JP7325017B2 - Vehicle-mounted device, roadside device, and information transmission method - Google Patents

Description

The present disclosure relates to a vehicle-mounted device, a roadside device, and an information transmission method.

In recent years, intelligent transport systems (ITS) have been developed to solve road traffic problems such as traffic accidents and traffic jams by transmitting and receiving information between roadside devices installed on roads and on-board devices installed in vehicles. Transport Systems) are being put into practical use. As a representative example of ITS, there is an electronic toll collection system (ETC) that allows a user to pass through a toll road without stopping at a toll gate.

The Ministry of Land, Infrastructure, Transport and Tourism is promoting the introduction of a service called "ETC2.0". In ETC 2.0, two-way communication based on DSRC (Dedicated Short Range Communication) is performed between a roadside device, which is an ITS spot, and a vehicle-mounted device mounted on a vehicle (see Patent Document 1, for example).

JP-A-2008-90568

Depending on the moving speed of the vehicle-mounted device, communication between the vehicle-mounted device and the roadside device may become tight. The vehicle-mounted device accumulates satellite reception information acquired inside and outside the communication area as information necessary for calculating the travel route of the vehicle, and transmits the information while it is in the communication area of the roadside device. Here, the information amount per unit time of the satellite reception information output from the GNSS receiver of the vehicle is constant regardless of the speed of the vehicle. For this reason, for example, when the moving speed of the vehicle-mounted device is slow, such as when a traffic jam occurs, the amount of satellite reception information transmitted from the vehicle-mounted device to the roadside device becomes large, and communication between the vehicle-mounted device and the roadside device becomes tight. Sometimes.

A non-limiting embodiment of the present disclosure contributes to the provision of a vehicle-mounted device, a roadside device, and an information transmission method that suppress communication pressure.

A vehicle-mounted device according to an aspect of the present disclosure, from a receiver that receives a positioning signal from a satellite during a period from the end of communication with a first roadside device to the start of communication with a second roadside device a transmitter for transmitting the output satellite reception information to the second roadside device ; and a processor for controlling a transmission amount of the satellite reception information.

A roadside device according to an aspect of the present disclosure includes: a transmitter that transmits satellite correction information for correcting a positioning signal received by the vehicle-mounted device from a satellite to the vehicle-mounted device; According to the running speed of the vehicle equipped with the on- board device after the communication is completed and before the communication with the roadside device is started, the transmission amount of the satellite correction information to be sent to the on-board device a controlling processor;

An information transmission method according to an aspect of the present disclosure is an information transmission method for a vehicle-mounted device, and during a period from the end of communication with a first roadside device to the start of communication with a second roadside device, Satellite reception information output from a receiver that receives positioning signals from satellites is transmitted to the second roadside unit, and according to the running speed of the vehicle equipped with the vehicle -mounted unit in the interval, Controlling the transmission amount of the satellite reception information transmitted to the second roadside unit.

An information transmission method according to an aspect of the present disclosure is an information transmission method for a roadside device, in which satellite correction information for correcting a positioning signal received by a vehicle-mounted device from a satellite is transmitted to the vehicle-mounted device; transmission to the vehicle-mounted device according to the traveling speed of the vehicle on which the vehicle-mounted device is mounted during the period from when the device completes communication with another roadside device to when it starts communication with the roadside device. Controlling the transmission amount of the satellite correction information.

In addition, these generic or specific aspects may be realized by systems, devices, methods, integrated circuits, computer programs, or recording media. may be realized by any combination of

According to an embodiment of the present disclosure, tight communication can be suppressed.

Further advantages and advantages of an embodiment of the disclosure are apparent from the specification and drawings. Such advantages and/or advantages are provided by the several embodiments and features described in the specification and drawings, respectively, not necessarily all provided to obtain one or more of the same features. no.

The figure which showed the structural example of the positioning system which concerns on 1st Embodiment. Diagram for explaining an example of communication of GNSS received data Diagram showing a block configuration example of a GNSS receiver Diagram showing an example of the block configuration of the on-board device Diagram showing a block configuration example of a roadside unit Diagram showing an example of server block configuration Diagram for explaining the outline of DSRC communication Diagram explaining ACTS FIG. 4 is a diagram for explaining an example of DSRC communication; Diagram explaining an operation example of the positioning system Diagram explaining an operation example of the positioning system Sequence diagram showing an operation example of the positioning system Diagram explaining an example of the effect of the positioning system The figure which showed the structural example of the positioning system which concerns on 2nd Embodiment. Diagram for explaining an example of the sampling rate of satellite reception information Diagram for explaining an example of the sampling rate of satellite reception information Diagram for explaining an example of the sampling rate of satellite reception information Diagram for explaining an example of decimation of satellite reception information Diagram for explaining an example of decimation of satellite reception information A diagram for explaining an example of changing the sampling rate of the received satellite information and thinning out the received satellite information. Flowchart showing an operation example of the on-board device Flowchart showing an operation example of the on-board device The figure which showed the structural example of the positioning system which concerns on 3rd Embodiment Sequence diagram explaining an operation example of the positioning system The figure which showed the structural example of the positioning system which concerns on 4th Embodiment. Sequence diagram explaining an operation example of the positioning system Sequence diagram explaining an operation example of the positioning system

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for a thorough understanding of the present disclosure by those skilled in the art and are not intended to limit the claimed subject matter.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of a positioning system 1 according to the first embodiment. As shown in FIG. 1 , the positioning system 1 has a GNSS (Global Navigation Satellite System) receiver 2 , a vehicle-mounted device 3 , a roadside device 4 , and a server 5 . The GNSS receiver 2 and the vehicle-mounted device 3 are mounted on the vehicle A1. The GNSS receiver 2 may be included in the vehicle-mounted device 3 . The positioning system 1 shown in FIG. 1, for example, calculates the travel route of the vehicle A1 and calculates the road toll based on the calculated travel route.

The GNSS receiver 2 receives positioning signals from GNSS satellites (not shown). GNSS is a general term for satellite navigation systems such as GPS (Global Positioning System), GLONASS, and Galileo, which have performance (accuracy and reliability) that can be used for civil aviation navigation. Positioning signals include L1 signals (1575.42 MHz) and L2 signals (1227.60 MHz) transmitted from GPS satellites.

The GNSS receiver 2 demodulates positioning signals received from GNSS satellites. The GNSS receiver 2 outputs the demodulated positioning signal to the vehicle-mounted device 3 .

The positioning signal demodulated by the GNSS receiver 2 is a data string (carrier data) carried on a carrier, and may be called GNSS reception data, RAW data, or positioning reception data. The positioning data is obtained by analyzing GNSS reception data. Positioning data includes pseudorange information, carrier phase information, Doppler frequency information, and the like.

The vehicle-mounted device 3 and the roadside device 4 perform two-way communication based on DSRC. The roadside device 4 forms, for example, a communication area A2 of several tens of meters. The roadside device 4 wirelessly communicates with the vehicle-mounted device 3 located within the communication area A2.

The vehicle-mounted device 3 transmits the GNSS reception data output from the GNSS receiver 2 to the roadside device 4 . The roadside device 4 receives the GNSS reception data transmitted from the vehicle-mounted device 3 . The roadside device 4 transmits the received GNSS reception data to the server 5 via a network (not shown) such as a LAN (Local Area Network) or the Internet.

The server 5 receives the GNSS reception data transmitted from the roadside device 4 . The server 5 calculates the travel route of the vehicle A1 from the received GNSS reception data. For example, the server 5 calculates the travel route of the vehicle A1 from the received GNSS reception data using the RTK (Real Time Kinematic) method. The server 5 calculates, for example, a road toll based on the travel route of the vehicle A1 from the calculated travel route.

Although only one vehicle is shown in FIG. 1, a plurality of vehicles may be present. In this case, the roadside device 4 communicates with vehicle-mounted devices mounted on a plurality of vehicles based on DSRC. The server 5 calculates travel routes for a plurality of vehicles.

FIG. 2 is a diagram illustrating a communication example of GNSS reception data. FIG. 2 shows the roadside unit 4, the server 5, and the vehicle A1 shown in FIG. The roadside machine 4 is, for example, spotted on the roadside. In FIG. 2, illustration of the GNSS receiver 2 and the vehicle-mounted equipment 3 which are mounted in vehicle A1 is abbreviate|omitted. In FIG. 2, vehicle A1 travels from left to right in FIG. 2, as indicated by arrow A3.

The GNSS receiver 2 mounted on the vehicle A1 receives and demodulates positioning signals sent from GNSS satellites, and periodically outputs GNSS reception data to the onboard device 3 . For example, the GNSS receiver 2 outputs the GNSS reception data to the vehicle-mounted device 3 at intervals of several Hz.

The vehicle-mounted device 3 cannot transmit the GNSS reception data output from the GNSS receiver 2 to the roadside device 4 outside the communication area A2 of the roadside device 4 . Therefore, the vehicle-mounted device 3 stores the GNSS reception data output from the GNSS receiver 2 in the storage unit outside the communication area A2 of the roadside device 4 . When the vehicle-mounted device 3 enters the communication area A<b>2 of the roadside device 4 , the vehicle-mounted device 3 transmits the GNSS reception data stored in the storage unit to the roadside device 4 . Moreover, the vehicle-mounted device 3 transmits the GNSS reception data periodically output from the GNSS receiver 2 to the roadside device 4 also within the communication area A2 of the roadside device 4 .

For example, the GNSS receiver 2 outputs the GNSS reception data to the vehicle-mounted device 3 with a period of several Hz in the section 1 shown in FIG. Since the vehicle-mounted device 3 cannot transmit the GNSS reception data to the roadside device 4 outside the communication area A2 of the roadside device 4 shown in the section 1a of FIG. When the vehicle-mounted device 3 enters the communication area A2 formed in the section 1 of FIG. Moreover, the vehicle-mounted device 3 transmits the GNSS reception data periodically output from the GNSS receiver 2 to the roadside device 4 also within the communication area A2 formed in the section 1 . That is, the vehicle-mounted device 3 transmits the GNSS reception data in the section 1 including the section 1 a to the roadside device 4 forming the communication area A2 in the section 1 .

The vehicle-mounted device 3 also transmits the GNSS reception data to the roadside device 4 in the sections 2 and 3 shown in FIG. 2 as in the section 1 . Thereby, the server 5 can calculate the route traveled by the vehicle A1 inside and outside the communication area A2 of the roadside device 4 .

FIG. 3 is a diagram showing a block configuration example of the GNSS receiver 2. As shown in FIG. As shown in FIG. 3 , the GNSS receiver 2 has a processor 11 , a storage section 12 , a communication section 13 , a receiver section 14 and a bus 15 .

Processor 11 controls other elements of GNSS receiver 2 via bus 15 . As the processor 11, for example, a general-purpose CPU (Central Processing Unit) is used. Also, the processor 11 generates GNSS reception data by executing a predetermined program.

