Vehicle-mounted device, vehicle-mounted device control method, and road charging system

Abstract

Provided is a vehicle-mounted device mounted on a vehicle, said vehicle-mounted device comprising: a position information measurement unit that uses an artificial satellite to measure position information; a distance measurement unit that uses electromagnetic waves from another vehicle to measure a first distance from the vehicle to said other vehicle; and a correction unit that corrects an error range of the position information on the basis of the difference between the first distance and a second distance which is based on the position information measured by the vehicle and on the position information measured by said other vehicle.

Description

In-vehicle device, control method for in-vehicle device, and road tolling system

[0001] The present disclosure relates to an in-vehicle device, a control method for an in-vehicle device, and a road tolling system.

[0002] Patent Document 1 describes a configuration related to a system for charging tolls (hereinafter referred to as a "road tolling system") that identifies a road section traveled by a vehicle (hereinafter referred to as a "vehicle") based on the travel position history of the vehicle calculated using position information obtained from the Global Navigation Satellite System (GNSS: Global Navigation Satellite System, hereinafter referred to as "GNSS").

[0003] In addition, Patent Document 2 describes the following device aiming to accurately determine whether the host vehicle is traveling on a travel path even if the reception accuracy from an artificial satellite decreases and an error included in the position information of the host vehicle changes. In the device described in Patent Document 2, it is determined whether the host vehicle is present within a travel lane by comparing the error range of position information with the overlap ratio of the lane width.

[0004] Japanese Patent Application Laid-Open No. 2020-201807, Japanese Patent Application Laid-Open No. 2018-169319

[0005] Incidentally, in a road tolling system based on position information as described in Patent Document 1, it is necessary to avoid the occurrence of erroneous charging, that is, charging a toll when no charge is required. However, for example, when a road that requires charging and a road that does not require charging are adjacent to each other, when the accuracy of position information decreases, there is a problem that the road may be erroneously determined, which may lead to the occurrence of erroneous charging.

[0006] The present disclosure has been made to solve the above-mentioned problem, and an object of the present disclosure is to provide an in-vehicle device, a control method for an in-vehicle device, and a road tolling system that can appropriately cope with a case where the accuracy of position information decreases.

[0007] To solve the above problems, the in-vehicle device according to the present disclosure is a device mounted on a vehicle and comprises: a position information measurement unit that measures position information using an artificial satellite; a distance measurement unit that measures a first distance, which is the distance from the vehicle to the other vehicle, using electromagnetic waves from the other vehicle; and a correction unit that corrects the error range of the position information based on the difference between the first distance and a second distance, which is the distance based on the position information measured by the vehicle and the position information measured by the other vehicle.

[0008] The control method for an in-vehicle device according to this disclosure uses a location information measurement unit, which is provided in a device mounted on a vehicle, to measure location information using artificial satellites, and a distance measurement unit, which measures a first distance, which is the distance from the vehicle to the other vehicle, using electromagnetic waves from the other vehicle, to correct the error range of the location information based on the difference between the first distance and a second distance, which is the distance based on the location information measured by the vehicle and the location information measured by the other vehicle.

[0009] The road toll system relating to this disclosure charges tolls based on the location information using the in-vehicle device.

[0010] According to the in-vehicle device, control method for the in-vehicle device, and road toll system of this disclosure, it is possible to respond appropriately when the accuracy of location information deteriorates.

[0011] This is a schematic diagram showing a basic configuration example of a road tolling system according to the first embodiment of this disclosure. This is a schematic plan view schematically showing a vehicle according to the first embodiment of this disclosure. This is a schematic diagram showing an example of the relationship between GNSS distance measurement distance and non-GNSS distance measurement distance according to the first embodiment of this disclosure. This is a schematic diagram showing an example of the difference between GNSS distance measurement distance and non-GNSS distance measurement distance according to the first embodiment of this disclosure. This is a schematic diagram for explaining the correction of the error range according to the first embodiment of this disclosure. This is a schematic diagram for explaining the correction of the error range according to the first embodiment of this disclosure. This is a flowchart showing the processing flow in each vehicle when there is a one-to-one vehicle relationship according to the first embodiment of this disclosure. This is a schematic diagram showing an example of a one-to-one vehicle relationship according to the first embodiment of this disclosure. This is a schematic diagram showing an example of a one-to-one vehicle relationship according to the first embodiment of this disclosure. This is a schematic diagram showing an example of a one-to-one vehicle relationship according to the first embodiment of this disclosure. This is a flowchart showing the processing flow in each vehicle when vehicle-to-vehicle communication is used when there are many vehicles according to the first embodiment of this disclosure. This is a flowchart showing the processing flow in each vehicle when server-to-server communication is used when there are many vehicles according to the first embodiment of this disclosure. This is a flowchart showing the processing flow in the server when server-to-server communication is used when there are many vehicles according to the first embodiment of this disclosure. This is a flowchart showing the data aggregation processing flow in each vehicle and server when there are many vehicles according to the first embodiment of this disclosure. This is a schematic diagram showing an example of many vehicles according to the first embodiment of this disclosure. This is a schematic diagram showing an example of many vehicles according to the first embodiment of this disclosure. This is a flowchart showing the processing flow in each vehicle according to the second embodiment of this disclosure. This is a schematic diagram showing an example of one-to-one vehicles according to the second embodiment of this disclosure. This is a schematic diagram showing an example of many vehicles according to the second embodiment of this disclosure. This is a schematic diagram showing an example of comparison results according to the second embodiment of this disclosure. This is a schematic diagram showing an example of many vehicles according to the second embodiment of this disclosure. This is a schematic diagram showing an example of comparison results according to the second embodiment of this disclosure.This is a schematic diagram showing an example of a number of vehicles according to the second embodiment of this disclosure. This is a schematic diagram showing an example of a number of vehicles according to the second embodiment of this disclosure. This is a schematic diagram showing a processing flow according to the third embodiment of this disclosure. This is a schematic diagram showing an example of data and processing according to the third embodiment of this disclosure. This is a schematic block diagram showing the configuration of a computer according to at least one embodiment.

[0012] Hereinafter, an in-vehicle device, a control method for the in-vehicle device, and a road tolling system according to the embodiments of this disclosure will be described with reference to Figures 1 to 30. In each figure, the same or corresponding components are given the same reference numerals, and their descriptions will be omitted as appropriate.

[0013] (First Embodiment) Figure 1 is a schematic diagram showing a basic configuration example of a road toll system 1 according to the first embodiment of the present disclosure. Figure 2 is a schematic plan view showing a vehicle V according to the first embodiment of the present disclosure. In the example shown in Figure 1, the road toll system 1 comprises a server 2, a plurality of vehicles V, and a communication network 4 that connects the server 2 and the plurality of vehicles V. The communication network 4 includes a mobile communication network, a fixed communication network, etc., and transmits predetermined information between the server 2 and the plurality of vehicles V. In this embodiment, the road toll system 1 has a function to charge tolls to the vehicles V by sending and receiving predetermined information, including location information acquired by each vehicle V using GNSS, between each vehicle V and the server 2. However, known configurations and operations can be used for the function of charging tolls, and a detailed explanation is omitted.

[0014] Furthermore, in this embodiment, the road tolling system 1 includes a function to appropriately correct the error range of the position information acquired by each vehicle V using GNSS. The function for correcting the error range of position information will be described below.

[0015] In this embodiment, the error range of the location information is the range of error (difference between the true value and the measured value) of the location information (latitude, longitude, and altitude). The error range of the location information can be expressed, for example, using the standard deviations of the semi-major axis and semi-minor axis of the error ellipse and the direction of the semi-major axis. The error ellipse (also called a probability ellipse, confidence ellipse, etc.) is an ellipse that represents the variance of a two-dimensional normal distribution (an ellipse that represents the range in which the data is scattered). Alternatively, the error range of the location information can be expressed, for example, using the standard deviations of the latitude error, longitude error, and altitude error. These standard deviations can be calculated and output, for example, by a commercially available GNSS positioning module.

[0016] Furthermore, in this embodiment, correcting the error range of the position information means expanding or contracting the error range, for example, by setting the error range of the position information to 1σ (where σ is the standard deviation) or 2σ.

[0017] Furthermore, it is difficult to accurately grasp differences in position that fall within the error range (for example, the distance difference between two positions that fall within the error range). In the road tolling system 1 of this embodiment, for example, it may be necessary to distinguish between driving in a predetermined location and driving in a location other than the predetermined location. However, for example, if the distance between the predetermined location and the location other than the predetermined location falls within the error range, there may be cases where it is not possible to distinguish between the predetermined location and the location other than the predetermined location. To address this, for example, if the distance between the predetermined location and the location other than the predetermined location falls within the error range, it is possible to prevent misjudgment of driving in a predetermined location and driving in a location other than the predetermined location. However, for example, if the error range is set smaller than the actual situation, there may be cases where it is not possible to prevent misjudgment. Therefore, in this embodiment, the error range of the location information can be appropriately corrected (set) by comparing the distance measurement result based on location information obtained using GNSS with the distance measurement result not based on location information.

