JP2018031744A - Fraud detection program, fraud detection method and fraud detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of detecting a fraud in a positioning signal received from a GNSS in real time.SOLUTION: Provided is a fraud detection program for causing a computer to execute the process of calculating the amount of deviation of a movement distance based on position information obtained from the statistical value of time-of-day information, the statistical value of ratio information about a carrier wave to noise ratio, the statistical value of visible satellite position information and the detection value of position information and an acceleration sensor among the positioning information obtained from a positioning signal received from a Global Navigation Satellite System (GNSS) and/or the amount of deviation of speed information obtained from speed information and the detection value of the acceleration sensor, and detecting a fraud in the positioning signal on the basis of the calculated result.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fraud detection program, a fraud detection method, and a fraud detection device.

  Deception (spoofing, spoofing) causes misrecognition of positioning information such as time information and position information obtained from a positioning signal by spoofing a positioning signal transmitted by a GNSS satellite. Therefore, deception is detected from the difference between the time information received from GNSS (Global Navigation Satellite System) and the time obtained from other systems, or the abnormal value of the movement amount (movement distance amount) calculated from the current time and the past time. There are known methods (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1).

JP 2015-14473 A JP 2012-208033 A

“GPS Spoofing Detection using Accelerometers and Performance Analysis with Probability of Detection”. Jung-Hoon Lee. Keum-Cheol Kwon. Dae-Sung An. and Duk‐Sun SHim

  However, in the above-mentioned patent document, for example, when deception is detected using the time information of GNSS, it is necessary to refer to the time of another system, and communication load when accessing another system is applied. There is a problem that deception cannot be detected in an environment where other systems cannot be used.

  In addition, when deception is detected from an abnormal value of the movement amount using the position information of the GNSS, deception can be detected if the movement amount is large in a short time, but deception detection accuracy is lacking under other conditions. There are challenges.

  Further, in Non-Patent Document 1, the acceleration is calculated from the speed information of GNSS, the standard deviation is calculated for the difference from the acceleration detected by the acceleration sensor provided in the device for detecting deception, and the allowable value is continuously obtained a plurality of times. If it exceeds, deception is detected. For this reason, there is a problem that it takes a long time to detect fraud.

  Thus, in one aspect, an object of the present invention is to improve the accuracy of deception detection of a positioning signal received from a GNSS in real time.

  In one proposal, among the positioning information obtained from the positioning signal received from GNSS (Global Navigation Satellite System), the statistical value of the time information, the statistical value of the ratio information of the carrier wave to the noise ratio, the statistical value of the visible satellite position information Calculating at least one of the shift amount of the movement amount based on the position information and the position information obtained from the detection value of the acceleration sensor, and the shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor; A deception detection program for detecting a deception of the positioning signal based on the calculated result and causing a computer to execute a process is provided.

  According to one aspect, it is possible to improve the accuracy of deception detection of a positioning signal received from a GNSS in real time.

The figure which shows an example of a function structure of the deception detection apparatus which concerns on one Embodiment. The figure which shows an example of the hardware constitutions of the deception detection apparatus which concerns on one Embodiment. The flowchart which shows an example of the deception detection process which concerns on 1st Embodiment. The timing chart which shows an example of the monitoring control of the time information which concerns on 1st Embodiment. The flowchart which shows an example of the deception detection process which concerns on 2nd Embodiment. The flowchart which shows an example of the deception detection process which concerns on 3rd Embodiment. The flowchart which shows an example of the deception detection process which concerns on 4th Embodiment. The flowchart which shows an example of the deception detection process which concerns on 5th Embodiment. The figure for demonstrating an azimuth angle and an elevation angle. The figure for demonstrating deception detection by the visible satellite position information which concerns on 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[Functional configuration of deception detection device]
First, the structure of the deception detection apparatus 10 which concerns on one Embodiment of this invention is demonstrated, referring FIG. FIG. 1 is a diagram illustrating an example of a functional configuration of a deception detection device 10 according to an embodiment. The deception detection device 10 according to this embodiment includes a smartphone, a PDA (Personal Digital Assistants), a mobile phone, a tablet terminal, a personal computer, a video camera, a digital camera, a portable music playback device, a portable video processing device, and a portable device. The present invention can be applied to game devices, wearable display devices such as HMD (Head Mount Display), and electronic devices that can receive positioning signals from GNSS.