The storage unit 12 acquires various information from other elements and holds the information temporarily or permanently. The storage unit 12 is a general term for so-called primary storage and secondary storage. A plurality of storage units 12 may be physically arranged. As the storage unit 12, for example, a DRAM (Direct Random Access Memory), HDD (Hard Disk Drive), SSD (Solid State Drive) is used.

The communication unit 13 communicates with an external device via a communication channel. The vehicle-mounted device 3 is included in the target device (communication target) with which the communication unit 13 communicates.

The receiver 14 receives positioning signals from satellites and outputs the positioning signals to the processor 11 via the bus 15 .

FIG. 4 is a diagram showing a block configuration example of the vehicle-mounted device 3. As shown in FIG. As shown in FIG. 4 , the vehicle-mounted device 3 has a processor 21 , a storage unit 22 , a communication unit 23 , a DSRC communication unit 24 and a bus 25 .

Processor 21 controls other elements of vehicle-mounted device 3 via bus 25 . For example, a general-purpose CPU is used as the processor 21 .

The storage unit 22 acquires various information from other elements and holds the information temporarily or permanently. Information stored in the storage unit 22 includes GNSS reception data output from the GNSS receiver 2 . The storage unit 22 is a general term for so-called primary storage and secondary storage. A plurality of storage units 22 may be physically arranged. For example, a DRAM, HDD, or SSD is used as the storage unit 22 .

The communication unit 23 communicates with an external device via a communication channel. The GNSS receiver 2 is included in the target (communication target) device with which the communication unit 23 communicates.

The DSRC communication unit 24 performs two-way communication with the roadside device 4 based on DSRC. For example, the DSRC communication unit 24 transmits the GNSS reception data received by the communication unit 23 from the GNSS receiver 2 to the roadside device 4 based on DSRC. Also, the DSRC communication unit 24 transmits the GNSS reception data stored in the storage unit 22 to the roadside device 4 based on the DSRC.

FIG. 5 is a diagram showing a block configuration example of the roadside unit 4. As shown in FIG. As shown in FIG. 5 , the roadside device 4 has a processor 31 , a storage unit 32 , a communication unit 33 , a DSRC communication unit 34 and a bus 35 .

Processor 31 controls other elements of roadside unit 4 via bus 35 . For example, a general-purpose CPU is used as the processor 31 .

The storage unit 32 acquires various information from other elements and holds the information temporarily or permanently. The storage unit 32 is a general term for so-called primary storage and secondary storage. A plurality of storage units 32 may be physically arranged. A DRAM, HDD, or SSD, for example, is used as the storage unit 32 .

The communication unit 33 communicates with external devices via a communication path. The server 5 is included in the target (communication target) device with which the communication unit 33 communicates.

The DSRC communication unit 34 performs two-way communication with the vehicle-mounted device 3 based on DSRC. For example, the DSRC communication unit 34 receives GNSS reception data transmitted from the vehicle-mounted device 3 based on DSRC.

FIG. 6 is a diagram showing a block configuration example of the server 5. As shown in FIG. As shown in FIG. 6 , the server 5 has a processor 41 , a storage section 42 , a communication section 43 and a bus 44 .

Processor 41 controls other elements of server 5 via bus 44 . For example, a general-purpose CPU is used as the processor 41 .

The storage unit 42 acquires various information from other elements and holds the information temporarily or permanently. The storage unit 42 is a general term for so-called primary storage and secondary storage. A plurality of storage units 42 may be physically arranged. A DRAM, HDD, or SSD, for example, is used as the storage unit 42 .

The communication unit 43 communicates with an external device via a communication channel. The roadside device 4 is included in the target (communication target) device with which the communication unit 43 communicates.

FIG. 7 is a diagram for explaining an outline of DSRC communication. A DSRC radio access system is a TDMA (Time Division Multiple Access) system. The roadside unit serves as a reference for communication timing. The roadside unit communicates with up to eight onboard units.

A DSRC frame has an FCMS (Flame Control Message Slot), an MDS (Message Data Slot), and an ACTS (Activation Slot). A DSRC frame is configured such that the MDS number and the ACTS number satisfy the following equations (1) and (2).

MDS number + ACTS number <= 8 (1)
Number of ACTS <= 3 (2)

In the FCMS, the frame structure such as MDS allocation is described by the roadside unit. MDS is a slot for downlink and uplink data communication between the vehicle-mounted device and the roadside device. The vehicle-mounted device refers to the FCMS and grasps the allocation of the MDS.

For example, the vehicle-mounted device A shown in FIG. 7 refers to FCMS and grasps the downlink allocation of MDS(1). The vehicle-mounted device A receives the downlink data of the roadside device in MDS(1).

Further, for example, the vehicle-mounted device B shown in FIG. 7 refers to the FCMS and grasps the uplink allocation of MDS(2). The vehicle-mounted device B transmits uplink data to the roadside device in MDS(2).

Further, the vehicle-mounted devices A, B, and C shown in FIG. 7 refer to the FCMS and grasp the downlink (broadcast) of MDS (4). The onboard units A, B, and C receive the downlink data (broadcast data) of the roadside units in the MDS (4).

ACTS is a slot for a vehicle-mounted device to request a link from a roadside device. The roadside device allocates MDS to the vehicle-mounted device in response to the link request from the vehicle-mounted device.

FIG. 8 is a diagram for explaining ACTS. As shown in FIG. 8, ACTS includes six ACTCs (Activation Channels). The vehicle-mounted device randomly selects one ACTC and makes a link request. For example, the vehicle-mounted device A shown in FIG. 8 selects the leading ACTC and makes a link request.

The FCMS included in the frame after the frame in which the link request is issued indicates the vehicle-mounted device ID of the vehicle-mounted device for which communication is permitted, and the MDS. The vehicle-mounted device that has made the link request communicates with the roadside device based on the vehicle-mounted device ID included in the FCMS and the MDS.

Link requests may collide. For example, the vehicle-mounted devices B and D shown in FIG. 8 select the third ACTC from the top and make a link request. In this case, the link requests of onboard units B and D collide. If the FCMS does not include the IDs of the onboard units B and D that have selected the same ACTC and made a link request, the roadside unit determines that the link request has not been accepted. Make a link request.

As described above, the roadside device can communicate with up to eight onboard devices. Therefore, when the roadside device has established links with eight roadside devices, it does not accept a link request from a new vehicle-mounted device.

The OBE ID of the OBE for which the link request was not accepted is not included in the FCMS. A vehicle-mounted device whose FCMS does not include the vehicle-mounted device ID despite having made a link request makes a link request again.

Note that, as shown in Equation (2) above, a DSRC frame can include up to three ACTSs. Therefore, the roadside unit can set up to 18 ACTCs in one frame.

FIG. 9 is a diagram for explaining an example of DSRC communication. In the conventional method of using DSRC communication, for example, as shown in FIG. 9, even if many vehicle-mounted devices exist within the communication area X1 due to traffic congestion or the like, there is a low possibility of communication congestion.

For example, DSRC communication is used for collection of toll information or notification of toll gate information. Since the size of these pieces of information is small, the DSRC communication completes the communication in a short transaction and is less likely to cause communication congestion.

Further, the vehicle-mounted device that has completed communication in the communication area X1 does not normally issue a link request within the communication area X1. For example, the vehicle-mounted device normally stops communicating after completing communication once in the communication area X1. This is because it is unlikely that toll information or tollgate information will be updated before moving to another communication area. In other words, when the vehicle-mounted device enters into the communication area X1, it communicates with the roadside device once and then stops communicating, so there is a low possibility that communication congestion will occur.

However, as described with reference to FIGS. 1 and 2, when the server 5 calculates the travel route of the vehicle A1 in detail including the travel lanes, the server 5 does not have to grasp the travel route of the vehicle A1 in detail. must not. The vehicle-mounted device 3 transmits GNSS reception data acquired inside or outside the communication area A2 to the roadside device 4 as information necessary for calculating the travel route. Since the GNSS reception data is information corresponding to the detailed position of the vehicle A1, the size of the information is large. Therefore, in the positioning system 1 described with reference to FIGS. 1 and 2, there is a high possibility that communication congestion will occur. Therefore, in the positioning system 1, the following processing is performed in order to suppress communication congestion between the vehicle-mounted device and the roadside device.

In addition, the vehicle-mounted device 3 transmits GNSS reception data inside and outside the communication area A2 to the roadside device 4 . That is, the vehicle-mounted device 3 transmits the GNSS reception data acquired and accumulated outside the communication area A2 while it is in the communication area A2. Moreover, since GNSS reception data are acquired at any time while it is in communication area A2, transmitting these GNSS reception data is also considered. For this reason, in the positioning system 1, the amount of GNSS reception data transmitted from the vehicle-mounted device 3 to the roadside device 4 becomes large, and the same vehicle-mounted device 3 may perform communication multiple times. Therefore, depending on how the slots are allocated, the amount of unsent data may increase in some vehicle-mounted devices. Therefore, in the positioning system 1, the following processing is performed so that the amount of unsent data does not increase in some vehicle-mounted devices.

FIG. 10 is a diagram illustrating an operation example of the positioning system 1. FIG. FIG. 10 shows three vehicle-mounted devices 3 (vehicle-mounted devices 3a to 3c) and one roadside device 4. FIG.

- When the vehicle-mounted device transmits the GNSS reception data to the roadside device 4, it notifies the roadside device of the unsent data capacity (information on the unsent data capacity). The unsent data volume is the remaining GNSS reception data volume after the vehicle-mounted device transmits the GNSS reception data to the roadside device 4 . The unsent data volume includes the data that has not been completely transmitted in the communication area of the previous roadside device 4 immediately after the vehicle-mounted device enters the communication area A2, and the data accumulated before entering the communication area A2. corresponds to the total capacity of GNSS data.

For example, as indicated by arrows A11a and A11b in FIG.

As will be described below, each of the vehicle-mounted devices 3a and 3b receives a threshold value (parameter) for determining whether or not to issue a link request from the roadside device 4 through broadcast communication. Each of the vehicle-mounted devices 3a and 3b transmits a link request to the roadside device 4 based on the comparison result between the threshold broadcasted from the roadside device 4 and the unsent data volume. The roadside device 4 allocates uplink MDSs to the onboard devices 3a and 3b in response to link requests from the onboard devices 3a and 3b. The vehicle-mounted devices 3a and 3b to which the MDS is assigned transmit the GNSS reception data indicated by the arrows A11a and A11b and the untransmitted data capacity to the roadside device 4.

・The roadside unit assigns MDS with priority to the onboard unit with a large amount of unsent data.