[0018] In the following, an error ellipse will be used as an example of the error range for positional information. In this case, correcting the error range means enlarging or shrinking the area of ​​the error ellipse that was set as the error range before the correction. For example, enlarging the error ellipse means increasing at least one of the major axis and minor axis, with or without changing the direction of the major axis of the ellipse. Note that the error ellipse will also include cases where the two foci of the ellipse coincide (i.e., it will include a circle).

[0019] As shown in Figure 1, in this embodiment, the server 2 comprises a processing unit 21, a storage device 22, and a communication device 23. The communication device 23 transmits and receives predetermined information to and from each vehicle V via the communication network 4. The processing performed by the processing unit 21 and the data stored in the storage device 22 will be described later.

[0020] Vehicle V is equipped with an on-board device 30 and various devices (not shown) used for driving the vehicle V. The on-board device 30 comprises an on-board unit 31, an imaging device 32, and an image processing device 33.

[0021] The on-board unit 31 is, for example, an OBU (On-Board Unit) for the road tolling system 1, and includes a control device 311, a positioning device 312, a server-to-server communication device 313, a vehicle-to-vehicle communication device 314, a storage device 315, and an output device 316.

[0022] The control device 311 controls each part within the in-vehicle unit 31. In this embodiment, the control device 311 includes a correction unit 3111, which is implemented, for example, by executing a predetermined program.

[0023] The positioning device 312 measures position information using GNSS. In the example shown in Figure 2, the vehicle V has an antenna AN mounted near the top of the front window WD of the vehicle V, which receives signals transmitted from satellites via GNSS. The positioning device 312 measures the position information of the vehicle V (latitude, longitude, and altitude (altitude may be omitted)) at the position of antenna AN. The positioning device 312 also includes, for example, an inertial sensor, which calculates and outputs information representing the error ellipse.

[0024] The server-to-server communication device 313 sends and receives predetermined information to and from the server 2 via the communication network 4.

[0025] The vehicle-to-vehicle communication device 314 transmits and receives predetermined information with the vehicle-to-vehicle communication device 314 installed in the on-board unit 31 mounted in another vehicle V. The antenna for transmitting and receiving radio signals used in vehicle-to-vehicle communication is, for example, integrated with the antenna AN of the positioning device 312. The vehicle-to-vehicle communication device 314, for example, under the control of the control device 311, broadcasts a message containing information such as the identification information of the on-board unit 31, time information, and position information measured by the positioning device 312 to the other vehicle V at a predetermined interval. The vehicle-to-vehicle communication device 314 also has a function to measure and output the signal strength (or radio wave level) of the radio signal transmitted by the other vehicle V. There are no limitations on the communication method used for vehicle-to-vehicle communication; for example, a communication method such as Bluetooth® 6.0 can be used. In this case, the vehicle-to-vehicle communication device 314 can measure the distance between devices based on signal strength (or, instead of measuring distance), measure the signal transmission time and phase change between devices, and calculate the distance from the measured information. Furthermore, the vehicle-to-vehicle communication device 314 can sometimes be omitted, for example, when communication is performed via the server 2.

[0026] The storage device 315 stores, for example, identification information of the in-vehicle device 31, a time series of location information measured by the positioning device 312, a time series of data representing the error ellipse, and information about distance calculated based on the location information, which will be described later.

[0027] The output device 316, under the control of the control device 311, outputs synthesized speech or outputs images using a display device provided by an external navigation system.

[0028] As shown in Figure 2, the imaging device 32 is mounted, for example, near the top of the window WD on the front F of the vehicle V, and captures moving images in the imaging direction PD (or captures still images at a predetermined period). The images captured by the imaging device 32 are stored, for example, in a storage device within the imaging device 32 or in the image processing device 33.

[0029] The image processing device 33 performs predetermined image processing on the image captured by the imaging device 32 (hereinafter also referred to as the captured image) to determine whether or not the license plate NP on the rear R of another vehicle V is included in the captured image, and to recognize the display content of the license plate NP. For example, when the image processing device 33 detects that the license plate NP is included in the captured image, it notifies the control device 311 of this fact. The image processing device 33 also outputs information representing the number of the recognized license plate NP to the control device 311.

[0030] Furthermore, the image processing device 33 measures the distance from the own vehicle V to the other vehicle V based on the image captured by the imaging device 32. The image processing device 33 measures the distance from the imaging device 32 to, for example, the license plate NP on the rear R of the other vehicle V, based on, for example, the pixel position of the license plate NP of the other vehicle V in the captured image, the pixel positions of multiple lane boundary lines included in the captured image, and predetermined parameters related to the optical system, image sensor, imaging direction PD, etc. of the imaging device 32. In addition, when measuring distance based on the captured image, the direction of the license plate NP can also be measured, for example, with respect to the imaging direction PD. The imaging device 32 and the image processing device 33 may be configured as an integrated unit.

[0031] As shown in Figure 3, in this embodiment, the distance measured using the imaging device 32 is called the non-GNSS distance, meaning the distance measured without using position information measured using GNSS. In the example shown in Figure 3, the non-GNSS distance DSN-AB between the own vehicle V-A (vehicle A) and the other vehicle V-B (vehicle B) is indicated by a white-filled arrow. In the example shown in Figure 3, the direction of the white-filled arrow is indicated in accordance with the direction of the other vehicle V-B as seen from the own vehicle V-A. In this embodiment, the alphanumeric characters after the symbol "-" in symbols such as "DSN-AB" are symbols used to distinguish vehicle V and parts of the configuration (conditions), and in the following, if vehicle V etc. are not specified, the part after the symbol "-" may be omitted.

[0032] Furthermore, as shown in Figure 3, in this embodiment, the distance between the GNSS positioning position MSP-A measured using GNSS on the vehicle V-A and the GNSS positioning position MSP-B measured using GNSS on the other vehicle V-B is called the GNSS distance (GNSS distance DSS-AB in Figure 3). Note that GNSS positioning position MSP-A and GNSS positioning position MSP-B are positions based on position information measured by the positioning device 312, and the GNSS distance is a distance based on position information. Also, in the example shown in Figure 3, GNSS positioning position MSP-A and GNSS positioning position MSP-B are far from the actual positions shown in the illustrations of vehicle V-A and vehicle V-B due to positioning errors.

[0033] Furthermore, in this embodiment, as shown in Figure 4, the difference between the non-GNSS distance DSN-AB and the GNSS distance DSS-AB is called the deviation distance DE (deviation distance DE-B in Figure 4). As described above, when measuring the non-GNSS distance DSN-AB using the imaging device 32, it is possible to measure the direction of the other vehicle V-B as seen from the vehicle V-A. Therefore, in the example shown in Figure 4, the endpoint of the arrow (vector) representing the non-GNSS distance DSN-AB, starting from the GNSS positioning position MSP-A, is defined as the position MNP-B (hereinafter also referred to as virtual position MNP) based on the non-GNSS distance DSN-AB and its direction, and the distance between the virtual position MNP-B and the GNSS positioning position MSP-B is defined as the deviation distance DE-B.

[0034] Furthermore, the correction unit 3111 corrects the error range (error ellipse) of the position information based on the difference (deviation distance DE) between the non-GNSS distance DSN and the GNSS distance DSS. For example, as shown in Figure 5, the correction unit 3111 compares the error ellipse EE, which is based on the GNSS positioning position MSP, with the arrow (vector) of the deviation distance DE, which starts from the GNSS positioning position MSP. If the arrow (vector) of the deviation distance DE falls within the error ellipse EE, the error ellipse EE is not corrected. Also, for example, as shown in Figure 6, if the arrow (vector) of the deviation distance DE, which starts from the GNSS positioning position MSP, does not fall within the error ellipse EE, the correction unit 3111 expands the error ellipse EE, for example, so that it is tangent to the arrow (vector) of the deviation distance DE. Error ellipse EE1 is an example of the expanded error ellipse.

[0035] Furthermore, as shown in Figure 7, even if the arrow (vector) of the deviation distance DE does not fit within either the error ellipse EE-A of vehicle A or the error ellipse EE-B of vehicle B (i.e., there is an overhang), if the arrow (vector) of the deviation distance DE is smaller than the sum of the error ellipses EE-A and EE-B (closed curve EE2), the correction unit 3111 may choose not to perform any correction. In addition, the correction unit 3111 may choose to enlarge only the error ellipse with the lower reliability (either EE-A or EE-B) based on the reliability of the position information of vehicle A and vehicle B (for example, the reliability of the positioning device 312) (or it may choose not to enlarge the error ellipse with the higher reliability). The reliability can be set according to, for example, differences in accuracy due to differences in the specifications or versions of the in-vehicle unit 31, or differences in accuracy due to the installation position of the antenna AN. Furthermore, when the correction unit 3111 enlarges the error ellipse, it may enlarge either the error ellipse EE-A of vehicle A or the error ellipse EE-B of vehicle B, or it may enlarge both the error ellipses (EE-A and EE-B) of vehicle A and vehicle B. Also, when determining whether correction is necessary, the closed curve EE2 may be enlarged or reduced by an arbitrary magnification.

