Positioning system, roadside device, onboard device, program, and positioning method

Abstract

To provide a positioning system, a roadside device, an onboard device, a program, and a positioning method that make it possible to maintain high-accuracy positioning even when the RTK reference stations to use are switched over.SOLUTION: A positioning system of an embodiment comprises a roadside device and an onboard device. The positioning system selects one positioning result from a plurality of positioning results including a first and a second positioning result, selects a first positioning result from among a plurality of positioning results including a first positioning result in which a fix solution is obtained and a second positioning result in which the fix solution is not obtained, and thereafter selects a second positioning result from among a plurality of positioning results including a first positioning result in which the fix solution is obtained and a second positioning result in which the fix solution is obtained.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a positioning system, a roadside device, an in-vehicle device, a program, and a positioning method. [Background technology]

[0002] RTK (real-time kinematic) is known as a technology for improving the positioning accuracy of GNSS (global navigation satellite system) such as GPS (Global Positioning System) (Patent Document 1). However, RTK requires time to obtain a fix solution. For this reason, a device using RTK cannot obtain a high-precision positioning result using a fix solution until the fix time has elapsed after starting positioning, and can only obtain a low-precision positioning result using a float solution. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6366357 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the error in RTK increases the further away from the RTK reference station, the error can be reduced by appropriately switching between RTK reference stations depending on the distance. However, as mentioned above, it takes time to fix, so unless some ingenuity is taken, the positioning accuracy will decrease every time the RTK reference station is switched. Also, depending on the environment, the float solution may not converge, making it impossible to perform the required positioning.

[0005] Patent Document 1 describes that in a method such as RTK in which positioning augmentation information is obtained from a terrestrial line, if positioning supplementary information cannot be obtained, positioning augmentation information obtained from a satellite line is used. Patent Document 1 describes that this makes it possible to improve the implementation rate of high-precision positioning.

[0006] The problem to be solved by the embodiments of the present invention is to provide a roadside device, a positioning device, a server device, a program, a transmission method, and a positioning method that can support switching of RTK reference stations while maintaining high-precision positioning. [Means for solving the problem]

[0007] A positioning system according to an embodiment includes a roadside device having a function corresponding to V2X communication, and an in-vehicle device capable of communicating with the roadside device and having a function corresponding to V2X communication, wherein the roadside device at least generates first correction information for correcting a position determined by the in-vehicle device, which is a mobile station, using a GNSS signal transmitted from a GNSS satellite, the first correction information being generated by a first RTK reference station, and correcting the position determined by the in-vehicle device using the GNSS signal being generated by a second RTK reference station different from the first RTK reference station. the on-board device includes an on-board communication unit for communicating with the roadside device, and a first communication unit for receiving second correction information for correcting a position measured using the GNSS signal from the first RTK reference station, the first correction information being generated at a first RTK reference station and a first positioning using the GNSS signal and the first correction information, the first correction information being generated at a second RTK reference station different from the first RTK reference station; a positioning unit that receives second correction information from the second RTK reference station for correcting a position determined using the GNSS signal, and performs second positioning using the GNSS signal and the second correction information, wherein the roadside device communicates with the in-vehicle device at a predetermined timing, the first correction information is correction information that is evaluated to have the smallest positioning error at the installation position of the roadside device, the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device, and the positioning unit receives the first correction information from the in-vehicle device at the predetermined timing, a roadside device that communicates with the vehicle-mounted device, the positioning unit having a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning, the vehicle-mounted device having a determination unit that, when there are a plurality of pieces of correction information, determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among the plurality of pieces of correction information, the determination unit gives priority to the correction information in the traveling direction of the vehicle-mounted device, and the traveling direction is a direction predicted by a traveling direction prediction unit that predicts the traveling direction based on past driving route data;or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, and the in-vehicle device includes a selection unit that selects one positioning result from a plurality of positioning results including the first positioning result and the second positioning result, selects the first positioning result from a plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selects the second positioning result from a plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained.

[0008] The second communication unit may broadcast the first correction information and the second correction information at the same time.

[0009] The selection unit may select the second positioning result from the multiple positioning results when the second RTK reference station is in the traveling direction of the vehicle-mounted device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result.

[0010] A roadside device of an embodiment is a roadside device having a function corresponding to V2X communication, and includes at least a first communication unit that receives first correction information generated at a first RTK reference station for correcting a position measured by an on-board device that is a mobile station using a GNSS signal transmitted from a GNSS satellite, and second correction information generated at a second RTK reference station different from the first RTK reference station for correcting a position measured by the on-board device using the GNSS signal, and a second communication unit that communicates with the on-board device, wherein the roadside device communicates with the on-board device at a predetermined timing, the first correction information is correction information that is evaluated to have the smallest positioning error at the installation position of the roadside device, and the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device.

[0011] The second communication unit may broadcast the first correction information and the second correction information at the same time.

[0012] An on-board device according to an embodiment is an on-board device capable of communicating with a roadside device and having a function corresponding to V2X communication, the on-board device including at least an on-board communication unit for communicating with the roadside device, a first RTK reference station for receiving a GNSS signal transmitted from a GNSS satellite, receiving first correction information from the first RTK reference station, the first correction information being generated at the first RTK reference station and used to correct a position determined using the GNSS signal, and a first positioning using the GNSS signal and the first correction information, and a second RTK reference station for performing a first positioning using the first RTK reference station. and a positioning unit that receives, from a second RTK reference station different from a TK reference station, second correction information for correcting a position measured using the GNSS signal, and performs second positioning using the GNSS signal and the second correction information, wherein the positioning unit communicates with the roadside device at a predetermined timing, and the positioning unit includes a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning, and when there are multiple pieces of correction information, the vehicle-mounted device performs multiple calculations. the vehicle-mounted device includes a determination unit that determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among a number of pieces of correction information, the determination unit preferentially determines the correction information in the traveling direction of the vehicle-mounted device, the traveling direction being a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past driving route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, the vehicle-mounted device includes a selection unit that selects one positioning result from among a plurality of positioning results including the first positioning result and the second positioning result, selects the first positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selects the second positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained.

[0013] The selection unit may select the second positioning result from the multiple positioning results when the second RTK reference station is in the traveling direction of the vehicle-mounted device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result.

[0014] A program according to an embodiment is a program that causes a processor of a roadside device having at least a first communication device and a second communication device, and a processor of an in-vehicle device, to function as a positioning system, the roadside device at least receiving first correction information for correcting a position measured by the in-vehicle device, which is a mobile station, using a GNSS signal transmitted from a GNSS satellite, the first correction information being generated at a first RTK reference station, and a position measured by the in-vehicle device using the GNSS signal being generated at a second RTK reference station different from the first RTK reference station. The vehicle-mounted device includes an on-board communication unit for communicating with the roadside device, and a first communication unit for receiving second correction information for correcting a position, the on-board device having at least an on-board communication unit for receiving a GNSS signal transmitted from a GNSS satellite, receiving first correction information from the first RTK reference station, the first correction information being generated at a first RTK reference station, for correcting a position measured using the GNSS signal, and performing a first positioning using the GNSS signal and the first correction information, and a second RTK reference station different from the first RTK reference station. a positioning unit that receives, from the second RTK reference station, second correction information for correcting a position determined using the GNSS signal, and performs second positioning using the GNSS signal and the second correction information, wherein the roadside device communicates with the in-vehicle device at a predetermined timing, the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, and the second correction information is correction information that is evaluated to have the second smallest positioning error at an installation position of the roadside device, and the positioning unit receives, from the second RTK reference station, second correction information for correcting a position determined using the GNSS signal, and performs second positioning using the GNSS signal and the second correction information, wherein the roadside device communicates with the in-vehicle device at a predetermined timing, the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, and the second correction information is correction information that is evaluated to have the second smallest positioning error at an installation position of the roadside device, the vehicle-mounted device communicates with the roadside device by a signal from a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning; the vehicle-mounted device includes a determination unit that, when there are a plurality of pieces of correction information, determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among the plurality of pieces of correction information; the determination unit gives priority to the correction information in the traveling direction of the vehicle-mounted device, and the traveling direction is a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past driving route data.or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, the in-vehicle device including a selection unit, the selection unit selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result, selecting the first positioning result from the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and thereafter selecting the second positioning result from the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained.