For example, assume that the untransmitted data capacity dc1 of the vehicle-mounted device 3a in FIG. 10 is larger than the untransmitted data capacity dc2 of the vehicle-mounted device 3b. In this case, the roadside device 4 makes the number of MDSs allocated to the vehicle-mounted device 3a greater than the number of MDSs allocated to the vehicle-mounted device 3b in the uplink MDS allocation of the vehicle-mounted devices 3a and 3b in the next and subsequent frames. That is, the roadside device 4 allocates MDS to each of the onboard devices 3a and 3b so that the difference between the unsent data volumes of the onboard devices 3a and 3 becomes small. As a result, it is possible to suppress the increase (concentration) of unsent data in some vehicle-mounted devices.

・When the roadside unit receives a link request from an on-board unit that does not know (send) the amount of unsent data, it allocates at least one MDS in the next frame and acquires the amount of unsent data.

For example, assume that the vehicle-mounted device 3c in FIG. In this case, the roadside device 4 does not grasp the unsent data volume of the vehicle-mounted device 3c. When the roadside device 4 receives the link request from the onboard device 3c that does not know the amount of unsent data, it allocates at least one uplink MDS to the onboard device 3c in the next frame. The onboard device 3c transmits the GNSS reception data and the unsent data capacity to the roadside device 4 in the allocated MDS, and the roadside device 4 acquires the unsent data capacity from the onboard device 3c.

The roadside device discards the unsent data volume received from the onboard device when the onboard device goes out of the communication area of the roadside device. In other words, when the roadside device goes out of the communication area of the roadside device, the roadside device does not know the amount of unsent data of the out-of-area onboard device.

・The roadside unit calculates a threshold value based on the amount of unsent data received from the onboard unit, and notifies the calculated threshold value to the onboard unit by broadcast communication. The threshold is a criterion for determining whether or not the vehicle-mounted device issues a link request to the roadside device based on the amount of unsent data.

For example, as indicated by an arrow A13 in FIG. 10, the roadside device 4 transmits the threshold values to the vehicle-mounted devices 3a to 3c by broadcast communication.

In addition, the threshold may be determined based on the total value of the unsent data capacity of each vehicle-mounted device. For example, the roadside unit may increase the threshold as the total value increases. In situations where the total value is large, there is a high possibility that there is an OBE with a large amount of unsent data, so by setting the threshold in this way, the OBE that makes a link request will be selected as an OBE with a large amount of unsent data. can be limited to

Also, the threshold may be determined based on the number of vehicle-mounted devices present within the communication area of the roadside device. For example, the roadside device may increase the threshold as the number of onboard devices increases. If a small threshold value is used in situations where there are a large number of OBEs in the communication area, there is a greater possibility that more OBEs will make link requests, and link requests from OBEs with a large amount of unsent data will be more likely to be rejected. This is because

Also, the threshold may be determined based on the total value of the unsent data volume of each vehicle-mounted device and the number of vehicle-mounted devices present within the communication area of the roadside device.

Also, the threshold may be a fixed value. When the threshold value is a fixed value, the threshold value may be recorded in each vehicle-mounted device in advance and broadcast communication may be omitted. This makes it possible to allocate slots used for broadcast communication to other uses.

- The vehicle-mounted device compares the threshold received by broadcast communication with the amount of unsent data, and if the amount of unsent data is greater than the threshold, issues a link request to the roadside unit. The vehicle-mounted device does not issue a link request to the roadside device if the unsent data volume is equal to or less than the threshold.

For example, the vehicle-mounted device 3c in FIG. 10 enters the communication area of the roadside device 4 and receives the threshold value through broadcast communication. The vehicle-mounted device 3c issues a link request to the roadside device 4 as indicated by an arrow A12 in FIG. 10 if the unsent data volume is greater than the threshold. On the other hand, the vehicle-mounted device 3c does not issue a link request to the roadside device 4 if the unsent data volume is equal to or less than the threshold. As a result, the link request of the vehicle-mounted device with a small amount of unsent data is limited, and the link request of the vehicle-mounted device with a large amount of unsent data is given priority. Therefore, congestion in communication between the roadside device and the vehicle-mounted device is suppressed.

FIG. 11 is a diagram illustrating an operation example of the positioning system 1. FIG. FIG. 11 shows the nth frame and the n+1th frame. The roadside machine shown in FIG. 11 corresponds to the roadside machine 4 shown in FIG. Vehicle-mounted units A to C shown in FIG. 11 correspond to vehicle-mounted units 3a to 3c shown in FIG.

The vehicle-mounted units A to C receive the threshold value from the roadside unit in MDS(1). MDS(1) is a broadcast slot. The vehicle-mounted devices A to C can refer to the FCMS and receive the threshold value from the roadside device in MDS(1) of the broadcast communication even if the link is not established with the roadside device.

The onboard units A and B refer to the FCMS and transmit the GNSS reception data to the roadside unit. At this time, the vehicle-mounted devices A and B transmit the unsent data volume to the roadside device.

In addition, the vehicle-mounted devices A and B compare the threshold value received in the frame before the n-th frame with the untransmitted data volume and transmit the link request to the roadside device. In response to the link request from the onboard units A and B in the frame before the nth frame, the roadside unit sends the uplink MDS to the onboard units A and B in the nth and n+1th frames as shown in FIG. assigned to B. When allocating the MDS to the vehicle-mounted devices A, B, the roadside device determines allocation of the MDS to the vehicle-mounted devices A, B based on the unsent data volume transmitted from the vehicle-mounted devices A, B. For example, when the unsent data capacity of the onboard device A is larger than the unsent data capacity of the onboard device B, the roadside device allocates more MDSs to the onboard device A than the MDSs to the onboard device B.

The vehicle-mounted device C compares the threshold received in MDS(1) of the n-th frame with the untransmitted data volume, and if the untransmitted data volume is greater than the threshold, the roadside device C issues a link request in the n-th frame ACTS. Send to When the roadside device receives the link request from the onboard device C, it allocates at least one uplink MDS to the onboard device C in the next n+1th frame. For example, the roadside device assigns MDS(7) of the n+1th frame to the onboard device C. Thereby, the roadside device can grasp the amount of unsent data of the onboard device C.

FIG. 12 is a sequence diagram showing an operation example of the positioning system. The roadside machine shown in FIG. 12 corresponds to the roadside machine 4 shown in FIG. Vehicle-mounted units A to C shown in FIG. 12 correspond to vehicle-mounted units 3a to 3c shown in FIG.

The roadside device notifies the vehicle-mounted devices A, B, and C within the communication area of the MDS allocation in the FCMS of the frame (S1). In the following, it is assumed that the roadside device has assigned MDS to the onboard devices A and B. Assume that the roadside device C has entered the communication area of the roadside device.

In MDS(1) of the frame, the roadside device notifies the threshold value to the vehicle-mounted devices A, B, and C within the communication area by broadcast communication (S2).

The vehicle-mounted device A transmits the GNSS reception data and the untransmitted data capacity to the roadside device according to the MDS allocation information in the FCMS of S1 (S3).

The vehicle-mounted device B transmits the GNSS reception data and the untransmitted data capacity to the roadside device according to the MDS allocation information in the FCMS of S1 (S4).

The vehicle-mounted device C, which has entered the communication area of the roadside device, compares the threshold broadcasted in S2 with the unsent data volume, and determines whether the unsent data volume is greater than the threshold (S5 ).

When the vehicle-mounted device C determines that the untransmitted data volume is larger than the threshold (Yes in S5), it transmits a link request to the roadside device in the ACTS of the frame (S6). On the other hand, when the vehicle-mounted device C determines that the untransmitted data volume is not larger than the threshold (No in S5), it does not transmit a link request to the roadside device.

When the roadside device receives the link request of S6, it determines whether or not it has grasped the unsent data capacity of the vehicle-mounted device C (S7).

When the roadside device determines that it has grasped the unsent data capacity of the onboard equipment C (Yes in S7), so that the number of slots corresponds to the unsent data capacity of each onboard equipment A, B, and C, MDS allocation is determined (S8).

On the other hand, when the roadside device determines that it does not grasp the unsent data capacity of the onboard device C (No in S7), it determines allocation of one MDS to the onboard device C (S9). Further, the roadside device determines allocation of MDS to the onboard devices A and B so that the number of slots corresponds to the untransmitted data capacity of the onboard devices A and B (S9).

When the roadside device determines Yes in S7, the roadside device determines a threshold value based on the unsent data capacity of the onboard devices A, B, and C, and when it determines No in S7, the onboard device A , B, the threshold is determined (S10).

The roadside device notifies the onboard devices A, B, and C within the communication area of the MDS allocation determined in S8 or S9 in the FCMS of the frame (S11).

In MDS(1) of the frame, the roadside device notifies the threshold determined in S10 to the vehicle-mounted devices A, B, and C within the communication area by broadcast communication (S12).

FIG. 13 is a diagram illustrating an example of the effects of the positioning system 1. FIG. FIG. 13 shows communication areas A21 to A23 formed by three roadside units (not shown).

As described above, the roadside device allocates more MDSs to the vehicle-mounted device with a large amount of unsent data than to the vehicle-mounted device with a small amount of unsent data. For example, the roadside device forming the communication area A21 allocates MDS to the onboard devices so that the unsent data capacity of each onboard device is uniform in the communication area A21.

As a result, in the communication areas A22 and A23 formed on the road that diverges beyond the communication area A21, unevenness in the amount of unsent data from the vehicle-mounted device is suppressed. The vehicle-mounted device passing through the communication areas A22 and A23 can transmit the GNSS reception data, which could not be transmitted in the communication area A21, in the communication areas A22 and A23. In addition, the roadside units forming the communication areas A22 and A23 can suppress reception omission of GNSS reception data.

As described above, the roadside device 4 includes the DSRC communication unit 34 that receives the GNSS reception data transmitted from each of the plurality of vehicle-mounted devices 3 and the unsent data capacity indicating the capacity of the unsent GNSS reception data. , a processor 31 that allocates a slot for transmitting GNSS received data to each of the plurality of vehicle-mounted devices 3 based on the untransmitted data capacity. Thereby, the roadside device 4 can appropriately allocate slots to the vehicle-mounted device 3 .

In addition, the vehicle-mounted device 3 refers to the FCMS describing the frame structure, and determines the slot for transmitting the GNSS reception data and the untransmitted data capacity indicating the capacity of the untransmitted GNSS reception data, and the processor 21 and a DSRC communication unit 24 that transmits GNSS received data and an untransmitted data capacity to the roadside device 4 in the slot determined by . Thereby, the roadside device 4 can appropriately allocate slots to the vehicle-mounted device 3 .

(Modification 1)
In the first embodiment, the vehicle-mounted device 3 transmits the untransmitted data capacity to the roadside device 4 together with the GNSS received data, but the present invention is not limited to this. For example, after establishing a link with the roadside device 4, the vehicle-mounted device 3 transmits the unsent data capacity to the roadside device 4 when transmitting the first GNSS received data, and then transmits the unsent data capacity to the roadside device 4. No need to send.