  The deception detection device 10 according to the present embodiment includes a GNSS reception unit 11, a storage unit 12, a monitoring unit 13, a detection unit 14, an alarm control unit 15, and a display unit 16.

  The GNSS receiver 11 receives a positioning signal transmitted from the GNSS satellite 1 via the antenna 19 and generates positioning information. The positioning information includes information such as time information, C / N information, visible satellite position information, position information, and speed information. C / N information is information indicating the ratio of carrier wave to noise. The visible satellite position information is information indicating the satellite number, elevation angle, and azimuth angle of the GNSS.

  The storage unit 12 includes a positioning information DB (database) 21 and a trajectory information DB 22. The positioning information DB (database) 21 stores positioning information obtained from positioning signals.

  The monitoring unit 13 includes a time information monitoring unit 23, a C / N information monitoring unit 24, a speed information monitoring unit 25, a position information monitoring unit 26, and a visible satellite position information monitoring unit 27. The time information monitoring unit 23 acquires a reliable reference time from NTP (Network Time Protocol) or the like only when the system is activated, and runs the monitoring time internally by the timer 23a. Then, the time information monitoring unit 23 compares the monitoring time with the time information received by the GNSS receiving unit 11 (hereinafter also referred to as “GNSS time information”), and the GNSS time information and the monitoring time information. It is monitored whether or not the deviation from the first threshold value deviates from the first threshold value indicating the deviation tolerance. For example, the time information monitoring unit 23 determines whether or not the difference between the received time information and the monitoring time information deviates from the first threshold every predetermined time (for example, every 1 second) or every time when new time information is acquired. You may monitor.

  The C / N information monitoring unit 24 monitors a change in the statistic of arbitrary C / N information on the time axis received by the GNSS receiving unit 11. The C / N information monitoring unit 24 monitors whether or not the statistical value of the C / N information deviates from the second threshold value indicating a normal statistical value. The C / N information monitoring unit 24 may calculate a statistical value such as a sample average value and a standard deviation value as a statistical value of the C / N information.

For example, the C / N information monitoring unit 24 uses the collected n pieces of C / N information (X ₁ , X ₂ , X ₃ ,... X _n ) as a standard based on the following formula (1). The deviation value σ can be calculated.

  For example, the C / N information monitoring unit 24 determines whether or not the statistical value of the C / N information deviates from the second threshold every predetermined time (for example, every 1 second) or every time C / N information is newly acquired. You may monitor. The statistical value of the C / N information is an example of the statistical value of the ratio information between the carrier wave and the noise ratio obtained from the positioning information.

  The speed information monitoring unit 25 compares and monitors the speed information received by the GNSS receiving unit 11 and the speed value obtained from the detection value detected by the acceleration sensor 41 or the like. The speed information monitoring unit 25 determines whether or not the difference between the speed information and the speed, which is the time integral value of the acceleration of the acceleration sensor provided in the deception detection device 10, deviates from the fifth threshold value indicating the deviation allowable value. Monitor. For example, the speed information monitoring unit 25 may monitor whether or not the statistical value of the speed information deviates from the fifth threshold every predetermined time (for example, every 1 second) or each time new speed information is acquired.

  The position information monitoring unit 26 includes a movement amount (movement distance amount) between two points at different times calculated from current and past position information (longitude and latitude) on the time axis received by the GNSS reception unit 11 and the acceleration sensor 41. The amount of movement obtained from the detected value is compared and monitored. The position information monitoring unit 26 has a difference between the movement distance amount calculated from the position information and the movement distance amount calculated from the position that is a time integral value of the speed obtained from the acceleration of the acceleration sensor provided in the deception detection device 10. Whether the deviation deviates from the fourth threshold value indicating the allowable deviation is monitored. For example, the position information monitoring unit 26 may monitor whether or not the statistical value of the position information deviates from the fourth threshold value every predetermined time (for example, every second) or every time new position information is acquired.

  The visible satellite position information monitoring unit 27 calculates from the visible satellite position information (satellite number, elevation angle, and azimuth angle) received by the GNSS receiver 11 and known orbit information (for example, almanac data, ephemeris data, etc.) for the satellite. The elevation angle and azimuth angle of the corresponding satellite under a certain reception condition (reception position and reception time) are compared and monitored. The visible satellite position information monitoring unit 27 indicates the satellite number, the elevation angle, and the azimuth angle of the visible satellite position information, and the satellite number in the reception position information and reception time information calculated from the known orbit information stored in the orbit information DB 22. It is monitored whether or not the deviation from the satellite position deviates from the third threshold value indicating the deviation tolerance.

