JP2020134350A - Location information acquisition device and satellite positioning system - Google Patents

Abstract

To provide a location information acquisition device and the like that can highly accurately perform spoofing detection and the like after satellite positioning is interrupted due to an operation stop of the location information acquisition device itself because of an engine stall.SOLUTION: A location information acquisition device comprises a GNSS reception unit, and acquires information on a vehicle speed from a vehicle. The location information acquisition device determines that spooning might occur on the basis of a result of comparing a movement distance based on location information on a first time point tp1 serving as a current time point obtained by the GNSS reception unit and location information on a third time point tp3 following the first time point tp1 with a running distance between the first time point tp1 and the third time point tp3 obtained from the information on the vehicle speed. Between the time point tp1 and the third time point tp3, a period in which the location information cannot be continuously acquired via the GNSS reception unit for a period between a second time point tp2 before the first time pont tp1 by the first time point and a fourth time point before the second time point tp2 by the second time is included.SELECTED DRAWING: Figure 7

Description

The present invention relates to a position information acquisition device and the like.

Conventionally, as in Patent Document 1, an in-vehicle device for detecting spoofing has been proposed.

Japanese Patent No. 6385651

However, it may be difficult to detect spoofing in the judgment when satellite positioning cannot be performed during traveling or when the engine is stopped.

Therefore, an object of the present invention is position information capable of detecting spoofing with high accuracy after satellite positioning is interrupted due to a change in the reception state of a satellite signal during traveling or an operation stop of the position information acquisition device itself due to an engine stop. It is to provide an acquisition device and the like.

The position information acquisition device according to the present invention includes a GNSS receiving unit and a spoofing detecting unit. The spoofing detection unit is the first position obtained from the position information of the first time point, which is the current time point, obtained by the GNSS receiving part, the moving distance based on the position information of the third time point, which is earlier than the first time point, and the information on the vehicle speed. Based on the comparison result with the mileage between the time point and the third time point, it is judged that there is a suspicion that spoofing has occurred. Between the first and third time points, it continues between the second time point, which is the first time past the first time point, and the fourth time point, which is the second time past the second time point. This includes the period during which the location information cannot be acquired via the GNSS receiver.

Since the vehicle speed based on the vehicle speed pulse (pulse vehicle speed) is unlikely to deviate significantly from the actual vehicle speed, the mileage based on the vehicle speed pulse is likely to substantially match the actual mileage. The movement distance obtained based on the satellite positioning result obtained by the GNSS receiver, which is the position information before and after the satellite positioning impossible period, is compared with the mileage based on the vehicle speed pulse, and spoofing is performed based on the comparison result. Is suspected to have occurred.
Therefore, spoofing can be detected with high accuracy after the satellite positioning is interrupted due to a change in the reception state of the satellite signal during traveling or the operation stop of the position information acquisition device itself due to the engine stop.

Preferably, the spoofing detection unit determines that there is a suspicion that spoofing has occurred when the moving distance is longer than the traveling distance.

Also, preferably, the spoofing detector is temporally continuous via the GNSS receiver during the first period, which is the period between the first time and the third time, which is shorter than the first time. When the position information can be acquired, the first vehicle speed based on the position information at the first time point obtained by the GNSS receiver and the position information at one time point in the first period, and the first vehicle speed obtained from the information on the vehicle speed. Based on the comparison result with the second vehicle speed at the time, it is judged that there is a suspicion that spoofing has occurred.

If the position information can be acquired continuously in time via the GNSS receiver, the vehicle speed based on the satellite positioning result (GNSS speed) is likely to be substantially the same as the vehicle speed based on the vehicle speed pulse (pulse vehicle speed). .. In addition, the vehicle speed based on the vehicle speed pulse (pulse vehicle speed) is unlikely to deviate significantly from the actual vehicle speed. Therefore, when the vehicle speed (GNSS speed) based on the position information obtained by the GNSS receiving unit is significantly different from the pulse vehicle speed, it can be determined that there is a suspicion that spoofing has occurred.

The spoofing detection unit acquires position information via the GNSS receiver in a time-continuous manner during the first period, which is a period between the first time point and the third time point, which is shorter than the first time point. If so, the first angular velocity based on the position information of the first time point obtained by the GNSS receiver and the position information of the two time points in the first period, and the first time point obtained from the sensor that acquires the information on the angular velocity. Based on the comparison result with the second angular velocity of, it is judged that there is a suspicion that spoofing has occurred.

When the position information can be acquired continuously through the GNSS receiving unit in time, the angular velocity based on the satellite positioning result (GNSS angular velocity) is likely to be substantially the same as the angular velocity based on the sensor (sensor angular velocity). In addition, the angular velocity based on the sensor (sensor angular velocity) is unlikely to deviate significantly from the actual angular velocity of the vehicle. Therefore, when the angular velocity (GNSS angular velocity) based on the position information obtained by the GNSS receiving unit is significantly different from the sensor angular velocity, it can be determined that there is a suspicion that spoofing has occurred.

Further, preferably, the spoofing detection unit is suspected of having spoofing based on the comparison result between the radio field strength at the first time point obtained by the GNSS receiving unit and the maximum value of the radio wave strength in the past. to decide.

The radio field strength (C / No value) of the signal received by the GNSS receiver from the spoofing source may be higher than the radio field strength (C / No value) of the signal received by the GNSS receiver from a normal satellite. Therefore, when the radio field strength of the signal received by the GNSS receiving unit is larger than the maximum value of the radio wave strength in the past, it can be determined that there is a suspicion that spoofing has occurred.

Further, preferably, the spoofing detection unit determines that there is a suspicion that spoofing has occurred based on the difference between the maximum value and the minimum value of the radio field intensity at the first time point obtained by the GNSS receiving unit.

When the GNSS receiver cannot receive the signal from a normal satellite and the GNSS receiver receives only the signal from the spoofing source, the radio field strength (C / No value) of the received signal varies. There may be few. Therefore, when the variation in the radio field strength of the signal received by the GNSS receiving unit is small (the difference between the maximum value and the minimum value is small), it can be determined that there is a suspicion that spoofing has occurred.

In addition, preferably, the spoofing detection unit determines whether or not spoofing has occurred based on the number of times it is determined that spoofing has occurred in a period retroactively by a fourth time from the first time point. to decide.

Whether or not spoofing has occurred is determined based on the number of times it is determined that spoofing has occurred in a period that is four hours back from the current time, using multiple determination methods for spoofing. Therefore, it becomes possible to accurately determine whether or not spoofing has occurred.

Further, preferably, the spoofing detection unit is in a state in which the position information cannot be acquired via the GNSS receiving unit at the first time, and is in a region corresponding to the last position information based on the information from the GNSS receiving unit in the past. Based on whether or not the position information can be acquired via the GNSS receiver, it is determined that there is a suspicion that an interfering wave is generated.

In the area where the position information could be acquired via the GNSS receiver in the past, if the position information cannot be acquired via the GNSS receiver, it can be determined that there is a suspicion that an interfering wave has occurred. ..

Further, preferably, the spoofing detection unit is in a state in which the position information cannot be acquired via the GNSS receiving unit at the first time, and is in a region corresponding to the last position information based on the information from the GNSS receiving unit in the past. Based on whether or not the position information can be acquired via the GNSS receiver or the GNSS receiver of another terminal, it is determined that there is a suspicion that an interfering wave is generated.

In the area where the position information could be acquired via the GNSS receiver in the past, if the position information cannot be acquired via the GNSS receiver, it can be determined that there is a suspicion that an interfering wave has occurred. ..
By using the information of other terminals, the position information of the search target is increased, and it becomes possible to judge the suspicion of the disturbing wave with high accuracy.

Further, preferably, the spoofing detection unit determines that there is a suspicion that an interfering wave is generated when the GNSS receiving unit cannot receive only a specific frequency band among the plurality of frequency bands.

Since there is a high possibility that the jamming wave is generated only in a specific frequency band, it is suspected that the jamming wave is generated when the position information cannot be acquired through the GNSS receiver only in the specific frequency band. It can be judged that there is.