Based on the unsent data volume initially transmitted from the onboard device 3 and the GNSS reception data transmitted from the onboard device 3, the roadside device 4 stores the unsent data of the onboard device 3 after receiving the unsent data volume. Capacity may be calculated. For example, the roadside device 4 subtracts the data amount of the GNSS reception data transmitted from the vehicle-mounted device 3 after that from the unsent data volume transmitted first, and calculates the unsent data volume of the vehicle-mounted device 3. good.

The vehicle-mounted device 3 may transmit the unsent data capacity to the roadside device 4 when the GNSS reception data is output from the GNSS receiver 2 and the unsent data capacity changes.

(Modification 2)
Although the vehicle-mounted device 3 transmits the GNSS reception data to the roadside device 4 in the first embodiment, the present invention is not limited to this. For example, when the GNSS receiver 2 outputs positioning data, the vehicle-mounted device 3 may transmit the positioning data to the roadside device 4 . Further, if the GNSS receiver 2 can calculate the position of the vehicle-mounted device 3 , the position data may be transmitted to the roadside device 4 . In other words, it is possible to adopt arbitrary data according to the design of the positioning system 1 as to which stage of data regarding positioning by GNSS is to be transmitted.

Moreover, the data which the onboard equipment 3 transmits to the roadside apparatus 4 are not restricted to the data relevant to GNSS. Other data may be used as long as it is useful to be collected by the vehicle-mounted device 3 and transmitted to the roadside device 4 . For example, the configuration of the first embodiment may be applied when the vehicle-mounted device 3 transmits to the roadside device 4 data such as the moving distance and moving speed calculated from the number of rotations of the tire.

(Modification 3)
In the first embodiment, the vehicle-mounted device 3 transmits the link request on the condition that the untransmitted data volume is greater than the preliminarily broadcast threshold. However, the vehicle-mounted device 3 may be configured not to determine whether or not its own unsent data volume is larger than the threshold. In this case, the vehicle-mounted device 3 transmits a link request as necessary, and the roadside device 4 determines whether or not to accept the link request and allocate a slot by its own judgment. By doing so, it is possible to reduce the number of items to be determined by the vehicle-mounted device 3, so that the configuration of the vehicle-mounted device 3 can be simplified. Also, since there is no need to broadcast the threshold, slots for broadcast transmission can be allocated for other purposes.

(Second embodiment)
In the second embodiment, the vehicle-mounted device thins out the data to be transmitted to the roadside device to suppress the tightness of the communication band. In addition, the roadside device thins out the data to be transmitted to the vehicle-mounted device to suppress the tightness of the communication band.

FIG. 14 is a diagram showing a configuration example of a positioning system 51 according to the second embodiment. As shown in FIG. 14 , the positioning system 51 has a vehicle-mounted device 52 and a roadside device 53 . The block configuration of the vehicle-mounted device 52 is the same as the block configuration of the vehicle-mounted device 3 described with reference to FIG. 4, and the description thereof will be omitted. The block configuration of the roadside device 53 is the same as the block configuration of the roadside device 4 described with reference to FIG. 5, and the description thereof is omitted.

The vehicle-mounted device 52 and the roadside device 53 perform two-way communication based on DSRC. The roadside units 53 are arranged on the roadside at intervals of, for example, several km to 20 km. The vehicle-mounted device 52 communicates with the roadside device 53 within the communication area A31 formed by the roadside device 53 .

The vehicle-mounted device 52 transmits satellite reception information to the roadside device 53 . The satellite reception information is information output from a GNSS receiver (not shown) that has received positioning signals from GNSS satellites. The satellite reception information is, for example, positioning signals, GNSS reception data, or various information obtained from positioning data.

The vehicle-mounted device 52 transmits the satellite reception information to the roadside device 53 within the communication area A31. The vehicle-mounted device 52 stores the satellite reception information in the storage unit outside the communication area A31. When the vehicle-mounted device 52 enters the communication area A31, the vehicle-mounted device 52 transmits the satellite reception information stored in the storage unit to the roadside device 53 .

During traffic congestion, many vehicle-mounted devices 52 and roadside devices 53 communicate within the communication area A31. In this embodiment, the position of the vehicle, which is measured periodically, is used to calculate the travel route of the vehicle. Therefore, the amount of satellite reception information output from the GNSS receiver per unit time is constant regardless of the speed of the vehicle. Therefore, the communication band between the vehicle-mounted device 52 and the roadside device 53 is tight during traffic congestion.

Therefore, the vehicle-mounted device 52 thins out the satellite reception information to be transmitted to the roadside device 53 on the time series based on the length of time the satellite reception information is stored (accumulated) in the storage unit, and transmits the satellite reception information to the roadside device 53. . In other words, the vehicle-mounted device 52 selects the satellite reception information to be transmitted to the roadside device 53 from the satellite reception information stored in the storage unit based on the communication interval Δt between the previous roadside device 53 and the next roadside device 53. Change the sampling rate to extract the .

15A, 15B, and 15C are diagrams illustrating examples of sampling rates of satellite reception information. The communication interval Δt shown in FIG. 15A indicates the difference between the time when the vehicle-mounted device 52 finished communicating with the roadside device 53 last time and the time when the vehicle-mounted device 52 started communicating with the roadside device 53 this time ( Δt). As shown in FIG. 15A, if there is no extreme deviation in the distances between the roadside units, the longer the communication interval Δt, the slower the average running speed of the vehicle equipped with the onboard unit 52 . In other words, the longer the communication interval Δt, the worse the traffic congestion.

As shown in FIG. 15A, the vehicle-mounted device 52 lowers the sampling rate of the satellite reception information as the communication interval Δt is longer. In other words, the vehicle-mounted device 52 lowers the sampling rate of the satellite reception information and reduces the amount of data to be transmitted to the roadside device 53 when there is a traffic jam.

For example, each rectangle shown in FIG. 15B indicates the satellite reception information stored in the storage unit of the vehicle-mounted device 52 during the communication interval Δt. The satellite reception information is, for example, stored in the storage unit every cycle (stored for each t-axis memory).

The vehicle-mounted device 52 changes the sampling rate of the satellite reception information in the storage unit to be transmitted to the roadside device 53 based on the communication interval Δt. In the example of FIG. 15B , the vehicle-mounted device 52 samples the hatched satellite reception information among the plurality of satellite reception information stored in the storage unit, and transmits the sampled satellite reception information to the roadside device 53 . The vehicle-mounted device 52 does not transmit the satellite reception information that is not hatched in FIG. 15B to the roadside device 53 . The vehicle-mounted device 52 increases the sampling rate of satellite reception information as the communication interval Δt is longer.

When the moving speed of the vehicle-mounted device 52 is fast, the communication interval Δt becomes short. Therefore, the data amount of untransmitted satellite reception information stored in the storage unit is also reduced.

For example, as shown in FIG. 15C, when the communication interval Δt is short, the amount of satellite reception information stored in the storage unit is small. In this case, the vehicle-mounted device 52 may sample all satellite reception information stored in the storage unit and transmit the sampled data to the roadside device 53, as shown in FIG. 15C.

In the above description, the vehicle-mounted device 52 changes the sampling rate for extracting the satellite reception information stored in the storage unit based on the communication interval Δt, and controls the amount of data transmitted to the roadside device 53. Information included in the satellite reception information transmitted to 53 may be thinned out.

16A and 16B are diagrams illustrating an example of decimation of satellite reception information. The communication interval Δt shown in FIG. 16A indicates the difference between the time when the vehicle-mounted device 52 finished communicating with the roadside device 53 last time and the time when the vehicle-mounted device 52 started communicating with the roadside device 53 this time ( Δt). As shown in FIG. 16A, there is a relationship that the longer the communication interval Δt, the lower the average running speed of the vehicle equipped with the onboard unit 52, unless the distances between the roadside units are extremely biased. In other words, the longer the communication interval Δt, the worse the traffic congestion.

As shown in FIG. 16A, the vehicle-mounted device 52 increases the thinning amount of information included in the satellite reception information as the communication interval Δt is longer. In other words, the vehicle-mounted device 52 increases the thinning amount of information included in the satellite reception information and reduces the amount of data to be transmitted to the roadside device 53 when traffic congestion occurs.

For example, each rectangle shown in FIG. 16B indicates satellite reception information stored in the storage unit of the vehicle-mounted device 52 . The satellite reception information is, for example, stored in the storage unit every cycle (stored for each t-axis memory).

The vehicle-mounted device 52 thins out the information included in the satellite reception information based on the communication interval Δt. In the case of the example of FIG. 16B, the vehicle-mounted device 52 thins out the information of the white part in the satellite reception information of each period, and transmits the information of the hatched part to the roadside device 53 as the satellite reception information. The vehicle-mounted device 52 increases the amount of information to be thinned out from the satellite reception information as the communication interval Δt is longer.

The information to be thinned out from the satellite reception information may be, for example, information that has little effect on the DOP (Dilution of Precision) value that indicates the goodness of the geometric arrangement of the satellites. Further, the information to be thinned out from the satellite reception information may be, for example, information that has little influence on the calculation of the FIX solution (high-precision positioning solution) in the RTK calculation. Also, the information to be thinned out from the satellite reception information may be, for example, satellite signal quality information such as satellite elevation angle, satellite signal strength, or cycle slip.

The vehicle-mounted device 52 may control the amount of information to be transmitted to the roadside device 53 by combining the change of the sampling rate of the received satellite information and the thinning of the received satellite information.

FIG. 17 is a diagram illustrating an example of changing the sampling rate of satellite reception information and thinning out the satellite reception information. The vehicle-mounted device 52 changes the sampling rate of the satellite reception information based on the communication interval Δt, as shown in FIG. 17 . In addition, as shown in FIG. 17, the vehicle-mounted device 52 thins out information included in the satellite reception information based on the communication interval Δt. Thus, the vehicle-mounted device 52 changes the sampling rate of the satellite reception information based on the communication interval Δt, thins out the information included in the satellite reception information, and reduces the amount of data to be transmitted to the roadside device 53. may be controlled.

FIG. 18 is a flow chart showing an operation example of the vehicle-mounted device 52 . The vehicle-mounted device 52 may perform the flowchart shown in FIG. 18, for example, from when the engine of the vehicle is started until it is stopped.

The vehicle-mounted device 52 determines whether or not it is located within the communication area of the roadside device 53 (S21).

When the vehicle-mounted device 52 determines that it is not located within the communication area of the roadside device 53 (No in S21), it stores the traveling speed of the vehicle in the storage unit (S22). The vehicle-mounted device 52 may acquire the traveling speed of the vehicle, for example, from the ECU (Electronic Control Unit) of the vehicle.