[0015] A positioning method according to an embodiment is a positioning method in a positioning system including a roadside device having a function corresponding to V2X communication, and an in-vehicle device capable of communicating with the roadside device and having a function corresponding to V2X communication, wherein the roadside device at least receives first correction information generated in a first RTK reference station for correcting a position determined by the in-vehicle device, which is a mobile station, using a GNSS signal transmitted from a GNSS satellite, and a second RTK reference station different from the first RTK reference station for correcting the position determined by the in-vehicle device using the GNSS signal. The on-board device at least receives a GNSS signal transmitted from a GNSS satellite, receives from the first RTK reference station first correction information for correcting a position determined using the GNSS signal, the first correction information being generated at the first RTK reference station, performs a first positioning using the GNSS signal and the first correction information, and receives from the second RTK reference station second correction information for correcting the position determined using the GNSS signal, the second correction information being generated at a second RTK reference station different from the first RTK reference station, and performs a first positioning using the GNSS signal and the first correction information. and performing a second positioning using correct information and the first correction information, the roadside device communicates with the vehicle-mounted device at a predetermined timing, the first correction information is correction information evaluated to have the smallest positioning error at the installation position of the roadside device, and the second correction information is correction information evaluated to have the second smallest positioning error at the installation position of the roadside device, the vehicle-mounted device communicates with the roadside device at a predetermined timing, and when there are a plurality of pieces of correction information, the vehicle-mounted device selects the first correction information to be input to a first calculation unit and the second correction information to be input to a second calculation unit from the plurality of pieces of correction information. determining a direction of travel of the on-vehicle device, giving priority to the correction information in the traveling direction of the on-vehicle device, the traveling direction being a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past travel route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel; selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result; and selecting the first positioning result from the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained;Then, the second positioning result is selected from the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained.

[0016] The roadside device of the embodiment includes a receiver and a transmitter. The receiver receives at least first correction information generated in a first reference station for correcting a position measured using a GNSS signal, and second correction information generated in a second reference station different from the first reference station for correcting a position measured using the GNSS signal. The transmitter transmits the first correction information and the second correction information at once via wireless communication.

[0017] The transmission unit may broadcast the first correction information and the second correction information at the same time. The first correction information is, for example, correction information that is evaluated to have the smallest positioning error at the installation position of the roadside device. The second correction information is, for example, correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device.

[0018] A positioning device according to an embodiment includes a positioning unit that performs at least one of a first positioning using a GNSS signal and first correction information generated in a first reference station for correcting a position determined by using the GNSS signal, and a second positioning using the GNSS signal and second correction information generated in a second reference station different from the first reference station for correcting a position determined by using the GNSS signal, in parallel or in parallel.

[0019] The positioning unit may include a first calculation unit that performs the first positioning, and a second calculation unit that performs the second positioning. The positioning device according to the embodiment may further include a determination unit, which, when there are three or more pieces of correction information, determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from the three or more pieces of correction information.

[0020] The determination unit may preferentially determine correction information for which a generated reference station is located in the traveling direction of the positioning device. The traveling direction is a direction predicted by a traveling direction prediction unit that predicts the traveling direction based on past travel route data.

[0021] The traveling direction is a direction determined by a route search unit that determines the route along which the vehicle is scheduled to travel. The positioning device according to the embodiment may further include a selection unit that selects one positioning result from a plurality of positioning results including the first positioning result and the second positioning result.

[0022] The selection unit may select a positioning result for which a fix solution has been obtained from among the plurality of positioning results. The selection unit may select the first positioning result from the multiple positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then select the second positioning result from the multiple positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained.

[0023] The selection unit may select the second positioning result from the multiple positioning results when the second reference station is in the direction of travel of the positioning device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result. The server device of the embodiment includes a server receiving unit and a server transmitting unit. The server receiving unit receives at least first correction information generated in a first reference station for correcting a position measured by using a GNSS signal, and second correction information generated in a second reference station different from the first reference station for correcting a position measured by using the GNSS signal. The server transmitting unit transmits the first correction information and the second correction information to a roadside device at the same time.

[0024] A program according to an embodiment causes a processor included in a roadside device including at least a first communication device and a second communication device to function as a reception control unit and a transmission control unit. The reception control unit controls the first communication device to receive at least first correction information generated in a first reference station for correcting a position measured using a GNSS signal, and second correction information generated in a second reference station different from the first reference station for correcting a position measured using the GNSS signal. The transmission control unit controls the second communication device to transmit the first correction information and the second correction information at once via wireless communication. A program according to an embodiment causes a processor included in a positioning device to function as a positioning unit. The positioning unit performs at least one of a first positioning using a GNSS signal and first correction information generated in a first reference station for correcting a position measured using the GNSS signal, and a second positioning using the GNSS signal and second correction information generated in a second reference station different from the first reference station for correcting a position measured using the GNSS signal, in parallel or in parallel.

[0025] A transmission method according to an embodiment includes receiving at least first correction information, which is generated in a first reference station and is for correcting a position measured by using a GNSS signal, and second correction information, which is generated in a second reference station different from the first reference station and is for correcting a position measured by using the GNSS signal. The transmission method according to an embodiment includes transmitting the first correction information and the second correction information at once by wireless communication. The positioning method of the embodiment performs at least one of a first positioning using a GNSS signal and first correction information generated at a first reference station for correcting a position determined by positioning using the GNSS signal, and a second positioning using the GNSS signal and second correction information generated at a second reference station different from the first reference station for correcting a position determined by positioning using the GNSS signal, in parallel or in parallel. Effect of the Invention

[0026] The present invention makes it possible to support switching of RTK reference stations while maintaining highly accurate positioning. [Brief description of the drawings]

[0027] [Figure 1] 1 is a diagram showing an overview of a positioning system according to an embodiment; [Diagram 2] 1 is a block diagram showing an example of a configuration of a positioning system according to an embodiment and essential components included in the positioning system; [Diagram 3] 3 is a block diagram showing an example of the configuration of a positioning calculation unit 360 in FIG. 2. [Figure 4] 3 is a flowchart showing an example of processing by a processor of the server device in FIG. 2. [Diagram 5] 3 is a flowchart showing an example of processing performed by a processor of the in-vehicle device in FIG. 2. [Figure 6] 11 is a diagram for explaining correction information CI1 and correction information CI2. FIG. [Figure 7] FIG. 1 is a diagram for explaining an example of an RTK reference station in the traveling direction of a vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a positioning system according to an embodiment will be described with reference to the drawings. Note that the scale of each part in each drawing used in the following description of the embodiment may be changed as appropriate. Also, for the sake of explanation, each drawing used in the following description of the embodiment may be shown with the configuration omitted. Also, in each drawing and in this specification, the same reference numerals indicate similar elements. The configuration of the positioning system 1 will be described with reference to Figs. 1 and 2. Fig. 1 is a diagram showing an overview of the positioning system 1 according to the embodiment. Fig. 2 is a block diagram showing an example of the main configuration of the positioning system 1 according to the embodiment and the components included in the positioning system 1. The positioning system 1 is a system for positioning the position of an in-vehicle device 300 using GNSS and RTK. The positioning system 1 includes, as an example, a roadside device 100, a server device 200, an in-vehicle device 300, an RTK reference station 400, a GNSS satellite 500, and a vehicle 600. Note that the positioning system 1 typically includes a plurality of roadside devices 100, a server device 200, an in-vehicle device 300, an RTK reference station 400, and a GNSS satellite 500.

[0029] The server device 200 and the RTK reference station 400 are connected to a network NW. The network NW is typically a communication network including the Internet. The network NW is typically a communication network including a WAN (wide area network). The network NW may be a communication network including a private network such as an intranet. The network NW may be a communication network including a LAN (local area network). The network NW may be a wireless line or a wired line, or may be a mixture of wireless and wired lines. The network NW may be a communication network including a dedicated line or a public mobile phone network.

[0030] The roadside device 100 is a device that provides a vehicle-to-everything (V2X) communication service and the like to various devices such as the in-vehicle device 300. The roadside device 100 is installed, for example, around a road or inside a road. FIG. 1 shows two roadside devices 100, a roadside device 100a and a roadside device 100b, as an example. The roadside device 100 includes, as an example, a processor 110, a read-only memory (ROM) 120, a random-access memory (RAM) 130, an auxiliary storage device 140, a communication interface 150, and a roadside communication interface (I / F) 160. A bus 170 and the like connect these units.

[0031] The processor 110 is a central part of a computer that performs processing such as calculations and control required for the operation of the roadside device 100, and performs various calculations and processing. The processor 110 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 110 is a combination of a plurality of these. The processor 110 may also be a combination of these with a hardware accelerator or the like. The processor 110 controls each part to realize various functions of the roadside device 100 based on programs such as firmware, system software, and application software stored in the ROM 120 or the auxiliary storage device 140. The processor 110 also executes processing described later based on the programs. A part or all of the programs may be incorporated in the circuit of the processor 110.

[0032] The ROM 120 and the RAM 130 are main memory devices of the computer with the processor 110 at its core. The ROM 120 is a non-volatile memory used exclusively for reading data. The ROM 120 stores, for example, firmware among the above programs. The ROM 120 also stores data used by the processor 110 when performing various processes. The RAM 130 is a memory used for reading and writing data. The RAM 130 is used as a work area for storing data that is temporarily used when the processor 110 performs various processes. The RAM 130 is typically a volatile memory.

