Positioning device and positioning method

Abstract

In a positioning device (100), an authentication processing unit (104) performs authentication processing on a plurality of GNSS signals using key data and authentication data. When there are one or more GNSS signals authenticated in the authentication processing but less than the required number, an authenticity estimation processing unit (106) performs first authenticity estimation processing for estimating the authenticity of the remaining GNSS signals on the basis of the authenticated GNSS signal. When the number of GNSS signals subjected to the authentication processing is 0, or the number of GNSS signals authenticated in the authentication processing is 0, the authenticity estimation processing unit (106) estimates the authenticity of the plurality of GNSS signals on the basis of a previously authenticated GNSS signal.

Description

Positioning device and positioning method

[0001] The present disclosure relates to a positioning device and a positioning method.

[0002] Satellite positioning systems known as GNSS (Global Navigation Satellite System) or RNSS (Regional Navigation Satellite System) are known (hereinafter, RNSS and GNSS will be collectively referred to as "GNSS"). Positioning devices that measure positions (specifically, positions at which GNSS signals are received) based on GNSS signals transmitted from GNSS satellites are mounted on mobile objects such as vehicles and are widely used. In recent years, GNSS signal spoofing has become a social issue, and as a countermeasure, signal authentication services that can verify whether GNSS signals received by a positioning device are actually transmitted from GNSS satellites have been put into practical use.

[0003] Generally, satellite positioning requires GNSS signals from at least four GNSS satellites. Therefore, it is desirable that at least four of the multiple GNSS signals received by a positioning device be authenticated through authentication processing. However, not all GNSS satellites support signal authentication services, and even if a positioning device receives four or more GNSS signals, there may be fewer than four GNSS signals that can be authenticated. Therefore, a technology for estimating the authenticity of GNSS signals that cannot be authenticated is desired. For example, Patent Document 1 listed below proposes a technology for estimating the authenticity of GNSS signals that cannot be authenticated using GNSS signals that have been authenticated through authentication processing among the multiple received GNSS signals.

[0004] Patent No. 7224647

[0005] The technology of Patent Document 1 requires that at least one of the multiple received GNSS signals be authenticated through authentication processing. Therefore, if none of the received GNSS signals can be authenticated, such as if all of the received GNSS signals cannot be authenticated or if all of the GNSS signals that have been authenticated are not authenticated, the technology of Patent Document 1 cannot be implemented.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a positioning device that can estimate the authenticity of a GNSS signal even when an authenticated GNSS signal cannot be obtained.

[0007] The positioning device according to the present disclosure includes a GNSS signal receiving unit that receives a plurality of GNSS signals and acquires positioning data and authentication data from each of the plurality of GNSS signals; a positioning processing unit that performs positioning processing based on the positioning data of the plurality of GNSS signals; an authentication target determining unit that determines whether each of the plurality of GNSS signals is to be subject to authentication processing based on the presence or absence of authentication data in the plurality of GNSS signals; an authentication processing unit that performs authentication processing of the plurality of GNSS signals using key data and authentication data; an authentication result database that stores past authentication results of the plurality of GNSS signals; and an authenticity estimation processing unit that performs authenticity estimation processing of the plurality of GNSS signals based on previously authenticated GNSS signals if the number of GNSS signals is 0 or if the number of GNSS signals authenticated in the authentication processing is 0, and if there is one or more GNSS signals authenticated in the authentication processing but this does not meet the required number, performs authenticity estimation processing of the remaining GNSS signals based on the authenticated GNSS signals; and a positioning result output unit that outputs the positioning result obtained in the positioning processing if the sum of the number of GNSS signals authenticated in the authentication processing and the number of GNSS signals estimated to be authentic in the estimation processing is equal to or greater than the required number.

[0008] According to the positioning device of the present disclosure, it is possible to estimate the authenticity of the GNSS signal even when an authenticated GNSS signal cannot be obtained.

[0009] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0010] FIG. 1 is a diagram showing a configuration of a positioning device according to embodiment 1. FIG. 2 is a diagram for explaining a second authenticity estimation process. FIG. 3 is a diagram for explaining a second authenticity estimation process. FIG. 4 is a diagram for explaining a second authenticity estimation process. FIG. 5 is a flowchart showing the operation of a positioning device according to embodiment 1. FIG. 6 is a diagram showing a configuration of a positioning device according to embodiment 2. FIG. 7 is a flowchart showing the operation of a positioning device according to embodiment 2. FIG. 8 is a diagram showing a configuration of a positioning device according to embodiment 3. FIG. 9 is a diagram showing a configuration of a positioning device according to embodiment 4. FIG. 10 is a flowchart showing the operation of a positioning device according to embodiment 4. FIG. 11 is a diagram showing a configuration of a positioning device according to embodiment 5. FIG. 12 is a diagram showing an example of a hardware configuration of a positioning device. FIG. 13 is a diagram showing an example of a hardware configuration of a positioning device.