The vehicle-mounted device 52 stores the satellite reception information output from the GNSS receiver in the storage unit (S23). After storing the satellite reception information in the storage unit, the vehicle-mounted device 52 shifts the processing to S21.

When the vehicle-mounted device 52 determines in S21 that it is located within the communication area of the roadside device 53 (Yes in S21), it calculates the communication interval Δt (S24). The communication interval Δt is calculated by the following formula (3).

Δt = current time - previous communication end time (3)

The vehicle-mounted device 52 determines transmission information to be transmitted to the roadside device 53 based on the communication interval Δt calculated in S24 (S25). For example, the vehicle-mounted device 52 determines transmission information to be transmitted to the roadside device 53 by changing the sampling rate for acquiring the satellite reception information from the storage unit based on the communication interval Δt, as described with reference to FIG. 15 . Alternatively, the vehicle-mounted device 52 determines transmission information to be transmitted to the roadside device 53 by changing the amount of thinning out information included in the satellite reception information based on the communication interval Δt, as described with reference to FIG. 16 . 17, the vehicle-mounted device 52 changes the sampling rate for acquiring the satellite reception information from the storage unit based on the communication interval Δt, and changes the amount of thinning out the information included in the satellite reception information. , determines transmission information to be transmitted to the roadside unit 53 .

The vehicle-mounted device 52 performs DSRC data communication (S26). That is, the vehicle-mounted device 52 transmits the transmission information determined in S25 to the roadside device 53 .

The vehicle-mounted device 52 stores the communication time in the storage unit (S27). The vehicle-mounted device 52 shifts the process to step S21.

As described above, the vehicle-mounted device 52 terminates communication with the first roadside device 53 (eg, the roadside device 53 on the left side in FIG. 14), and then communicates with the second roadside device 53 (eg, the right side device in FIG. 14). The length of time between the DSRC communication unit that transmits the satellite reception information output from the GNSS receiver to the second roadside device 53 and the time until communication is started with the roadside device 53) (for example , Δt) in FIG. 14, and a processor for controlling the amount of satellite reception information to be transmitted to the second roadside unit 53 . As a result, for example, even if a traffic jam occurs, tight communication between the roadside device 53 and the vehicle-mounted device 52 is suppressed.

In the above description, it was assumed that the longer the communication interval Δt, the slower the average running speed. This relationship holds when there is no great variation in the distances between the roadside units, but in reality, there are situations where there are variations in the range of several kilometers to several tens of kilometers. If the distance between roadside units varies greatly, the reason why the communication interval Δt is long is because the distance between the roadside unit that communicated last time and the roadside unit that communicated this time is long, or the reason why the communication interval Δt is short is the opposite. This may be because the distance between the roadside device that communicated last time and the roadside device that communicated this time is short. However, even in such a case, as a result of the GNSS receiver outputting satellite reception information at a constant cycle, the longer Δt is, the more satellite reception information is accumulated. That is, regardless of whether the difference in Δt is due to the difference in average moving speed or the variation in distance between roadside units, the longer Δt is, the more satellite reception information is accumulated. Therefore, regardless of the length of the cause, the longer Δt is, the more satellite reception information is thinned out, thereby suppressing the tightness of the communication band. It should be noted that the fact that the length of Δt does not necessarily depend on the average running speed, and that even in such a case the tightness of the communication band can be suppressed is the same in the following modifications.

(Modification 1)
The roadside device 53 may control the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 based on the communication interval Δt of the vehicle-mounted device 52 . Satellite correction information is information for correcting errors in GNSS reception data, and is, for example, RRS (Real Reference Station) data and VRS (Virtual Reference Station) data.

For example, the vehicle-mounted device 52 transmits the communication interval Δt to the roadside device 53 when it enters the communication area of the roadside device 53 . The roadside device 53 controls the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 based on the communication interval Δt transmitted from the vehicle-mounted device 52 .

More specifically, the roadside device 53 changes the sampling rate of the satellite correction information based on the communication interval Δt of the vehicle-mounted device 52 to control the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 . Alternatively, the vehicle-mounted device 52 thins out information included in the satellite correction information based on the communication interval Δt of the vehicle-mounted device 52 and controls the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 . Alternatively, the roadside device 53 controls the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 by combining the change of the sampling rate of the satellite correction information and the thinning.

Thus, the second roadside device 53 includes a DSRC communication unit that transmits satellite correction information for the onboard device 52 to correct GNSS received data to the onboard device 52 , and the onboard device 52 is the first roadside device 53 A processor that controls the amount of satellite correction information to be transmitted to the vehicle-mounted device 52 according to the length of time between the completion of communication with the second roadside device 53 and the start of communication with the second roadside device 53; have. As a result, for example, even if a traffic jam occurs, tight communication between the roadside device 53 and the vehicle-mounted device 52 is suppressed.

Either one of the vehicle-mounted device 52 and the server may perform the high-precision positioning calculation. For example, when the roadside device 53 receives satellite reception information from the vehicle-mounted device 52, the server may perform high-precision positioning calculation using the satellite reception information. Further, when the vehicle-mounted device 52 receives the satellite correction information from the roadside device 53, using the satellite correction information received by the vehicle-mounted device 52 from the roadside device 53 and the GNSS reception data output from the GNSS receiver, high-precision A positioning calculation may be performed. The results of high-precision positioning calculations may be used to identify whether the vehicle is traveling in a vehicle lane or a passing lane.

(Modification 2)
A vehicle may, for example, travel in an environment surrounded by skyscrapers. In this case, the number of satellites that the GNSS receiver of the vehicle-mounted device 52 can use decreases, and the vehicle-mounted device 52 or the server may not be able to obtain an appropriate positioning solution. Therefore, the vehicle-mounted device 52 or the roadside device 53 may control the amount of information to be communicated according to the number of satellites with which the GNSS receiver communicates.

For example, when the communication interval Δt of the vehicle-mounted device 52 or the roadside device 53 is longer than a predetermined time, and the number of satellites communicated by the GNSS receiver is smaller than a predetermined number, the amount of information to be communicated is reduced. Reduce the amount of reduction.

More specifically, when the communication interval Δt of the vehicle-mounted device 52 or the roadside device 53 is longer than a predetermined time, and the number of satellites that the GNSS receiver communicates with is 10 or more, the sampling rate of the information is to 10 second intervals. When the communication interval Δt of the vehicle-mounted device 52 is longer than a predetermined time, the vehicle-mounted device 52 or the roadside device 53 sets the information sampling rate to 6 seconds when the number of satellites with which the GNSS receiver communicates is 9 or less and 6 or more. Set to interval. As a result, the vehicle-mounted device 52 or the roadside device 53 can obtain an appropriate positioning solution by increasing the sampling rate even when the number of satellites with which the GNSS receiver communicates is small.

If the number of satellites is less, the vehicle-mounted device 52 or server may not be able to calculate an appropriate FIX solution. In this case, the vehicle-mounted device 52 or the roadside device 53 may conversely increase the reduction amount of the information to be communicated. For example, when the communication interval Δt of the vehicle-mounted device 52 is longer than a predetermined time, the vehicle-mounted device 52 or the roadside device 53 changes the information sampling rate to 20 seconds if the number of satellites that the GNSS receiver communicates with is 5 or less. can be set to

In addition, when the average traveling speed of the vehicle-mounted device 52 or the roadside device 53 is slower than a predetermined speed, when the number of satellites communicated by the GNSS receiver is smaller than a predetermined number, the amount of information to be communicated is reduced. The amount of reduction may be small.

(Modification 3)
In the above-described second embodiment, the vehicle-mounted device 52 controls the amount of satellite reception information to be transmitted to the roadside device 53 based on the communication interval Δt, but the present invention is not limited to this. The vehicle-mounted device 52 may control the amount of satellite reception information to be transmitted to the roadside device 53 based on the average running speed of the vehicle in the non-communication area. Moreover, the vehicle-mounted device 52 may control the information amount of the satellite reception information transmitted to the roadside device 53 based on the number of satellites with which the GNSS receiver communicates.

FIG. 19 is a flow chart showing an operation example of the vehicle-mounted device 52 . The vehicle-mounted device 52 may perform the flowchart shown in FIG. 19, for example, from when the engine of the vehicle is started until it is stopped.

The vehicle-mounted device 52 acquires the GNSS reception data output from the GNSS receiver (S81).

The vehicle-mounted device 52 calculates the travel speed of the vehicle on which the vehicle-mounted device 52 is mounted (S82). For example, the vehicle-mounted device 52 may calculate the Doppler shift amount of the carrier wave from the GNSS reception data and calculate the running speed of the vehicle. Alternatively, the vehicle-mounted device 52 may execute code positioning and calculate the running speed of the vehicle from the previous code positioning solution and the current code positioning solution. Note that the code positioning solution is a rough positioning solution that can be obtained by simpler calculations than the high-precision positioning solution. Alternatively, the vehicle-mounted device 52 may calculate the running speed of the vehicle from the vehicle speed pulse signal.

The vehicle-mounted device 52 determines whether or not the traveling speed calculated in S82 is equal to or greater than the threshold (S83).

When the vehicle-mounted device 52 determines that the traveling speed calculated in S82 is equal to or higher than the threshold value (Yes in S83), it determines that the vehicle is traveling normally (for example, traveling when there is no traffic jam), and RTK A satellite to be used for calculation is determined (S84). For example, the vehicle-mounted device 52 determines a satellite to be used for RTK calculation based on the satellite elevation angle and signal strength information included in the GNSS reception data.

The vehicle-mounted device 52 stores the GNSS reception data used for the RTK calculation in the storage unit at the first sampling interval (S85). Note that the first sampling interval (St1), the second sampling interval (St2) explained in S90, the third sampling interval (St3) explained in S92, and the fourth sampling interval (St4) explained in S93 There is a relationship of the following formula (4) between them.

St4>St2>St1=St3 (4)

The vehicle-mounted device 52 determines whether it is located in the communication area of the roadside device 53 (S86).

When the vehicle-mounted device 52 determines that it is located in the communication area of the roadside device 53 (Yes in S86), it transmits the GNSS reception data stored in the storage unit to the roadside device 53 (S87).

On the other hand, when the vehicle-mounted device 52 determines that it is not located in the communication area of the roadside device 53 (No in S86), the process proceeds to S81.

When the vehicle-mounted device 52 determines that the running speed is not equal to or greater than the threshold in S83 (No in S83), it determines that the vehicle is running at a low speed (for example, running when a traffic jam occurs), and the RTK calculation is performed. A satellite to be used is determined (S88).

The vehicle-mounted device 52 determines whether or not the determined number of satellites is greater than or equal to the first threshold (S89).