[0036] In the first embodiment, the on-board device 30 is a device mounted on a vehicle V. The positioning device 312 is an example of a configuration of the "location information measurement unit" according to this disclosure, and measures location information using artificial satellites. The combination of the imaging device 32 and the image processing device 33, or the image processing device 33 alone, is an example of a configuration of the "distance measurement unit" according to this disclosure, and measures the non-GNSS distance DSN, which is the distance from the own vehicle V to the other vehicle V, using electromagnetic waves from the other vehicle V. The non-GNSS distance DSN corresponds to the "first distance" according to this disclosure. In this case, the "electromagnetic waves from the other vehicle V" are light reflected by the other vehicle V, and include at least one of visible light and infrared light. The combination of the imaging device 32 and the image processing device 33, or the image processing device 33 alone, measures the non-GNSS distance DSN (first distance) based on an image captured using the imaging device 32 mounted on the own vehicle V, which includes the other vehicle V.

[0037] Furthermore, the correction unit 3111 corrects the error range of the position information based on the difference between the non-GNSS distance measurement distance DSN (first distance) and the GNSS distance measurement distance DSS (second distance), which is the distance based on the position information measured by the vehicle V and the position information measured by the other vehicle V. The GNSS distance measurement distance DSS corresponds to the "second distance" in this disclosure.

[0038] Next, referring to Figures 8 to 12, the processing flow in the on-board device 30 will be described for the case where there is one vehicle V (one of the own vehicle V) to one vehicle V (one of the other vehicle V). Figure 8 is a flowchart showing the processing flow of the on-board device 30 in each vehicle V when there is one vehicle V according to the first embodiment of this disclosure. Figures 9 to 12 are schematic diagrams showing an example of one vehicle V according to the first embodiment of this disclosure. Note that the flow in the case of one vehicle V shown in Figure 8 corresponds to both cases in which information is transmitted and received between vehicles V via vehicle-to-vehicle communication and communication via server 2. In the following, the case in which it is performed via vehicle-to-vehicle communication will be described as an example.

[0039] The process shown in Figure 8 is executed in parallel on each vehicle V. The process shown in Figure 8 will be explained using two vehicles, V-A1 and V-B1, shown in Figure 9, as an example. In the example shown in Figure 9, vehicle V-A1 is traveling in lane L2 of road RD, which has three lanes L1 to L3 on each side. Vehicle V-B1 is following behind vehicle V-A1 and traveling in lane L3. Assume that there are no other vehicles V in the vicinity (within the range where vehicle-to-vehicle communication is possible).

[0040] In the process shown in Figure 8, when the imaging device 32 (labeled as camera in the drawing) and image processing device 33 of vehicle V-B1 detect (recognize) the license plate NP of vehicle V-A1, the on-board device 30 of vehicle V-B1 moves from a standby state (step S101) through steps S102 and S103, and in step S104, the image processing device 33 performs image recognition processing. In this case, vehicle V-B1 is the distance measuring vehicle, and vehicle V-A1 is the vehicle being measured.

[0041] In step S104, the distance (non-GNSS distance DSN-BA1) and direction to the vehicle being measured (vehicle V-A1) are measured by image recognition (step S104).

[0042] Next, the distance measuring vehicle (vehicle V-B1) transmits a signal (1) to the vehicle being measured (vehicle V-A1) via vehicle-to-vehicle communication (step S105). The signal (1) includes the GNSS positioning position MSP-B1 of the distance measuring vehicle (vehicle V-B1), and data representing the non-GNSS distance measurement DSN-BA1 and direction. The signal (1) may also include data representing the GNSS positioning position MSP-B1 and data representing the error ellipse. In this example, it is assumed that it includes data representing the error ellipse (the same applies hereafter). The signal (1) may also include data representing the measurement time of the non-GNSS distance measurement DSN-BA1 (for example, the time of acquisition of the image), data representing the identification information of the on-board device 30 and the on-board unit 31, etc. Furthermore, the GNSS positioning position MSP-B1 may be the value measured at the measurement time of the non-GNSS distance measurement DSN-BA1.

[0043] Furthermore, in vehicle-to-vehicle communication from the distance-measuring vehicle (vehicle V-B1) to the distance-measured vehicle (vehicle V-A1), for example, a signal (1) can be transmitted by broadcast with a condition that limits the responding side to the distance-measured vehicle (vehicle V-A1). This condition can be, for example, that the vehicle V has a license plate NP that matches the information obtained as a result of the recognition of the license plate NP. Alternatively, if it is confirmed that there is only one other vehicle V in the vicinity that is traveling in the same direction and periodically transmits position information by broadcast, a signal (1) may be transmitted by unicast to the source of the broadcast signal.

[0044] Next, for example, the correction unit 3111 of the ranging vehicle (vehicle V-B1) waits for a certain period of time, and determines whether a signal (2) described later has been received via vehicle-to-vehicle communication during the waiting period (step S106). If the signal (2) is received during the waiting period (step S106: YES), the correction unit 3111 enlarges the error ellipse of the own vehicle V-B1 (step S107), and returns to the standby state (from step S108 to step S101). If the signal (2) is not received during the waiting period (step S106: NO), the correction unit 3111 returns to the standby state (from step S108 to step S101). The certain period of time in the determination of step S106 is a time for waiting for the signal (2) to be transmitted from the measured vehicle, and can be set based on the time considered to allow reception of the signal (2).

[0045] In contrast, when the signal (1) transmitted by the vehicle V-B1 is received by the vehicle-to-vehicle communication device 314 of the vehicle V-A1 (measured vehicle), the in-vehicle device 30 of the vehicle V-A1 proceeds from the standby state (step S101) through steps S102 and S109, and in step S110, the correction unit 3111 of the vehicle V-A1 calculates a GNSS ranging distance DSS-BA1 from the GNSS positioning position MSP-B1 of the ranging vehicle (V-B1) and the GNSS positioning position MSP-A1 of the measured vehicle (V-A1) (step S110). In step S110, for the GNSS positioning position MSP-B1 of the ranging vehicle (V-B1) and the GNSS positioning position MSP-A1 of the measured vehicle (V-A1) used to calculate the GNSS ranging distance DSS-BA1, for example, values measured at the same time (or substantially the same time) can be used. This same time can be, for example, the measurement time of the non-GNSS ranging distance DSN-BA1.

[0046] Next, the correction unit 3111 of the vehicle V-A1 determines whether there is a deviation between the non-GNSS ranging distance DSN-BA1 included in the received signal (1) and the GNSS ranging distance DSS-BA1 calculated in step S110 (step S111). A determination that there is a deviation in step S111 means that the deviation distance DE-A1 between the non-GNSS ranging distance DSN-BA1 and the GNSS ranging distance DSS-BA1 is equal to or greater than a predetermined threshold. If it is determined that there is no deviation (step S111: NO), the correction unit 3111 of the vehicle V-A1 returns to the standby state (from step S108 to step S101). For example, as shown in FIG. 9, when the error in the position information of the vehicle V-B1 and the vehicle V-A1 is relatively small (in the example of FIG. 9, the GNSS positioning position MSP-A1 and the GNSS positioning position MSP-B1 substantially match the actual positions of the respective vehicles V), the deviation distance DE-A1 between the virtual position MNP-A1, which is the end point of the arrow (vector) representing the non-GNSS ranging distance DSN-AB1 starting from the GNSS positioning position MSP-B1, and the GNSS positioning position MSP-A1 is less than the threshold for the determination in step S111 (step S111: NO).

[0047] On the other hand, for example, as shown in FIG. 10, when the error between the actual position of the vehicle V-B1 and the GNSS positioning position MSP-B2 is relatively large, it is determined that there is a deviation in step S111 (step S111: YES). In the example shown in FIG. 10, the GNSS positioning position MSP-B1 of the vehicle V-B1 shown in FIG. 9 is shifted to the GNSS positioning position MSP-B2. Note that the actual position of the vehicle V-B1 (the position in the drawing), the actual position of the vehicle V-A1, the GNSS positioning position MSP-A1 of the vehicle V-A1, and the non-GNSS ranging distance DSN-AB1 and its direction are the same in FIG. 9 and FIG. 10.

[0048] In the example shown in FIG. 10, it is assumed that the deviation distance DE-A2 between the virtual position MNP-A2, which is the end point of the arrow (vector) representing the non-GNSS ranging distance DSN-AB1 starting from the GNSS positioning position MSP-B2 of the vehicle V-B1, and the GNSS positioning position MSP-A1 is equal to or greater than the threshold for the determination in step S111.

[0049] If a discrepancy is determined in step S111 (step S111: YES), the correction unit 3111 of vehicle V-A1 determines whether the discrepancy distance DE is greater than the sum of the error ellipses of each vehicle (step S112), as explained with reference to Figure 7. If it is not greater (step S112: NO), the correction unit 3111 of vehicle V-A1 returns to the standby state (steps S108 to S101).

[0050] If the error is large (step S112: YES), the correction unit 3111 of vehicle V-A1 enlarges the error ellipse of its own vehicle V-A1 (step S113). Next, the correction unit 3111 of vehicle V-A1 transmits signal (2) to the distance measuring vehicle (vehicle V-B1) via vehicle-to-vehicle communication (step S114). Signal (2) includes data representing the sum of the deviation distance DE-A2 shown in Figure 10 and the error ellipse. Signal (2) is transmitted (replied) to the source of signal (1) (distance measuring vehicle (vehicle V-B1)) for example by unicast.

