JP2009110093A - Inter-vehicle communication system - Google Patents

Abstract

Provided is a vehicle-to-vehicle communication system in which position correction information can be shared and used by vehicle-to-vehicle communication between vehicles that are next approaching the intersection even when there is no preceding vehicle ahead of the intersection on the road.
A position specifying means for receiving signals transmitted from satellites and specifying a current position based on these signals, and a signal provided before an intersection on the road and including information on the installed position The receiving means 10 that receives the position information from the DSSS optical beacon that transmits the position information, the position information received by the receiving means is compared with the current position specified by the position specifying means 1, and the difference between the position information and the current position Error information calculating means 20 for obtaining error information indicating the error information, and transmitting means 30 for transmitting error information calculated by the error information calculating means.
[Selection] Figure 1

Description

  The present invention relates to an inter-vehicle communication system, and more particularly to an inter-vehicle communication system suitable for correcting a positioning error of a navigation device using GPS.

  Navigation systems using GPS (Global Positioning System) are widely used. This navigation system simultaneously receives a plurality of radio waves from a plurality of GPS satellites orbiting a predetermined satellite orbit, obtains a pseudo distance between the GPS satellite and the receiver, and then corrects the pseudo distance. Thus, the true position of a receiver (such as a vehicle equipped with a navigation system) is obtained. However, GPS is a system originally built for military purposes, and in the case of GPS standard positioning service (SPS), which is partly open to the private sector, about 10m to 38m from the true position. It is undeniable that this error will occur. For this reason, in order to improve the position detection accuracy, position correction information consisting of the difference between the position information obtained from the GPS satellites received at a known location and the true position information is obtained, and this position correction information is transmitted to the FM broadcast. On the other hand, on the receiver (navigation system) side, a D-GPS (Differential GPS) system is known which receives position correction information superimposed on FM broadcast radio waves and corrects GPS measurement errors. It has been. According to this D-GPS system, it is possible to make positioning error within about 5 m.

  In a navigation system using GPS, for example, while traveling on a road or the like sandwiched between tunnels or high-rise buildings, the navigation system may not be able to receive signals from GPS satellites (radio dead zone). There is also known a position correction device that estimates the current vehicle position from the position of the host vehicle, the speed of the host vehicle, and the moving direction measured immediately before reaching the radio dead zone when the vehicle reaches the radio dead zone.

  On the other hand, as a system using this type of GPS, there is a system that prevents collision accidents by exchanging vehicle position information with one function of advanced safety vehicle (ITS) (Advanced Safety Vehicle) of ITS (Advanced Road Traffic System). . This system, for example, detects a stopped vehicle that is difficult to detect from sensors mounted on the vehicle at places with poor visibility such as intersections and curves, and prevents a collision accident. This collision accident prevention system performs vehicle-to-vehicle communication via a communication device mounted on a vehicle, and supports safe driving by mutually transmitting vehicle conditions (vehicle position, speed, moving direction, etc.). . In such a system, vehicle status is exchanged using inter-vehicle communication based on vehicle position information obtained from a navigation system. For example, in Patent Document 1, own vehicle position correction information is acquired using an existing DSSS optical beacon previously installed at an intersection on a road, and the information is transmitted to a subsequent intersection approaching vehicle. The approaching vehicle uses the received own vehicle position correction information and describes the contents used for its own position correction.

JP 2006-349405 A

  When using an existing DSSS optical beacon as in Patent Document 1, this DSSS optical beacon is installed on the outflow side of the intersection (beyond the intersection) because the main purpose of use is the itinerary to the next intersection. Yes. For this reason, the position correction information can be calculated for the preceding vehicle passing through the intersection, and when there is no preceding vehicle, this position correction information can be shared and used by inter-vehicle communication between the vehicles next approaching the intersection. There is a problem that cannot be done.

  The present invention has been made to solve the above-described problems, and its purpose is to provide position correction information between vehicles that are next approaching an intersection even when there is no preceding vehicle ahead of the intersection on the road. An object is to provide a vehicle-to-vehicle communication system that can be shared by communication.

  In order to achieve the above-described object, the inter-vehicle communication system according to claim 1 receives a signal transmitted from a satellite and specifies a current position based on these signals, and before the intersection on the road. Receiving means for receiving the position information from the optical beacon that transmits a signal including the installed position information, and the position information received by the receiving means and the current position specified by the position specifying means. It is characterized by comprising error information calculation means for obtaining error information indicating a deviation between position information and the current position by comparison, and transmission means for transmitting error information calculated by the error information calculation means.