[0011] <Embodiment 1> Fig. 1 is a diagram showing the configuration of a positioning device 100 according to embodiment 1. As shown in Fig. 1 , the positioning device 100 includes a GNSS signal receiving unit 101, a positioning processing unit 102, an authentication target determining unit 103, an authentication processing unit 104, an authentication result database 105, an authenticity estimation processing unit 106, and a positioning result output unit 107.

[0012] The GNSS signal receiving unit 101 receives multiple GNSS signals transmitted from multiple GNSS satellites and performs signal processing such as AD conversion and filtering on each GNSS signal to obtain positioning data and authentication data from each GNSS signal. Note that, depending on the system configuration, the positioning data and authentication data may be transmitted as separate signals from the GNSS satellites. In the present disclosure, a signal including positioning data and a signal including authentication data are treated together as a single GNSS signal.

[0013] The positioning processing unit 102 performs positioning processing to measure the position of the positioning device 100 (the position at which the GNSS signals are received) based on the positioning data of the multiple GNSS signals acquired by the GNSS signal receiving unit 101 .

[0014] The authentication target determination unit 103 determines whether or not each of the multiple GNSS signals is to be subject to authentication processing based on the presence or absence of authentication data in the multiple GNSS signals. That is, the authentication target determination unit 103 determines, among the multiple GNSS signals, those from which the GNSS signal receiving unit 101 was able to acquire authentication data as GNSS signals to be subject to authentication processing, and determines those from which the GNSS signal receiving unit 101 was unable to acquire authentication data as GNSS signals not to be subject to authentication processing. GNSS signals that are not subject to authentication processing, i.e., GNSS signals without authentication data, are likely to be GNSS signals that do not support authentication processing, but may also be GNSS signals with poor reception conditions or spoofed GNSS signals.

[0015] The authentication processing unit 104 performs authentication processing for the GNSS signals determined to be targets for authentication processing by the authentication target determination unit 103. Specifically, the authentication processing unit 104 performs authentication processing for each GNSS signal determined to be targets for authentication processing, using predetermined key data and authentication data for each GNSS signal acquired by the GNSS signal receiving unit 101.

[0016] The authentication result database 105 is a storage medium that stores the results of the authentication process of the GNSS signal (hereinafter referred to as "authentication result") performed by the authentication processing unit 104. That is, the authentication result database 105 stores past authentication results of a plurality of GNSS signals.

[0017] The authenticity estimation processing unit 106 performs an authenticity estimation process to estimate the authenticity of a GNSS signal that is determined not to be subject to authentication processing by the authentication target determination unit 103 when the number of GNSS signals authenticated by the authentication processing unit 104 among the multiple GNSS signals received is less than a predetermined required number (the number of GNSS signals required for positioning, for example, four).

[0018] The authenticity estimation process performed by the authenticity estimation processing unit 106 is divided into two types. The first authenticity estimation process is a process for estimating the authenticity of the remaining GNSS signals (GNSS signals not subject to the authentication process and GNSS signals not authenticated in the authentication process) based on the GNSS signals authenticated by the authentication processing unit 104. The first authenticity estimation process is performed when one or more GNSS signals are authenticated in the authentication process but the required number is not met. The first authenticity estimation process corresponds to the well-known technology disclosed in the above-mentioned Patent Document 1, etc., and therefore a detailed description thereof will be omitted here.

[0019] The second authenticity estimation process is a process for estimating the authenticity of the latest GNSS signals (GNSS signals that are not the target of the authentication process and GNSS signals that were not authenticated in the authentication process) based on previously authenticated GNSS signals stored in the authentication result database 105. The second authenticity estimation process is performed when the number of GNSS signals that the authentication target determination unit 103 has determined to be the target of the authentication process is zero, or when the number of GNSS signals that have been authenticated by the authentication processing unit 104 is zero.