[0051] After step S114, the correction unit 3111 of vehicle V-A1 returns to the standby state (steps S108 to S101).

[0052] Meanwhile, when the vehicle-to-vehicle communication device 314 of vehicle V-B1 receives the signal (2) transmitted by vehicle V-A1 (step S106: YES), the correction unit 3111 of vehicle V-B1 enlarges the error ellipse of its own vehicle V-B1 (step S107) and returns to the standby state (steps S108 to S101).

[0053] In the process shown in Figure 8, the decision of whether or not to enlarge the error ellipse is made in two stages: a decision based on the comparison result between the threshold and the deviation distance DE in step S111, and a decision based on the comparison result between the sum of the error ellipses and the arrow (vector) of the deviation distance DE in step S112. In this case, if the result in step S111 is less than the threshold (step S111: NO), the decision in step S112 does not need to be performed. The decision in step S112 requires an operation to calculate the sum of the error ellipses, but if the result in step S111 is less than the threshold (step S111: NO), this operation can be omitted.

[0054] In the process described with reference to Figure 8, the error ellipse is corrected based on the comparison result between the error ellipse and the deviation distance. As a modified example of the process shown in Figure 8, the relative relationship of the error ellipses of each vehicle may be added to the decision of whether or not to correct the error ellipse, as follows.

[0055] For example, if a discrepancy is determined in step S111 (step S111: YES), the system can determine whether or not to perform a correction based on whether or not there is an overlap between the error ellipse of the ranging vehicle (vehicle V-B1) and the error ellipse of the vehicle being measured (vehicle V-A1). Even if there is a discrepancy between the non-GNSS ranging distance DSN and the GNSS ranging distance DSS, if the elliptic errors of the ranging vehicle and the vehicle being measured overlap, it means that although there is an error, the error ellipse is reliable. Therefore, even if there is a discrepancy, if there is an overlap with the error ellipse, the system can choose not to perform a correction. The error ellipses of the ranging vehicle and the vehicle being measured may be enlarged or reduced by any magnification.

[0056] Figure 11 shows an example where there is no overlap, and Figure 12 shows an example where there is overlap. Figures 11 and 12 are figures with an example of an error ellipse added to Figure 10. In the example shown in Figure 11, the error ellipse EE-B1 is set based on the GNSS positioning position MSP-B2 of vehicle V-B1, and the error ellipse EE-A1 is set based on the GNSS positioning position MSP-A1 of vehicle V-A1. Furthermore, the error ellipse EE-B1a is the same error ellipse as the error ellipse EE-B1 based on the virtual position MNP-A2. In the example shown in Figure 11, the error ellipse EE-A1 and the error ellipse EE-B1a do not overlap. Therefore, in the example shown in Figure 11, the error ellipse will be corrected.

[0057] On the other hand, in the example shown in Figure 12, an error ellipse EE-B2 larger than the error ellipse EE-B1 shown in Figure 11 is set based on the GNSS positioning position MSP-B2 of vehicle V-B1, and an error ellipse EE-A2 larger than the error ellipse EE-A1 shown in Figure 11 is set based on the GNSS positioning position MSP-A1 of vehicle V-A1. Furthermore, the error ellipse EE-B2a is the same error ellipse as the error ellipse EE-B2 based on the virtual position MNP-A2. In the example shown in Figure 12, the error ellipse EE-A2 and the error ellipse EE-B2a overlap in region DU1. Therefore, in the example shown in Figure 12, correction of the error ellipse is unnecessary.

[0058] Next, referring to Figures 13 to 18, the processing flow in the in-vehicle device 30 and server 2 when there are many vehicles V will be described. Figure 13 shows the processing flow in each vehicle V when vehicle-to-vehicle communication is used when there are many vehicles V. Figure 14 shows the processing flow in each vehicle V when server-to-server communication is used when there are many vehicles V. Figure 15 shows the processing flow in server 2 when server-to-server communication is used when there are many vehicles V. Figure 16 shows the data aggregation processing flow in each vehicle V and server 2 when there are many vehicles V. Figures 17 and 18 are schematic diagrams showing examples of many vehicles V. In this embodiment, when there are many vehicles V, one of two operations can be selectively used: an operation in which each vehicle V shares information without using server 2, and an operation in which each vehicle V shares information via server 2. When server 2 is not used, processing is performed according to the flows in Figures 13 and 16. When server 2 is used, processing is performed according to the flows in Figures 14, 15 and 16.

[0059] Figures 17 and 18 show an example in which, in addition to the two vehicles V-B1 and V-A1 shown in Figure 10, vehicle V-C1 traveling in lane L1 and vehicle V-D1 traveling in lane L2 are added behind vehicle V-B1. In Figures 17 and 18, the GNSS positioning position MSP-C1 of vehicle V-C1 is almost error-free from the actual position. Similarly, the GNSS positioning position MSP-D1 of vehicle V-D1 is also almost error-free from the actual position. In vehicle V-C1, a non-GNSS distance measurement distance DSN-CA1 with vehicle V-A1 as the vehicle being measured and a non-GNSS distance measurement distance DSN-CB1 with vehicle V-B1 as the vehicle being measured are measured. Vehicle V-D1 measures a non-GNSS distance DSN-DA1 with vehicle V-A1 as the vehicle being measured, and a non-GNSS distance DSN-DB1 with vehicle V-B1 as the vehicle being measured.

[0060] Furthermore, the errors in each distance and direction for the non-GNSS distances DSN-CA1, DSN-CB1, DSN-DA1, and DSN-DB1 are approximately zero. In addition, the endpoint of the arrow (vector) representing the non-GNSS distance DSN-CB1, starting from GNSS positioning position MSP-C1, and the endpoint of the arrow (vector) representing the non-GNSS distance DSN-DB1, starting from GNSS positioning position MSP-D1, coincide at virtual position MNP-B1. The distance between virtual position MNP-B1 and GNSS positioning position MSP-B2 is the deviation distance DE-B2. The endpoint of the arrow (vector) representing the non-GNSS distance DSN-CA1, starting from GNSS positioning position MSP-C1, and the endpoint of the arrow (vector) representing the non-GNSS distance DSN-DA1, starting from GNSS positioning position MSP-D1, coincide at virtual position MNP-A1. The distance between virtual position MNP-A1 and GNSS positioning position MSP-A1 is the deviation distance DE-A1.

[0061] Furthermore, in Figures 17 and 18, the distance between the GNSS positioning position MSP-B2 of vehicle V-B1 and the GNSS positioning position MSP-C1 of vehicle V-C1 is the GNSS distance DSS-CB1. The distance between the GNSS positioning position MSP-B2 of vehicle V-B1 and the GNSS positioning position MSP-D1 of vehicle V-D1 is the GNSS distance DSS-DB1.

[0062] Furthermore, Figure 18 adds error ellipse EE-B4a, which is based on the virtual position MNP-A2, and error ellipse EE-B4b, which is an enlarged version of error ellipse EE-B4a, to Figure 17.

[0063] The process shown in Figure 13 is executed in parallel on each vehicle V. The process shown in Figure 13 starts in the standby state of step S201. The determination process in step S203 is executed when the distance measurement start trigger is activated in the determination in step S202. The distance measurement start trigger is a trigger necessary to synchronize the distance measurement timing with surrounding vehicles V. Note that the trigger condition may be "being in a specific location". Alternatively, the trigger condition may be that the speed is constant. Furthermore, multiple conditions may be combined.

[0064] In the determination process of step S203, if license plate NP is found, the process branches to branch 1; if signal (1) is received, the process branches to branch 2; if signal (3) is received, the process branches to branch 3; and if the aggregation start condition is met, the process branches to branch 4. The aggregation start condition can be, for example, that a predetermined time (for example, a few seconds) has elapsed since the trigger was activated.

[0065] If the imaging device 32 and image processing device 33 of the vehicle V detect the license plate NP of another vehicle V, the vehicle V's onboard device 30 moves from a standby state (step S201) through steps S202 to S204, and in step S205, image recognition processing is performed by the image processing device 33. In this case, the vehicle V becomes the distance measuring vehicle. The vehicle V from which the license plate NP was detected becomes the distance measuring vehicle.

[0066] In step S205, the distance (non-GNSS distance DSN) and direction to the vehicle being measured (other vehicle V) are measured by image recognition (step S205).

[0067] Next, signal (1) is transmitted from the distance-measuring vehicle (own vehicle V) to the distance-to-be-measured vehicle (other vehicle V1) via vehicle-to-vehicle communication (step S206). Signal (1) is the same signal as signal (1) described with reference to Figure 8, and includes data representing the GNSS positioning position MSP of the distance-measuring vehicle (own vehicle V), the non-GNSS distance measurement distance DSN and direction, and may also include data representing the error ellipse. After step S206, the on-board device 30 returns to a standby state (steps S207 to S201).