Further, preferably, the spoofing detection unit is in a state in which the position information cannot be acquired via the GNSS receiving unit at the first time, and is in a region corresponding to the last position information based on the information from the GNSS receiving unit in the past. Based on whether or not the position information can be acquired via the GNSS receiver, it is determined that there is a suspicion that an interfering wave is generated. The spoofing detection unit determines that there is a suspicion that an interfering wave is generated when the GNSS receiving unit cannot receive only a specific frequency band among a plurality of frequency bands. The spoofing detection unit determines whether or not an interfering wave is generated based on the number of times it is determined that an interfering wave is suspected to be generated in a period retroactive by a fourth time from the first time point.

Whether or not an interfering wave is generated based on the number of times when it is determined that an interfering wave is suspected to be generated in a period four times back from the current time using multiple determination methods for the interfering wave. In order to determine whether or not an interfering wave is generated, it becomes possible to accurately determine whether or not an interfering wave is generated.

The satellite positioning system according to the present invention includes a position information acquisition device having a GNSS receiving unit and a communication unit that transmits information obtained by the GNSS receiving unit and information on vehicle speed. The satellite positioning system communicates with the communication unit, and obtains it from the position information of the first time point obtained by the GNSS receiving part, the moving distance based on the position information of the third time point earlier than the first time point, and the information on the vehicle speed. It is provided with a terminal on the business side that determines that there is a suspicion of spoofing based on the comparison result with the mileage between the first and third time points. Between the first and third time points, there is a continuation between the second time point, which is the first time past the first time point, and the fourth time point, which is the second time past the second time point. The period during which the position information based on the information from the GNSS receiver is not calculated is included.

Preferably, the business terminal is in a state where the position information cannot be acquired via the GNSS receiving unit at the first time, and is in the area corresponding to the last position information based on the information from the GNSS receiving unit in the past. It is determined that there is a suspicion that an interfering wave is generated based on whether or not the position information can be acquired via the GNSS receiving unit or the GNSS receiving unit of another terminal from the position information acquiring device.

As described above, according to the present invention, spoofing can be detected with high accuracy after satellite positioning is interrupted due to a change in the reception state of a satellite signal during traveling or an operation stop of the position information acquisition device itself due to an engine stop. It is possible to provide a possible position information acquisition device and the like.

It is a block diagram of the satellite positioning system in the case of making a determination on the user equipment side in this embodiment. It is a flowchart which shows the operation procedure of the spoofing detection part. It is a block diagram of the satellite positioning system including a plurality of user equipment when the judgment is made on the user equipment side. It is a flowchart which shows the operation procedure of the 3rd determination. It is a flowchart which shows the operation procedure of 4th determination. It is a time chart which shows the case which is determined Yes and the case which is determined No in step S43 in the 4th determination. It is a figure which shows the position of the vehicle at the 3rd time point, and the position of the vehicle at the 1st time point-second time point. It is a flowchart which shows the operation procedure of the 5th determination. It is a flowchart which shows the operation procedure of 6th determination. It is a figure which shows the example of the C / No table. It is a flowchart which shows the operation procedure of 7th determination. It is a flowchart which shows the operation procedure of the 8th determination. It is a flowchart which shows the operation procedure of the 9th determination. It is a block diagram of the satellite positioning system when the judgment is made on the business terminal side. It is a block diagram of the satellite positioning system including a plurality of user devices when the determination is made on the business terminal side.

Hereinafter, this embodiment will be described with reference to the drawings.
The embodiment is not limited to the following embodiments. In principle, the contents described in one embodiment are similarly applied to other embodiments. In addition, each embodiment and each modification can be combined as appropriate.

The satellite positioning system 1 in the present embodiment includes a user device (position information acquisition device) 10, a cellular communication network 30 that performs cellular communication with the user device 10, and a vehicle 50 equipped with the user device 10 and a vehicle speed pulse generator 51 ( (See FIGS. 1 to 13).

(Explanation of each part)
The user device 10 includes a GNSS (Global Navigation Satellite System) receiving unit 11, a cellular communication unit 13, a spoofing detection unit 15, a main processing unit 17, a sensor 19, and a first database D1 to a sixth database D6.
As a specific example of the user device 10, a car navigation system or the like can be considered.
The GNSS receiving unit 11, the cellular communication unit 13, the spoofing detection unit 15, and the main processing unit 17 may be realized by software executed by a control unit such as a CPU provided in the user device 10, or each function thereof. It may be realized by separate hardware having.
In this embodiment, an example in which the GNSS receiving unit 11, the cellular communication unit 13, the spoofing detection unit 15, and the main processing unit 17 are separately configured is shown.

The third time t3, which will be described later, corresponds to the fourth time in the claims.
Further, the fourth time t4 corresponds to the third time in the claims.
Further, the fifth time t5 corresponds to the first time in the claims.
Further, the sixth time t6 corresponds to the second time in the claims.

The GNSS receiving unit 11 receives satellite signals (GNSS satellite information) transmitted by GNSS satellites corresponding to a plurality of frequency bands.
However, in order to perform the first determination to the eighth determination, it is not essential that the GNSS receiving unit 11 corresponds to a plurality of frequency bands, and the GNSS receiving unit 11 corresponds to only one frequency band. There may be. On the other hand, in order to make the ninth determination, the GNSS receiving unit 11 needs to correspond to a plurality of frequency bands.
The GNSS receiving unit 11 calculates the position information of the user device 10 and the time information at the current time based on the GNSS satellite information, and outputs these as the positioning result of satellite positioning to the main processing unit 17 and the spoofing detection unit 15. ..
The calculation of the position information and the time information by the GNSS receiving unit 11 may be performed by the main processing unit 17 or the spoofing detection unit 15.

The cellular communication unit 13 communicates with the cellular base station 31 near the user device 10.
The cellular communication unit 13 can use the cellular base station 31 and the center system 33 to perform communication used in a normal mobile phone.
The cellular communication unit 13 calculates the position information of the user device 10 and the time information at the current time based on the result of communication with the cellular base station 31 via the cellular communication unit 13, and uses these as the positioning result of the base station positioning. Is output to the main processing unit 17 and the spoofing detection unit 15.
The user device 10 communicates with the operator side terminal 35 by communication via the cellular communication unit 13.
In particular, in the present embodiment, the user device 10 transmits the results of the spoofing determination and the interference wave determination to the operator side terminal 35 by communication via the cellular communication unit 13.
The calculation of the position information and the time information by the cellular communication unit 13 may be performed by the main processing unit 17 or the spoofing detection unit 15.

The spoofing detection unit 15 executes spoofing determination (1st determination to 7th determination) and interference wave determination (8th determination to 9th determination) based on GNSS satellite information and the like. The spoofing detection unit 15 outputs the determination result to an output device such as a monitor provided in the user device 10 or transmits the determination result to the operator side terminal 35 via the cellular communication unit 13.
The spoofing detection unit 15 is obtained by the sensor 19 as a positioning result of satellite positioning obtained by the GNSS receiving unit 11 and a positioning result of base station positioning obtained by the cellular communication unit 13 at the time of spoofing determination or interference wave determination. Information on the angular speed, information on the vehicle speed pulse obtained from the vehicle speed pulse generator 51 of the vehicle 50, and information recorded in the first database D1 to the sixth database D6 are acquired.

The main processing unit 17 controls each unit of the user device 10 to output position information based on GNSS satellite information and the like, information related to communication via the cellular communication unit 13, and the like.

The sensor 19 has an angular velocity sensor and detects the angular velocity of the user device 10.
The angular velocity of the user device 10 is used not only for specifying the position information in the main processing unit 17, but also in the fifth determination in the spoofing detection unit 15 in the present embodiment.
In the present embodiment, the sensor 19 is provided in the user device 10, but may be provided in the vehicle 50 equipped with the user device 10.

The first database D1 to the sixth database D6 are provided in the storage of the user device 10.