[0020] The second authenticity estimation process will be described using a specific example. Here, it is assumed that at past time t-1, the positioning device 100 captured GNSS satellite A1 transmitting authenticated GNSS signal a1 as shown in Fig. 2, but at current time t, it has only captured GNSS satellites B1 to B4 transmitting unauthenticated GNSS signals b1 to b4 (GNSS signals that are not subject to the authentication process or GNSS signals that were not authenticated in the authentication process) as shown in Fig. 3.

[0021] In the second authenticity estimation process, the authenticity estimation processing unit 106 performs a positioning calculation using the GNSS signal a1 at time t-1 and three of the GNSS signals b1 to b4 at time t. This positioning calculation is performed for all three combinations selected from the GNSS signals b1 to b4. That is, a positioning calculation using the GNSS signals a1, b1, b2, and b3, a positioning calculation using the GNSS signals a1, b2, b3, and b4, a positioning calculation using the GNSS signals a1, b1, b3, and b4, and a positioning calculation using the GNSS signals a1, b1, b2, and b4 are performed, and the respective positioning results P1, P2, P3, and P4 are obtained.

[0022] The authenticity estimation processing unit 106 estimates the authenticity of the GNSS signals b1 to b4 based on the distribution of the positioning results P1, P2, P3, and P4. For example, if the variation in the positioning results P1, P2, P3, and P4 is below a certain value, the authenticity estimation processing unit 106 estimates that all of the GNSS signals b1 to b4 are authentic. However, if any of the positioning results P1, P2, P3, and P4 deviates from the other positioning results, the authenticity estimation processing unit 106 estimates that one of the GNSS signals b1 to b4 is not authentic, and determines which GNSS signal is not authentic based on the distribution of the positioning results P1, P2, P3, and P4. For example, as shown in Figure 4, if only the positioning result P2, in which GNSS signal b1 is not used, deviates from the other positioning results P1, P3, and P4, the authenticity estimation processing unit 106 estimates that GNSS signals b2, b3, and b4 are authentic, and only GNSS signal b1 is not authentic.

[0023] The second authenticity estimation process is not limited to the above method, and any method can be used as long as it can estimate the authenticity of the latest GNSS signals (GNSS signals that are not subject to the authentication process and GNSS signals that were not authenticated in the authentication process) based on GNSS signals that have been authenticated in the past.

[0024] The positioning result output unit 107 outputs the positioning result obtained by the positioning processing by the positioning processing unit 102 to an external device (e.g., a vehicle's automatic driving system or a navigation system) when the sum of the number of GNSS signals authenticated by the authentication processing unit 104 and the number of GNSS signals estimated to be authentic by the authenticity estimation processing unit 106 is greater than or equal to the required number.

[0025] 5 is a flowchart showing the operation of the positioning device 100 according to embodiment 1. The operation of the positioning device 100 will be described below with reference to the flowchart in FIG.

[0026] When the positioning device 100 starts operating, the GNSS signal receiving unit 101 receives multiple GNSS signals transmitted from multiple GNSS satellites and acquires positioning data and authentication data from each GNSS signal (step S101).The positioning processing unit 102 performs positioning processing to measure the position of the positioning device 100 based on the positioning data of the multiple GNSS signals acquired by the GNSS signal receiving unit 101 (step S102).

[0027] The authentication target determination unit 103 determines whether each GNSS signal is to be subject to authentication processing based on the presence or absence of authentication data in each GNSS signal, and confirms whether there are GNSS signals to be subject to authentication processing (step S103). If there are GNSS signals to be subject to authentication processing (YES in step S103), the authentication processing unit 104 performs authentication processing of the GNSS signals to be subject to authentication processing (step S104). If, as a result of the authentication processing, there are a required number or more authenticated GNSS signals (YES in step S105), the process proceeds to step S109, which will be described later.

[0028] If the number of GNSS signals authenticated in the authentication process is less than the required number (NO in step S105), it is confirmed whether there is one or more authenticated GNSS signals (step S106). If there is one or more authenticated GNSS signals (YES in step S106), the authenticity estimation processing unit 106 performs a first authenticity estimation process to estimate the authenticity of the remaining GNSS signals based on the GNSS signals authenticated by the authentication processing unit 104 (step S107), and proceeds to step S109, which will be described later.

[0029] Furthermore, if the number of GNSS signals to be subject to the authentication process is 0 (NO in step S103), or if the number of authenticated GNSS signals is 0 (NO in step S106), the authenticity estimation processing unit 106 performs a second authenticity estimation process to estimate the authenticity of each GNSS signal based on previously authenticated GNSS signals stored in the authentication result database 105 (step S108), and then proceeds to step S109.