[0033] The auxiliary storage device 140 is an auxiliary storage device of a computer with the processor 110 at its core. The auxiliary storage device 140 is, for example, an EEPROM (electric erasable programmable read-only memory), a HDD (hard disk drive), or a flash memory. The auxiliary storage device 140 stores, for example, system software and application software among the above programs. The auxiliary storage device 140 also stores data used by the processor 110 in performing various processes, data generated by the processes in the processor 110, various setting values, and the like.

[0034] The communication interface 150 is an interface for communicating with the server device 200 and the like. The communication interface 150 communicates with the server device 200, for example, via a network NW. Alternatively, the communication interface 150 may communicate with the server device 200 directly without via the network NW. The communication interface 150 is an example of a first communication device.

[0035] The roadside communication I / F 160 is an interface for the roadside device 100 to communicate with various devices, such as the in-vehicle device 300, within a communication range AR by communication such as V2X communication. The communication range AR indicates, for example, a range in which the roadside device 100 and the in-vehicle device 300 can communicate with each other. The roadside communication I / F 160 typically performs wireless communication. The roadside communication I / F 160 includes an antenna for wireless communication. The roadside communication I / F 160 is an example of a second communication device.

[0036] The server device 200 is, for example, a device that receives correction information CI for RTK from an RTK reference station and transmits it to the roadside device 100. The correction information CI is information for correcting a position measured by GNSS. By using the correction information CI, a positioning error is reduced. One server device 200 transmits correction information CI to one or more roadside devices 100, for example. FIG. 1 shows two server devices 200, namely, server device 200a and server device 200b, as an example. Furthermore, the number of roadside devices 100 to which the correction information CI is transmitted for each of the server devices 200 shown in FIG. 1 is one. Note that the roadside device 100 may have the same function as the server device 200 and perform the same operation as the server device 200. In this case, the server device 200 is not necessary. The server device 200 includes, for example, a processor 210, a ROM 220, a RAM 230, an auxiliary storage device 240, and a communication interface 250. A bus 260 and the like connect these units.

[0037] The processor 210 is a central part of a computer that performs various calculations and processes such as calculations and control required for the operation of the server device 200. The processor 210 is, for example, a CPU, an MPU, an SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor 210 is a combination of a plurality of these. The processor 210 may also be a combination of these with a hardware accelerator. The processor 210 controls each part to realize various functions of the server device 200 based on programs such as firmware, system software, and application software stored in the ROM 220 or the auxiliary storage device 240. The processor 210 also executes processes described below based on the programs. A part or all of the programs may be incorporated in the circuitry of the processor 210.

[0038] The ROM 220 and the RAM 230 are the main memory devices of the computer with the processor 210 at its core. The ROM 220 is a non-volatile memory used exclusively for reading data. The ROM 220 stores, for example, firmware among the above programs. The ROM 220 also stores data used by the processor 210 when performing various processes. The RAM 230 is a memory used for reading and writing data. The RAM 230 is used as a work area for storing data that is temporarily used when the processor 210 performs various processes. The RAM 230 is typically a volatile memory.

[0039] The auxiliary storage device 240 is an auxiliary storage device of a computer with the processor 210 at its core. The auxiliary storage device 240 is, for example, an EEPROM, a HDD, or a flash memory. The auxiliary storage device 240 stores, for example, system software and application software among the above programs. The auxiliary storage device 240 also stores data used by the processor 210 in performing various processes, data generated by the processes in the processor 210, various setting values, and the like.

[0040] The communication interface 250 is an interface for the server device 200 to communicate via a network NW etc. The communication interface 250 may communicate with the roadside device 100 without via the network NW.

[0041] The on-vehicle device 300 is mounted on a vehicle 600 or the like. The on-vehicle device 300 is a mobile station in RTK. Note that FIG. 1 shows vehicles 600a to 600c as the vehicles 600. The vehicles 600a to 600c show the same vehicle 600 moving. That is, the vehicles 600 move in the order of vehicle 600a, vehicle 600b, and vehicle 600c. The on-vehicle device 300 mounted on the vehicle 600a is, for example, within the communication range ARa of the roadside device 100a, and communicates with the roadside device 100a. The on-vehicle device 300 mounted on the vehicle 600b is, for example, within the communication range ARa and within the communication range ARb of the roadside device 100b, but communicates with the roadside device 100b, for example, because the communication strength with the roadside device 100b is strong. The on-vehicle device 300 mounted on the vehicle 600c is in the communication range ARb, for example, and therefore communicates with the roadside device 100b. In this manner, the on-vehicle device 300 switches the roadside device 100 with which it communicates as the vehicle 600 moves.

[0042] The in-vehicle device 300 includes, for example, a processor 310, a ROM 320, a RAM 330, an auxiliary storage device 340, a roadside communication I / F 350, a positioning calculation unit 360, a display device 370, and an input device 380. A bus 390 and the like connect these units together. The in-vehicle device 300 is an example of a positioning device.

[0043] The processor 310 is a central part of a computer that performs processes such as calculations and control required for the operation of the in-vehicle device 300, and performs various calculations and processes. The processor 310 is, for example, a CPU, an MPU, an SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor 310 is a combination of a plurality of these. The processor 310 may also be a combination of these with a hardware accelerator. The processor 310 controls each part to realize various functions of the in-vehicle device 300 based on programs such as firmware, system software, and application software stored in the ROM 320 or the auxiliary storage device 340. The processor 310 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuitry of the processor 310.

[0044] The ROM 320 and the RAM 330 are the main memory devices of the computer with the processor 310 at its core. The ROM 320 is a non-volatile memory used exclusively for reading data. The ROM 320 stores, for example, firmware among the above programs. The ROM 320 also stores data used by the processor 310 when performing various processes. The RAM 330 is a memory used for reading and writing data. The RAM 330 is used as a work area for storing data that is temporarily used when the processor 310 performs various processes. The RAM 330 is typically a volatile memory.

[0045] The auxiliary storage device 340 is an auxiliary storage device of a computer with the processor 310 as its core. The auxiliary storage device 340 is, for example, an EEPROM, a HDD, or a flash memory. The auxiliary storage device 340 stores, for example, system software and application software among the above programs. The auxiliary storage device 340 also stores data used by the processor 310 in performing various processes, data generated by the processes in the processor 310, various setting values, and the like.

[0046] The roadside communication I / F 350 is an interface for the in-vehicle device 300 to communicate with the roadside device 100 and the like by V2X communication or the like. The roadside communication I / F 350 includes an antenna for wireless communication and the like.

[0047] FIG. 3 is a block diagram showing an example of the configuration of the positioning calculation unit 360. As shown in FIG. The positioning calculation unit 360 is an integrated circuit (IC) or a module that performs positioning by calculation using GNSS and RTK. The positioning calculation unit 360 includes, for example, a satellite receiving unit 361, an RTK input unit 362, a selection unit 363, an RTK calculation unit 364, a result selection unit 365, a management control unit 366, and a prediction unit 367. The positioning calculation unit 360 includes a plurality of RTK calculation units 364. The positioning calculation unit 360 is an example of a positioning device.

[0048] The satellite receiving unit 361 receives the GNSS signal GS transmitted by the GNSS satellite 500. The satellite receiving unit 361 includes, for example, an antenna for receiving the GNSS signal GS. The satellite receiving unit 361 also outputs the received GNSS signal GS. The output GNSS signal GS is input to each of the multiple RTK calculation units 364.

[0049] The RTK input unit 362 is, for example, an interface that receives input of correction information CI generated by an RTK reference station.

[0050] The selection unit 363 distributes the multiple correction information CI input to the RTK input unit 362 to multiple RTK calculation units 364. When there are three or more pieces of correction information, the selection unit 363 is an example of a determination unit that determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from the three or more pieces of correction information.

[0051] The RTK calculation unit 364 is an IC or a module that performs RTK calculation processing using one input correction information CI and GNSS signal GS. The RTK calculation processing is processing for performing positioning using GNSS and RTK using the correction information CI and the GNSS signal GS. The RTK calculation unit 364 outputs a processing result. The output processing result is input to the result selection unit 365. The positioning calculation unit 360 can perform RTK calculation processing in parallel simultaneously for the number of RTK calculation units 364 included, for example. The multiple RTK calculation units 364 are an example of a positioning unit that performs at least a first positioning using the GNSS signal and the first correction information and a second positioning using the GNSS signal and the second correction information in parallel or in parallel. Any two of the multiple RTK calculation units 364 are an example of a first calculation unit and a second calculation unit. The positioning by the first calculation unit is an example of the first positioning. And the positioning by the second calculation unit is an example of the second positioning.