When the vehicle-mounted device 52 determines that the determined number of satellites is equal to or greater than the first threshold (Yes in S89), it stores the GNSS reception data used for the RTK calculation in the storage unit at the second sampling interval (S90). That is, when the number of satellites determined in S88 is a sufficient number to obtain a positioning solution in the RTK calculation, the vehicle-mounted device 52 stores the GNSS received data at the second sampling interval larger than the first sampling interval. memorize to That is, in order to reduce the GNSS reception data to be transmitted to the roadside device 53 when it is determined that the vehicle is traveling at a low speed, the vehicle-mounted device 52 stores the GNSS reception data at a second sampling interval larger than the first sampling interval. memorize to

On the other hand, when the vehicle-mounted device 52 determines that the determined number of satellites is not equal to or greater than the first threshold (No in S89), it determines whether or not the determined number of satellites is equal to or greater than a second threshold (S91). Note that the second threshold is a value smaller than the first threshold in S89.

When the vehicle-mounted device 52 determines that the determined number of satellites is equal to or greater than the second threshold (Yes in S91), the vehicle-mounted device 52 stores the GNSS reception data used for the RTK calculation in the storage unit at the third sampling interval (S92). That is, the number of satellites determined in S88 is a sufficient number to obtain a positioning solution in the RTK calculation, but the vehicle-mounted device 52 is smaller than the first threshold, the same third sampling interval as the first sampling interval to store the GNSS reception data in the storage unit. That is, when the number of satellites is less than the first threshold and equal to or more than the second threshold, the vehicle-mounted device 52 reduces the sampling interval of the GNSS received data (increases the sampling rate) to improve the positioning solution accuracy in the RTK calculation.

On the other hand, when the vehicle-mounted device 52 determines that the determined number of satellites is not equal to or greater than the second threshold (No in S91), it stores the GNSS reception data used for the RTK calculation in the storage unit at the fourth sampling interval (S93). That is, when the number of satellites determined in S88 is not a sufficient number to obtain a positioning solution in the RTK calculation, the vehicle-mounted device 52 stores the GNSS reception data in the storage unit at the fourth sampling interval larger than the second sampling interval. Remember. That is, the vehicle-mounted device 52 reduces the amount of information of the GNSS reception data transmitted to the roadside device 53 when the number of satellites determined in S88 is not sufficient to obtain a positioning solution in the RTK calculation.

In this way, the vehicle-mounted device 52 receives satellite reception information output from the GNSS receiver during the period from the end of communication with the first roadside device 53 to the start of communication with the second roadside device 53. , the information amount of the satellite reception information to be transmitted to the second roadside device 53 is controlled according to the running speed between the DSRC communication unit transmitting to the second roadside device 53 and the vehicle equipped with the vehicle-mounted device 52. a processor; As a result, for example, even if a traffic jam occurs, tight communication between the roadside device 53 and the vehicle-mounted device 52 is suppressed.

In addition, in the modification 3, although the sampling rate of the GNSS reception data output from the GNSS receiver was changed and memorize|stored in the memory|storage part, it is not restricted to this. The GNSS reception data output from the GNSS receiver may be stored in the storage unit, and the sampling rate of the GNSS reception data extracted from the storage unit may be changed.

In S91 of Drawing 19, onboard equipment 52 does not need to sample GNSS reception data, when it judges with the number of determined satellites not being more than the 2nd threshold (No of S91). That is, the vehicle-mounted device 52 does not have to transmit the GNSS reception data to the roadside device 53 .

Moreover, although the vehicle-mounted device 52 has been described in the modified example 3, the roadside device 53 may similarly control the amount of information to be communicated based on the traveling speed. The roadside unit 53 may thin out the information based on the traveling speed of the vehicle, or may combine changing the sampling rate with thinning.

That is, the second roadside device 53 is a DSRC communication unit that transmits satellite correction information for the onboard device 52 to correct the GNSS received data to the onboard device 52, and the onboard device 52 communicates with the first roadside device 53. Control the amount of satellite correction information to be sent to the on-board device 52 according to the running speed of the vehicle on which the on-board device 52 is mounted during the period from the completion of communication to the start of communication with the second roadside device 53. a processor that performs As a result, tight communication between the roadside device 53 and the vehicle-mounted device 52 is suppressed.

(Modification 4)
In the above-described second embodiment, the vehicle-mounted device 52 changes the sampling rate for extracting the satellite reception information stored in the storage unit, but the present invention is not limited to this. The vehicle-mounted device 52 may change the sampling rate for extracting the GNSS reception data output from the GNSS receiver and store the extracted GNSS reception data in the storage unit.

(Third Embodiment)
In the third embodiment, the roadside device distributes reference station data (RTCM: Radio Technical Commission For Maritime Service) to the vehicle-mounted device, and the vehicle-mounted device performs RTK calculation.

The reference station data is RRS data or VRS data covering the traveling route of the vehicle-mounted device. The shorter the distance between the reference station that distributes the reference station data and the vehicle-mounted device, the better. Below, reference station data (RRS data or VRS data) may be referred to as correction information.

FIG. 20 is a diagram showing a configuration example of a positioning system 61 according to the third embodiment. As shown in FIG. 20, the positioning system 61 has onboard units 62a to 62c mounted on vehicles A41 to A43, roadside units 63a to 63c, a server 64, RRS 65a, 65b, and VRS 66a, 66b. are doing. The block configuration of the vehicle-mounted devices 62a to 62c is the same as the block configuration of the vehicle-mounted device 3 described with reference to FIG. 4, and the description thereof will be omitted. The block configuration of the roadside units 63a to 63c is the same as the block configuration of the roadside unit 4 described with reference to FIG. 5, so description thereof will be omitted. The block configuration of the server 64 is the same as the block configuration of the server 5 described with reference to FIG. 6, so description thereof will be omitted.

Hereinafter, the vehicle-mounted devices 62a to 62c are referred to as the vehicle-mounted device 62 when not distinguished. When the roadside units 63a to 63c are not distinguished, they are referred to as a roadside unit 63. When RRS65a and 65b are not distinguished, they are described as RRS65. When VRS66a and 66b are not distinguished, they are referred to as VRS66. RRS 65 and VRS 66 may be referred to as reference stations.

The vehicle-mounted device 62 and the roadside device 63 perform two-way communication based on DSRC. The vehicle-mounted device 62 communicates with the roadside device 63 within the communication area formed by the roadside device 63 .

Vehicles A41-A43 are equipped with GNSS receivers (not shown). Each of the vehicle-mounted devices 62a to 62c receives GNSS reception data output from the GNSS receiver.

FIG. 20 shows a non-communication area X11 in which the communication area of the roadside device 63 is not formed. The non-communication area X11 includes the travel route of the vehicle passing through the communication area of the roadside device 63a and passing through the communication area of the roadside device 63c. In addition, the non-communication area X11 includes the travel route of the vehicle passing through the communication area of the roadside device 63b and passing through the communication area of the roadside device 63c. The vehicle-mounted device 62 cannot perform DSRC-based communication with the roadside device 63 in the non-communication area X11.

The vehicle-mounted device 62 calculates a code positioning solution using the GNSS reception data. The vehicle-mounted device 62 transmits the calculated code positioning solution to the server 64 via the roadside device 63 . Moreover, the vehicle-mounted device 62 performs RTK calculation using the GNSS reception data and the correction information distributed from the roadside device 63, and calculates a high-precision positioning solution.

The server 64 calculates the center of the distribution of the code positioning solutions (distribution of positions) transmitted from the vehicle-mounted device 62 . The server 64 acquires the correction information of the RRS 65 or VRS 66 closest to the calculated center. For example, in the example of FIG. 20, the server 64 acquires the correction information of the RRS 65a. In other words, the server 64 acquires correction information near the center of the distribution of travel routes for which DSRC communication cannot be performed. The server 64 distributes the acquired correction information to the vehicle-mounted device 62 via the roadside device 63 .

An operation example of the positioning system 61 will be described below. First, uploading the code positioning solution in the non-communication area X11 to the server 64 will be described.

The vehicle A41 shown in FIG. 20 passes through the communication area of the roadside device 63a and the non-communication area X11, and enters the communication area of the roadside device 63c. While traveling in the non-communication area X11, the vehicle-mounted device 62a of the vehicle A41 calculates a code positioning solution using the GNSS reception data output from the GNSS receiver, and stores the calculated code positioning solution in the storage unit. do. That is, the vehicle-mounted device 62a calculates the code positioning solution of the travel route from the end of communication with the roadside device 63a to the start of communication with the roadside device 63c, and stores it in the storage unit.

When the vehicle-mounted device 62a enters the communication area of the roadside device 63c, it transmits the code positioning solution stored in the storage unit to the roadside device 63c. The roadside device 63c transmits to the server 64 the code positioning solution transmitted from the vehicle-mounted device 62a.

Similarly, the vehicle A42 shown in FIG. 20 passes through the communication area of the roadside device 63b and the non-communication area X11, and enters the communication area of the roadside device 63c. While traveling in the non-communication area X11, the vehicle-mounted device 62b of the vehicle A42 calculates a code positioning solution using the GNSS reception data output from the GNSS receiver, and stores the calculated code positioning solution in the storage unit. do. That is, the vehicle-mounted device 62b calculates the code positioning solution of the travel route from the end of communication with the roadside device 63b to the start of communication with the roadside device 63c, and stores it in the storage unit.

When the vehicle-mounted device 62b enters the communication area of the roadside device 63c, it transmits the code positioning solution stored in the storage unit to the roadside device 63c. The roadside device 63c transmits to the server 64 the code positioning solution transmitted from the vehicle-mounted device 62b.

In this way, the code positioning solutions in the non-communication area X11 of the vehicle-mounted devices 62 a and 62 b are uploaded to the server 64 .

Next, an operation example up to the RTK calculation in the vehicle-mounted device 62c will be described using a sequence diagram.

FIG. 21 is a sequence diagram illustrating an operation example of the positioning system 61. As shown in FIG. Below, it is assumed that the vehicle-mounted devices 62 a and 62 b pass through the communication area of the roadside device 63 c and upload the code positioning solutions of the vehicle-mounted devices 62 a and 62 b to the server 64 .

Further, in the following description, the vehicle-mounted device 62c passes through the communication area of the roadside device 63a and the non-communication area X11, and enters the communication area of the roadside device 63c. It is assumed that the vehicle-mounted device 62c is currently moving within the communication area of the roadside device 63a.

The vehicle-mounted device 62c determines whether it is outside the communication area of the roadside device 63a (S31). When the vehicle-mounted device 62c determines that it is not outside the communication area of the roadside device 63c (No in S31), it repeats the processing of S31.

On the other hand, when the vehicle-mounted device 62c determines that it is out of the communication area of the roadside device 63a (Yes in S31), it stores the GNSS reception data output from the GNSS receiver in the storage unit (S32). That is, the vehicle-mounted device 62c memorize|stores the GNSS reception data output from a GNSS receiver in a memory|storage part, when it leaves the communication area of the roadside device 63a and carries out area-in to the non-communication area X11.