The first database D1 is a positioning result database, which is detailed information of satellite positioning results obtained every first time t1 (for example, t1 = 1 second), and is t2 for the second time (for example, t2) from the present time. = 1 day) Record the period going back.
Detailed information on satellite positioning results includes position information such as coordinates and time information such as time, as well as information on the number of satellites that the GNSS receiver 11 can communicate with, the angle (elevation angle) and altitude of each satellite, and GNSS. It includes information on the moving speed (GNSS speed) of the user device 10 including the receiving unit 11.

The second database D2 is a C / No (Carrier to Noise Density Ratio) database, and the C / No value and positioning satellite for each received satellite in the GNSS information obtained every t1 for the first hour. It shows the relationship between the type of and the frequency band (or signal code), and records all the past things going back from the present time.
In the present embodiment, the C / No value is used as the value of the radio field intensity received by the GNSS receiving unit 11 from the satellite, but other values may be used as the value of the radio field strength.

The third database D3 is a positioning coordinate database, which is simple information of satellite positioning results obtained every t1 in the first hour, and records all the past ones going back from the present time.
The simple information of the satellite positioning result includes position information such as coordinates and time information such as time, and does not include other information such as the number of satellites.

The fourth database D4 is a vehicle speed pulse database, which is information on the vehicle speed pulse (indicating the relationship between the time information and the vehicle speed pulse) obtained from the vehicle speed pulse generator 51 of the vehicle 50, and is the second time t2 from the present time. Record only the period retroactive.

The fifth database D5 is a spoofing suspicion database, and records information regarding the date and time when it is determined in the spoofing determination (first determination to seventh determination) that spoofing is suspected to occur.

The sixth database D6 is an interfering wave suspicion database, and records information on the date and time when it is determined that an interfering wave is suspected to be generated in the interfering wave determination (8th determination to 9th determination).

The cellular communication network 30 includes a cellular base station 31, a center system (core network) 33, and a terminal 35 on the operator side.

The cellular base station 31 forms a wireless link facing the user device 10.
A plurality of cellular base stations 31 are provided, and the plurality of cellular base stations 31 form a radio access network.

The center system 33 includes a gateway switch (GMSC: Gateway Mobile Switching Center), an HLR (Home Location Register), a mobile switch (MSC: Mobile Switching Center), and the like.
Gateway exchanges are used to connect to telephone networks such as other telecommunications carriers.
HLR is a database that manages user information such as mobile phone numbers and terminal identification numbers.
The mobile exchange performs routines (selection of communication routes), call setting / disconnection, billing, etc. of mobile phones.

The business operator terminal 35 receives the determination result transmitted from the spoofing detection unit 15 and transmits information based on the determination result to the other user device 10.

The vehicle 50 holds the user device 10 and the vehicle speed pulse generator 51.
The vehicle speed pulse generator 51 generates a pulse in proportion to the rotation speed of the axle of the vehicle 50, and transmits information about the vehicle speed pulse to the user device 10.
The vehicle 50 may be in a form of transmitting information on the vehicle speed to the user device 10 instead of the information on the vehicle speed pulse. In this case, the ECU (Electronic Control Unit) of the vehicle 50 calculates the vehicle speed (pulse vehicle speed) based on the vehicle speed pulse information obtained from the vehicle speed pulse generator 51, and spoofing the calculated pulse vehicle speed information. It is transmitted to the detection unit 15 and the like.
The information regarding the vehicle speed pulse (or information regarding the vehicle speed) is used not only for specifying the position information in the main processing unit 17, but also for the fourth determination in the spoofing detection unit 15.

(Operation procedure of spoofing detector)
Next, the operation procedure of the spoofing detection unit 15 will be described with reference to the flowchart of FIG.
The processes of steps S11 to S18, steps S20 to S24, and steps S26 to S27 are performed every t1 of the first time.
That is, step S11 is started every first hour t1.
However, the mode is not limited to the form in which step S11 is started every t1 of the first time. For example, each step of steps S11 to S18, steps S20 to S24, and steps S26 to S27 may be executed at intervals of the first time t1.

In step S11, the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 is input to the spoofing detection unit 15 every t1 of the first time.

In step S12, the spoofing detection unit 15 outputs the information obtained by the GNSS receiving unit 11 to the first database D1 to the third database D3.
Specifically, the spoofing detection unit 15 causes the first database D1 to record detailed information on the satellite positioning result.
The spoofing detection unit 15 causes the second database D2 to record information regarding the C / No value in the GNSS information.
The spoofing detection unit 15 causes the third database D3 to record simple information of the satellite positioning result.

In step S13, information about the vehicle speed pulse is input to the spoofing detection unit 15 from the vehicle speed pulse generator 51 of the vehicle 50.

In step S14, the spoofing detection unit 15 causes the fourth database D4 to record information regarding the vehicle speed pulse.

In step S15, the spoofing detection unit 15 executes spoofing determination (first determination to seventh determination).
Details of the first determination to the seventh determination will be described later.
The first determination to the seventh determination are performed in order.
However, the order of the first determination to the seventh determination may be performed in another order.
Further, although all of the first determination to the seventh determination may be performed, at least one of the first determination to the seventh determination may be performed.

In step S16, the spoofing detection unit 15 determines whether or not it is determined in any of the first determination to the seventh determination that there is a suspicion that spoofing has occurred.
If it is determined that spoofing has occurred in at least one of the first to seventh determinations, the process proceeds to step S17.
If it is determined that there is no suspicion that spoofing has occurred in all of the first determination to the seventh determination, the process proceeds to step S21.

In step S17, the spoofing detection unit 15 causes the fifth database D5 to record information on the date and time, and then, from the fifth database D5, information on the date and time when it is determined that spoofing has occurred in the past. Extract.

In step S18, the spoofing detection unit 15 determines that spoofing is suspected to have occurred in the period retroactive by the third time t3 (for example, t3 = 1 minute) from the current time point (number of suspected spoofing) n1. However, it is determined whether or not the spoofing suspicion frequency threshold x1 has been exceeded.
If the number of suspected spoofing n1 does not exceed the threshold number of suspected spoofing x1, the process proceeds to step S21.
If the number of suspected spoofing n1 exceeds the threshold number of suspected spoofing x1, the process proceeds to step S20.

In step S20, the spoofing detection unit 15 determines that spoofing has occurred at the present time, and in step S12, the latest information recorded in the first database D1 to the third database D3 (third time t3 from the current time). (Only for the period retroactive) is deleted.

In step S21, the spoofing detection unit 15 executes the interference wave determination (8th determination to 9th determination).
Details of the eighth determination to the ninth determination will be described later.
The eighth determination to the ninth determination are performed in order.
However, the eighth determination to the ninth determination may be performed in the reverse order.
Further, although both the 8th determination to the 9th determination may be performed, the 8th determination to the 9th determination may be performed.

In step S22, the spoofing detection unit 15 determines whether or not it is determined that there is a suspicion that an interfering wave is generated in any of the eighth determination to the ninth determination.
If it is determined that there is a suspicion that an interfering wave is generated in at least one of the eighth determination to the ninth determination, the process proceeds to step S23.
If it is determined that there is no suspicion that an interfering wave is generated in all of the eighth determination to the ninth determination, the process proceeds to step S27.

In step S23, the spoofing detection unit 15 causes the sixth database D6 to record information on the date and time, and then, from the sixth database D6, information on the date and time when it is determined that an interference wave has occurred in the past. Is extracted.

In step S24, the spoofing detection unit 15 determines that the number of times that a disturbing wave is suspected (the number of times that a disturbing wave is suspected) n2 is the number of times that a disturbing wave is suspected in the period retroactive by the third time t3 from the current time. It is determined whether or not the threshold value x2 has been exceeded.
If the number of suspected interfering waves n2 does not exceed the threshold number of suspected interfering waves x2, the process proceeds to step S27.
If the number of suspected interfering waves n2 exceeds the threshold number of suspected interfering waves x2, the process proceeds to step S26.
In step S26, the spoofing detection unit 15 determines that an interfering wave is generated at the present time, and in step S12, the latest information recorded in the first database D1 to the third database D3 (third time from the current time). (Those with a period retroactive by t3) are deleted.