[0052] The result selection unit 365 decides which processing result to adopt from among the processing results input from the multiple RTK calculation units 364. Then, the result selection unit 365 outputs the processing result that it has decided to adopt. The processing result output from the result selection unit 365 is output from the positioning calculation unit 360. The result selection unit 365 is an example of a selection unit that selects one positioning result from among multiple positioning results.

[0053] The management control unit 366 manages and controls the positioning calculation unit 360 as a whole.

[0054] The prediction unit 367 predicts the traveling direction of the vehicle 600 using artificial intelligence (AI). The prediction unit 367 may include an AI accelerator such as an NPU (neural processing unit). If the positioning calculation unit 360 does not predict the traveling direction of the vehicle 600 using artificial intelligence, it is not necessary to include the prediction unit 367. The prediction unit 367 is an example of a traveling direction prediction unit that predicts the traveling direction based on past driving route data.

[0055] The display device 370 displays a screen for notifying various pieces of information to the operator of the in-vehicle device 300. The display device 370 is, for example, a display such as a liquid crystal display or an organic EL (electro-luminescence) display.

[0056] The input device 380 accepts operations by an operator of the in-vehicle device 300. The input device 380 is, for example, a keyboard, a keypad, a touchpad, a mouse, or a controller. The input device 380 may also be a device for voice input. A touch panel may also be used as the display device 370 and the input device 380. In this case, the display panel of the touch panel functions as the display device 370. And, a pointing device by touch input of the touch panel functions as the input device 380.

[0057] The bus 390 includes a control bus, an address bus, a data bus, etc., and transmits signals exchanged among the various components of the in-vehicle device 300 .

[0058] The RTK reference station 400 is a fixed station in RTK. The RTK reference station 400 receives a GNSS signal GS from a GNSS satellite 500. The RTK reference station 400 generates correction information CI using the GNSS signal GS. The RTK reference station 400 also transmits the correction information CI. FIG. 1 shows two RKT reference stations 400, ie, the RKT reference station 400a and the RKT reference station 400b, as an example. The correction information CI generated by the RTK reference station 400a is correction information CIa, and the correction information CI generated by the RTK reference station 400b is correction information CIb. The configuration of the RTK reference station 400 is, for example, a known configuration. Any two of the multiple RTK reference stations 400 are examples of the first reference station and the second reference station. The correction information CI generated by the first reference station is an example of first correction information for correcting the position of positioning using the GNSS signal. The correction information CI generated by the second reference station is an example of second correction information for correcting the position of the positioning using the GNSS signal.

[0059] The GNSS satellite 500 is a satellite that transmits a GNSS signal GS. The configuration of the GNSS satellite 500 is, for example, a known configuration.

[0060] The vehicle 600 may be a car, a motorcycle, etc. The vehicle 600 includes an on-board computer 610, for example.

[0061] The on-board computer 610 is, for example, an ECU (electronic control unit) etc. The on-board computer 610 is, for example, a computer that performs overall control of the vehicle 600. The on-board computer 610 may be capable of driving the vehicle 600 automatically.

[0062] The operation of the positioning system 1 according to the embodiment will be described below with reference to Figs. 4 and 5. Note that the contents of the process in the following operation description are merely examples, and various processes capable of obtaining similar results can be appropriately used. Fig. 4 is a flowchart showing an example of the process by the processor 210 of the server device 200. The processor 210 executes the process of Fig. 4 based on a program stored in, for example, the ROM 220 or the auxiliary storage device 240. Fig. 5 is a flowchart showing an example of the process by the processor 310 of the in-vehicle device 300. The processor 310 executes the process of Fig. 5 based on a program stored in, for example, the ROM 320 or the auxiliary storage device 340.

[0063] In step ST11 of Fig. 4, the processor 210 of the server device 200 acquires the correction information CI to be transmitted to the roadside device 100 that is the destination of the correction information CI. The auxiliary storage device 240 stores, for example, destination information that determines which correction information CI to transmit to each roadside device 100. The processor 210 determines from which RTK reference station 400 the correction information CI is to be acquired based on the destination information. The processor 210 controls the communication interface 250 to acquire the correction information CI from each of the multiple RTK reference stations 400 via the network NW.

[0064] The correction information CI to be transmitted to the roadside device 100 as determined by the destination information is, for example, N correction information CIs among the correction information CIs that the server device 200 can acquire, in order of the smallest evaluation value of the positioning error at the installation point (installation position) P1 of the roadside device 100. Here, N is an integer of 2 or more. In addition, as a method for evaluating the magnitude of the positioning error of the correction information CI, for example, there is a method using the distance from the RTK reference station 400 that generated the correction information CI to the point P1. The greater the distance from the RTK reference station 400 that generated the correction information CI to the point P1, the larger the positioning error when the correction information CI is used. Therefore, the correction information CI to be transmitted to the roadside device 100 as determined by the destination information is, for example, N correction information CIs generated at N RTK reference stations 400 in order of the shortest distance from the installation point P1 of the roadside device 100, among the correction information CIs that the server device 200 can acquire. In the following explanation, unless otherwise specified, only the RTK reference station 400 that generates the correction information CI and the legal information that the server device 200 can acquire will be handled, and other correction information and RTK reference stations will be ignored. An RTK reference station from which the server device 200 cannot acquire correction information is, for example, an RTK reference station installed for exclusive use by the installer himself. In addition, an RTK reference station that cannot be used due to a malfunction or other reason may also be treated as an RTK reference station from which the server device 200 cannot acquire correction information. The correction information CI having the smallest evaluation value of the positioning error is an example of the first correction information, and the correction information CI having the second smallest evaluation value of the positioning error is an example of the second correction information.

[0065] Alternatively, the correction information CI to be transmitted to the roadside device 100, which is determined by the destination information, may include, for example, the correction information CI1 and the correction information CI2 among the correction information CI that can be acquired by the server device 200. The correction information CI1 and the correction information CI2 will be described with reference to FIG.

[0066] FIG. 6 is a diagram for explaining the correction information CI1 and the correction information CI2. Point Q1 is the installation location of the RTK reference station 400 (hereinafter referred to as the "RTK reference station 400-1") that generated the correction information CI1. Point Q2 is the installation location of the RTK reference station 400 (hereinafter referred to as the "RTK reference station 400-2") that generated the correction information CI2. Point Q3 is a location where the RTK reference station 400 is not installed. Furthermore, road R1 is a road including a road connecting points P1 and P2. Point P2 is, for example, a point located at the end of road R1 from point P1. Alternatively, point P2 may be a point located in a straight line in a predetermined direction from point P1, regardless of road R1.

[0067] The correction information CI1 is the correction information CI with the smallest evaluation value of the positioning error at the installation point P1. Here, the method of evaluating the magnitude of the positioning error can be, for example, a method using the distance from the RTK reference station 400 to the point P1 as described above. Therefore, the correction information CI1 is, for example, the correction information CI generated by the RTK reference station 400 that is closest to the installation point P1 of the roadside device 100. For example, between points Q1 and Q2, point Q1 is closer to point P1. Therefore, if there is no RTK reference station 400 closer to point P1 than point Q1, the correction information CI generated by the RTK reference station 400-1 is the correction information CI1 for the roadside device 100 at point P1.

[0068] The correction information CI2 is correction information CI such that the evaluation value of the positioning error is smaller when the correction information CI2 is used than when the correction information CI1 is used at a certain point P2. However, it is preferable that there is no correction information CI such that the evaluation value of the positioning error at the point P2 is smaller than the correction information CI2. In this case, the method of using the distance from the RTK reference station 400 to the point P2 can be used as a method of evaluating the magnitude of the positioning error as in the above case. Therefore, the correction information CI2 is correction information CI such that, for example, at a certain point P2, the distance from the RTK reference station 400 that generated the correction information CI2 is shorter than the distance from the RTK reference station 400 that generated the correction information CI1. However, it is preferable that there is no RTK reference station 400 closer to the point P2 than the RTK reference station 400 that generated the correction information CI2. For example, between the points Q1 and Q2, the point Q2 is closer to the point P2. Therefore, if there is no RTK reference station 400 located closer to point P2 than point Q2, the correction information CI generated by the RTK reference station 400-2 is the correction information CI2 for the roadside device 100 at point P1. However, it is preferable that there is no point P3 between the points P1 and P2 that satisfies the following condition. The point P3 is, for example, any point between the point P1 and the point P2 via the road R1. Alternatively, the point P3 may be any point on the straight line connecting the points P1 and P2. The point P3 is a point where there is correction information CI such that the evaluation value of the positioning error is smaller than both the evaluation value of the positioning error when the correction information CI1 is used and the evaluation value of the positioning error when the correction information CI2 is used. As a method for evaluating the magnitude of the positioning error in this case, a method using the distance from the RTK reference station 400 to the point P3 can also be used. Therefore, the point P3 is, for example, a point where the RTK reference station 400 exists at a distance shorter than both the distance from the RTK reference station 400 that generated the correction information CI1 to the point P3 and the distance from the RTK reference station 400 that generated the correction information CI2 to the point P3. For example, if the RTK reference station 400-3 is located at point Q3 as shown in FIG. 1, there is a point P3 whose closest point among points Q1 to Q3 is point Q3. In this case, the correction information CI generated by the RTK reference station 400-2 is not correction information CI2. And, the correction information CI generated by the RTK reference station 400-3 is correction information CI2. However, if point P3 defined above exists when point P3 is treated as point P2, similarly, the correction information CI generated by the RTK reference station 400-3 is not correction information CI2.