  The visible satellite position information monitoring unit 27 acquires, for example, whether or not the elevation angle and azimuth angle of the visible satellite position information deviate from the third threshold every predetermined time (for example, every 1 second) or newly. You may monitor every time. The elevation angle and azimuth angle of the visible satellite position information are examples of statistical values of the visible satellite position information obtained from the positioning information.

  The detection unit 14 includes a statistical value of time information, a statistical value of C / N information, a statistical value of visible satellite position information, a shift in movement amount based on position information and a detection value of an acceleration sensor, and speed information. The deception of the positioning signal is detected based on at least one of the speed deviations obtained from the detection value of the acceleration sensor.

  The alarm control unit 15 outputs an alarm when the detection unit 14 detects a deception of the positioning signal. As an example of outputting an alarm, the alarm control unit 15 may display on the display unit 16 that deception has been detected.

  After outputting the alarm, the alarm control unit 15 transmits an off signal to the GNSS receiving unit 11 and controls the GNSS receiving unit 11 to stop receiving the positioning signal from the GNSS satellite determined to be deceived. . Further, after outputting an alarm, the alarm control unit 15 may transmit the off signal to the GNSS receiving unit 11 and control the GNSS receiving unit 11 so as to stop receiving the positioning signals from all the GNSS satellites. . Instead of the control, the alarm control unit 15 may continue outputting the alarm until no deception of the positioning signal is detected from all of the time information, C / N information, visible satellite position information, position information, and speed information. Good.

[Hardware configuration of deception detection device]
Next, an example of the hardware configuration of the deception detection device 10 according to the present embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a hardware configuration of the deception detection device 10 according to an embodiment. The deception detection device 10 according to the present embodiment includes a CPU 31, a memory 32, an input / output I / F 33, a touch panel 34, a display 35, a communication I / F 36, a recording medium 37, a positioning signal receiver 39, an acceleration sensor 41, and an angular velocity sensor ( The sensor 40 of the gyro sensor 42 is provided.

  In the present embodiment, the acceleration sensor 41 and the angular velocity sensor 42 are built in or externally attached to the deception detection device 10. The acceleration sensor 41 measures the acceleration of the deception detection device 10. In the present embodiment, the acceleration sensor 41 measures the acceleration in the axial directions of the X axis, the Y axis, and the Z axis with respect to the orientation of the deception detection device 10.

  The angular velocity sensor 42 measures the angular velocity of the deception detection device 10. In the present embodiment, the angular velocity sensor 42 measures angular velocities around the X axis, the Y axis, and the Z axis with respect to the orientation of the deception detection device 10.

  The CPU 31 performs a process of detecting a deception of the positioning signal received from the GNSS satellite 1 according to the procedure described in the deception detection program 38 stored in the memory 32. The memory 32 is, for example, a semiconductor memory, and stores a program executed by the CPU 31, data referred to by the CPU 31, data acquired as a result of processing executed by the CPU 31, and the like.

  The deception detection program 38 may be stored in the recording medium 37 and copied to the memory 32 as necessary, or the acquired data may be copied from the memory 32 to the recording medium 37 as necessary. The recording medium 37 is a non-volatile recording medium such as a flash memory.

  The input / output I / F 33 is an interface for receiving input of information from a user of the deception detection device 10 and providing information to the user. For example, the input / output I / F 33 receives input of information from an input device such as a touch panel 34, a keyboard, a button, or a pointing device. The input / output I / F 33 notifies the user or the system administrator of the deception detection result or the like using an output device such as the display 35.

  For example, the CPU 31 periodically acquires the angular velocity and acceleration by controlling the angular velocity sensor 42 and the acceleration sensor 41 after being instructed to start receiving the positioning signal from the GNSS satellite 1 until it is instructed to finish. . The communication I / F 36 is an interface that is connected to a network and communicates with other devices such as server devices. The positioning signal receiver 39 is connected to the antenna, receives a positioning signal transmitted from the GNNS satellite 1, and generates positioning information from these positioning signals.