[0030] In step S109, the positioning result output unit 107 checks whether the sum of the number of GNSS signals authenticated by the authentication processing unit 104 and the number of GNSS signals estimated to be authentic by the authenticity estimation processing unit 106 is equal to or greater than a required number. If the value of this sum is equal to or greater than the required number, the positioning result output unit 107 outputs the positioning result obtained by the positioning process in step S102 (step S110). However, if the value of this sum is less than the required number, step S110 is skipped, and the positioning result is not output from the positioning result output unit 107.

[0031] The positioning device 100 repeatedly executes the above flow as necessary.

[0032] 5 shows an example in which the positioning process (step S102) by the positioning processing unit 102 is performed before the authentication process (step S104) of the GNSS signal by the authentication processing unit 104 and the authenticity estimation process (step S107 or S108) of the GNSS signal by the authenticity estimation processing unit 106, but the positioning process may be performed after the authentication process and the authenticity estimation process. That is, the positioning process may be performed when the sum of the number of authenticated GNSS signals and the number of GNSS signals estimated to be authentic is equal to or greater than the required number (when YES is determined in step S109). Furthermore, the positioning process may be performed in parallel with the authentication process and the authenticity estimation process.

[0033] Furthermore, the past authentication results stored in the authentication result database 105 may be assigned a validity period during which they can be used in the second authenticity estimation process.

[0034] According to the positioning device 100 of this embodiment, even if an authenticated GNSS signal cannot be obtained, the authenticity of the GNSS signal can be estimated by the second authenticity estimation process.

[0035] <Embodiment 2> In a situation where the number of captured GNSS satellites (i.e., the number of received GNSS signals) is large, such as in an open-sky environment, the processing load of the authentication processing unit 104 for authenticating the GNSS signals and the authenticity estimation processing unit 106 for estimating the authenticity of the GNSS signals increases, lengthening the time required for the authentication processing and the authenticity estimation processing. In this case, there is a concern that delays will occur in the output of the positioning results, making it impossible to perform real-time positioning processing. Embodiment 2 describes a positioning device 100 that can solve this problem.

[0036] Fig. 6 is a diagram showing the configuration of a positioning device 100 according to embodiment 2. The configuration of the positioning device 100 in Fig. 6 is obtained by adding a resource management unit 108 to the configuration in Fig. 1.

[0037] The resource management unit 108 monitors the resource usage of the positioning device 100, calculates the resources required for the authentication processing by the authentication processing unit 104 and the authenticity estimation processing by the authenticity estimation processing unit 106, and determines whether a delay in the output of the positioning results will occur due to a lack of resources when the authentication processing and authenticity estimation processing are performed.

[0038] If the resource management unit 108 determines that performing the authentication process and the authenticity estimation process will cause a delay in outputting the positioning result, the authentication processing unit 104 and the authenticity estimation processing unit 106 do not perform the authentication process and the authenticity estimation process. Also, the positioning result output unit 107 outputs the positioning result by the positioning processing unit 102 without waiting for the authentication process and the authenticity estimation process to be completed.

[0039] Fig. 7 is a flowchart showing the operation of the positioning device 100 according to embodiment 2. The flowchart in Fig. 7 is obtained by adding step S201 after step S102 to the flowchart in Fig. 5. Since the other steps are the same as those in Fig. 5, differences from the flow in Fig. 5 will be described here.

[0040] While the positioning processing unit 102 is performing the positioning processing (step S102), the resource management unit 108 monitors the resource usage of the positioning device 100. When the positioning processing is completed, in step S201, the resource management unit 108 calculates the resources required for the authentication processing by the authentication processing unit 104 and the authenticity estimation processing by the authenticity estimation processing unit 106, based on the number of captured GNSS satellites, etc., and determines whether a delay in the output of the positioning result will occur due to a lack of resources when the authentication processing and the authenticity estimation processing are performed, based on the amount of resources used in the positioning processing and the amount of resources required for the authentication processing and the authenticity estimation processing.

[0041] If it is determined that the authentication process and authenticity estimation process will not result in a delay in the output of the positioning results (NO in step S201), the process proceeds to step S103, and the GNSS signal authentication process and authenticity estimation process are carried out, as in embodiment 1.