In step S27, the spoofing detection unit 15 outputs the results of the spoofing determination and the interference wave determination.

Spoofing is performed using multiple judgment methods (1st to 7th judgments) and based on the number of times it is judged that spoofing is suspected to have occurred in the period 3 hours t3 from the current time. Since it is determined whether or not spoofing has occurred, it is possible to accurately determine whether or not spoofing has occurred.

Based on the number of times it is determined that there is a suspicion that an interfering wave has occurred in a period that is 3 hours t3 back from the current time, using multiple determination methods (8th to 9th determination) for the interfering wave. Since it is determined whether or not an interfering wave is generated, it is possible to accurately determine whether or not an interfering wave is generated.

Prior to the spoofing determination and the determination of whether or not spoofing has occurred (steps S15 to S18 and step S2O), the interference wave determination and the determination of whether or not an interference wave has occurred (steps S21 to S24). , And step S26) may be performed.
Further, a spoofing determination and a determination as to whether or not spoofing has occurred (steps S15 to S18 and step S2O), and an interference wave determination and a determination as to whether or not an interference wave has occurred (steps S21 to S24, and step). It may be a form in which only one of S26) is performed.

(Specific example of judgment result output)
When it is determined that spoofing (or interfering wave) is occurring, the spoofing detection unit 15 sends the spoofing detection unit 15 to the operator side terminal 35 via the cellular communication unit 13, the cellular base station 31, and the center system 33. Spoofing (or interference wave) is generated, and the position information and time information of the user device 10 (user device A in FIG. 3) are transmitted (see the white arrow (1) in FIG. 3).
Here, the position information and time information of the user device 10 transmitted from the user device 10 to the business terminal 35 are not the current position information and time information based on the satellite positioning result obtained by the GNSS receiving unit 11. It is desirable that the latest position information and time information in the past, that is, the position information and time information in which it is not determined that spoofing or interfering waves are generated in the third time t3 or more than the present time.
Alternatively, the position information and time information of the user device 10 transmitted from the user device 10 to the business terminal 35 are the current position information and time information based on the base station positioning result obtained by the cellular communication unit 13. May be good.

Further, the spoofing detection unit 15 informs the main processing unit 17 of at least a part of information processing using position information based on GNSS satellite information until it is determined that no spoofing or interference wave is generated. To stop.

Further, the spoofing detection unit 15 generates spoofing (or interference wave) through an output device such as a monitor provided in the user device 10 until it is determined that no spoofing or interference wave is generated. Output what you are doing.

The operator-side terminal 35 generates spoofing (or jamming waves) with respect to other user devices 10 that are close to the user device 10 that is determined to have spoofing (or jamming waves). The location information of the user device 10 that has detected the spoofing (or spoofing) is transmitted (see the dotted arrow (3) in FIG. 3).

When there are a plurality of user devices 10 that have detected spoofing, area information including the positions of the plurality of user devices 10 is also transmitted.
The user device 10 to be transmitted is not limited to the one including the spoofing detection unit 15.
The other user devices 10 (user devices B to D in FIG. 3) that have received the information from the operator-side terminal 35 are converted to GNSS satellite information until they move to a position away from the position information included in the information. Stop at least part of the information processing using the based location information.

Further, the other user devices 10 (user devices B to D in FIG. 3) that have received the information from the business terminal 35 are the user devices until they move to a position away from the position information included in the information. It is output that spoofing (or interfering wave) is generated through an output device such as a monitor provided in 10.

(Operation procedure of the first judgment)
Next, the operation procedure of the spoofing determination (first determination) will be described.

The spoofing detection unit 15 compares the position information obtained by the GNSS receiving unit 11 with the position information obtained by the cellular communication unit 13.
When the difference between the position information obtained by the GNSS receiving unit 11 and the position information obtained by the cellular communication unit 13 (position information difference) is large (the distance between the two is longer than the distance threshold), the spoofing detection unit 15 Determines that spoofing is suspected.

The position information (position information based on base station positioning) obtained by the cellular communication unit 13 is unlikely to be significantly out of the range in which radio waves from the base station can be received. Therefore, when the position information obtained by the GNSS receiving unit 11 is significantly different from the position information obtained by the cellular communication unit 13, it can be determined that there is a suspicion that spoofing has occurred.

(Operation procedure of the second judgment)
Next, the operation procedure of the spoofing determination (second determination) will be described.

The spoofing detection unit 15 compares the time information obtained by the GNSS receiving unit 11 with the time information obtained by the cellular communication unit 13.
If the difference between the time information obtained by the GNSS receiving unit 11 and the time information obtained by the cellular communication unit 13 (time information difference) is large, the spoofing detection unit 15 may suspect that spoofing has occurred. Judge.

The time information (time information based on base station positioning) obtained by the cellular communication unit 13 is unlikely to deviate significantly from the accurate time as long as the radio waves from the base station can be received. Therefore, when the time information obtained by the GNSS receiving unit 11 is significantly different from the time information obtained by the cellular communication unit 13, it can be determined that there is a suspicion that spoofing has occurred.

(Operation procedure of the third judgment)
Next, the operation procedure of the spoofing determination (third determination) will be described with reference to the flowchart of FIG.

When the spoofing detection unit 15 can acquire the position information through the GNSS receiving unit 11 continuously in time, the position information at the current time point (first time point tp1) obtained by the GNSS receiving unit 11 and the latest position information. Compare the current vehicle speed (GNSS speed) based on the position information of the vehicle with the current vehicle speed (pulse vehicle speed) based on the vehicle speed pulse, and if there is a large difference, it is judged that there is a suspicion that spoofing has occurred.

The current vehicle speed (GNSS speed) obtained based on the position information obtained by the GNSS receiving unit 11 is defined as the first vehicle speed in the claims.
Further, the current vehicle speed obtained based on information on the vehicle speed transmitted from the vehicle 50 to the user device 10 such as the pulse vehicle speed is defined as the second vehicle speed in the claims.

In step S31, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S32.
If the satellite positioning result is not input, the third determination is terminated.

In step S32, the spoofing detection unit 15 reads the position information and the time information (positioning result) from the first database D1.
The position information and time information read from the first database D1 in step S32 are the period between the current time point (first time point tp1) and the time point retroactive by the fourth time t4 (for example, t4 = 5 seconds) from the current time point. It is for the first period tt1).
The fourth hour t4 is shorter than the fifth hour t5 described later.

In step S33, the spoofing detection unit 15 determines whether or not the information regarding the satellite positioning result read from the first database D1 is temporally continuous.
Specifically, the spoofing detection unit 15 determines whether or not the satellite positioning result is obtained every first hour t1 during the first period tt1.
If the information regarding the satellite positioning result is continuous in time, the process proceeds to step S34.
If the information regarding the satellite positioning result is not continuous in time, the third determination is terminated.

In step S34, the spoofing detection unit 15 calculates the current vehicle speed (GNSS speed) based on the satellite positioning result.
Specifically, the spoofing detection unit 15 calculates the GNSS speed from the current position information and time information based on the satellite positioning result and the immediately preceding position information and time information based on the satellite positioning result.
As the immediately preceding position information and time information, those at the time when the time goes back by the first time t1 from the current time point are used, but the other time point in the first period tt1 (for example, the time when the time goes back by the fourth time t4 from the current time point) is used. The one at the time point) may be used.
The calculation of the GNSS speed may be performed by the spoofing detection unit 15 or may be performed by the GNSS receiving unit 11.

In step S35, the spoofing detection unit 15 calculates the current vehicle speed (pulse vehicle speed) based on the information regarding the vehicle speed pulse sent from the vehicle speed pulse generator 51 of the vehicle 50.
The calculation of the pulse vehicle speed may be performed by the spoofing detection unit 15 or may be performed on the side of the vehicle 50 (for example, the ECU of the vehicle 50).