  In the deception detection device 10 having such a configuration, the function of the GNSS reception unit 11 in FIG. 1 is mainly realized by the positioning signal receiver 39. The function of the storage unit 12 is mainly realized by the memory 32. The functions of the monitoring unit 13, the detection unit 14, and the alarm control unit 15 are mainly realized by the CPU 31. The function of the display unit 16 is mainly realized by the display 35. In addition, you may memorize | store the information memorize | stored in positioning information DB21 and information orbit information DB in the server on the cloud connected to the deception detection apparatus 10 via a network instead of memorize | storing in the memory 32. FIG.

  Note that FIG. 1 depicts a block diagram focusing on functions, and each unit indicated by these functional blocks can be realized by hardware alone, software alone, or a combination of hardware and software.

Below, the deception detection process of the 1st-5th embodiment which the deception detection apparatus 10 of the said function structure and hardware configuration performs is demonstrated in order.
<First Embodiment>
[Deception detection processing (time information monitoring)]
The deception detection process according to the first embodiment is performed by monitoring time information obtained from the positioning signal. FIG. 3 is a flowchart illustrating an example of deception detection processing according to the first embodiment. FIG. 4 is a timing chart illustrating an example of time information monitoring control according to the first embodiment.

  When this process is started, the time information monitoring unit 23 initializes the monitoring time based on the reference time (step S10). The time information monitoring unit 23 acquires a reliable reference time from, for example, NTP only when the system is activated, and self-runs the monitoring time using the built-in timer 23a. In the example of FIG. 4, the monitoring time when the system is started is initialized with a reliable reference time as shown in (1).

  Returning to FIG. 3, next, the time information monitoring unit 23 determines whether or not the positioning in the GNSS receiving unit 11 is in the Fix state (step S12). The time information monitoring unit 23 waits until the positioning is in the Fix state. When the positioning is in the Fix state, the time information monitoring unit 23 acquires the GNSS time information as one of the positioning information of the GNSS satellite 1 from the GNSS receiving unit 11 (Step S1). S14). Next, the time information monitoring unit 23 compares the acquired GNSS time information with the monitoring time, and calculates the difference (step S16).

  Next, the detection unit 14 determines whether or not the difference between the GNSS time information and the monitoring time is greater than or equal to the first threshold (step S18). The first threshold value is set in advance to allow a difference between the GNSS time information and the monitoring time.

  When it is determined that the difference between the GNSS time information and the monitoring time is less than the first threshold, the detection unit 14 initializes the monitoring time again with the latest GNSS time information (step S20). Thereby, accumulation of errors in the monitoring time can be eliminated, and the accuracy of the monitoring time can be maintained. In the example of FIG. 4, while the monitoring time comparison result is OK (less than the threshold), the monitoring time is initialized with the latest GNSS time information as shown in (2) and (3).

  Returning to FIG. 3, after initialization of the monitoring time in step S <b> 20, the process returns to step S <b> 12, and the time information monitoring unit 23 repeats the processing after step S <b> 12. As a result, new GNSS time information is acquired, and deception monitoring is continued.

  On the other hand, if the detection unit 14 determines in step S18 that the difference between the GNSS time information and the monitoring time is equal to or greater than the first threshold value, the alarm control unit 15 displays an alarm notifying deception detection on the display unit 16. Output to. Thereby, it can inform the user who owns the deception detection device 10 that the deception has been detected. In the example of FIG. 4, when the monitoring time comparison result is NG (greater than or equal to the threshold), it is determined that the GNSS time information is deception and an alarm is output. The alarm output may be displayed on the display unit of the device owned by the system administrator.

  In step S22 of FIG. 3, the alarm control unit 15 outputs an alarm, and then outputs an off signal to the GNSS receiving unit 11 so as to stop receiving the positioning signal from the GNSS satellite 1 (step S22). Exit. Thereby, reception of the positioning signal with the possibility of deception can be stopped.

  As described above, according to the deception detection process according to the first embodiment, the time continuity (time skipping, that is, the monitoring time and the GNSS time) based on the time information of the GNSS and the monitoring time for self-running. When the deviation from the time information exceeds a set threshold value, it is judged as deception (spoofing, spoofing) and an alarm is output. At this time, in the deception detection process according to the present embodiment, since the monitoring time is self-propelled, periodic access to other systems as the reference time is unnecessary. Thereby, the accuracy of fraud detection can be improved based on the time information of GNSS in real time without increasing the communication load due to periodic access to other systems.