[0042] If it is determined that performing the authentication process and authenticity estimation process will cause a delay in the output of the positioning result (YES in step S201), the authentication process and authenticity estimation process of the GNSS signal are skipped, and the process proceeds to step S110, where the positioning result output unit 107 outputs the positioning result from the positioning processing unit 102.

[0043] According to the positioning device 100 of this embodiment, the authentication process and authenticity estimation process of the GNSS signal are performed within a range that does not cause a delay in the output of the positioning result, thereby preventing a delay in the output of the positioning result and allowing the positioning device 100 to maintain real-time positioning processing.

[0044] <Embodiment 3> Fig. 8 is a diagram showing the configuration of a positioning device 100 according to embodiment 3. The configuration of the positioning device 100 in Fig. 8 is obtained by adding a positioning result database 109 to the configuration in Fig. 1.

[0045] The positioning result database 109 is a storage medium that stores the positioning results obtained by the positioning processing unit 102. That is, the positioning result database 109 stores past positioning results.

[0046] The positioning processing unit 102 corrects the latest positioning result obtained by the positioning process using the GNSS signals based on the past positioning results stored in the positioning result database 109. Correcting the latest positioning result based on the past positioning results is a common process also performed in conventional positioning devices. However, in this embodiment, the positioning processing unit 102 refers to the past positioning results stored in the positioning result database 109 and the past authentication results stored in the authentication result database 105, and corrects the latest positioning result based on the past positioning results obtained only from authenticated GNSS signals. Conversely, the positioning processing unit 102 does not use the past positioning results obtained from unauthenticated GNSS signals to correct the positioning result.

[0047] According to the positioning device 100 of this embodiment, only past positioning results obtained from unauthenticated GNSS signals are used to correct the positioning results, thereby improving the accuracy and reliability of the corrected positioning results.

[0048] <Fourth Embodiment> The second authenticity estimation process performed by the authenticity estimation processing unit 106 estimates the authenticity of the latest GNSS signal based on past authentication results (previously authenticated GNSS signals) stored in the authentication result database 105. However, for example, immediately after the positioning device 100 starts the positioning process, the past authentication results required for the second authenticity estimation process are not stored, and the authenticity estimation processing unit 106 cannot perform the second authenticity estimation process. In the fourth embodiment, a positioning device 100 that can solve this problem is shown.

[0049] Fig. 9 is a diagram showing the configuration of a positioning device 100 according to embodiment 4. The configuration of the positioning device 100 in Fig. 9 is obtained by adding a spoofing model database 110 to the configuration in Fig. 1 .

[0050] The spoofing model database 110 is a storage medium in which spoofing models, which are information representing the characteristics of spoofed GNSS signals, are stored in advance. Examples of the information representing the characteristics of spoofed GNSS signals include information regarding inconsistencies in positioning data between temporally consecutive GNSS signals, information regarding timing inconsistencies between temporally consecutive GNSS signals, and strength information specific to spoofed GNSS signals.

[0051] In this embodiment, when the authentication result database 105 does not store previously authenticated GNSS signals and there are insufficient past authentication results (previously authenticated GNSS signals) required for the second authenticity estimation process, the authenticity estimation processing unit 106 performs a third authenticity estimation process that estimates the authenticity of multiple GNSS signals based on a spoofing model. That is, in the third authenticity estimation process, a GNSS signal that has the same or similar characteristics as the spoofing model is determined to be inauthentic.

[0052] Fig. 10 is a flowchart showing the operation of the positioning device 100 according to embodiment 4. The flowchart in Fig. 10 is obtained by adding steps S301 and S302 to the flowchart in Fig. 5. Since the other steps are the same as those in Fig. 5, differences from the flow in Fig. 5 will be described here.

[0053] Step S301 is performed when there are no GNSS signals to be the subject of authentication processing (NO in step S103) or when the number of authenticated GNSS signals is 0 (NO in step S105). In step S301, the authenticity estimation processing unit 106 accesses the authentication result database 105 and checks whether past authentication results (previously authenticated GNSS signals) required for the second authenticity estimation processing are stored.

[0054] If the authentication result database 105 stores past authentication results necessary for the second authenticity estimation process (YES in step S301), the process proceeds to step S108, where the authenticity estimation processing unit 106 performs the second authenticity estimation process. However, if the authentication result database 105 does not store past authentication results necessary for the second authenticity estimation process (NO in step S301), the authenticity estimation processing unit 106 performs a third authenticity estimation process to estimate the authenticity of multiple GNSS signals based on a spoofing model (step S302), and then the process proceeds to step S109.