In step S37, the spoofing detection unit 15 determines whether the difference (vehicle speed difference) between the vehicle speed (GNSS speed) based on the satellite positioning result and the vehicle speed (pulse vehicle speed) based on the vehicle speed pulse is equal to or greater than the threshold value (vehicle speed difference threshold value). Judge whether or not.

If the vehicle speed difference is equal to or greater than the vehicle speed difference threshold value, in step S38, the spoofing detection unit 15 determines that there is a suspicion that spoofing has occurred.

If the vehicle speed difference is not equal to or greater than the vehicle speed difference threshold value, the spoofing detection unit 15 determines in step S39 that there is no suspicion that spoofing has occurred.

If the position information can be acquired continuously in time via the GNSS receiver 11, the vehicle speed (GNSS speed) based on the satellite positioning result may be substantially the same as the vehicle speed (pulse vehicle speed) based on the vehicle speed pulse. high. Further, the vehicle speed based on the vehicle speed pulse (pulse vehicle speed) is unlikely to deviate significantly from the actual speed of the vehicle 50. Therefore, when the vehicle speed (GNSS speed) based on the position information obtained by the GNSS receiving unit 11 is significantly different from the pulse vehicle speed, it can be determined that there is a suspicion that spoofing has occurred.

(Operation procedure of the 4th judgment)
Next, the operation procedure of the spoofing determination (fourth determination) will be described with reference to the flowchart of FIG.

The spoofing detection unit 15 calculates the moving distance based on the position information with the current time point (first time point tp1) obtained by the GNSS receiving unit 11 and the position information of the third time point tp3 past the first time point tp1. To do.
The spoofing detection unit 15 calculates the mileage between the first time point tp1 and the third time point tp3 obtained from the information on the vehicle speed.
The spoofing detection unit 15 compares the travel distance with the travel distance, and determines that there is a suspicion that spoofing has occurred when the travel distance is longer than the travel distance.
Between the current time point (first time point tp1) and the third time point tp3 of the position information used for calculating the movement distance, the fifth time t5 (for example, t5 = 10 seconds) past the first time point tp1. During the 6th time t6 (for example, t6 = 1 minute) than the 2nd time point tp2 and the 4th time point tp4 in the past, the position information cannot be continuously acquired via the GNSS receiver 11. The period (satellite positioning impossible period) is included.

In step S41, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S42.
If the satellite positioning result is not input, the fourth determination is terminated.

In step S42, the spoofing detection unit 15 reads the position information and the time information from the first database D1.
The position information and time information read from the first database D1 in step S42 include those for a certain period in the past.
The past fixed period is a time point that goes back by the fifth hour t5 from the current time point (first time point tp1) (second time point tp2) and a time point that goes back further by the sixth hour t6 from the second time point tp2 (fourth time point). It is a period between tp4).

In step S43, the spoofing detection unit 15 determines whether or not the position information read from the first database D1 includes information for a certain period in the past (second time point tp2 to fourth time point tp4).
Specifically, whether or not the spoofing detection unit 15 could read the information on the satellite positioning result from the first database D1 obtained in the period from the second time point tp2 to the fourth time point tp4. To judge.

In the case of Case 1 shown in FIG. 6, the position information read from the first database D1 does not include the information obtained in the past fixed period. Therefore, it is determined that the satellite positioning impossible period is a certain period (second time point tp2 to fourth time point tp4) that goes back from the present time point (first time point tp1) to a predetermined time point (second time point tp2). ..
In the case of 1 second after the case 1 shown in FIG. 6, the position information read from the first database D1 does not include the information obtained in the past fixed period. Therefore, it is determined that the satellite positioning impossible period is a certain period that goes back from a predetermined time point in the past from the present time point.
In the case of 2 seconds after the case 1 shown in FIG. 6, the position information read from the first database D1 includes the information obtained in the past fixed period. Therefore, it is determined that a part of a certain period that goes back from a predetermined time point in the past from the present time point is not a satellite positioning impossible period.
In the case of Case 2 shown in FIG. 6, the position information read from the first database D1 includes the information obtained in the past fixed period. Therefore, it is determined that a part of a certain period that goes back from a predetermined time point in the past from the present time point is not a satellite positioning impossible period.
In the case of Case 3 shown in FIG. 6, the position information read from the first database D1 does not include the information obtained in the past fixed period. Therefore, it is determined that the satellite positioning impossible period is a certain period that goes back from a predetermined time point in the past from the present time point.

If the position information read from the first database D1 includes the information obtained in the fixed period, the fourth determination is terminated.
If the position information read from the first database D1 does not include the location information obtained in the fixed period, the process proceeds to step S44.

In step S44, the spoofing detection unit 15 reads the position information and the time information from the first database D1.
The position information and time information read from the first database D1 in step S44 are past and latest than the time point (fourth time point tp4) that goes back by the fifth time t5 and the sixth time t6 from the current time point (first time point tp1). This is the position information and time information (previous positioning result) that could be acquired at the time point (third time point tp3), that is, the position information and time information that could be acquired last before the satellite positioning impossible period.

In step S45, the spoofing detection unit 15 calculates the movement distance (GNSS movement distance) based on the satellite positioning result.
Specifically, the spoofing detection unit 15 calculates the moving distance from the current position information based on the satellite positioning result and the position information of the third time point tp3 based on the satellite positioning result.

In step S46, the spoofing detection unit 15 reads information about the vehicle speed pulse from the fourth database D4.
The information regarding the vehicle speed pulse read from the fourth database D4 in step S46 is between the current time point and the third time point tp3.
Then, in step S46, the spoofing detection unit 15 calculates the mileage based on the vehicle speed pulse.
Specifically, the spoofing detection unit 15 calculates the mileage from the value obtained by integrating the vehicle speed pulses obtained between the current time point and the third time point tp3.

In step S47, the spoofing detection unit 15 determines whether or not the moving distance calculated in step S45 is longer than the traveling distance calculated in step S46.

If the moving distance is longer than the traveling distance, in step S48, the spoofing detection unit 15 determines that there is a suspicion that spoofing has occurred.
If the travel distance is not longer than the travel distance, in step S49, the spoofing detection unit 15 determines that there is no suspicion that spoofing has occurred.
As shown in FIG. 7, when there is a satellite positioning impossible period, the mileage between the current time point and the third time point tp3 is greater than or equal to the travel distance if spoofing has not occurred.
On the other hand, if spoofing occurs and positioning cannot be performed correctly, the moving distance may become longer than the mileage.

Since the vehicle speed based on the vehicle speed pulse (pulse vehicle speed) is unlikely to deviate significantly from the actual vehicle speed, the mileage based on the vehicle speed pulse is likely to substantially match the actual mileage. The movement distance obtained based on the satellite positioning result obtained by the GNSS receiver 11 which is the position information before and after the satellite positioning impossible period is compared with the mileage based on the vehicle speed pulse, and the movement distance determines the mileage. If it exceeds, it can be judged that there is a suspicion that spoofing has occurred.
Therefore, spoofing can be detected based on the positioning result after the interruption due to a change in the reception state of the satellite signal during traveling or an operation stop of the user device 10 itself due to the engine stop.

(Operation procedure of the 5th judgment)
Next, the operation procedure of the spoofing determination (fifth determination) will be described with reference to the flowchart of FIG.

When the spoofing detection unit 15 can acquire the position information through the GNSS receiving unit 11 continuously in time, the position information at the current time point (first time point tp1) obtained by the GNSS receiving unit 11 and the latest position information. Comparing the current angular velocity (GNSS angular velocity) based on the position information of, and the current angular velocity (sensor angular velocity) based on the information from the sensor 19, if there is a large difference, there is a suspicion that spoofing has occurred. to decide.

In the claims, the current angular velocity (GNSS angular velocity) obtained based on the position information obtained by the GNSS receiving unit 11 is defined as the first angular velocity.
Further, the current angular velocity (sensor angular velocity) obtained based on the information on the angular velocity from the sensor 19 is defined as the second angular velocity in the claims.