[0068] When the vehicle-to-vehicle communication device 314 of the vehicle V receives a signal (1) transmitted by another vehicle V (distance measuring vehicle), the vehicle V, as the distance measuring vehicle, has its onboard device 30, from a standby state (step S201), go through steps S202 to S203 and 208, and in step S209, transmit a signal (3) to the surrounding vehicles V via vehicle-to-vehicle communication broadcast. The signal (3) includes the identification information and GNSS positioning position MSP of the distance measuring vehicle V, the identification information and GNSS positioning position MSP of the distance measuring vehicle V, the non-GNSS distance measurement distance DSN, and direction. After step S209, the onboard device 30 returns to a standby state (steps S207 to S201).

[0069] When the vehicle-to-vehicle communication device 314 of the vehicle V receives a signal (3) transmitted by another vehicle V (the vehicle being measured), the vehicle-on-board device 30 of the vehicle V returns to the standby state (steps S207 to S201) after going through steps S202 to S203 and 210, saving the information contained in the signal (3) in step S211 (step S211). The signal (3) is received by all vehicles V capable of receiving the signal (3), except for the vehicle V that transmitted the signal (3).

[0070] When the conditions for starting aggregation are met, the on-board device 30 of the vehicle V goes from a standby state (step S201) through steps S202 to S203, and in step S212 executes the data aggregation process shown in Figure 16 (step S212), and returns to the standby state after the execution of the data aggregation process (steps S207 to S201).

[0071] The data aggregation process shown in Figure 16 is performed by each vehicle V (for example, the correction unit 3111) in the case of vehicle-to-vehicle communication shown in Figure 13 (step S212), and by the server 2 (processing device 21) in the case of communication via a server shown in Figure 15 (step S404).

[0072] In the process shown in Figure 16, first, all previously acquired (saved) GNSS distance measurement DSS and corresponding non-GNSS distance measurement DSN are compared (step S502). Here, "previously acquired" means acquired since the previously acquired information was reset in step S509 (when each vehicle V performs the data aggregation process) or step S407 (when server 2 performs the data aggregation process). Next, it is determined whether there is a distance discrepancy between the own vehicle V (the own vehicle V when each vehicle V performs the data aggregation process) or the vehicle V in question (the one vehicle V selected when server 2 performs the data aggregation process) and other vehicles V (step S503). If there is no distance discrepancy (step S503: NO), for example, the acquired information is reset (saved information is erased) (step S509), and the process shown in Figure 16 ends. Here, step S509 is executed only in the case of vehicle-to-vehicle communication and not in the case of communication via the server. In this embodiment, the correction of the error ellipse of the vehicle V or the vehicle V is performed based on the deviation related to the vehicle V (the vehicle V). If there is no deviation related to the vehicle V or the vehicle V (hereinafter referred to as "the vehicle V"), the determination from step S504 onward can be omitted.

[0073] If there is a discrepancy in distance (Step S503: YES), it is determined whether the rate of discrepancies between the vehicle V in question and other vehicles V is above a certain level (Step S504). If it is above a certain level (Step S504: YES), it is determined whether the discrepancies are concentrated between a specific vehicle V (multiple vehicles are possible) and other vehicles V (Step S505). In Step S505, the discrepancies in distance between other vehicles V are also checked.

[0074] If the vehicles are concentrated (step S505: YES), it is determined whether the "specific vehicle" is the vehicle in question (step S506). If the "specific vehicle" is the vehicle in question (step S506: YES), it is determined whether the deviation distance is greater than the error ellipse (step S507). If the deviation distance is greater than the error ellipse (step S507: YES), the error ellipse is enlarged (in the case of vehicle-to-vehicle communication) (or correction information instructing the enlargement of the error ellipse is generated (in the case of communication via a server)) (step 508).

[0075] On the other hand, if the distance is not above a certain level (step S504: NO), if the data is not concentrated (step S505: NO), or if the deviation distance is not greater than the error ellipse (step S507: NO), for example, the acquired information is reset (step S509), and the process shown in Figure 16 is terminated. Here, step S509 is executed only in the case of vehicle-to-vehicle communication, and not in the case of communication via a server.

[0076] In the process shown in Figure 16, the discrepancy between the GNSS distance measurement DSS and the corresponding non-GNSS distance measurement DSN between multiple vehicles V is statistically confirmed. If the discrepancy is concentrated in one or more specific vehicles V, it is decided to perform error ellipse correction for those vehicles V.

[0077] The process shown in Figure 14 is executed in parallel on each vehicle V. The process shown in Figure 14 starts in the standby state of step S301. The determination process in step S303 is executed when the distance measurement start trigger is activated in the determination in step S302. The distance measurement start trigger is a trigger necessary to synchronize the distance measurement timing with surrounding vehicles V. Note that "being in a specific location" may also be a trigger condition.

[0078] In the determination process of step S303, if license plate NP is found, the process branches to branch 1; if signal (1) is received, the process branches to branch 2; if signal (4) is received, the process branches to branch 3; and if a predetermined time has elapsed without branching to branches 1 to 3, the process branches to branch 4.

[0079] If the imaging device 32 and image processing device 33 of the vehicle V detect the license plate NP of another vehicle V, the vehicle V's onboard device 30 moves from a standby state (step S301) through steps S302 to S304, and in step S305, image recognition processing is performed by the image processing device 33. In this case, the vehicle V becomes the distance measuring vehicle. The vehicle V from which the license plate NP was detected becomes the distance measuring vehicle.

[0080] In step S305, the distance (non-GNSS distance DSN) and direction to the vehicle being measured (other vehicle V) are measured by image recognition (step S305).

[0081] Next, signal (1) is transmitted from the distance-measuring vehicle (own vehicle V) to the distance-to-measure vehicle (other vehicle V1) via communication through the server (step S306). Signal (1) is the same signal as signal (1) described with reference to Figure 8, and includes data representing the GNSS positioning position MSP of the distance-measuring vehicle (own vehicle V), the non-GNSS distance DSN, and the direction. Signal (1) may also include data representing the error ellipse. After step S306, the on-board device 30 returns to the standby state (steps S307 to S301).

[0082] When the server-to-server communication device 313 of the vehicle V receives a signal (1) transmitted by another vehicle V (range-measuring vehicle) via the server 2, the vehicle V, as the vehicle being measured, has its onboard device 30 send a signal (3) to the server 2 in step S309, after going through steps S302 to S303 and 308, from a standby state (step S301). The signal (3) is the same as the signal (3) described with reference to Figure 13. After step S309, the onboard device 30 returns to the standby state (steps S307 to S301).

[0083] When the inter-server communication device 313 of the vehicle V receives the signal (4) transmitted by the server 2 (described later), the on-board device 30 of the vehicle V returns to the standby state (step S301) after going through steps S302 to S303 and 310, and in step S311, it enlarges the error ellipse according to the correction information (step S311), and returns to the standby state (steps S307 to S301).

[0084] In step S303, if, for example, a predetermined time has elapsed and the vehicle has not branched to branch 1 to 3, the vehicle's onboard device 30 returns to a standby state as branch 4 (from steps S307 to S301).

[0085] The process shown in Figure 15 is executed on server 2. The process shown in Figure 15 starts in the standby state of step S401. In the determination process of step S402, the processing unit 21 of server 2 determines whether or not the aggregation start conditions have been met (step S402). The aggregation start conditions can be, for example, that the signal (3) has been received a predetermined number of times or more, or that a predetermined amount of time has elapsed since the previous processing.

[0086] If the aggregation start condition is met (step S402: YES), the processing unit 21 selects one vehicle V from which information has been uploaded and creates a group with surrounding vehicles V (step S403). Here, the vehicle V from which information has been uploaded is the vehicle V that sent the signal (3). The surrounding vehicles V are all vehicles V included in the signal (3) received by the server 2 from the selected vehicle V. The processing unit 21 sequentially stores the contents of the signal (3) received from each vehicle V in the storage device 22.

[0087] Next, the processing unit 21 executes the data aggregation process shown in Figure 16 as described above (step S404). Next, the processing unit 21 determines whether or not it has performed the data aggregation process for all vehicles V whose information has been uploaded (step S405). If it has not been performed (step S405: NO), the processing unit 21 repeats the process from step S403 onwards. If it has been performed (step S405: YES), the processing unit 21 transmits a signal (4) based on the processing result of the data aggregation process (step S404) (step S406). The signal (4) includes identification information of the vehicle V, information indicating whether correction is necessary, information indicating the content of the correction, etc. Note that in step S406, the server 2 may transmit the signal (4) only to vehicles V that require correction.

[0088] Next, the processing unit 21 resets the acquired information (deletes the processed information from the storage device 22) (step S407). The acquired information is the information uploaded from each vehicle V. Next, the processing unit 21 returns to the standby state (step S401). In step S407, the acquired information may be saved separately if it is necessary for big data utilization.

[0089] According to the process described with reference to the flowcharts shown in Figures 13 to 16, for example, as shown in Figure 17, if the deviation distance DE-B2 related to vehicle V-B1 and vehicles V-C1 and V-D1, and the deviation distance DE-A2 related to vehicle V-B1 and vehicle V-A1 are relatively large (for example, compared to the deviation distance DE-A1), then vehicle V-B1 is the only vehicle V related to both the large deviation distances DE-B2 and DE-A2. In this case, for vehicle V-B1, for example, as shown in Figure 18, the error ellipse EE-B4a is expanded to the error ellipse EE-B4b.

