wireless device that performs wireless communication and a roadside wireless device that performs next wireless communication are estimated, the process proceeds to step S110.

  In step S110, the time required to enter the communication range of the roadside apparatus that performs the next wireless communication is calculated. In the example described with reference to FIG. 7, after leaving the communication range T <b> 51 of the roadside wireless device 51 that was performing wireless communication, until entering the communication range T <b> 53 of the roadside wireless device 53 that performs the next wireless communication. The distance is d2-d4, and when the vehicle speed detected by the vehicle speed sensor 7 is V1, the time required to travel the above-mentioned distance is (d2-d4) / V1.

  In step S120, it is determined whether time (d2-d4) / V1 calculated in step S110 is shorter than a predetermined time T1. If it is determined that the time (d2-d4) / V1 calculated in step S110 is shorter than the predetermined time T1, the process proceeds to step S130. If it is determined that the time is equal to or longer than the predetermined time T1, the process proceeds to step S140.

  In step S130, based on the information stored in the information storage device 2, the radio frequency of the next next roadside radio device is specified. In the example illustrated in FIG. 7, the radio frequency assigned to the roadside apparatus 53 is specified. On the other hand, in step S140, the radio frequency of the next roadside radio device is specified based on the information stored in the information storage device 2. In the example illustrated in FIG. 7, the radio frequency assigned to the roadside apparatus 52 is specified. When the process of step S130 or S140 is performed, the process proceeds to step S30. Steps S30 and S40 are the same as steps S30 and S40 in the flowchart shown in FIG.

  According to the vehicle wireless communication device in the third embodiment, the next roadside wireless device that performs wireless communication and the next roadside wireless device that performs wireless communication are estimated, and the next wireless communication is performed. The time required to enter the communication range of the roadside wireless device to be calculated is calculated, and if the calculated time is shorter than the predetermined time, the next roadside wireless device is not attempted without performing wireless communication with the next roadside wireless device. Attempt wireless communication with. As a result, when the wireless communication time with the next roadside wireless device is not sufficient, the wireless communication with the next roadside wireless device can be started as soon as possible to make the communication time as long as possible.

  The present invention is not limited to the embodiments described above. For example, the information storage device 2 stores information on the positions and radio frequencies of a plurality of roadside radio devices in advance. However, when the information on the roadside radio device is changed, a new roadside radio device is used. If, for example, new data is transmitted from a roadside wireless device or an information center (not shown) to the vehicle wireless communication device via radio, the data in the information storage device 2 is updated. May be. In this case, the information storage device 2 can always store new data. In addition, by transmitting new data to the vehicle wireless communication device via wireless, it is not necessary for the user to go to a service factory or the like to update the data, which increases convenience for the user.

  Next, the roadside wireless device that performs wireless communication is estimated by detecting the traveling direction of the vehicle by detecting the position of the vehicle a plurality of times at different timings, and detecting the roadside wireless device that exists in the traveling direction of the vehicle. However, it can also be estimated by other methods. For example, in a system equipped with a car navigation device, a recommended route from the current location of the vehicle to the destination can be calculated and displayed on the display. In this case, since the traveling direction of the vehicle can be predicted based on the vehicle position detected by the GPS sensor 1 and the calculated recommended route, the roadside wireless device existing in the predicted traveling direction is then wirelessly communicated. It can be estimated as a roadside apparatus.

  The correspondence between the constituent elements of the claims and the constituent elements of the first to third embodiments is as follows. That is, the information storage device 2 is storage means, the GPS sensor 1 is position detection means, the controller 3 is estimation means, radio frequency identification means, antenna angle adjustment means, time calculation means, and determination means, the communication device 4 and The communication antenna 5 constitutes communication means. In addition, the above description is an example to the last, and when interpreting invention, it is not limited to the correspondence of the component of said embodiment and the component of this invention at all.