[0069] From the above, the correction information CI2 is correction information CI that reduces the positioning error, i.e., improves the positioning accuracy, when a moving body using the correction information CI1 switches from the correction information CI1 to the correction information CI2 at a further point on the road.

[0070] The destination information may include multiple pieces of correction information CI2 for one roadside device 100. In this case, the multiple pieces of correction information CI2 each have a different position of point P2. Note that points P2 and P3 are points used to define the correction information CI2. Therefore, the destination information does not need to be generated considering points P2 and P3.

[0071] The processor 210 may generate destination information as described above using the installation point P1 of the roadside device 100, the installation points of each RTK reference station 400, and information on the error of each correction information CI, and store the destination information in the auxiliary storage device 140. Alternatively, the processor 210 may receive destination information transmitted from an external device and store the destination information in the auxiliary storage device 140.

[0072] As an example, the roadside apparatus 100 to which the server apparatus 200 is to transmit is assumed to be two, the roadside apparatus 100a and the roadside apparatus 100c. As an example, the destination information is assumed to store the correction information CIa and the correction information CIb to be transmitted to the roadside apparatus 100a, and the correction information CIb and the correction information CIc to be transmitted to the roadside apparatus 100c. In this case, the processor 210 acquires the correction information CIa, the correction information CIb, and the correction information CIc from the RTK reference station 400a, the RTK reference station 400b, and the RTK reference station 400c.

[0073] As described above, the processor 210 works in cooperation with the communication interface 250 to process step ST11, thereby receiving multiple correction information CI, and functions as an example of a server receiving unit that receives at least first correction information and second correction information.

[0074] In step ST12, the processor 210 instructs the communication interface 250 to transmit a plurality of pieces of correction information CI to the roadside device 100. The correction information CI is a plurality of pieces of correction information CI determined by the destination information, among the plurality of pieces of correction information CI acquired in step ST11. In response to this transmission instruction, the communication interface 250 transmits the correction information CI to the roadside device 100. The transmitted correction information CI is received by the communication interface 150 of the roadside device 100. When transmitting correction information CI to a plurality of roadside devices 100, the processor 210 performs the same process for each roadside device 100 that is the destination of the correction information CI. After the process of step ST12, the processor 210 returns to step ST11. As described above, the processor 210 cooperates with the communication interface 250 to perform the process of step ST12, and thereby functions as an example of a server transmission section that transmits the first correction information and the second correction information at the same time.

[0075] Meanwhile, the processor 110 of the roadside device 100 waits for the correction information CI to be received by the communication interface 150. When the correction information CI is received, the processor 110 stores the correction information CI in the auxiliary storage device 140. However, if correction information CI generated by the same RTK reference station 400 has already been stored in the auxiliary storage device 140, the processor 110 overwrites the information and stores the latest one, for example. As described above, the processor 110 functions as an example of a receiving unit that receives at least the first correction information and the second correction information by receiving the multiple correction information CI in cooperation with the communication interface 150. Also, the processor 110 functions as an example of a reception control unit that controls the first communication device to receive at least the first correction information and the second correction information by controlling the communication interface 150 to receive the multiple correction information CI.

[0076] Furthermore, the processor 110 controls the roadside communication I / F 160 to repeatedly transmit multiple pieces of correction information CI at once by broadcasting. The correction information CI transmitted here is stored in the auxiliary storage device 340. Therefore, when new correction information CI is received and the correction information CI stored in the auxiliary storage device 340 is overwritten, the processor 110 broadcasts the newly received correction information CI. The roadside device 100 may transmit each piece of correction information CI separately by multiplexing using a frequency division multiplexing method or a time division multiplexing method, etc., to transmit the pieces of correction information CI at once. Alternatively, the roadside device 100 may transmit multiple pieces of correction information CI one by one in order to transmit the pieces of correction information CI at once. As described above, the processor 110 functions as an example of a transmission unit that wirelessly transmits the first correction information and the second correction information by cooperating with the roadside communication I / F 160 to transmit the multiple correction information CI. The processor 110 also functions as an example of a transmission control unit that controls the second communication device to transmit the first correction information and the second correction information at once by wireless communication, by controlling the roadside communication I / F 160 to transmit the multiple correction information CI.

[0077] 5, the processor 310 of the in-vehicle device 300 controls the roadside communication I / F 350 to receive a plurality of pieces of correction information CI transmitted by the roadside device 100. As a result, the processor 310 acquires the correction information CI. When the processor 310 can receive correction information CI from a plurality of roadside devices 100, the processor 310 receives the correction information CI from, for example, the nearest roadside device 100. Alternatively, the processor 310 receives the correction information CI from the roadside device 100 having the highest reception strength at which the roadside communication I / F receives radio waves or the like transmitted from the roadside device 100.

[0078] In step ST22, the processor 310 inputs the multiple pieces of correction information CI acquired in step ST21 to the positioning calculation section 360. Furthermore, the processor 310 instructs the positioning calculation section 360 to perform positioning using the correction information CI.

[0079] The correction information CI to be input to the positioning calculation unit 360 is input to the selection unit 363 via the RTK input unit 362.

[0080] The selection unit 363 distributes the input correction information CI to the multiple RTK calculation units 364. Here, if the number of input correction information CIs is greater than the number of RTK calculation units 364, the selection unit 363 selects, for example, from the multiple correction information CIs, the same number of correction information CIs as the number of RTK calculation units 364, and discards the remaining correction information CIs that were not selected. Here, if there is a correction information CI generated by the same RTK reference station 400 as the correction information CI used in the processing result last adopted by the result selection unit 365, the selection unit 363 preferentially selects such correction information CI. Then, for the remaining correction information CIs, the selection unit 363 selects correction information CIs, for example, in order of the smallest evaluation value of the positioning error. As a method for evaluating the magnitude of the positioning error in this case, a method using the distance from the current location to the RTK reference station 400 can also be used. Therefore, for the remaining correction information CIs, the selection unit 363 selects correction information CIs in order of the shortest distance from the current location to the generated RTK reference station 400. The selection unit 363 may preferentially select the correction information CI generated by the RTK reference station 400 in the traveling direction of the vehicle 600, that is, in the traveling direction of the positioning calculation unit 360 mounted on the vehicle 600. Here, an example of the RTK reference station 400 in the traveling direction of the vehicle 600 will be described with reference to FIG.

[0081] FIG. 7 is a diagram for explaining an example of the RTK reference station 400 in the traveling direction of the vehicle 600. The RTK reference station 400 in the traveling direction of the vehicle 600 is, for example, an RTK reference station 400 in a range within a predetermined angle θ from the direction D1 in which the vehicle 600 is currently traveling, with the current position of the vehicle 600 as the center. For example, it is assumed that there are RTK reference stations 400 at points Q11 to Q13. And, the point Q11 is the installation position of the RTK reference station 400 closest to the vehicle 600. The point Q12 is a point in the traveling direction of the vehicle 600. The point Q13 is a point that is not in the traveling direction of the vehicle 600. In this case, the selection unit 363 may give priority to the correction information CI generated by the RTK reference station 400 at the point Q12 over the correction information CI generated by the RTK reference station 400 at the point Q13. However, the selection unit 363 may not give this priority if the difference or ratio between the distance from the vehicle 600 to the point Q12 and the distance from the vehicle 600 to the point Q13 is greater than a predetermined value. Alternatively, the RTK reference station in the traveling direction of the vehicle 600 may be, for example, an RTK reference station whose distance to the vehicle 600 will be shorter than the distance from the vehicle 600 to the point Q11 first if the vehicle 600 continues to travel in the direction D1 in which the vehicle 600 is currently traveling. Alternatively, the RTK reference station in the traveling direction of the vehicle 600 may be, for example, an RTK reference station whose distance to the vehicle 600 will be shorter than the distance from the vehicle 600 to the point Q11 first if the vehicle 600 continues to travel on the road in which the vehicle 600 is currently traveling. For example, the vehicle 600 is traveling from point P1 in FIG. 6 toward point P2. In this case, the RTK reference station 400-2 is the RTK reference station 400 whose distance to the vehicle 600 initially becomes shorter than the distance from the vehicle 600 to point Q1.