[0090] As described above, in this embodiment, the in-vehicle device 30 is a device mounted on a vehicle V and includes a position information measurement unit (positioning device 312) that measures position information using artificial satellites, a distance measurement unit (a combination of an imaging device 32 and an image processing device 33, or an image processing device 33) that measures a first distance (non-GNSS distance measurement distance DSN), which is the distance from the vehicle V to the other vehicle V, using electromagnetic waves from the other vehicle V, and a correction unit 3111 that corrects the error range (error ellipse EE) of the position information based on the difference (deviation distance DE) between the first distance (non-GNSS distance measurement distance DSN) and a second distance (GNSS distance measurement distance DSS), which is the distance based on the position information measured by the vehicle V (GNSS positioning position MSP) and the position information measured by the other vehicle V (GNSS positioning position MSP). With this configuration, the error range of the position information (error ellipse EE) can be corrected based on the above difference, so that it is possible to respond appropriately when the accuracy of the position information deteriorates.

[0091] In this embodiment, the electromagnetic wave includes at least one of visible light and infrared light, and the distance measuring unit (a combination of the imaging device 32 and the image processing device 33, or the image processing device 33 alone) measures the first distance (non-GNSS distance measurement distance DSN) based on an image captured using the imaging device 32 mounted on the vehicle V, which includes another vehicle V. With this configuration, the first distance (non-GNSS distance measurement distance DSN) can be measured with a simple configuration.

[0092] Furthermore, the correction unit 3111 expands the error range (error ellipse EE) of the vehicle V if the difference (deviation distance DE) is greater than the current error range (error ellipse EE). With this configuration, the error range can be appropriately expanded.

[0093] Furthermore, the correction unit 3111 expands the error range of the own vehicle V when there is no overlap between the error range based on the position information of the own vehicle V and the error range based on the position information of other vehicles V. With this configuration, the error range can be appropriately expanded.

[0094] Furthermore, the correction unit 3111 does not expand the error range of the own vehicle V if the reliability of the position information measurement unit (positioning device 312) of the own vehicle V is higher than the reliability of the position information measurement unit (positioning device 312) of another vehicle V. With this configuration, it is possible to select a vehicle V whose error range is corrected according to the reliability of the position information measurement unit.

[0095] Furthermore, the correction unit 3111 corrects the error range of the vehicle V based on the difference (deviation distance DE) between the first distance (non-GNSS measuring distance DSN) and the second distance (GNSS measuring distance DSS) between the vehicle V and multiple other vehicles V. With this configuration, it is possible to correct the error range of a specific vehicle V among multiple vehicles V, for example, if the deviation distance DE is large.

[0096] In this embodiment, the error range can be used to prevent the road tolling system 1 from misjudging whether driving in a predetermined location is occurring or not.

[0097] Furthermore, the control method for the in-vehicle device 30 according to this embodiment uses a location information measurement unit, which measures location information using artificial satellites, and a distance measurement unit, which measures a first distance, which is the distance from the vehicle to another vehicle, using electromagnetic waves from other vehicles. Based on the difference between the first distance and a second distance, which is the distance based on the location information measured by the vehicle and the location information measured by the other vehicle, the error range of the location information is corrected. With this configuration, it is possible to respond appropriately when the accuracy of the location information deteriorates.

[0098] Furthermore, the road tolling system 1 according to this embodiment charges tolls based on location information using the above-described in-vehicle device 30. This configuration allows for appropriate responses when the accuracy of location information deteriorates.

[0099] (Second Embodiment) A second embodiment of the in-vehicle device 30 according to the present disclosure will be described with reference to Figures 19 to 27. The configuration of the in-vehicle device 30 in the second embodiment is basically the same as the configuration of the in-vehicle device 30 of the first embodiment shown in Figure 1, with some exceptions. Configurations in the second embodiment that are the same as (or correspond to) those in the first embodiment will be described with reference to Figure 1. In the second embodiment, unlike the first embodiment, the non-GNSS distance measurement distance DSN, which is the first distance between the vehicle V and the other vehicle V, is measured based on the signal strength of the wireless signal transmitted by the other vehicle V, which is received using the vehicle-to-vehicle communication device 314 mounted on the vehicle V. Therefore, in the second embodiment, some of the processing of the correction unit 3111 and some of the operation of the vehicle-to-vehicle communication device 314 are different. The vehicle-to-vehicle communication device 314 is one example of the configuration of the "receiving device" according to the present disclosure.

[0100] Figure 19 is a flowchart showing the processing flow in the on-board device 30 of each vehicle V according to the second embodiment. Figure 20 is a schematic diagram showing an example of one-to-one vehicles V according to the second embodiment.

[0101] The process shown in Figure 19 is executed in parallel on each vehicle V. In the process shown in Figure 19, first, for example, the correction unit 3111 defines the transmission time of the next broadcast from the vehicle V (step S601). In the process shown in Figure 19, the vehicle-to-vehicle communication broadcast transmits the location information of the vehicle V (information representing the GNSS positioning position MSP) to other surrounding vehicles V. Next, the correction unit 3111 performs the determination process in step S602 (step S602). In step S602, if a broadcast from another vehicle V is received, it branches to branch 1, and if it is the transmission time, it branches to branch 2.

[0102] If the determination in step S602 determines that a broadcast from another vehicle V has been received (step S602: branch 1), the vehicle V is treated as a receiving vehicle, and the correction unit 3111 receives the broadcast signal with the vehicle-to-vehicle communication device 314 (step S603). The vehicle-to-vehicle communication device 314 also measures the signal strength of the broadcast signal (step S604). Next, the correction unit 3111 estimates the area where the vehicle V (receiving vehicle) is located as seen from the transmitting vehicle (hereinafter referred to as the estimated vehicle location area or estimated location area) from the GNSS positioning position MSP of the transmitting vehicle V, the signal strength of the received radio signal, and the GNSS positioning position MSP of the vehicle V (step S605).

[0103] Figure 20 shows an example of the estimated vehicle presence area EEA. In the example shown in Figure 20, vehicle V-A is the receiving vehicle, and vehicle V-E is the broadcast signal transmitting vehicle. The radio waves transmitted by vehicle V-E are received by vehicle V-A and the signal strength is measured. In Figure 20, the GNSS distance DSS-AE between vehicle V-A and vehicle V-E is the distance between the GNSS positioning position MSP-A1 of vehicle V-A and the GNSS positioning position MSP-E1 of vehicle V-E. Each vehicle V is equipped with, for example, a model (calculation formula) or table that shows the relationship between signal strength and distance, and when it receives a broadcast signal transmitted by another vehicle V, it estimates the distance between its own vehicle and the other vehicle V (for example, the probability distribution of distance) based on the signal strength of the received broadcast signal.

[0104] Vehicle V-A calculates that the estimated vehicle presence area EEA-AE, which is the shaded donut-shaped (ring-shaped) area, is the region where it is estimated that other vehicle V will receive the broadcast signal transmitted by vehicle V-E at the same signal strength as measured by vehicle V-A, when vehicle V-E is located at GNSS positioning position MSP-E1. In this case, the estimated vehicle presence area EEA-AE is the "estimated presence area of ​​vehicle V-A as seen from vehicle V-E" calculated by vehicle V-A. Vehicle V located within the estimated vehicle presence area EEA-AE is estimated to receive the broadcast signal at the same signal strength as vehicle V-A. Furthermore, the distance from vehicle V-E's GNSS positioning position MSP-E1 to the estimated vehicle presence area EEA-AE becomes the non-GNSS distance DSN-EA between vehicle V-A and vehicle V-E. Unlike the non-GNSS distance measurement DSN of the first embodiment, the non-GNSS distance measurement DSN of the second embodiment does not include information indicating direction (angle).

[0105] Returning to Figure 19, after step S605, the correction unit 3111 saves the comparison result between the estimated vehicle presence area (estimated vehicle presence area EEA) and the GNSS distance measurement DSS to the storage device 315 (step S606), and returns to step S602. The comparison result can be, for example, a value indicating whether the discrepancy distance DE between the non-GNSS distance measurement DSN based on the estimated vehicle presence area EEA and the GNSS distance measurement DSS is greater than or equal to a predetermined value (in this embodiment, "discrepancy" is used when it is greater than or equal to a predetermined value, and "match" is used when it is less than a predetermined value).