[0055] According to the positioning device 100 of this embodiment, even if there are insufficient past authentication results required for the second authenticity estimation process, it is possible to estimate the authenticity of the GNSS signal by the third authenticity estimation process.

[0056] <Fifth Embodiment> For example, when a moving body (e.g., a vehicle) equipped with the positioning device 100 is moving at high speed, the difference between the position at which the latest GNSS signal is received and the position at which a previously authenticated GNSS signal stored in the authentication result database 105 is received becomes large, which may result in a decrease in estimation accuracy of the second authenticity estimation process. In the fifth embodiment, a positioning device 100 that can solve this problem is shown.

[0057] Fig. 11 is a diagram showing the configuration of a positioning device 100 according to embodiment 5. The configuration of the positioning device 100 in Fig. 11 is obtained by adding a movement detection unit 111 to the configuration in Fig. 1 .

[0058] The movement detection unit 111 detects the movement distance and movement direction of the positioning device 100 based on the output of a sensor (not shown) provided in the moving object that carries the positioning device 100. If the moving object is a vehicle, the movement detection unit 111 detects the movement distance and movement direction of the positioning device 100 from the output of an acceleration sensor, gyroscope, etc. of the vehicle.

[0059] In this embodiment, when performing the second authenticity estimation process, the authenticity estimation processing unit 106 takes into account the movement distance and movement direction of the positioning device 100 detected by the movement detection unit 111. Specifically, the authenticity estimation processing unit 106 acquires from the movement detection unit 111 the movement distance and movement direction of the GNSS signal receiving unit 101 from the reception time of a previously authenticated GNSS signal to the reception time of a GNSS signal whose authenticity is to be estimated. Then, based on the movement distance and movement direction, the authenticity estimation processing unit 106 corrects for an error caused by a difference in reception position between the previously authenticated GNSS signal and the GNSS signal whose authenticity is to be estimated, and then performs the second authenticity estimation process.

[0060] According to the positioning device 100 of this embodiment, it is possible to prevent a decrease in the estimation accuracy of the second authenticity estimation process when the location at which the latest GNSS signal was received and the moving speed of the mobile body equipped with the positioning device 100 increase.

[0061] Sixth Embodiment In the above-described embodiments, the "previously authenticated GNSS signal" used in the second authenticity estimation process is a GNSS signal with the same signal specifications as the GNSS signal whose authenticity is to be estimated, and is a GNSS signal that is received by the same positioning device 100 as the GNSS signal whose authenticity is to be estimated. However, the "previously authenticated GNSS signal" may be a GNSS signal with different signal specifications (such as frequency) from the GNSS signal whose authenticity is to be estimated, or a GNSS signal that is received by a positioning device different from that of the GNSS signal whose authenticity is to be estimated.

[0062] Generally, a GNSS satellite transmits a plurality of GNSS signals having different signal specifications. For example, if the positioning device 100 receives an L1C / A signal and an L5 signal from the same GNSS satellite and only the L5 signal is authenticated, the authenticity estimation processing unit 106 may perform a second authenticity estimation process for the L1C / A signal based on the previously authenticated L5 signal.

[0063] Furthermore, for example, the positioning device 100 mounted on a vehicle may acquire GNSS signals received and authenticated by positioning devices mounted on other vehicles traveling nearby using a communication means such as V2V (vehicle-to-vehicle communication) and store the signals in the authentication result database 105. Then, the authenticity estimation processing unit 106 may perform the second authenticity estimation process based on GNSS signals that have been authenticated in the past by positioning devices of other vehicles.

[0064] According to the positioning device 100 of this embodiment, the number of options for "previously authenticated GNSS signals" that can be used in the second authenticity estimation process is increased, thereby reducing the possibility of a shortage of past authentication results required for the second authenticity estimation process.