[0082] The selection unit 363 may determine the correction information CI to be selected using the traveling direction of the vehicle 600 predicted by the AI. The prediction unit 367 stores a trained AI that has performed machine learning using, for example, past travel route data of a plurality of vehicles as input data for learning. The prediction unit 367 uses, for example, deep learning using LSTM (long short-term memory) as the machine learning. The trained AI uses past travel route data of the vehicle 600, such as the travel route data of the vehicle 600 up to the present, as input data for predicting the traveling direction of the vehicle 600, and outputs output data indicating the future traveling direction of the vehicle 600. The output data includes, for example, data indicating what route the vehicle 600 will travel from here on. Note that the output data includes, for example, one or more route candidates. When the output data includes multiple route candidates, it also includes the probability that the vehicle 600 will travel along the route for each route candidate. The prediction unit 367 inputs the output data to, for example, the selection unit 363. For example, based on the output data, the selection unit 367 selects an RTK reference station in the traveling direction of the vehicle 600 that first has a distance to the vehicle 600 that is shorter than the distance from the vehicle 600 to the point Q11 when the vehicle 600 travels along a route indicated by the output data. When the output data includes a plurality of route candidates, the selection unit 367 selects an RTK reference station in the traveling direction of the vehicle 600 that first has a distance to the vehicle 600 that is shorter than the distance from the vehicle 600 to the point Q11 when the vehicle 600 travels along each route. However, the selection unit 367 preferentially selects correction information CI generated by an RTK reference station in the traveling direction of the vehicle 600 when the vehicle 600 travels along a route with a high probability of traveling among the plurality of correction information CI.

[0083] The prediction unit 367 may use not only the travel route data but also one or more types of data other than the travel route as input data for learning and input data for predicting the traveling direction of the vehicle 600. Examples of the types of data other than the travel route include the season, the time period, the vehicle model, the vehicle size, and the vehicle type. Moreover, the prediction unit 367 may perform machine learning using only past driving route data of one vehicle 600. The vehicle 600 is a vehicle 600 equipped with a positioning calculation unit 360 including the prediction unit 367. In addition, the prediction unit 367 may perform additional learning on the trained AI as appropriate.

[0084] The selection unit 363 may also obtain the traveling direction of the vehicle 600 from a car navigation system or the like, and use the traveling direction to determine the correction information CI to be selected. The car navigation system determines a route recommended as a route from the current location of the vehicle 600 to the destination. The route is a route along which the vehicle 600 is scheduled to travel. The selection unit 363 obtains data indicating the route from the car navigation system or the like as data indicating the traveling direction of the vehicle 600. The in-vehicle device 300 may have a function as a car navigation system. Alternatively, the vehicle 600 may have a device having a function as a car navigation system, separate from the in-vehicle device 300.

[0085] The selection unit 367 uses the traveling direction of the vehicle 600 acquired from a car navigation system or the like to determine the RTK reference station in the traveling direction of the vehicle 600, similarly to the case where the traveling direction of the vehicle 600 predicted by AI is used. The selection unit 367 determines the RTK reference station in the traveling direction of the vehicle 600 as the RTK reference station in the traveling direction of the vehicle 600, which is the RTK reference station whose distance to the vehicle 600 is first shorter than the distance from the vehicle 600 to the point Q11 when the vehicle 600 travels along the route of the vehicle 600 acquired from a car navigation system or the like.

[0086] The selection unit 363 may also acquire the traveling direction of the vehicle 600 from an automatic driving system that automatically drives the vehicle 600, and use the traveling direction to determine the correction information CI to be selected. For example, the selection unit 363 determines a route along which the vehicle 600 is scheduled to travel for automatic driving of the vehicle 600 from the on-board computer 610. The selection unit 363 acquires data indicating the route as data indicating the traveling direction of the vehicle 600 from the on-board computer 610 that constitutes the automatic driving system, etc.

[0087] The selection unit 367 uses the traveling direction of the vehicle 600 acquired from an automatic driving system or the like to determine the RTK reference station in the traveling direction of the vehicle 600, similarly to the case where the traveling direction of the vehicle 600 predicted by AI is used. The selection unit 367 determines the RTK reference station in the traveling direction of the vehicle 600 as the RTK reference station in the traveling direction of the vehicle 600, which is the RTK reference station whose distance to the vehicle 600 is first shorter than the distance from the vehicle 600 to the point Q11 when the vehicle 600 travels along the route of the vehicle 600 acquired from an automatic driving system or the like.

[0088] A car navigation system or an in-vehicle device 300 having a function as a car navigation system is an example of a route search unit that determines a route along which the vehicle 600 is scheduled to travel. The autonomous driving system or the in-vehicle computer 610 that constitutes the autonomous driving system is an example of a route search unit that determines the route along which the vehicle 600 is scheduled to travel.

[0089] Furthermore, when there is correction information CI for which a fix solution has already been obtained, the selection unit 363 may select such correction information CI in preference to correction information CI for which a fix solution has not been obtained.

[0090] The selection unit 363 inputs each selected correction information CI to each RTK calculation unit 364. However, when inputting the correction information CI to the RTK calculation unit 364, the selection unit 363 inputs the correction information CI generated by the same RTK reference station 400 as the correction information CI input previously. This allows the RTK calculation unit 364 to perform positioning by continuously using the correction information CI generated by the same RTK reference station 400. If there is no such correction information CI, the selection unit 363 inputs the correction information CI generated by a different RTK reference station 400 from the correction information CI input previously to the RTK calculation unit 364.

[0091] Each RTK calculation unit 364 performs RTK calculation processing using the correction information CI input from the selection unit 363 and the GNSS signal GS input from the satellite reception unit 361. Then, each RTK calculation unit 364 outputs position information as a processing result.

[0092] When there are multiple pieces of position information output from the multiple RTK calculation units 364 for which a fix solution has been obtained, the result selection unit 365 selects one piece of position information from the position information for which a fix solution has been obtained. Here, the result selection unit 365 selects, for example, position information with the smallest evaluation value of the positioning error. As a method for evaluating the magnitude of the positioning error in this case, a method using the distance from the current location to the RTK reference station 400 can also be used. Therefore, the result selection unit 365 selects, for example, position information in which the distance to the RTK reference station 400 from which the correction information CI used in the positioning calculation is generated is the shortest from the current location. Note that the result selection unit 365 may preferentially select position information in which the correction information CI generated by the RTK reference station 400 in the traveling direction of the vehicle 600 is used in the positioning calculation over other position information. In this case, when there are multiple pieces of position information in which the correction information CI generated by the RTK reference station 400 in the traveling direction of the vehicle 600 is used in the positioning calculation, the result selection unit 365 selects the position information with the smallest evaluation value of the positioning error among them. When one of the pieces of position information output from the multiple RTK calculation units 364 has a fix solution, the result selection unit 365 selects the one piece of position information. When none of the pieces of position information output from the multiple RTK calculation units 364 has a fix solution, the result selection unit 365 selects one piece of position information regardless of whether a fix solution has been obtained. Here, the result selection unit 365 selects, for example, position information with the smallest positioning error. As a method for evaluating the magnitude of the positioning error in this case, a method using the distance from the current location to the RTK reference station 400 can also be used. Therefore, the result selection unit 365 selects, for example, position information with the shortest distance from the current location to the RTK reference station 400 that generated the correction information CI used in the positioning calculation. Note that, like the selection unit 363, the result selection unit 365 may select position information using the traveling direction of the vehicle 600 predicted by the prediction unit 367. Then, the result selection unit 365 causes the positioning calculation unit 360 to output the selected piece of location information.

[0093] The result selection unit 365 functions as an example of a selection unit that selects a positioning result for which a fix solution has been obtained from a plurality of position information by selecting location information for which a fix solution has been obtained from a plurality of position information.

[0094] Also, consider two types of position information, position information L1 and position information L2. The position information L1 and position information L2 are generated by different RTK reference stations 400 that have different correction information CI used in the positioning calculation. Also, assume that the distance from the current location to the RTK reference station 400 that generated the correction information CI is closer for the position information L2 than for the position information L1. Furthermore, assume that the RTK reference station 400 that generated the correction information CI used in the positioning calculation is in the traveling direction of the vehicle 600 for both the position information L1 and the position information L2. In this case, consider a case where the position information L1 is position information for which a fix solution has been obtained, and the position information L2 is position information for which a fix solution has not been obtained. In this case, the result selection unit 365 selects, for example, the position information L1. Then, assume that when the result selection unit 365 next selects position information, the position information L2 has changed to position information for which a fix solution has been obtained. In this case, the result selection unit 365 selects, for example, the position information L2 with a smaller evaluation value of the positioning error. In this way, the result selection unit 365 functions as an example of a selection unit that selects the location information L1 for which a fix solution has been obtained, and then selects the location information L2 for which a fix solution has been obtained in the next selection, thereby selecting a first positioning result from among a plurality of positioning results including a first positioning result for which a fix solution has been obtained and a second positioning result for which a fix solution has not been obtained, and then selecting a second positioning result from among a plurality of positioning results including a first positioning result for which a fix solution has been obtained and a second positioning result for which a fix solution has been obtained. The location information L1 is an example of the first positioning result. The location information L2 is an example of the second positioning result. In addition, the result selection unit 365 functions as an example of a selection unit that selects the second positioning result from multiple positioning results when the second reference station is in the traveling direction of the positioning device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result by selecting the position information L2 from the position information L1 for which a fix solution has been obtained and the position information L2 for which a fix solution has been obtained, where the RTK reference station 400 from which the correction information CI was generated is in the traveling direction of the vehicle 600 and the evaluation value of the positioning error is smaller than that of the positioning result.