  According to a second aspect of the present invention, the vehicle-to-vehicle communication system according to the first aspect further comprises position correction means for receiving the error information transmitted by the transmission means and correcting the current position specified by the position specifying means. It is a feature.

  Specifically, the above-described beacon is an optical beacon that is installed on a road as a DSSS (Driving Safety Support Systems) safe driving support system, for example, as shown in FIG. Information on the location (position information) of the place where the light projecting / receiving unit 50 is arranged with respect to a vehicle passing through a predetermined range immediately below the light projecting / receiving unit 50 (for example, a range of about 3.5 m with respect to the traveling direction) In addition, various information such as traffic jam information and road fault information is transmitted. Incidentally, the light projecting / receiving unit 50 for sending a DSSS beacon (optical beacon) is installed in front of the intersection on the vehicle entry side in a certain range in the vicinity of the intersection on the road. Is provided.

  The inter-vehicle communication system described above identifies the current position based on a signal transmitted from a GPS satellite, and receives the position information from a beacon that is provided on the road and transmits a signal including the installed position information. Then, the current position measured by the signal transmitted from the GPS satellite is compared with the position information transmitted from the beacon to obtain the measurement error measured by the GPS satellite. Then, error information that can correct the deviation of the current position specified by the GPS satellites is transmitted to neighboring vehicles. The transmission means preferably transmits satellite identification information indicating the satellite used for specifying the current position.

  The inter-vehicle communication system of the present invention is characterized by comprising position correction means for receiving the error information transmitted by the transmission means and correcting the current position specified by the position specifying means. As a result, the vehicle-to-vehicle communication system described above receives this error information from the neighboring vehicle before the intersection that has obtained error information for correcting the measurement error of the current position measured by the GPS satellite, and accurately determines the current vehicle position. to correct.

  According to the present invention, a signal from an optical beacon that is installed in front of an intersection and transmits known position information is received, and a deviation (error) from a current position specified by a signal from a GPS satellite is obtained. Since this error information is transmitted to neighboring vehicles, even if there is no preceding vehicle ahead of the intersection, the neighboring vehicles that have received this correction information will correct the position of the navigation system installed in each vehicle. It can be performed. This position correction is performed every time a nearby vehicle receives a signal from an optical beacon, so even if there is a change in the propagation state of the signal transmitted from the satellite or the position of the satellite, the latest GPS is always updated. Position correction information (error information) can be transmitted.

  According to the present invention, the vehicle is provided with the position correction means for receiving the error information transmitted from the transmission means and the information for specifying the satellite and correcting the current position specified by the position specifying means. Every time a beacon signal is received, it can be corrected to the correct position. Moreover, since this beacon uses a DSSS optical beacon, there is no need to construct a new infrastructure, and there is a great practical effect, and the accuracy of the proximity calculation between vehicles located in the vicinity is improved. Therefore, it can be applied to a collision accident prevention system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a main part configuration diagram showing an outline of a configuration of an apparatus main body in a vehicle-to-vehicle communication system according to an embodiment of the present invention. In this figure, reference numeral 1 denotes a navigation device that measures the current position of the vehicle using signals transmitted from a plurality of GPS satellites (not shown). The navigation device 1 receives a signal transmitted from each of a plurality of GPS satellites, and calculates and obtains the position of the vehicle on which the navigation device 1 is mounted from the signal received by the GPS receiver 2. A GPS position calculation unit 3, a D-GPS reception unit 4 that receives correction information transmitted by being superimposed on an FM broadcast radio wave that corrects an error in a measurement position measured by a GPS satellite, the D-GPS reception unit 4, and a later-described A position correction processing unit 5 that corrects the current position information obtained by the GPS position calculation unit 3 from the GPS position error correction value to be displayed, a display that generates display information in response to each of the corrected current position information and the state of surrounding vehicles described later The control part 6 is provided with the display part 7 which shows the passenger | crew etc. of the information produced | generated by this display control part 6. FIG.

  In FIG. 1, reference numeral 10 denotes a DSSS device that receives information from an optical beacon (DSSS beacon) used in a safe driving support system (DSSS). The DSSS device 10 is provided in front of an intersection on the road as shown in FIG. 5, for example, and a DSSS receiver 11 that receives a signal from a DSSS projector / receiver 50 that transmits road traffic information including its position information as an optical beacon. And a DSSS position calculation unit 12 for obtaining position information where the light projecting / receiving unit 50 (controller 51) included in the road traffic information transmitted by the optical beacon is arranged.