[0065] 12 and 13 are diagrams showing examples of the hardware configuration of the positioning device 100. The functions of the components of the positioning device 100 shown in Fig. 1 are realized, for example, by a processing circuit 50 shown in Fig. 12. That is, the positioning device 100 receives a plurality of GNSS signals, acquires positioning data and authentication data from each of the plurality of GNSS signals, performs positioning processing based on the positioning data of the plurality of GNSS signals, determines whether or not to subject each of the plurality of GNSS signals to authentication processing based on the presence or absence of authentication data in the plurality of GNSS signals, performs authentication processing of the plurality of GNSS signals using key data and authentication data, stores past authentication results of the plurality of GNSS signals, and if the number of GNSS signals that have been subject to authentication processing is 0, or The present invention includes a processing circuit 50 for performing an authenticity estimation process for a plurality of GNSS signals based on previously authenticated GNSS signals when the number of GNSS signals authenticated in the authentication process is zero, performing an authenticity estimation process for the remaining GNSS signals based on the authenticated GNSS signals when one or more GNSS signals are authenticated in the authentication process but this does not meet the required number, and outputting a positioning result obtained by the positioning process when the sum of the number of GNSS signals authenticated in the authentication process and the number of GNSS signals estimated to be authentic in the estimation process is equal to or greater than the required number. The processing circuit 50 may be dedicated hardware, or may be configured using a processor (also called a central processing unit (CPU), processing device, arithmetic device, microprocessor, microcomputer, or DSP (Digital Signal Processor)) that executes a program stored in memory.

[0066] When the processing circuitry 50 is dedicated hardware, the processing circuitry 50 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. The functions of the components of the positioning device 100 may be realized by individual processing circuits, or these functions may be realized together by a single processing circuit.

[0067] 13 shows an example of the hardware configuration of the positioning device 100 when the processing circuit 50 is configured using a processor 51 that executes a program. In this case, the functions of the components of the positioning device 100 are realized by software, etc. (software, firmware, or a combination of software and firmware). The software, etc. is written as a program and stored in the memory 52. ​​The processor 51 realizes the functions of each unit by reading and executing the program stored in the memory 52. ​​That is, when executed by the processor 51, the positioning device 100 receives multiple GNSS signals and acquires positioning data and authentication data from each of the multiple GNSS signals; performs positioning processing based on the positioning data of the multiple GNSS signals; determines whether each of the multiple GNSS signals is to be subject to authentication processing based on the presence or absence of authentication data in the multiple GNSS signals; performs authentication processing on the multiple GNSS signals using key data and authentication data and stores past authentication results for the multiple GNSS signals; and, if the number of GNSS signals that have been subject to authentication processing is zero, or The positioning device 100 includes a memory 52 for storing a program that ultimately executes the following processes: a process for estimating the authenticity of multiple GNSS signals based on previously authenticated GNSS signals when the number of GNSS signals authenticated in the authentication process is zero, a process for estimating the authenticity of the remaining GNSS signals based on the authenticated GNSS signals when there is one or more GNSS signals authenticated in the authentication process but this number is less than the required number, and a process for outputting the positioning result obtained in the positioning process when the sum of the number of GNSS signals authenticated in the authentication process and the number of GNSS signals estimated to be authentic in the estimation process is equal to or greater than the required number. In other words, this program causes a computer to execute the procedures and methods of the operations of the components of the positioning device 100.

[0068] Here, the memory 52 may be, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), or an EEPROM (Electrically Erasable Programmable Read Only Memory), a HDD (Hard Disk Drive), a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD (Digital Versatile Disc), and a drive device for such a disk, or any other storage medium that will be used in the future.

[0069] The above describes a configuration in which the functions of the components of the positioning device 100 are realized either by hardware or software, etc. However, the present invention is not limited to this, and the positioning device 100 may be configured such that some components are realized by dedicated hardware and other components are realized by software, etc. For example, some components may have their functions realized by the processing circuit 50 as dedicated hardware, and other components may have their functions realized by the processing circuit 50 as the processor 51 reading and executing a program stored in the memory 52.

[0070] As described above, the positioning device 100 can realize the above-described functions by hardware, software, or a combination of these.

[0071] It should be noted that the embodiments can be freely combined, and the embodiments can be modified or omitted as appropriate.

[0072] The above description is illustrative in all respects, and it is understood that countless variations not illustrated can be envisioned.

[0073] 100 Positioning device, 101 GNSS signal receiving unit, 102 Positioning processing unit, 103 Authentication target determination unit, 104 Authentication processing unit, 105 Authentication result database, 106 Authenticity estimation processing unit, 107 Positioning result output unit, 108 Resource management unit, 109 Positioning result database, 110 Spoofing model database, 111 Movement detection unit, 50 Processing circuit, 51 Processor, 52 Memory.