[0095] In step ST23, the processor 310 acquires the position information output from the positioning calculation unit 360. Then, the processor 310 generates, for example, an image including the position information. Then, the processor 310 instructs the display device 370 to display the generated image. In response to the display instruction, the display device 370 displays the image. After the process of step ST23, the processor 310 returns to step ST21.

[0096] According to the positioning system 1 of the embodiment, the roadside device 100 transmits a plurality of pieces of correction information CI. This allows the in-vehicle device 300 to use a plurality of pieces of correction information CI. This allows the in-vehicle device 300 to switch the correction information CI to be used. In this way, the positioning system 1 of the embodiment can support the switching of the correction information CI by transmitting a plurality of pieces of correction information CI.

[0097] According to the positioning system 1 of the embodiment, the roadside device 100 broadcasts a plurality of pieces of correction information CI. This allows the roadside device 100 of the embodiment to have a lower processing speed and communication speed than when unicast transmission is performed.

[0098] According to the positioning system 1 of the embodiment, the roadside device 100 transmits the correction information CI with the smallest positioning error. This allows the vehicle-mounted devices 300 in the vicinity of the roadside device 100 to use the correction information CI with the smallest positioning error.

[0099] According to the positioning system 1 of the embodiment, the roadside device 100 transmits the correction information with the smallest positioning error and the correction information CI with the second smallest positioning error. This allows the vehicle-mounted device 300 in the vicinity of the roadside device 100 to use multiple correction information CIs with small positioning errors.

[0100] Moreover, according to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 perform positioning using a plurality of correction information CI. As a result, the in-vehicle device 300 and the positioning calculation unit 360 can obtain a fix solution for each correction information CI. Therefore, the in-vehicle device 300 and the positioning calculation unit 360 do not need a fix time even when the correction information CI to be used is switched. Also, as a result, even when the correction information CI to be used is switched, the in-vehicle device 300 and the positioning calculation unit 360 do not significantly decrease the positioning error as long as a fix solution has already been obtained. Therefore, the in-vehicle device 300 and the positioning calculation unit 360 can maintain high-precision positioning.

[0101] Moreover, according to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 include a plurality of RTK calculation units 364. This allows the in-vehicle device 300 and the positioning calculation unit 360 to perform a plurality of positioning operations using a plurality of correction information CI.

[0102] According to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 determine the correction information CI to be input to the multiple RTK calculation units 364. This enables each RTK calculation unit 364 to perform positioning using appropriate correction information CI.

[0103] Moreover, according to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 preferentially determine the correction information CI generated by the RTK reference station 400 in the traveling direction of the in-vehicle device 300 or the positioning calculation unit 360 as the correction information CI to be input to the RTK calculation unit 364. This enables each RTK calculation unit 364 to perform positioning using the correction information CI that is predicted to reduce the positioning error in the future.

[0104] According to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 select one of the multiple positioning results. This allows the in-vehicle device 300 and the positioning calculation unit 360 to output a positioning result with less positioning error from the multiple positioning results.

[0105] According to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 select a positioning result for which a fix solution is obtained from a plurality of positioning results. This allows the in-vehicle device 300 and the positioning calculation unit 360 to output a positioning result with less positioning error from among the plurality of positioning results.

[0106] According to the positioning system 1 of the embodiment, when a positioning result for which a fix solution has not been obtained changes to a positioning result for which a fix solution has been obtained, the in-vehicle device 300 and the positioning calculation unit 360 select the changed positioning result. This enables the in-vehicle device 300 and the positioning calculation unit 360 to output a positioning result with less positioning error among a plurality of positioning results.

[0107] According to the positioning system 1 of the embodiment, the in-vehicle device 300 and the positioning calculation unit 360 use the correction information CI generated by the RTK reference station 400 in the traveling direction of the in-vehicle device 300 or the positioning calculation unit 360 for the positioning calculation, and select the positioning result with the smallest evaluation value of the positioning error. This enables the in-vehicle device 300 and the positioning calculation unit 360 to output the positioning result with the smallest positioning error among the multiple positioning results.

[0108] The above embodiment can be modified as follows. In the above embodiment, the roadside device 100 transmits the correction information CI to the in-vehicle device 300 by broadcasting it. However, the roadside device 100 may transmit the correction information CI to each roadside device 100 by another method such as unicast.

[0109] The on-board device 300 may transmit acquisition information indicating which correction information CI it wishes to acquire to the roadside device 100. If the correction information CI indicated in the acquisition information is already stored in the auxiliary storage device 340, the roadside device 100 acquires the correction information CI indicated in the acquisition information from the auxiliary storage device 340 and transmits it to the on-board device 300. If the correction information CI indicated in the acquisition information is not stored in the auxiliary storage device 340, the roadside device 100 cooperates with the server device 200 to acquire the correction information CI from the RTK reference station 400. Then, the roadside device 100 transmits the acquired correction information CI to the on-board device 300.

[0110] The on-board device 300 may receive the correction information CI without going through the roadside device 100. In this case, the RTK reference station 400 or the like broadcasts the correction information CI by wireless communication, for example. The on-board device 300 includes an antenna or the like for receiving the correction information CI, and receives the correction information CI by the antenna or the like. Alternatively, the on-board device 300 includes a communication interface for connecting to the network NW. The on-board device 300 then receives the correction information CI from the RTK reference station 400 or the server device 200 or the like via the network NW.

[0111] In the above embodiment, one RTK calculation unit 364 performs one RTK calculation process using one correction information CI and a GNSS signal. However, one RTK calculation unit 364 may perform multiple RTK calculation processes. That is, the RTK calculation unit 364 receives an input of a GNSS signal GS and multiple correction information CI, and performs RTK calculation processes for each correction information CI. Then, the RTK calculation unit 364 outputs the processing result. When one RTK calculation unit 364 performs multiple RTK calculation processes, the one RTK calculation unit 364 performs the same process as the multiple RTK calculation units 364, so the number of RTK calculation units 364 included in the positioning calculation unit 360 may be one. When one RTK calculation unit 364 performs multiple RTK calculation processes, the one RTK calculation unit 364 performs multiple RTK calculation processes at least in parallel or in parallel.

[0112] The positioning calculation unit 360 does not need to include the selection unit 363. In this case, the processor 310 or the RTK calculation unit 364 has the same function as the selection unit 363 and performs the same processing as the selection unit 363. The positioning calculation unit 360 may not include the result selection unit 365. In this case, the processor 310 or the RTK calculation unit 364 has the same function as the result selection unit 365 and performs the same processing as the result selection unit 365.

[0113] A part or all of the processing performed by any of the components of the positioning calculation unit 360 in the above embodiment may be performed by other components of the positioning calculation unit 360.

[0114] In the above embodiment, a part or all of the processing performed by the positioning calculation unit 360 may be performed by the processor 310. In the above embodiment, a part or all of the processing performed by the processor 310 may be performed by the positioning calculation unit. When the processor 310 performs all of the processes performed by the positioning calculation unit 360 in the above embodiment, the in-vehicle device 300 does not need to include the positioning calculation unit 360. In this case, however, the in-vehicle device 300 includes an antenna for receiving the GNSS signal GS and the like. In addition, the processor 310 functions as an example of a positioning unit, for example, when performing the processing performed by multiple RTK calculation units 364 in the above embodiment.

[0115] A moving body other than a vehicle may be equipped with the on-vehicle device 300. The moving body may be, for example, a train or a ship. The moving body may be a manned or unmanned aircraft. The moving body may also be a person or another animal. In this case, the animal carries the on-vehicle device 300. In this case, the on-vehicle device 300 is, for example, a GNSS terminal, a GNSS tracker, a smartphone, a tablet terminal, or a notebook PC.

[0116] The roadside device 100 may perform a part or all of the processes performed by the server device 200 in the above embodiment. The server device 200 may perform part of the processes performed by the roadside device 100 in the above embodiment.

[0117] The processor 110, the processor 210, the processor 310 and the positioning calculation unit 360 may implement part or all of the processes implemented by programs in the above embodiments by a hardware circuit configuration.