In step S51, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S52.
If the satellite positioning result is not input, the fifth determination is terminated.

In step S52, the spoofing detection unit 15 reads the position information and the time information from the first database D1.
The position information and time information read from the first database D1 in step S52 are for the period between the current time point and the time point advanced by the fourth time t4 from the current time point (first period tt1).

In step S53, the spoofing detection unit 15 determines whether or not the information regarding the satellite positioning result read from the first database D1 is temporally continuous.
Specifically, the spoofing detection unit 15 determines whether or not the satellite positioning result is obtained every first hour t1 during the first period tt1.
If the information regarding the satellite positioning result is continuous in time, the process proceeds to step S54.
If the information regarding the satellite positioning result is not continuous in time, the fifth determination is terminated.

In step S54, the spoofing detection unit 15 calculates the angular velocity (GNSS angular velocity) based on the satellite positioning result.
Specifically, the spoofing detection unit 15 is based on the current position information and time information based on the satellite positioning result and the position information and time information at two time points in the first period tt1 based on the satellite positioning result. Calculate the GNSS angular velocity. The position information at the two time points is, for example, the position information 2 seconds before the current time point and the position information 4 seconds before the current time point.

In step S55, the spoofing detection unit 15 calculates the current angular velocity (sensor angular velocity) based on the information regarding the angular velocity detected by the sensor 19.

In step S57, the spoofing detection unit 15 determines that the difference (angular velocity difference) between the angular velocity (GNSS angular velocity) based on the satellite positioning result and the angular velocity (sensor angular velocity) based on the information on the angular velocity detected by the sensor 19 is a threshold value (angular velocity difference). Judge whether or not it is equal to or higher than the threshold value).

If the angular velocity difference is equal to or greater than the angular velocity difference threshold, in step S58, the spuffing detection unit 15 determines that there is a suspicion that spuffing has occurred.

If the angular velocity difference is not equal to or greater than the angular velocity difference threshold value, in step S59, the spoofing detection unit 15 determines that there is no suspicion that spoofing has occurred.

If the position information can be acquired continuously through the GNSS receiver 11 in time, the angular velocity based on the satellite positioning result (GNSS angular velocity) may be substantially the same as the angular velocity based on the sensor 19 (sensor angular velocity). high. Further, the angular velocity based on the sensor 19 (sensor angular velocity) is unlikely to deviate significantly from the actual angular velocity of the vehicle 50. Therefore, when the angular velocity (GNSS angular velocity) based on the position information obtained by the GNSS receiving unit 11 is significantly different from the sensor angular velocity, it can be determined that there is a suspicion that spoofing has occurred.

(Operation procedure of 6th judgment)
Next, the operation procedure of the spoofing determination (sixth determination) will be described with reference to the flowchart of FIG.

The spoofing detection unit 15 compares the radio field intensity (C / No value) at the present time point (first time point tp1) obtained by the GNSS receiving unit 11 with the maximum value of the past radio wave strength (C / No value). , It is judged that there is a suspicion that spoofing has occurred when the radio field strength (C / No value) at the present time is high.

In step S61, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S62.
If the satellite positioning result is not input, the sixth determination is terminated.

In step S62, the spoofing detection unit 15 uses information on the C / No value of the satellite used to acquire the current position information, for each type of positioning satellite and for each frequency band (or signal code). The maximum value of the C / No value is extracted.

In step S63, the spoofing detection unit 15 reads information on the C / No value from the second database D2, and extracts the maximum and minimum values of the C / No value for each type and frequency band (or signal code) of the positioning satellite. Generate the C / No table.
The information regarding the C / No value read from the second database D2 in step S63 is all recorded in the second database D2 except the one at the present time.
As shown in FIG. 10, the C / No table shows the type of positioning satellite (for example, GPS, GLONASS, Galileo, etc.), the type of signal code corresponding to the frequency band (L1 C / A, L2C, E1, etc.), and C. The relationship between the maximum value of the / No value and the minimum value of the C / No value is shown.
The generation of the C / No table may be performed in the operation of step S63, or may be performed at the timing when the second database D2 is updated.

Further, in step S63, the spoofing detection unit 15 determines the C / No value (C corresponding to the current positioning result) obtained in step S62 for each type of positioning satellite and for each frequency band (or signal code). The maximum value of (/ No value) is compared with the maximum value of the C / No value of the type and frequency band (or signal code) of the positioning satellite corresponding to the C / No value in the C / No table.
For example, when the C / No value obtained by the current positioning corresponds to the positioning satellite type: GPS and the frequency band: L2C, the comparison with the maximum value: 43 in the C / No table is performed. Will be done.

In step S64, in the spoofing detection unit 15, the C / No value (current maximum C / No value) obtained by the positioning at the present time is the maximum value of the C / No value in the C / No table (past maximum C / No). Determine if it is greater than (value).

If the current maximum C / No value is larger than the past maximum C / No value in any frequency band (or signal code), the spoofing detection unit 15 suspects that spoofing has occurred in step S65. Judge that there is.

If the current maximum C / No value is not larger than the past maximum C / No value in any frequency band (or signal code), the spoofing detection unit 15 suspects that spoofing has occurred in step S66. Judge that there is no.

When the GNSS receiving unit 11 corresponds to only one frequency band, the spoofing detection unit 15 extracts the maximum value of the C / No value (step S62), generates a C / No table (step S63), and C. The comparison of / No values (step S63) and the determination of whether or not the value is larger than the maximum C / No value in the past (step S64) are performed for each type of positioning satellite.

The signal strength (C / No value) of the signal received by the GNSS receiver 11 from the spoofing source may be higher than the signal strength (C / No value) of the signal received by the GNSS receiver 11 from a normal satellite. is there. Therefore, when the radio field strength of the signal received by the GNSS receiving unit 11 is larger than the maximum value of the radio wave strength in the past, it can be determined that there is a suspicion that spoofing has occurred.

(7th judgment operation procedure)
Next, the operation procedure of the spoofing determination (7th determination) will be described with reference to the flowchart of FIG.

The spoofing detection unit 15 suspects that spoofing has occurred when the difference between the maximum value (C / No value) of the radio field intensity (C / No value) at the current time point (first time point tp1) obtained by the GNSS receiving unit 11 is small. Judge that there is.

In step S71, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S72.
If the satellite positioning result is not input, the seventh determination is terminated.

In step S72, the spoofing detection unit 15 extracts the number of satellites used in the positioning calculation from the information on the C / No value of the satellites used to acquire the current position information.

In step S73, the spoofing detection unit 15 determines whether or not the number of satellites (the number of satellites used) obtained in step S72 is equal to or greater than the threshold value (threshold number of satellites used: for example, five).
If the number of satellites used is equal to or greater than the threshold number of satellites used, the process proceeds to step S74.
If the number of satellites used is not equal to or greater than the threshold number of satellites used, the seventh determination is terminated.

In step S74, the spoofing detection unit 15 uses information on the C / No value of the satellite used to acquire the current position information to obtain C / for each positioning satellite and for each frequency band (or signal code). Extract the maximum and minimum No values.

In step S75, the spoofing detection unit 15 determines the difference between the maximum value and the minimum value (C / No value difference) obtained in step S74 for each type of positioning satellite and for each frequency band (or signal code). It is determined whether or not it is equal to or less than the threshold value (C / No value difference threshold value).

If the C / No value difference is equal to or less than the C / No value difference threshold value in any of the frequency bands (or signal codes), the spoofing detection unit 15 suspects that spoofing has occurred in step S76. Judge that there is.

If the C / No value difference is not equal to or less than the C / No value difference threshold value in any frequency band (or signal code), the spoofing detection unit 15 determines that there is no suspicion that spoofing has occurred in step S77. to decide.

When the GNSS receiving unit 11 corresponds to only one frequency band, the spoofing detection unit 15 extracts the maximum and minimum values of the C / No value (step S74), and whether the difference is equal to or less than the threshold value. The determination of whether or not (step S75) is performed for each type of positioning satellite.