  This apparatus main body compares the current position obtained from the navigation apparatus 1 with the position information obtained from the DSSS apparatus 10 and the deviation between the current position obtained based on the GPS satellite and the true position (positioning error). A GPS position error correction calculation unit 20 that calculates error information for correcting the error by calculation is provided. Further, the apparatus main body includes a transmission information processing unit 21 that converts error information obtained by the GPS position error correction calculation unit 20 and positioning data (raw data) measured by the navigation device 1 into a predetermined data format, and a transmission information processing unit. There is provided a wireless communication unit 30 including a transmission unit 31 that transmits a frame converted by 21 to a nearby vehicle (not shown) and a reception unit 32 that receives a frame transmitted from another vehicle. The frequency transmitted and received by the wireless communication unit 30, the transmission output of the transmission unit 31, the type of radio wave, the modulation method, etc. may be radio waves regulated by the Radio Law, etc., or weak radio waves not applicable to radio law regulations. There is no particular limitation.

  In addition to the above-described error information and positioning data (raw data), the transmission information processing unit 21 also includes various types of information such as vehicle type, company name, color, etc. as vehicle information, and latitude / longitude, vehicle speed, etc. as position information. It plays a role of transmitting via the transmission unit 31 in the data format.

  On the other hand, the frame including the above-described various information transmitted from the own vehicle and the other vehicle is received by the receiving unit 32 and is provided to the reception information processing unit 22 that processes the various information included in this frame. The reception information processing unit 22 has a function of extracting the vehicle information described above in addition to the error information included in the received frame. Then, the obtained error information is configured to be provided to the position correction processing unit 5 of the navigation device 1 as GPS position error correction information.

  Control of the vehicle-to-vehicle communication system having such a configuration will be described with reference to the flowchart shown in FIG. FIG. 2 is a flowchart showing the control contents of the apparatus main body mounted on the vehicle that has received the DSSS beacon. In this control, the GPS receiver 2 receives the position information of the person from the GPS satellite in step S1. In step S2, it is determined whether the DSSS receiver 11 has received a DSSS beacon (optical beacon). When it is determined that the DSSS receiver 11 has received an optical beacon, the process proceeds to step S3, where the DSSS position calculator 12 includes position information (DSSS projector / receiver 50 is included in the optical beacon transmitted by the DSSS projector / receiver 50. (Position information of the place where it is placed) is calculated. In step S4, the GPS position error correction calculation unit 20 obtains a GPS position error correction value by obtaining a difference between the DSSS position information obtained in step S3 and the GPS position information obtained by the GPS position calculation unit 3 of the navigation device 1. . In step S <b> 5, the obtained position error correction value is converted into a predetermined format by the transmission information processing unit 21 and transmitted to another vehicle via the transmission unit 31.

  In this way, the information sent from the transmission unit 31 is received by the reception unit 32 of the host vehicle and another vehicle (not shown). FIG. 3 is a flowchart of control contents for correcting the vehicle position based on the error information received by the receiving unit 32.

  In step S <b> 1 of FIG. 3, the navigation device 1 mounted on the vehicle receives signals transmitted from a plurality of GPS satellites by the GPS receiver 2 and obtains the current position of the vehicle by the GPS position calculator 3. . In step S11, the reception information processing unit 22 determines whether or not the reception unit 32 has received a frame including error information from the own vehicle and another vehicle (not shown). If it is determined in step S11 that the reception information processing unit 22 has received a frame including error information, the process proceeds to step S12, where error information included in the frame is received, and the host vehicle proceeds. It is determined whether or not it is error information with respect to the direction (for example, whether or not it is error information [correction information] for correcting the true position of an intersection that will proceed from now on).

  In step S12, when the reception information processing unit 22 determines that error information in the traveling direction is included, in step S13, the error information is given to the position correction processing unit 5 to correct the current position of the vehicle. .

  On the other hand, in step S11, when the reception information processing unit 22 determines that the reception unit 32 has not received a frame including error information from the own vehicle and another vehicle (not shown), and the direction in which the own vehicle proceeds from step S12. If it is determined that the error information is not the error information, the process proceeds to step S14, and the correction value received by the D-GPS receiving unit 4 is given to the position correction processing unit 5 to correct the current position.

  As step S14, position correction may be further added as follows. For example, before the process of step S14, a plurality of GPS satellites obtained by the navigation apparatus 1 of the own vehicle in the reception information processing unit 22 and the GPS satellites received when the other vehicle generates error information match. If a processing step for determining whether or not to do so is added, and it is determined that there is no match in this step, the navigation of the own vehicle is again performed based on the GPS satellite information used when the other vehicle generates error information. The current position may be obtained by the apparatus 1 and the previously received error information may be given to the position correction processing unit 5 to correct the current position of the own vehicle.