[0118] The program for implementing the process of the embodiment is transferred, for example, in a state stored in the device. However, the device may be transferred without the program stored therein. The program may be transferred separately and written to the device. The program may be transferred, for example, by recording it on a removable storage medium or by downloading it via a network such as the Internet or a LAN.

[0119] Although the embodiment of the present invention has been described above, it is merely an example and does not limit the scope of the present invention. The embodiment of the present invention can be implemented in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0120] 1 Positioning System 100 Roadside equipment 110,210,310 processors 120,220,320 ROM 130,230,330 RAM 140,240,340 Auxiliary storage 150,250 Communication Interface 160,350 Roadside communication I / F 170,260,390 Bus 200 Server Device 300 Onboard equipment 360 Positioning calculation unit 361 Satellite Receiving Unit 362 RTK input section 363 Sorting Department 364 RTK calculation section 365 Result Selection Section 366 Management and Control Unit 367 Prediction Department 370 Display Devices 380 Input Devices 400 RTK reference station 500 GNSS satellites 600 vehicles

Claims

1. A positioning system including a roadside device having a function corresponding to V2X communication, and an in-vehicle device capable of communicating with the roadside device and having a function corresponding to V2X communication, The roadside device includes: a first communication unit that receives at least first correction information generated in a first RTK reference station for correcting a position measured by an in-vehicle device that is a mobile station using a GNSS signal transmitted from a GNSS satellite, and second correction information generated in a second RTK reference station different from the first RTK reference station for correcting a position measured by the in-vehicle device using the GNSS signal; a second communication unit for communicating with the in-vehicle device; Equipped with The in-vehicle device includes: an in-vehicle communication unit for communicating with the roadside device; a positioning unit that receives at least a GNSS signal transmitted from a GNSS satellite, receives first correction information generated at a first RTK reference station for correcting a position determined using the GNSS signal from the first RTK reference station, and performs a first positioning using the GNSS signal and the first correction information, and receives second correction information generated at a second RTK reference station different from the first RTK reference station for correcting a position determined using the GNSS signal from the second RTK reference station, and performs a second positioning using the GNSS signal and the second correction information; Equipped with the roadside device communicates with the vehicle-mounted device at a predetermined timing; the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device, the positioning unit communicates with the roadside device at a predetermined timing; the positioning unit includes a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning, the in-vehicle device includes a determination unit that determines, when there are a plurality of pieces of correction information, the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among the plurality of pieces of correction information; The determination unit determines the correction information in a traveling direction of the in-vehicle device with priority, the traveling direction is a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past travel route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, The in-vehicle device includes a selection unit, The selection unit is selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result; selecting the first positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selecting the second positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained. Positioning system.

2. The positioning system according to claim 1 , wherein the second communication unit broadcasts the first correction information and the second correction information at the same time.

3. 2. The positioning system according to claim 1, wherein the selection unit selects the second positioning result from among the multiple positioning results when the second RTK reference station is in the traveling direction of the vehicle-mounted device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result.

4. A roadside device having a function corresponding to V2X communication, a first communication unit that receives at least first correction information generated in a first RTK reference station for correcting a position measured by an in-vehicle device that is a mobile station using a GNSS signal transmitted from a GNSS satellite, and second correction information generated in a second RTK reference station different from the first RTK reference station for correcting a position measured by the in-vehicle device using the GNSS signal; a second communication unit for communicating with the in-vehicle device; Equipped with the roadside device communicates with the vehicle-mounted device at a predetermined timing; the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device; Roadside equipment.

5. The roadside device according to claim 4 , wherein the second communication unit broadcasts the first correction information and the second correction information at the same time.

6. An in-vehicle device capable of communicating with a roadside device and having a function corresponding to V2X communication, The in-vehicle device includes: an in-vehicle communication unit for communicating with the roadside device; a positioning unit that receives at least a GNSS signal transmitted from a GNSS satellite, receives first correction information generated at a first RTK reference station for correcting a position determined using the GNSS signal from the first RTK reference station, and performs a first positioning using the GNSS signal and the first correction information, and receives second correction information generated at a second RTK reference station different from the first RTK reference station for correcting a position determined using the GNSS signal from the second RTK reference station, and performs a second positioning using the GNSS signal and the second correction information; Equipped with the positioning unit communicates with the roadside device at a predetermined timing; the positioning unit includes a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning, the in-vehicle device includes a determination unit that, when there are a plurality of pieces of correction information, determines the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among the plurality of pieces of correction information; The determination unit is determining the correction information in the traveling direction of the vehicle-mounted device with priority; the traveling direction is a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past travel route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, The in-vehicle device includes a selection unit, The selection unit is selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result; selecting the first positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selecting the second positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained. In-vehicle device.

7. The vehicle-mounted device according to claim 6, wherein the selection unit selects the second positioning result from among the multiple positioning results when the second RTK reference station is in the traveling direction of the vehicle-mounted device and the positioning error of the second positioning result is evaluated to be smaller than that of the first positioning result.

8. A program for causing a processor of a roadside device having at least a first communication device and a second communication device, and a processor of an in-vehicle device to function as a positioning system, the program comprising: The roadside device includes: a first communication unit that receives at least first correction information generated in a first RTK reference station for correcting a position measured by an in-vehicle device that is a mobile station using a GNSS signal transmitted from a GNSS satellite, and second correction information generated in a second RTK reference station different from the first RTK reference station for correcting a position measured by the in-vehicle device using the GNSS signal; a second communication unit for communicating with the in-vehicle device; Equipped with The in-vehicle device includes: an in-vehicle communication unit for communicating with the roadside device; a positioning unit that receives at least a GNSS signal transmitted from a GNSS satellite, receives first correction information generated at a first RTK reference station for correcting a position determined using the GNSS signal from the first RTK reference station, and performs a first positioning using the GNSS signal and the first correction information, and receives second correction information generated at a second RTK reference station different from the first RTK reference station for correcting a position determined using the GNSS signal from the second RTK reference station, and performs a second positioning using the GNSS signal and the second correction information; Equipped with the roadside device communicates with the vehicle-mounted device at a predetermined timing; the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device, the positioning unit communicates with the roadside device at a predetermined timing; the positioning unit includes a first calculation unit that performs the first positioning and a second calculation unit that performs the second positioning, the in-vehicle device includes a determination unit that determines, when there are a plurality of pieces of correction information, the first correction information to be input to the first calculation unit and the second correction information to be input to the second calculation unit from among the plurality of pieces of correction information; The determination unit is determining the correction information in the traveling direction of the vehicle-mounted device with priority; the traveling direction is a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past travel route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, The in-vehicle device includes a selection unit, The selection unit is selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result; selecting the first positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selecting the second positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained; A program that functions as a positioning system.

9. A positioning method in a positioning system including a roadside device having a function corresponding to V2X communication and an in-vehicle device capable of communicating with the roadside device and having a function corresponding to V2X communication, The roadside device includes: Receive at least first correction information generated by a first RTK reference station for correcting a position measured by an in-vehicle device that is a mobile station using a GNSS signal transmitted from a GNSS satellite, and second correction information generated by a second RTK reference station different from the first RTK reference station for correcting a position measured by the in-vehicle device using the GNSS signal; The in-vehicle device includes: at least, receiving a GNSS signal transmitted from a GNSS satellite, receiving from a first RTK reference station first correction information for correcting a position determined using the GNSS signal, the first correction information being generated at the first RTK reference station, and performing a first positioning using the GNSS signal and the first correction information, and receiving from a second RTK reference station second correction information for correcting a position determined using the GNSS signal, the second correction information being generated at a second RTK reference station different from the first RTK reference station, and performing a second positioning using the GNSS signal and the second correction information; the roadside device communicates with the vehicle-mounted device at a predetermined timing; the first correction information is correction information that is evaluated to have the smallest positioning error at an installation position of the roadside device, the second correction information is correction information that is evaluated to have the second smallest positioning error at the installation position of the roadside device, The in-vehicle device includes: Communicating with the roadside device at a predetermined timing; When there are a plurality of pieces of correction information, the first correction information to be input to a first calculation unit and the second correction information to be input to a second calculation unit are determined from the plurality of pieces of correction information; determining the correction information in the traveling direction of the vehicle-mounted device with priority; the traveling direction is a direction predicted by a traveling direction prediction unit that predicts a traveling direction based on past travel route data, or a direction determined by a route search unit that determines a route along which the vehicle is scheduled to travel, selecting one positioning result from a plurality of positioning results including the first positioning result and the second positioning result; selecting the first positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has not been obtained, and then selecting the second positioning result from among the plurality of positioning results including the first positioning result for which a fix solution has been obtained and the second positioning result for which a fix solution has been obtained. Positioning method.

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