The vehicle-mounted device 62c calculates a code positioning solution using the GNSS reception data, and stores it in the storage unit (S33).

The vehicle-mounted device 62c determines whether or not it has entered the communication area of the roadside device 63c, which is the next roadside device (S34).

When the vehicle-mounted device 62c determines that it is not in the communication area of the roadside device 63c (No in S34), the process proceeds to S32.

On the other hand, when the vehicle-mounted device 62c determines that it has entered the communication area of the roadside device 63c (Yes in S34), it transmits the code positioning solution stored in the storage unit to the roadside device 63c (S35).

The roadside device 63c transmits the code positioning solution transmitted in S35 to the server 64 (S36).

The server 64 calculates the center of the distribution of the code positioning solution of the vehicle-mounted device 62c transmitted in S36 and the code positioning solutions of the other vehicle-mounted devices including the vehicle-mounted devices 62a and 62b (S37).

The server 64 selects the RSS 65 or VSR 66 closest to the center position calculated in S37, and transmits the correction information of the selected RSS 65 or VSR 66 to the roadside device 63c (S38).

The roadside device 63c transmits the correction information transmitted in S38 to the vehicle-mounted device 62c (S39). That is, the roadside device 63c transmits the correction information in the non-communication area X11 to the vehicle-mounted device 62c that has passed through the non-communication area X11.

The vehicle-mounted device 62c calculates a high-precision positioning solution in the non-communication area X11 by RTK calculation using the GNSS reception data stored in the storage unit in S32 and the correction information transmitted in S39 (S40). .

The roadside devices 63a and 63b also distribute correction information in the same manner as the roadside device 63c. Vehicle-mounted devices passing through the communication areas of the roadside devices 63a and 63b receive correction information distributed from the roadside devices 63a and 63b and GNSS reception in the non-communication areas passed before entering the communication areas of the roadside devices 63a and 63b. A high-precision positioning solution for a non-communication area is calculated from the data.

Further, in S37 of FIG. 21, the server 64 calculates the center of the distribution of the code positioning solution of the vehicle-mounted device 62c and the code-positioning solutions of the other vehicle-mounted devices including the vehicle-mounted devices 62a and 62b, but the present invention is not limited to this. The server 64 may calculate the center of the distribution of the code positioning solutions of the other vehicle-mounted devices including the vehicle-mounted devices 62a and 62b, except for the vehicle-mounted device 62c.

As described above, the vehicle-mounted device 62c receives correction information from the roadside device 63c during the period from the end of communication with the roadside device 63a (or roadside device 63b) to the start of communication with the roadside device 63c. a DSRC communication unit; and a processor for calculating a high-precision positioning solution between said stations using GNSS received data and correction information between said stations. Thereby, the vehicle-mounted device 62c can calculate a high-precision positioning solution in the non-communication area X11.

In addition, the server 64 uses the GNSS reception data from the vehicle-mounted devices 62a and 62b to calculate the code positioning solutions between the end of communication with the roadside devices 63a and 63b and the start of communication with the roadside device 63c. , a communication unit that receives data via the roadside device 63c; a processor that selects a reference station that outputs correction information between the above based on the code positioning solution; and a transmitter for transmitting to the device 62c. Thereby, the vehicle-mounted device 62c can calculate a high-precision positioning solution in the non-communication area X11.

In the embodiment, the onboard devices 62a, 62b, and 62c are all different onboard devices, but at least the onboard devices 62a and 62c may be the same onboard device. This is because this vehicle-mounted device has recorded code positioning solutions in the non-communication area X11 that it has already passed through, and records code positioning solutions at the positions of both the vehicle-mounted devices 62a and 62c. In addition, since the center of the distribution can be calculated by obtaining code positioning solutions at least two positions, if the vehicle-mounted devices 62a and 62c are the same vehicle-mounted device, the code from the other vehicle-mounted device 62b can be calculated. A positioning solution may not be used. By doing so, it is possible to calculate a highly accurate positioning solution in the non-communication area 11 even on roads with little traffic.

In the third embodiment, the server 64 also uses the code positioning solutions of the other onboard devices 62a and 62b that were uploaded before the onboard device 62c that uploaded the code positioning solution, and the center of the distribution of the code positioning solutions. was calculated, but it is not limited to this. The server 64 may calculate the center of the distribution of the code positioning solutions using the code positioning solution of the onboard device 62c that has uploaded the code positioning solutions without using the code positioning solutions of the other onboard devices 62a and 62b. Then, the server 64 may select a reference station closer to the calculated center and transmit the correction information of the selected reference station to the vehicle-mounted device 62c. This is because if the vehicle-mounted device 62c calculates and records code positioning solutions at two or more positions in the non-communication area X11 that has already passed through, the center of the distribution can be obtained based on those code positioning solutions. be. The center of the distribution can be calculated by obtaining code positioning solutions at least two positions. can calculate the center of the distribution without using the code positioning solutions of the other vehicle-mounted devices 62a and 62b. By doing so, it is possible to calculate a highly accurate positioning solution in the non-communication area 11 even on roads with little traffic.

(Fourth embodiment)
In the third embodiment, the vehicle-mounted device a posteriori calculates a high-precision positioning solution in the non-communication area through which the vehicle has passed. In the fourth embodiment, the vehicle-mounted device calculates in real time (while passing through the non-communication area) a high-precision positioning solution in the passing non-communication area.

FIG. 22 is a diagram showing a configuration example of a positioning system 71 according to the fourth embodiment. As shown in FIG. 22, the positioning system 71 includes vehicle-mounted devices 72a to 72c mounted on vehicles A51 to A53, roadside devices 73a to 73c, a server 74, RRSs 75a to 75c, and a VRS 76. there is The block configuration of the vehicle-mounted devices 72a to 72c is the same as the block configuration of the vehicle-mounted device 3 described with reference to FIG. 4, and the description thereof will be omitted. The block configuration of the roadside units 73a to 73c is the same as the block configuration of the roadside unit 4 described with reference to FIG. 5, so description thereof will be omitted. The block configuration of the server 74 is the same as the block configuration of the server 5 described with reference to FIG. 6, so description thereof will be omitted.

Hereinafter, the vehicle-mounted devices 72a to 72c are referred to as the vehicle-mounted device 72 when not distinguished. When the roadside units 73a to 73c are not distinguished, they are referred to as the roadside unit 73. When RRS75a-75c are not distinguished, they are described as RRS75.

The vehicle-mounted device 72 and the roadside device 73 perform two-way communication based on DSRC. The vehicle-mounted device 72 communicates with the roadside device 73 within the communication area formed by the roadside device 73 .

Vehicles A51-A53 are equipped with GNSS receivers (not shown). Each of the vehicle-mounted devices 72a to 72c receives GNSS reception data output from the GNSS receiver.

FIG. 22 shows a non-communication area X21 in which the communication area of the roadside device 73 is not formed. The non-communication area X21 includes the travel route of the vehicle passing through the communication area of the roadside device 73a and passing through the communication area of the roadside device 73b. The non-communication area X21 includes the travel route of the vehicle passing through the communication area of the roadside device 73a and passing through the communication area of the roadside device 73c. The vehicle-mounted device 72 cannot perform DSRC-based communication with the roadside device 73 in the non-communication area X21.

The vehicle-mounted device 72 calculates a code positioning solution using the GNSS reception data. The vehicle-mounted device 72 transmits the calculated code positioning solution to the server 74 via the roadside device 73 . Moreover, the vehicle-mounted device 72 performs RTK calculation using the GNSS reception data and the correction information distributed from the roadside device 73, and calculates a high-precision positioning solution.

The server 74 calculates the center of the distribution (distribution of positions) of the code positioning solutions transmitted from the vehicle-mounted device 72 . The server 74 acquires the correction information of the RRS 75 or VRS 76 closest to the calculated center. For example, in the example of FIG. 20, the server 74 acquires the correction information of the RRS 75a. In other words, the server 74 acquires correction information near the center of the distribution of travel routes for which DSRC communication cannot be performed. The server 74 distributes the acquired correction information to the vehicle-mounted device 72 via the roadside device 73 .

An operation example of the positioning system 71 will be described below. First, uploading the code positioning solution in the non-communication area X21 to the server 74 will be described.

The vehicle A52 shown in FIG. 22 passes through the communication area of the roadside device 73a and the non-communication area X21, and enters the communication area of the roadside device 73b. While traveling in the non-communication area X21, the vehicle-mounted device 72b of the vehicle A52 calculates the code positioning solution using the GNSS reception data output from the GNSS receiver, and stores the calculated code positioning solution in the storage unit. do. That is, the vehicle-mounted device 72b calculates the code positioning solution of the travel route from the end of communication with the roadside device 73a to the start of communication with the roadside device 73b, and stores the code positioning solution in the storage unit.

When the vehicle-mounted device 72b enters the communication area of the roadside device 73b, it transmits the code positioning solution stored in the storage unit to the roadside device 73b. The roadside device 73b transmits to the server 74 the code positioning solution transmitted from the vehicle-mounted device 72b.

Similarly, the vehicle A53 shown in FIG. 22 passes through the communication area of the roadside device 73a and the non-communication area X21, and enters the communication area of the roadside device 73c. While traveling in the non-communication area X21, the vehicle-mounted device 72c of the vehicle A53 calculates a code positioning solution using the GNSS reception data output from the GNSS receiver, and stores the calculated code positioning solution in the storage unit. do. That is, the vehicle-mounted device 72c calculates the code positioning solution of the traveling route from the end of communication with the roadside device 73a to the start of communication with the roadside device 73c, and stores the code positioning solution in the storage unit.

When the vehicle-mounted device 72c enters the communication area of the roadside device 73c, it transmits the code positioning solution stored in the storage unit to the roadside device 73c. The roadside device 73c transmits to the server 74 the code positioning solution transmitted from the vehicle-mounted device 72c.

In this way, the code positioning solutions in the non-communication area X21 of the vehicle-mounted devices 72b and 72c are uploaded to the server 74. FIG.

Next, an operation example up to the RTK calculation in the vehicle-mounted device 72a will be described using a sequence diagram.

23A and 23B are sequence diagrams illustrating an operation example of the positioning system 71. FIG. In the following description, the vehicle-mounted device 72b enters the communication area of the roadside device 73a, passes through the non-communication area X21, and enters the communication area of the roadside device 73b. When the vehicle-mounted device 72b enters the communication area of the roadside device 73a, it receives the correction information for the non-communication area X21 from the server 74 via the roadside device 73a.

In the following description, the vehicle-mounted device 72c enters the communication area of the roadside device 73a, passes through the non-communication area X21, and enters the communication area of the roadside device 73c. When the vehicle-mounted device 72c enters the communication area of the roadside device 73a, it receives the correction information for the non-communication area X21 from the server 74 via the roadside device 73a.