  The display control unit 6 that has received the vehicle position information with the current position corrected in this way performs correction so that the correct vehicle position is indicated on the map that the display control unit 6 performs display control, and the reception unit. Peripheral vehicle state information indicating the state of the surrounding vehicle (for example, the position and speed of the other vehicle) received by 32 is given to the display unit 7. And the display part 7 provides these various information to the passenger of a vehicle, etc.

  Specifically, as shown in FIG. 4, the vehicle ST that has received the optical beacon transmitted from the light projecting / receiving unit 50 receives signals transmitted from a plurality of GPS satellites, and based on these signals, Identify the location. At this time, as described above, in the case of the GPS standard positioning service SPS, the position may be shifted by about 10 m to 38 m from the true position, and the navigation device 1 that has received the signals transmitted from the same GPS satellites displays them. Although the current position may be outside the road, such as the vehicles SS and RS, for example, the inter-vehicle communication system of the present invention can be corrected by the position information transmitted by the DSSS optical beacon. That is, the vehicle navigation apparatus 1 that has received the DSSS optical beacon corrects the current vehicle position and displays the true position ST. Further, the vehicle ST that has received the DSSS optical beacon transmits correction information for correcting the current position specified by the GPS satellite to vehicles in the vicinity. For this reason, the surrounding vehicle which received this signal can correct | amend from vehicle position RS containing an error to RT which is a true vehicle position, and can display it on the display part 7 of the navigation apparatus 1. FIG.

  According to the inter-vehicle communication system configured as described above, the known position information transmitted by the DSSS optical beacon arranged before the intersection is received and specified by the position information and signals received from a plurality of GPS satellites. Since the deviation information (error) from the current position is calculated and this error information is transmitted to vehicles existing around the vehicle, neighboring vehicles that have received this correction information are mounted on the respective vehicles. The position correction of the navigation system can be performed. In addition, this position correction is performed every time a nearby vehicle receives a signal from the DSSS optical beacon, the GPS satellite position has moved, or the propagation state of the signal transmitted from the GPS satellite has changed. However, the latest GPS position correction information (error information) can always be transmitted.

  In addition, since the inter-vehicle communication system of the present invention performs position correction using the DSSS optical beacon, it is not necessary to construct a new infrastructure, and in an ASV (Advanced Safety Vehicle) using GPS. There are practically great effects such as an increase in the accuracy of the vehicle position. Moreover, since the accuracy of the calculation of the degree of approach between vehicles located in the vicinity is improved, it can be applied to a collision accident prevention system.

  The inter-vehicle communication system of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

  For example, in the inter-vehicle communication system of the present invention, the positioning data (raw data) itself measured by the navigation apparatus 1 is also converted into a predetermined data format by the transmission information processing unit 21 and transmitted. For this reason, even when it is not necessary to perform position correction on the receiving side or when raw data is required, it is applicable.

It is a schematic block diagram which shows the principal part of the vehicle-to-vehicle communication system which concerns on one Embodiment of this invention. It is a flowchart which shows the control content of the transmission information processing part shown in FIG. It is a flowchart which shows the control content of the reception information processing part shown in FIG. It is a figure which shows an example by which the position of the vehicle to which the inter-vehicle communication system which concerns on one Embodiment of this invention is applied is correct | amended to a true position. It is a figure which shows an example of schematic structure of the DSSS optical beacon transmission / reception part arrange | positioned in the road vicinity, and its transmission / reception range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 2 GPS receiving part 3 GPS position calculating part 4 D-GPS receiving part 5 Position correction process part 6 Display control part 7 Display part 10 DSSS apparatus 11 DSSS receiving part 12 DSSS position calculating part 20 GPS position error correction calculating part 21 Transmission information processing unit 22 Reception information processing unit 30 Wireless communication unit

Claims (2)

Position specifying means for receiving signals transmitted from satellites and specifying the current position based on these signals;
Receiving means for receiving the position information from an optical beacon that is provided in front of an intersection on the road and transmits a signal including the installed position information;
Error information calculating means for comparing the position information received by the receiving means with the current position specified by the position specifying means to obtain error information indicating a deviation between the position information and the current position;
A vehicle-to-vehicle communication system comprising transmission means for transmitting the error information calculated by the error information calculation means. The inter-vehicle communication system according to claim 1,
A vehicle-to-vehicle communication system comprising: position correction means for receiving the error information transmitted by the transmission means and correcting the current position specified by the position specifying means.

Images