When the GNSS receiving unit 11 cannot receive the signal from the normal satellite and the GNSS receiving unit 11 receives only the signal from the spoofing source, the radio field strength (C / No value) of the received signal There may be little variation. Therefore, when the variation in the radio field intensity of the signal received by the GNSS receiving unit 11 is small (the difference between the maximum value and the minimum value is small), it can be determined that there is a suspicion that spoofing has occurred.

(Operation procedure of the 8th judgment)
Next, the operation procedure of the interference wave determination (eighth determination) will be described with reference to the flowchart of FIG.

The spoofing detection unit 15 is in a state where positioning cannot be performed at the present time (first time point tp1) (position information cannot be acquired via the GNSS reception unit 11), and the last position information obtained by the GNSS reception unit 11 is not possible. It is determined that there is a suspicion that an interfering wave is generated when the position information can be acquired via the GNSS receiving unit 11 in the past in the area corresponding to.

In step S81, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
When the satellite positioning result is input, the eighth determination is terminated.
If there is no input of the satellite positioning result, the process proceeds to step S82.

In step S82, the spoofing detection unit 15 reads the position information and the time information (positioning result) from the first database D1.
The position information and time information read from the first database D1 in step S82 are for the period between the current time point (first time point tp1) and the time point retroactive by the fourth time t4 from the current time point (first time point tt1). is there.

In step S83, the spoofing detection unit 15 determines whether or not the position information of the first period tt1 is available, that is, whether or not the position information or the like can be read from the first database D1 in step S82.
If there is position information for the first period tt1, the eighth determination is ended.
If there is no position information for the first period tt1, the process proceeds to step S84.

In step S84, the spoofing detection unit 15 reads the position information and the time information from the first database D1.
The position information and time information read from the first database D1 in step S84 are those that can be acquired at the time point B immediately before the time point that goes back by the fourth time t4 from the current time point, that is, the position information and time information that can be acquired last. Is.

In step S85, the spoofing detection unit 15 searches for position information that is older than the time point B recorded in the third database D3 and is included in the area corresponding to the position information at the time point B.
The region corresponding to the position information at the time point B can be considered, for example, a predetermined range from the coordinates corresponding to the position information.
Further, the region corresponding to the position information at the time point B is determined from the coordinates corresponding to the current time position calculated based on the position information, the information on the angular velocity from the sensor 19, and the information on the vehicle speed from the vehicle. It may be a range.

In step S86, the spoofing detection unit 15 determines whether or not the position information past the time point B recorded in the third database D3 is included in the area corresponding to the position information at the time point B, that is, the past. It is determined whether or not positioning is possible (there is a positioning solution) in the vicinity of the position information at time point B.

If there is position information past the time point B recorded in the third database D3 that is included in the area corresponding to the position information at the time point B, in step S87, the spoofing detection unit 15 has a disturbing wave. Judge that there is a suspicion that it has occurred.

If there is no position information past the time point B recorded in the third database D3 that is included in the area corresponding to the position information at the time point B, in step S88, the spoofing detection unit 15 has a disturbing wave. Judge that there is no suspicion that it has occurred.

In the area where the position information could be acquired via the GNSS receiving unit 11 in the past, if the position information cannot be acquired via the GNSS receiving unit 11, it is judged that there is a suspicion that an interference wave is generated. Can be done.

(A form using information from another user device 10)
In the present embodiment, it has been described that the search target in step S85 of the eighth determination is the position information recorded in the third database D3 of the user device 10 including the spoofing detection unit 15.
However, the location information recorded in the third database D3 of the other user device 10 may also be used to perform the search in step S85 of the eighth determination.
In this case, the position information recorded in the third database D3 of the other user device 10 is transmitted to the spoofing detection unit 15 via the cellular communication network 30 (or another network).
By using the information of the other user device 10, the position information of the search target is increased, and it becomes possible to determine the suspicion of the disturbing wave with high accuracy.

(Operation procedure of 9th judgment)
Next, the operation procedure of the interference wave determination (9th determination) will be described with reference to the flowchart of FIG.

The spoofing detection unit 15 determines that there is a suspicion that an interfering wave is generated when the GNSS receiving unit 11 cannot receive only a specific frequency band among the plurality of frequency bands.

In step S91, the spoofing detection unit 15 inputs the information (satellite positioning result, etc.) obtained by the GNSS receiving unit 11 to the spoofing detection unit 15, that is, the first database D1 to the third database D3 by the spoofing detection unit 15. Determine if the update has been done.
If the satellite positioning result is input, the process proceeds to step S92.
If the satellite positioning result is not input, the ninth determination is terminated.

In step S92, the spoofing detection unit 15 extracts the number of satellites used in the positioning calculation for each frequency band from the information on the C / No value of the satellites used to acquire the current position information.

In steps S93 to S95, the spoofing detection unit 15 determines whether or not there is no satellite that can be used for positioning calculation only in a certain frequency band, and there is a satellite that can be used for positioning calculation in another frequency band.
In the present embodiment, steps S93 to S95 will be described assuming that the GNSS receiving unit 11 can receive signals in two frequency bands (first frequency band L1 and second frequency band L2).
However, the GNSS receiving unit 11 may be able to receive signals in three or more frequency bands.

In step S93, the spoofing detection unit 15 determines whether or not there is a satellite that can be used for positioning calculation in the first frequency band L1.
If there is a satellite that can be used for positioning calculation in the first frequency band L1, the process proceeds to step S94.
If there is no satellite that can be used for positioning calculation in the first frequency band L1, the process proceeds to step S95.

In step S94, the spoofing detection unit 15 determines whether or not there is a satellite that can be used for positioning calculation in the second frequency band L2.
If there is a satellite that can be used for positioning calculation in the second frequency band L2, the process proceeds to step S97.
If there is no satellite that can be used for positioning calculation in the second frequency band L2, the process proceeds to step S96.

In step S95, the spoofing detection unit 15 determines whether or not there is a satellite that can be used for positioning calculation in the second frequency band L2.
If there is a satellite that can be used for positioning calculation in the second frequency band L2, the process proceeds to step S96.
If there is no satellite that can be used for positioning calculation in the second frequency band L2, the process proceeds to step S97.

In step S96, the spuffing detection unit 15 determines that there is a suspicion that an interfering wave is being generated.

In step S97, the spoofing detection unit 15 determines that there is no suspicion that an interfering wave is being generated.

Since there is a high possibility that the interfering wave is generated only in a specific frequency band, it is suspected that the interfering wave is generated when the position information cannot be acquired via the GNSS receiver 11 only in the specific frequency band. It can be judged that there is.

(A form in which the judgment is made by the terminal on the business side)
In the present embodiment, the spoofing detection unit 15 and the first database D1 to the sixth database D6 are provided in the user device 10, but these may be provided in the business terminal 35. Good (see FIGS. 14 and 15).
In this case, the user device 10 transmits the position information, the time information, the vehicle speed information, and the angular velocity information to the operator terminal 35 every first hour t1 via the cellular communication unit 13.
The spoofing detection unit provided in the terminal 35 on the business side updates the first database D1 to the sixth database D2, spoofing and interference waves occur based on the position information sent from each of the user devices 10. Judge whether or not it is.
Further, in the eighth determination step S85, not only the data of the user device 10 to be determined but also the data of another user device may be used.

When it is determined that spoofing (or jamming wave) is occurring, the operator terminal 35 uses the center system and the cellular base station 31 to provide location information on which spoofing (or jamming wave) is detected. Spoofing (or jamming wave) is generated in the user device 10 (user device A in FIG. 15) that transmitted the message, and the user device 10 (user device A in FIG. 15) in which spoofing (or jamming wave) is detected. ) Position information and time information are transmitted (see the white arrow (2) in FIG. 15).
Here, the position information and time information of the user device 10 transmitted from the business terminal 35 to the user device 10 are not the current position information and time information based on the satellite positioning result obtained by the GNSS receiving unit 11. It is desirable that the position information and time information are more recent than the present time point, that is, the position information and time information that are not judged to have spoofing or interference waves.
Alternatively, the position information and time information of the user device 10 transmitted from the business terminal 35 to the user device 10 are the current position information and time information based on the base station positioning result obtained by the cellular communication unit 13. May be good.