As shown in FIG. 23B, the vehicle-mounted device 72b determines whether it is outside the communication area of the roadside device 73a (S51). When the vehicle-mounted device 72b determines that it is not outside the communication area of the roadside device 73a (No in S51), it repeats the processing of S51.

On the other hand, when the vehicle-mounted device 72b determines outside the communication area of the roadside device 73a (Yes in S51), the correction information in the non-communication area X21 received from the roadside device 73a, the GNSS reception data output from the GNSS receiver, and is used to perform RTK calculation (S52). That is, when the vehicle-mounted device 72b exits the communication area of the roadside device 73a and enters the non-communication area X21, the vehicle-mounted device 72b uses the correction information in the non-communication area X21 received from the roadside device 73a to adjust the height in the non-communication area X21. Calculate the precision positioning solution in real time.

The vehicle-mounted device 72b calculates a code positioning solution using the GNSS reception data output from the GNSS receiver, and stores it in the storage unit (S53). That is, when the vehicle-mounted device 72b leaves the communication area of the roadside device 73a and enters the non-communication area X21, it calculates the code positioning solution and stores it in the storage unit.

The high-precision positioning solution calculated in step S52 may be stored in the storage unit instead of the code positioning solution calculated in step S53. However, since the high-precision positioning solution calculated in step S52 is a positioning solution at a past point in time, the code positioning solution calculated in step S53 may reflect the latest position of the vehicle-mounted device 72b. is high. Therefore, the code positioning solution may be stored in the storage unit in situations where the position is likely to change, such as when the vehicle-mounted device 72b is moving at high speed, and the high-precision positioning solution may be stored in the situation where the position is difficult to change, such as traffic congestion. Note that when the high-precision positioning solution is stored in step S52, the high-precision positioning solution may be used in subsequent steps instead of the code positioning solution.

The vehicle-mounted device 72b determines whether or not it has entered the communication area of the roadside device 73b, which is the next roadside device (S54).

When the vehicle-mounted device 72b determines that it is not in the communication area of the roadside device 73b (No in S54), the process proceeds to S52.

On the other hand, when the vehicle-mounted device 72b determines that it has entered the communication area of the roadside device 73b (Yes in S54), it transmits the code positioning solution stored in the storage unit to the roadside device 73b (S55).

The roadside device 73b transmits the code positioning solution transmitted in S55 to the server 74 (S56).

As shown in FIG. 23B, the vehicle-mounted device 72c determines whether it is outside the communication area of the roadside device 73a (S61). When the vehicle-mounted device 72c determines that it is not outside the communication area of the roadside device 73a (No in S61), it repeats the processing of S61.

On the other hand, when the vehicle-mounted device 72b determines outside the communication area of the roadside device 73a (Yes in S61), the correction information in the non-communication area X21 received from the roadside device 73a and the GNSS reception data output from the GNSS receiver. is used to perform RTK calculation (S62). That is, when the vehicle-mounted device 72c exits the communication area of the roadside device 73a and enters the non-communication area X21, the vehicle-mounted device 72c uses the correction information in the non-communication area X21 received from the roadside device 73a to determine the height in the non-communication area X21. Calculate the precision positioning solution in real time.

The vehicle-mounted device 72c calculates a code positioning solution using the GNSS reception data output from the GNSS receiver, and stores it in the storage unit (S63). That is, when the vehicle-mounted device 72c leaves the communication area of the roadside device 73a and enters the non-communication area X21, it calculates the code positioning solution and stores it in the storage unit.

The high-precision positioning solution calculated in step S62 may be stored in the storage unit instead of the code positioning solution calculated in step S63. However, since the high-precision positioning solution calculated in step S62 is a positioning solution at a past point in time, the code positioning solution calculated in step S63 may reflect the latest position of the vehicle-mounted device 72c. is high. Therefore, the code positioning solution may be stored in the storage unit when the position is likely to change, such as when the vehicle-mounted device 72c is moving at high speed. Note that when the high-precision positioning solution is stored in step S62, the high-precision positioning solution may be used in subsequent steps instead of the code positioning solution.

The vehicle-mounted device 72c determines whether or not it has entered the communication area of the roadside device 73c, which is the next roadside device (S64).

When the vehicle-mounted device 72c determines that it is not in the communication area of the roadside device 73c (No in S64), the process proceeds to S62.

On the other hand, when the vehicle-mounted device 72c determines that it has entered the communication area of the roadside device 73c (Yes in S64), it transmits the code positioning solution stored in the storage unit to the roadside device 73c (S65).

The roadside device 73c transmits the code positioning solution transmitted in S65 to the server 74 (S66).

As shown in FIG. 23A, the server 74 calculates the center of the distribution of the code positioning solutions of the other vehicle-mounted devices (S71). The code positioning solutions of the other vehicle-mounted devices include the code-positioning solutions of the vehicle-mounted devices 72b and 72c transmitted in S56 and S66 of FIG. 23B.

The server 74 selects the RSS 75 or VSR 76 closest to the center position calculated in S71, and transmits the correction information of the selected RSS 75 or VSR 76 to the roadside device 73a (S72).

The roadside device 73a transmits the correction information transmitted in S72 to the vehicle-mounted device 72a (S73). That is, after passing through the communication area of the roadside device 73a, the roadside device 73a transmits the correction information in the non-communication area X21 to the vehicle-mounted device 72a passing through the non-communication area X21.

The vehicle-mounted device 72a uses the GNSS reception data output from the GNSS receiver and the correction information transmitted in S73 to calculate a high-precision positioning solution in the non-communication area X21 by RTK calculation (S74). That is, the vehicle-mounted device 72a calculates a high-precision positioning solution in a non-communication area in real time.

In addition, in the sequence diagram of FIG. 23A, description of the process before the vehicle-mounted device 72a enters the communication area of the roadside device 73a is omitted.

As described above, the vehicle-mounted device 72a receives correction information from the roadside device 73a during the period from the end of communication with the roadside device 73a to the start of communication with the roadside device 73b (or roadside device 73c). a DSRC communication unit; and a processor for calculating a high-precision positioning solution between said stations using GNSS received data and correction information between said stations. Thereby, the vehicle-mounted device 72a can calculate a high-precision positioning solution in the non-communication area X21.

In addition, the server 74 uses the GNSS reception data received from the satellite by the vehicle-mounted devices 72b and 72c to calculate the a communication unit that receives the code positioning solution via the roadside units 73b and 73c; and a transmitter for transmitting to the vehicle-mounted device 72a via the device 73a. Thereby, the vehicle-mounted device 72a can calculate a high-precision positioning solution in the non-communication area X21.

In the above-described embodiments, the notation "... part" used for each component may be "... circuit (circuitry)", "... device", "... unit", or " . . module” may be substituted.

Although the embodiments have been described above with reference to the drawings, the present disclosure is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims. It is understood that such variations or modifications are also within the technical scope of the present disclosure. Further, each component in the embodiment may be combined arbitrarily within the scope of the present disclosure.

The present disclosure can be implemented in software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments is partially or wholly realized as an LSI, which is an integrated circuit, and each process described in the above embodiments is partially or wholly implemented as It may be controlled by one LSI or a combination of LSIs. An LSI may be composed of individual chips, or may be composed of one chip so as to include some or all of the functional blocks. The LSI may have data inputs and outputs. LSIs are also called ICs, system LSIs, super LSIs, and ultra LSIs depending on the degree of integration.

The method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Alternatively, an FPGA that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of the circuit cells inside the LSI may be used. The present disclosure may be implemented as digital or analog processing.

Furthermore, if an integration technology that replaces the LSI appears due to advances in semiconductor technology or another derived technology, the technology may naturally be used to integrate the functional blocks. Application of biotechnology, etc. is possible.

INDUSTRIAL APPLICABILITY The present disclosure is useful for a positioning system that calculates a travel route of a vehicle using positioning signals from satellites.

1, 51, 61, 71 Positioning system 2 GNSS receiver 3, 3a to 3c, 52, 62a to 62c, 72a to 72c Vehicle-mounted device 4, 53, 63a to 63c, 73a to 73c Roadside device 5, 64, 74 Server 65a , 65b, 75a-75c RRS
66a, 66b, 76 VRS
A1 vehicle A2, A31, X1 communication area X11, X21 non-communication area

Claims (10)

In-vehicle equipment,
The satellite reception information output from the receiver that receives the positioning signal from the satellite during the period from the end of communication with the first roadside device to the start of communication with the second roadside device is the second a transmission unit that transmits to the roadside unit of
a processor for controlling a transmission amount of the satellite reception information to be transmitted to the second roadside unit according to the traveling speed of the vehicle equipped with the vehicle-mounted device during the interval;
on-board equipment. The processor controls the transmission amount of the satellite reception information to be transmitted to the second roadside unit by changing the sampling rate of the satellite reception information according to the traveling speed.
The vehicle-mounted device according to claim 1. The processor further modifies the sampling rate according to the number of satellites with which the receiver communicates.
The vehicle-mounted device according to claim 2. The processor controls the transmission amount of the satellite reception information to be transmitted to the second roadside unit by changing the thinning amount of information included in the satellite reception information according to the traveling speed.
The vehicle-mounted device according to any one of claims 1 to 3. The processor further changes the decimation amount according to the number of the satellites with which the receiver communicates.
The vehicle-mounted device according to claim 4. A roadside unit,
A transmission unit that transmits satellite correction information for correcting a positioning signal received by the vehicle-mounted device from a satellite to the vehicle-mounted device;
According to the running speed of the vehicle equipped with the on- board device after the on-board device completes communication with another roadside device and before starting communication with the roadside device, the on-board device a processor for controlling a transmission amount of the satellite correction information to be transmitted;
A roadside unit with The processor controls the transmission amount of the satellite correction information to be transmitted to the vehicle-mounted device by changing the sampling rate of the satellite correction information according to the running speed.
The roadside machine according to claim 6. The processor controls the transmission amount of the satellite correction information to be transmitted to the vehicle-mounted device by changing the thinning amount of information included in the satellite correction information according to the running speed.
The roadside machine according to claim 6 or 7. An information transmission method for an on-vehicle device,
The satellite reception information output from the receiver that receives the positioning signal from the satellite during the period from the end of communication with the first roadside device to the start of communication with the second roadside device is the second to the roadside unit of
controlling the transmission amount of the satellite reception information to be transmitted to the second roadside unit according to the traveling speed of the vehicle equipped with the onboard unit during the interval;
How information is sent. A roadside unit information transmission method,
Sending satellite correction information for correcting the positioning signal received by the vehicle-mounted device from the satellite to the vehicle-mounted device,
According to the running speed of the vehicle equipped with the on- board device after the on-board device completes communication with another roadside device and before starting communication with the roadside device, the on-board device controlling the amount of satellite correction information to be transmitted;
How information is sent.

Images