[0106] Figure 21 shows a comparative example of the estimated vehicle presence area EEA and the GNSS distance DSS. In the example shown in Figure 21, the vehicle transmitting the broadcast signal is vehicle V-A, and the vehicle receiving the signal is vehicle V-E. In the example shown in Figure 21, the "estimated presence area of ​​vehicle V-E as seen from vehicle V-A" calculated by vehicle V-E is the estimated vehicle presence area EEA-EA. The GNSS positioning positions MSP of vehicles V-A to E are assumed to be GNSS positioning positions MSP-A1, B1, C1, D1, and E1. In the example shown in Figure 21, the non-GNSS distance DSN-EA between vehicle V-A and vehicle V-E is defined as the distance from vehicle V-A's GNSS positioning position MSP-A1 to the center of the estimated vehicle presence area EEA-EA, and is indicated by a white arrow aligned with the direction of the line connecting GNSS positioning position MSP-A1 to vehicle V-E's GNSS positioning position MSP-E1. The GNSS distance DSS-EA between vehicle V-A and vehicle V-E is the distance between vehicle V-A's GNSS positioning position MSP-A1 and vehicle V-E's GNSS positioning position MSP-E1. In this case, the discrepancy DE-EA between the non-GNSS distance DSN-EA and the GNSS distance DSS-EA is as shown in Figure 21. The correction unit 3111, when it is likely that the GNSS distance measurement distance DSS-EA ≠ non-GNSS distance measurement distance DSN-EA, determines that there is a possibility that the GNSS positioning position MSP of either vehicle V-A or vehicle V-E is incorrect, based on the logic of judgment that there is a possibility that the deviation distance DE-EA is greater than or equal to a predetermined threshold (predetermined value), and saves the comparison result as shown in Figure 22.

[0107] Figure 23 shows another comparative example of the estimated vehicle presence area EEA and GNSS distance DSS. In the example shown in Figure 23, the vehicle transmitting the broadcast signal is vehicle V-D, and the vehicle receiving the signal is vehicle V-E. In the example shown in Figure 23, the "estimated presence area of ​​vehicle V-E as seen from vehicle V-D" calculated by vehicle V-E is the estimated vehicle presence area EEA-ED. Note that the arrangement of vehicles V-A to V-E and the GNSS positioning position MSP of each vehicle V in Figure 23 are the same as in the example in Figure 21.

[0108] Furthermore, the GNSS distance DSS-ED between vehicle V-D and vehicle V-E is the distance between the GNSS positioning position MSP-D1 of vehicle V-D and the GNSS positioning position MSP-E1 of vehicle V-E. In this case, the discrepancy DE-ED between the non-GNSS distance DSN-ED and the GNSS distance DSS-ED is approximately zero. The correction unit 3111 determines that no discrepancy has occurred between vehicle V-E and vehicle V-D and saves the comparison results as shown in Figure 24.

[0109] In the examples shown in Figures 21 and 23, the correction unit 3111 saves the comparison results for vehicle V-E, for example, as shown in Figure 25, in step S606.

[0110] On the other hand, if the determination in step S602 of Figure 19 determines that it is time to send the signal (step S602: branch 2), the vehicle V is treated as the sending vehicle, and the correction unit 3111 sends a broadcast signal from the vehicle-to-vehicle communication device 314 that includes data representing the GNSS positioning position MSP of the vehicle V (step S607).

[0111] Next, the correction unit 3111 determines whether the number of comparison results for the vehicle V saved in step S606 is greater than or equal to a predetermined number (step S608). If the number of comparison results is less than the predetermined number (step S608: NO), the correction unit 3111 returns to step S601 and defines the transmission time of the next broadcast from the vehicle V (step S601). If the number of comparison results is greater than or equal to the predetermined number (step S608: YES), the correction unit 3111 determines whether a certain percentage of the comparison results match (step S609). If a certain percentage does not match (step S609: NO), the correction unit 3111 expands the error range of the vehicle V (step S611), erases the saved comparison results (step S610), returns to step S601, and defines the transmission time of the next broadcast from the vehicle V (step S601). If a certain percentage matches (step S609: YES), the correction unit 3111 erases the saved comparison results (step S610), returns to step S601, and defines the transmission time of the next broadcast from the vehicle V (step S601). In the process shown in Figure 19, the correction unit 3111 can, for example, correct the error range of the vehicle V if the percentage of other vehicles V whose deviation distance DE is greater than or equal to a predetermined value is greater than or equal to a certain value.

[0112] In the process shown in Figure 19, the comparison result between the non-GNSS distance measurement distance DSN and the GNSS distance measurement distance DSS, based on the deviation distance DE, is expressed as a binary value indicating agreement or deviation. However, the comparison result may also be expressed using a deviation degree represented by a continuous value or a number of discrete values. Furthermore, if there are differences in the performance of the in-vehicle devices 31, for example, the comparison result may be expressed as a weighted value according to the performance.

[0113] In this embodiment, the actual position of vehicle V can sometimes be estimated depending on the overlapping state of multiple estimated vehicle location regions EEA. In the example shown in Figure 26, when vehicles V-A to V-D are the transmitting vehicles, there is no position where all of the estimated vehicle location regions EEA-EA to ED of vehicle V-E, as viewed from vehicles V-A to V-D, as calculated by vehicle V-E, overlap. On the other hand, in the example shown in Figure 27, there is a position where all of the estimated vehicle location regions EEA-EA to ED overlap (the region near the actual position of vehicle V-E). The on-board device 30 may, for example, notify the magnitude of the deviation and the direction of the deviation from the output device 316 when multiple estimated vehicle location regions EEA overlap and there is a large deviation from the GNSS positioning position MSP. The user can then appropriately consider countermeasures according to the notification content.

[0114] As described above, in this embodiment, the in-vehicle device 30 is a device mounted on a vehicle V and includes a position information measurement unit (positioning device 312) that measures position information using artificial satellites, a distance measurement unit (vehicle-to-vehicle communication device 314, or a combination of vehicle-to-vehicle communication device 314 and correction unit 3111, etc.) that measures a first distance (non-GNSS distance measurement distance DSN), which is the distance from the vehicle V to the other vehicle V, using electromagnetic waves from the other vehicle V, and a correction unit 3111 that corrects the error range (error ellipse EE) of the position information based on the difference (deviation distance DE) between the first distance (non-GNSS distance measurement distance DSN) and a second distance (GNSS distance measurement distance DSS), which is the distance based on the position information measured by the vehicle V (GNSS position measurement position MSP) and the position information measured by the other vehicle V (GNSS position measurement position MSP). With this configuration, the error range of the position information (error ellipse EE) can be corrected based on the above difference, so that it is possible to respond appropriately when the accuracy of the position information deteriorates.

[0115] In this embodiment, electromagnetic waves include radio waves, and the distance measuring unit (vehicle-to-vehicle communication device 314, or a combination of vehicle-to-vehicle communication device 314 and correction unit 3111, etc.) measures the first distance (non-GNSS distance measurement distance DSN) based on the signal strength of the radio signal transmitted by another vehicle V, which is received using a receiving device (vehicle-to-vehicle communication device 314) mounted on the vehicle V. With this configuration, the first distance (non-GNSS distance measurement distance DSN) can be measured with a simple configuration.

[0116] Furthermore, in this embodiment, the correction unit 3111 corrects the error range of its own vehicle V when, for example, the proportion of other vehicles V whose difference (deviation distance DE) is greater than or equal to a predetermined value is greater than or equal to a certain value. In this case, it is possible to appropriately determine whether or not to perform the correction based on statistical information.

[0117] Furthermore, the configuration of the first embodiment and the configuration of the second embodiment can be used in combination.

[0118] (Third Embodiment) A third embodiment of the present disclosure will be described with reference to Figures 28 and 29. Figure 28 is a schematic diagram showing the processing flow according to the third embodiment of the present disclosure. Figure 29 is a schematic diagram showing an example of data and processing according to the third embodiment of the present disclosure. In the third embodiment, the processing unit 21 of the server 2 stores predetermined data collected from a plurality of in-vehicle devices 31 in a storage device 22, and the processing unit 21 generates information regarding the constant correction of the error range and information prompting the repair of the positioning device 312 based on the stored data, and provides these to the in-vehicle devices 31, etc., and the server 2 or the road tolling system 1 implements such a function.

[0119] As shown in Figure 28, in this embodiment, in step S701, when the in-vehicle device 30 attempts to correct the error ellipse for the server 2 to perform constant correction using big data of the error, the in-vehicle device 30 records that information and periodically transmits the recorded information to the server 2 (however, in the case of correction via the server 2, it is not necessary for the in-vehicle device 30 to transmit information to the server 2). The information can be transmitted, for example, on a daily to weekly basis.

[0120] Next, in step S702, server 2 searches for commonalities in the accumulated information, for example, from the perspective of "who, when, where, and what happens."

[0121] Next, in step S703, if there are any commonalities, the server 2 performs a process to prompt the target to perform permanent corrections or repairs.

[0122] Furthermore, as shown in Figure 29, the information IN1 sent from the in-vehicle device 30 to the server 2 in step S701 of Figure 28 can be, for example, only information about the own vehicle, or information about all received vehicles (including the own vehicle). In addition, information IN1 can represent information such as speed, time, time since startup, determined deviation information, whether or not a correction was made and the correction details, vehicle No. (license plate NP information), vehicle type, OBU type, GNSS positioning position, error ellipse, and non-GNSS distance.

[0123] Furthermore, regarding the commonalities IN2 in step S702, examples of "who" include a specific car, a specific type of OBU, a specific type of car, all cars, etc. Examples of "when" include during low-speed movement, immediately after startup, etc. Examples of "where" include a specific location, at the exit of a tunnel, in a city with many buildings, etc. Examples of "what happens" include frequently receiving corrections (no commonalities or unknown errors), frequently receiving corrections (errors biased in a specific direction), etc.