Further, the spoofing detection unit 15 informs the main processing unit 17 of at least a part of information processing using position information based on GNSS satellite information until it is determined that no spoofing or interference wave is generated. To stop.

Further, the spoofing detection unit 15 generates spoofing (or interference wave) through an output device such as a monitor provided in the user device 10 until it is determined that no spoofing or interference wave is generated. Output what you are doing.

Further, the operator-side terminal 35 generates spoofing (or jamming wave) with respect to another user device 10 which is close to the user device 10 which is determined to have spoofing (or jamming wave). The position information of the user device 10 that has detected the spoofing (or spoofing wave) is transmitted (see the dotted arrow (3) in FIG. 15).
When there are a plurality of user devices 10 that have detected spoofing, area information including the positions of the plurality of user devices 10 is also transmitted.

The user device 10 to be transmitted is not limited to the one including the spoofing detection unit 15.
The other user devices 10 (user devices B to D in FIG. 15) that have received the information from the operator-side terminal 35 are converted to GNSS satellite information until they move to a position away from the position information included in the information. Stop at least part of the information processing using the based location information.

Further, the other user devices 10 (user devices B to D in FIG. 15) that have received the information from the business terminal 35 are the user devices until they move to a position away from the position information included in the information. It is output that spoofing (or interfering wave) is generated through an output device such as a monitor provided in 10.

In the present embodiment, it has been described that the user device 10 is mounted on the vehicle 50.
However, the user device 10 does not have to be mounted on the vehicle 50 for the first determination, the second determination, and the fifth to ninth determinations.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

1 Satellite positioning system, 10 User equipment (position information acquisition device), 11 GNSS receiver, 13 Cellular communication unit, 15 Spoofing detection unit, 17 Main processing unit, 30 Cellular communication network, 31 Cellular base station, 33 Center system (core) Network), 35 operator terminal, 50 vehicles, 51 vehicle speed pulse generator, D1 to D6 1st to 6th databases, n1 spoofing suspected count, n2 jamming suspected count, t1 1st hour (example: 1 second) , T2 2nd hour (eg: 1 day), t3 3rd hour (4th time example: 1 minute), t4 4th hour (3rd time example: 5 seconds), t5 5th hour (1st) Time example: 10 seconds), t6 6th time (2nd time example: 1 minute), tp1 1st time point (current time point), tp2 2nd time point, tp3 3rd time point, tp4 4th time point, tt1 1st period , X1 Spoofing suspected count threshold, x2 Interfering wave suspected count threshold

Claims (13)

With the GNSS receiver,
Equipped with a spoofing detector
The spoofing detection unit is obtained from the position information of the first time point, which is the current time point, obtained by the GNSS receiving part, the moving distance based on the position information of the third time point, which is earlier than the first time point, and the information on the vehicle speed. Based on the comparison result with the mileage between the first time point and the third time point, it is judged that there is a suspicion that spoofing has occurred.
Between the first time point and the third time point, there is a second time point that is the first time past the first time point and a fourth time point that is the second time past the second time point. A position information acquisition device that includes a period during which the position information cannot be continuously acquired via the GNSS receiving unit. The position information acquisition device according to claim 1, wherein the spoofing detection unit determines that there is a suspicion that spoofing has occurred when the moving distance is longer than the traveling distance. The spoofing detection unit is connected through the GNSS receiving unit in a time-continuous manner during the first period, which is a period between the first time point and the time point advanced by a third time shorter than the first time point. When the position information can be acquired, it can be obtained from the position information at the first time point obtained by the GNSS receiving unit, the first vehicle speed based on the position information at one time point in the first period, and the information on the vehicle speed. The position information acquisition device according to any one of claims 1 and 2, wherein it is determined that there is a suspicion that spoofing has occurred based on the result of comparison with the second vehicle speed at the first time point. The spoofing detection unit is connected via the GNSS receiving unit in a time-continuous manner during the first period, which is a period between the first time point and the time point advanced by a third time shorter than the first time point. When the position information can be acquired, the position information of the first time point obtained by the GNSS receiving unit, the first angular velocity based on the position information of the two time points in the first period, and the information on the angular velocity are acquired. The position information acquisition device according to any one of claims 1 and 2, which determines that there is a suspicion that spoofing has occurred based on the comparison result with the second angular velocity at the first time point obtained from the sensor. .. The spoofing detection unit determines that there is a suspicion that spoofing has occurred based on the result of comparison between the radio field strength at the first time point obtained by the GNSS receiving unit and the maximum value of the radio wave strength in the past. , The position information acquisition device according to any one of claims 1 to 4. The spoofing detection unit determines that there is a suspicion that spoofing has occurred based on the difference between the maximum value and the minimum value of the radio field intensity at the first time point obtained by the GNSS receiving unit. The position information acquisition device according to any one of claims 5. The spoofing detection unit determines whether or not spoofing has occurred based on the number of times it is determined that spoofing is suspected to have occurred in a period retroactive by a fourth time from the first time point. The position information acquisition device according to any one of claims 3 to 6. The spoofing detection unit is a region corresponding to the last position information based on the information from the GNSS receiving unit in a state where the position information cannot be acquired via the GNSS receiving unit at the first time point. The position information acquisition device according to any one of claims 1 to 7, wherein it is determined that there is a suspicion that an interfering wave is generated based on whether or not the position information can be acquired via the GNSS receiving unit. The spoofing detection unit is a region corresponding to the last position information based on the information from the GNSS receiving unit in a state where the position information cannot be acquired via the GNSS receiving unit at the first time point. Any of claims 1 to 7, wherein it is determined that there is a suspicion that an interfering wave is generated based on whether or not the position information can be acquired via the GNSS receiving unit or the GNSS receiving unit of another terminal. The position information acquisition device described in. Claims 1 to 9, wherein the spoofing detection unit determines that there is a suspicion that an interfering wave is generated when the GNSS receiving unit cannot receive only a specific frequency band among a plurality of frequency bands. The position information acquisition device described in any of them. The spoofing detection unit is a region corresponding to the last position information based on the information from the GNSS receiving unit in a state where the position information cannot be acquired via the GNSS receiving unit at the first time point. Based on whether or not the position information could be acquired via the GNSS receiver, it was determined that there was a suspicion that an interfering wave was being generated.
The spoofing detection unit determines that there is a suspicion that an interfering wave is generated when the GNSS receiving unit cannot receive only a specific frequency band among a plurality of frequency bands.
The spoofing detection unit determines whether or not an interfering wave is generated based on the number of times it is determined that an interfering wave is suspected to be generated in a period retroactively by a fourth time from the first time point. The position information acquisition device according to claim 1. A position information acquisition device having a GNSS receiving unit and a communication unit for transmitting information obtained by the GNSS receiving unit and information on vehicle speed.
It communicates with the communication unit and is obtained from the position information at the first time point obtained by the GNSS receiving unit, the moving distance based on the position information at the third time point prior to the first time point, and the information regarding the vehicle speed. It is equipped with a terminal on the business side that determines that there is a suspicion of spoofing based on the comparison result with the mileage between the first time point and the third time point.
Between the first time point and the third time point, between the second time point, which is the first time before the first time point, and the fourth time point, which is the second time before the second time point. , A satellite positioning system including a period during which position information is not continuously calculated based on information from the GNSS receiving unit. The operator-side terminal is in a state in which position information cannot be acquired via the GNSS receiving unit at the first time point, and is a region corresponding to the last position information based on the information from the GNSS receiving unit in the past. Based on whether or not the position information can be acquired via the GNSS receiving unit or the GNSS receiving unit of a terminal different from the position information acquisition device, it is determined that there is a suspicion that an interfering wave is generated. Item 12. The satellite positioning system according to Item 12.

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