The figure which shows the structure of the radio | wireless communication apparatus for vehicles in 1st Embodiment. The figure for demonstrating the method by which the radio | wireless communication apparatus for vehicles mounted in the moving vehicle performs radio | wireless communication with roadside radio | wireless communication. The flowchart which shows the processing content performed by the radio | wireless communication apparatus for vehicles in 1st Embodiment. The figure for demonstrating the method of adjusting the direction of a communication antenna with the movement of a vehicle The figure which shows the structure of the radio | wireless communication apparatus for vehicles in 3rd Embodiment. The figure for demonstrating the condition which performs radio | wireless communication between the radio | wireless communication apparatus for vehicles mounted in the moving vehicle, and several roadside radio | wireless apparatuses. The figure for demonstrating the determination method of whether it can perform sufficient communication with the following roadside radio | wireless apparatus. The flowchart which shows the processing content performed by the radio | wireless communication apparatus for vehicles in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... GPS sensor, 2 ... Information storage device, 3 ... Controller, 4 ... Communication apparatus, 5 ... Communication antenna, 7 ... Vehicle speed sensor

Claims (6)

In a vehicle wireless communication device that performs wireless communication using one of the plurality of roadside wireless devices and a wireless frequency assigned to the roadside wireless device,
Storage means for storing at least information on the position of each roadside apparatus and the radio frequency assigned to the roadside apparatus;
Position detecting means for detecting the position of the vehicle;
Estimation means for estimating a roadside wireless device that performs wireless communication next, based on the vehicle position detected by the position detection means, and information stored in the storage means;
Radio frequency specifying means for specifying a radio frequency assigned to the roadside apparatus estimated by the estimating means based on information stored in the storage means;
A vehicular radio communication device, comprising: a communication unit that attempts to perform radio communication with the roadside radio device estimated by the estimation unit using the radio frequency specified by the radio frequency specification unit. The vehicle wireless communication device according to claim 1,
A communication range specifying means for specifying a communication range of the roadside apparatus estimated by the estimating means;
When the communication means enters a range that is a predetermined distance away from the communication range specified by the communication range specifying means, the communication means tries radio communication with the roadside apparatus estimated by the estimation means. Vehicle wireless communication device. In the vehicle wireless communication device according to claim 1 or 2,
The communication means includes a communication antenna for transmitting and receiving radio waves,
Direction detection means for detecting the direction of the roadside apparatus estimated by the estimation means with reference to the communication antenna;
A vehicular wireless communication apparatus, further comprising: an antenna angle adjustment unit that adjusts an angle of the communication antenna so that a directivity of the communication antenna matches a direction detected by the direction detection unit. In the vehicle radio communication device according to any one of claims 1 to 3,
The estimation means includes a roadside radio apparatus that performs radio communication next to a roadside radio apparatus that performs radio communication next, based on a vehicle position detected by the position detection means and information stored in the storage means. Estimate
Time calculating means for calculating the time required to enter the communication range of the next roadside wireless device estimated by the estimating means;
Determining means for determining whether the time calculated by the time calculating means is shorter than a predetermined time;
If it is determined by the determination means that the time required to enter the communication range of the next next roadside wireless device is shorter than a predetermined time, the communication means does not attempt wireless communication with the next roadside wireless device. Next, a wireless communication device for a vehicle that attempts wireless communication with the next roadside wireless device. In the vehicle radio communication device according to any one of claims 1 to 4,
The vehicular radio characterized in that the communication means receives via wireless the data for updating the position of the roadside apparatus stored in the storage means and the information of the assigned radio frequency. Communication device. In the vehicle wireless communication method for performing wireless communication using one of the plurality of roadside wireless devices and a wireless frequency assigned to the roadside wireless device,
Store in advance information on the position of each roadside device and the radio frequency assigned to that roadside device,
Based on the position of the vehicle and the information on the position of each roadside wireless device stored in advance, the roadside wireless device that performs wireless communication next is estimated,
Based on the radio frequency information stored in advance, identify the radio frequency assigned to the roadside radio device estimated to perform the next radio communication,
A wireless communication method for a vehicle, wherein wireless communication with a roadside wireless device estimated to perform wireless communication next is attempted using the specified wireless frequency.

Images