[0124] Furthermore, regarding correction example IN3 in step S703, as example 1), when a specific vehicle is involved, when there is no commonality, where there is no commonality, and what happens is that the vehicle frequently receives corrections (no commonality), the vehicle in question is prompted to undergo repairs. As example 2), when a specific type of OBU is involved, when there is no commonality, where there is no commonality, and what happens is that the vehicle frequently receives corrections (no commonality), correction information is sent to the OBU and the vehicle on which it is installed to permanently enlarge the error ellipse at the tunnel exit. As example 3), when a specific type of vehicle is involved, when there is no commonality, where there is a specific location, and what happens is that the vehicle frequently receives corrections (the error is biased in a specific direction), correction information is sent to the vehicle in question to permanently correct the latitude and longitude at that location.

[0125] As described above, in this embodiment, for example, the correction unit 3111 can correct the error range at a location determined based on the correction history of its own vehicle V and multiple other vehicles V, based on the location information, as determined based on the history.

[0126] Furthermore, the in-vehicle device 30 can notify, for example, that countermeasures are necessary if the frequency of correction by the correction unit 3111 exceeds a predetermined value, via the output device 316. Note that the output device 316 is one example of the configuration of the "output unit" according to this disclosure.

[0127] (Function and Effects) According to the in-vehicle device 30, the control method for the in-vehicle device, and the road tolling system 1 of each embodiment, it is possible to respond appropriately when the accuracy of location information deteriorates.

[0128] (Other Embodiments) Although embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of the present disclosure.

[0129] (Computer Configuration) Figure 30 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. The computer 90 includes a processor 91, main memory 92, storage 93, and interface 94. The above-mentioned in-vehicle device 30, in-vehicle unit 31, imaging device 32, image processing device 33, processing device 21, etc., are implemented in the computer 90. The operation of each of the above-mentioned processing units is stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93 and loads it into the main memory 92, and executes the above-mentioned processing according to the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to each of the above-mentioned storage units according to the program.

[0130] The program may be for implementing a part of the functions to be performed by the computer 90. For example, the program may perform functions in combination with other programs already stored in storage, or in combination with other programs implemented in other devices. In other embodiments, the computer may be equipped with a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), etc. In this case, some or all of the functions implemented by the processor may be implemented by the integrated circuit.

[0131] Examples of storage 93 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or a communication line. Furthermore, if this program is distributed to the computer 90 via a communication line, the computer 90 that receives the distribution may expand the program into the main memory 92 and execute the above processing. In at least one embodiment, storage 93 is a tangible storage medium that is not temporary.

[0132] <Note> The in-vehicle device 30 described in each embodiment can be understood, for example, as follows.

[0133] (1) The in-vehicle device 30 according to the first embodiment is a device mounted on a vehicle and includes: a position information measurement unit that measures position information using an artificial satellite; a distance measurement unit that measures a first distance, which is the distance from the vehicle to the other vehicle, using electromagnetic waves from the other vehicle; and a correction unit that corrects the error range of the position information based on the difference between the first distance and a second distance, which is the distance based on the position information measured by the vehicle and the position information measured by the other vehicle. According to this embodiment and the following embodiments, it is possible to respond appropriately when the accuracy of the position information deteriorates.

[0134] (2) The in-vehicle device 30 according to the second embodiment is the in-vehicle device 30 of (1), wherein the electromagnetic wave includes at least one of visible light and infrared light, and the distance measuring unit measures the first distance based on an image captured using an imaging device mounted on the vehicle, which includes the other vehicle.

[0135] (3) The in-vehicle device 30 according to the third embodiment is the in-vehicle device 30 of (1) or (2), wherein the electromagnetic wave includes radio waves, and the distance measuring unit measures the first distance based on the signal strength of a radio signal transmitted by the other vehicle, which is received using a receiving device mounted on the vehicle.

[0136] (4) The in-vehicle device 30 according to the fourth embodiment is the in-vehicle device 30 of (1) to (3), wherein the correction unit expands the error range of the vehicle when the difference is greater than the current error range.

[0137] (5) The in-vehicle device 30 according to the fifth embodiment is the in-vehicle device 30 of (1) to (4), wherein the correction unit expands the error range of the own vehicle when there is no overlap between the error range based on the position information of the own vehicle and the error range based on the position information of the other vehicle.

[0138] (6) The in-vehicle device 30 according to the sixth embodiment is the in-vehicle device 30 of (1) to (5), wherein the correction unit does not expand the error range of the own vehicle when the reliability of the position information measurement unit of the own vehicle is higher than the reliability of the position information measurement unit of the other vehicle.

[0139] (7) The in-vehicle device 30 according to the seventh embodiment is the in-vehicle device 30 of (1) to (6), wherein the correction unit corrects the error range of the own vehicle based on the difference between the first distance and the second distance between the own vehicle and the plurality of other vehicles.

[0140] (8) The in-vehicle device 30 according to the eighth embodiment is the in-vehicle device 30 of (1) to (7), wherein the correction unit corrects the error range of the own vehicle when the proportion of other vehicles whose difference is equal to or greater than a predetermined value is equal to or greater than a certain value.

[0141] (9) The in-vehicle device 30 according to the ninth embodiment is the in-vehicle device 30 of (1) to (8), and includes an output unit that notifies that countermeasures are necessary when the frequency of correction by the correction unit is equal to or greater than a predetermined value.

[0142] (10) The vehicle-mounted device 30 according to the tenth embodiment is the vehicle-mounted device 30 of (1) to (9), wherein the error range is used in the road tolling system to prevent misjudging between driving in a predetermined location and driving in a location other than the predetermined location.

[0143] (11) The in-vehicle device 30 according to the eleventh embodiment is the in-vehicle device 30 of (1) to (10), wherein the correction unit corrects the error range at a location determined based on the correction history of the own vehicle and a plurality of other vehicles, based on the position information, as determined based on the history.

[0144] According to each aspect of the present invention, it is possible to appropriately respond when the accuracy of location information deteriorates.

[0145] 1...Road toll system 2...Server 4...Communication network 21...Processing device 22...Storage device 23...Communication device 30...In-vehicle device 31...In-vehicle unit 311...Control device 3111...Correction unit 312...Positioning device 313...Inter-server communication device 314...Vehicle-to-vehicle communication device 315...Storage device 316...Output device 32...Imaging device 33...Image processing device V...Vehicle MSP...GNSS positioning position DSS...GNSS distance DSN...Non-GNSS distance DE...Distance difference EE...Error ellipse

Claims

1. An in-vehicle device comprising: a location information measurement unit that measures location information using an artificial satellite; a distance measurement unit that measures a first distance, which is the distance from the vehicle to the other vehicle, using electromagnetic waves from the other vehicle; and a correction unit that corrects the error range of the location information based on the difference between the first distance and a second distance, which is the distance based on the location information measured by the vehicle and the location information measured by the other vehicle.

2. The in-vehicle device according to claim 1, wherein the electromagnetic wave includes at least one of visible light and infrared light, and the distance measuring unit measures the first distance based on an image captured using an imaging device mounted on the vehicle, which includes the other vehicle.

3. The in-vehicle device according to claim 1, wherein the electromagnetic wave includes radio waves, and the distance measuring unit measures the first distance based on the signal strength of a wireless signal transmitted by another vehicle, which is received using a receiving device mounted on the vehicle itself.

4. The in-vehicle device according to claim 1, wherein the correction unit expands the error range of the vehicle when the difference is greater than the current error range.

5. The in-vehicle device according to claim 1, wherein the correction unit expands the error range of the vehicle when there is no overlap between the error range based on the position information of the vehicle itself and the error range based on the position information of the other vehicle.

6. The in-vehicle device according to claim 1, wherein the correction unit does not expand the error range of the vehicle if the reliability of the position information measurement unit of the vehicle is higher than the reliability of the position information measurement unit of the other vehicle.

7. The in-vehicle device according to claim 1, wherein the correction unit corrects the error range of the vehicle based on the difference between the first distance and the second distance between the vehicle and a plurality of other vehicles.

8. The in-vehicle device according to claim 7, wherein the correction unit corrects the error range of the own vehicle when the proportion of other vehicles whose difference is greater than or equal to a predetermined value is greater than or equal to a certain value.

9. The in-vehicle device according to claim 1, further comprising an output unit that notifies that countermeasures are necessary when the frequency of correction by the correction unit exceeds a predetermined value.

10. The in-vehicle device according to claim 1, wherein the error range is used in a road tolling system to prevent misjudging between driving in a predetermined location and driving outside of the predetermined location.

11. The in-vehicle device according to any one of claims 1 to 7, 9, and 10, wherein the correction unit corrects the error range at a location determined based on the history of the correction by the vehicle itself and a plurality of other vehicles, based on the position information, as determined based on the history.

12. A control method for an in-vehicle device that uses a position information measurement unit, which measures position information using artificial satellites, and a distance measurement unit, which measures a first distance, which is the distance from the vehicle to the other vehicle, using electromagnetic waves from the other vehicle, to correct the error range of the position information based on the difference between the first distance and a second distance, which is the distance based on the position information measured by the vehicle and the position information measured by the other vehicle.

13. A road tolling system that charges tolls based on location information using the in-vehicle device described in claim 10.

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