Claims

1. A GNSS signal receiving unit that receives a plurality of GNSS signals and acquires positioning data and authentication data from each of the plurality of GNSS signals; a positioning processing unit that performs positioning processing based on the positioning data of the plurality of GNSS signals; an authentication target determining unit that determines whether each of the plurality of GNSS signals is to be subject to authentication processing based on the presence or absence of the authentication data in the plurality of GNSS signals; an authentication processing unit that performs the authentication processing of the plurality of GNSS signals using key data and the authentication data; and an authentication result database that stores past authentication results for the plurality of GNSS signals. a genuineness estimation processing unit that, if the number of GNSS signals that were the subject of the authentication processing is 0 or the number of GNSS signals authenticated in the authentication processing is 0, performs genuineness estimation processing of multiple GNSS signals based on the GNSS signals that have been authenticated in the past, and, if there is one or more GNSS signals authenticated in the authentication processing but this does not meet the required number, performs genuineness estimation processing of the remaining GNSS signals based on the authenticated GNSS signals; and a positioning result output unit that outputs the positioning result obtained in the positioning processing when the sum of the number of GNSS signals authenticated in the authentication processing and the number of GNSS signals estimated to be genuine in the estimation processing is equal to or greater than the required number.

2. The positioning device of claim 1, further comprising a resource management unit that monitors the resource usage of the positioning device, calculates the amount of resources required for the authentication process and the authenticity estimation process, and determines whether or not a delay in outputting the positioning result will occur due to a lack of resources when the authentication process and the authenticity estimation process are performed, and if it is determined that a delay in outputting the positioning result will occur when the authentication process and the authenticity estimation process are performed, the authentication processing unit and the authenticity estimation processing unit do not perform the authentication process and the authenticity estimation process, and the positioning result output unit outputs the positioning result.

3. A positioning device as described in claim 1 or claim 2, comprising a positioning result database in which past positioning results are stored, and the positioning processing unit refers to the past positioning results stored in the positioning result database and the past authentication results stored in the authentication result database, and corrects the latest positioning result based on the past positioning results obtained only from the authenticated GNSS signals.

4. A positioning device as described in any one of claims 1 to 3, comprising a spoof model database in which a spoof model, which is information representing the characteristics of the spoofed GNSS signals, is stored, and if the authentication result database does not store past authentication results necessary to perform the authenticity estimation processing of the multiple GNSS signals, the authenticity estimation processing unit performs the authenticity estimation processing of the multiple GNSS signals based on the spoof model.

5. A positioning device as described in any one of claims 1 to 4, comprising a movement detection unit that detects the distance and direction of movement of the positioning device, and wherein the authenticity estimation processing unit, when performing the authenticity estimation processing of multiple GNSS signals based on previously authenticated GNSS signals, corrects the previously authenticated GNSS signals based on the distance and direction of movement of the positioning device from the time of reception of the previously authenticated GNSS signal to the time of reception of the multiple GNSS signals.

6. A positioning device as claimed in any one of claims 1 to 5, wherein the authenticity estimation processing unit uses, as the previously authenticated GNSS signal in the authenticity estimation process, a GNSS signal having signal specifications different from that of the GNSS signal whose authenticity is to be estimated, or a GNSS signal received by a positioning device other than that of the GNSS signal whose authenticity is to be estimated.

7. A GNSS signal receiving unit of a positioning device receives a plurality of GNSS signals and acquires positioning data and authentication data from each of the plurality of GNSS signals; a positioning processing unit of the positioning device performs positioning processing based on the positioning data of the plurality of GNSS signals; an authentication object determination unit of the positioning device determines whether each of the plurality of GNSS signals is to be subject to authentication processing based on the presence or absence of the authentication data in the plurality of GNSS signals; an authentication processing unit of the positioning device performs the authentication processing of the plurality of GNSS signals using key data and the authentication data; an authentication result database of the positioning device stores past authentication results of the plurality of GNSS signals; if the number of the GNSS signals that were subject to the authentication processing is 0 or the number of the GNSS signals authenticated in the authentication processing is 0, an authenticity estimation processing unit of the positioning device performs authenticity estimation processing of the plurality of GNSS signals based on the GNSS signals that were previously authenticated; a positioning method, wherein, when one or more GNSS signals are authenticated in the authentication process but the number is less than the required number, the authenticity estimation processing unit performs the authenticity estimation processing of the remaining GNSS signals based on the authenticated GNSS signals, and a positioning result output unit of the positioning device outputs the positioning result obtained in the positioning processing when the sum of the number of GNSS signals authenticated in the authentication process and the number of GNSS signals estimated to be authentic in the estimation process is equal to or greater than the required number.

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