Second Embodiment
[Deception detection processing]
The deception detection process according to the second embodiment is performed using C / N information obtained from the positioning signal. FIG. 5 is a flowchart illustrating an example of deception detection processing according to the second embodiment. Of the steps of the deception detection process according to the second embodiment shown in FIG. 5, the same step number is assigned to the step that performs the same process as the flowchart of the deception detection process according to the first embodiment shown in FIG. 3. By attaching, the processing of the same step will be omitted or simplified.

  When this processing is started, the C / N information monitoring unit 24 acquires C / N information, which is one of the positioning information of the GNSS satellite 1, from the GNSS receiving unit 11 (step S30) and stores it in the positioning information DB 21. (Step S32). Next, the C / N information monitoring unit 24 calculates a sample average value and a standard change value from the C / N information accumulated in the positioning information DB 21 (step S34). However, the sample average value and the standard change value are examples of the statistical value of the ratio information between the carrier wave and the noise ratio, and the C / N information monitoring unit 24 calculates other statistical values regarding the ratio information between the carrier wave and the noise ratio. May be. The ratio information between the carrier wave and the noise ratio used for calculating the statistical value may be all of the C / N information stored in the positioning information DB 21 or one of the C / N information stored in the positioning information DB 21. Part. For example, the C / N information monitoring unit 24 may calculate a statistical value related to C / N information using a predetermined number of C / N information stored in the latest (latest) positioning information DB 21.

  Next, the detection unit 14 determines whether or not the calculated statistical value related to the C / N information is greater than or equal to (or less than) the second threshold value (step S36). As the second threshold, a normal range threshold for a statistical value related to C / N information is set in advance. Alternatively, the second threshold value may dynamically set a range, an upper limit value, or a lower limit value indicating normality of statistical values related to C / N information from the C / N information accumulated in the positioning information DB 21.

  Regarding the GNSS C / N information, the GNSS signal that is a deception signal has a higher C / N level than the GNSS signal that is not a deception signal. Therefore, for example, when a sample average value is calculated as a statistical value related to C / N information, if the sample average value is equal to or greater than the second threshold value, it is determined to be fraudulent.

  Further, the GNSS signal that is a deception signal has a smaller standard deviation value than the GNSS signal that is not a deception signal. Therefore, for example, when a standard deviation value is calculated as a statistical value related to C / N information, it is determined to be fraud when the standard deviation value is equal to or smaller than the second threshold value.

  When the detection unit 14 determines that the sample average value is larger than the second threshold value (or the sample average value is less than the second threshold value), the detection unit 14 returns to step S30, and the C / N information monitoring unit 24 performs step S30 and subsequent steps. Repeat the process. As a result, new GNSS C / N information is acquired, and deception monitoring is continued.

  On the other hand, when the detection unit 14 determines in step S36 that the sample average value is equal to or smaller than the second threshold value (or the sample average value is equal to or larger than the second threshold value), the alarm control unit 15 acquires the C / N acquired last. An alarm is output as information is deceived (step S22). After outputting the alarm, the alarm control unit 15 outputs an off signal to the GNSS receiving unit 11 (step S22), and ends this process. Thereby, reception of the positioning signal with the possibility of deception can be stopped.

  As described above, according to the deception detection process according to the second embodiment, the statistical value (average value, standard deviation value, etc.) of C / N information obtained based on the information received from GNSS is calculated, When it exceeds (or falls below) a preset threshold value, it is determined to be deceptive and an alarm is output. Thereby, the precision of deception detection can be improved based on C / N information in real time.

<Third Embodiment>
[Deception detection processing]
The deception detection process according to the third embodiment is performed using velocity information obtained from the positioning signal, the acceleration sensor 41, and the angular velocity sensor 42. FIG. 6 is a flowchart illustrating an example of deception detection processing according to the third embodiment. Of the steps of the deception detection process according to the third embodiment shown in FIG. 6, the same step number is assigned to the step that performs the same process as the flowchart of the deception detection process according to the first embodiment shown in FIG. 3. By attaching, the processing of the same step will be omitted or simplified.

  When this process is started, first, the speed information monitoring unit 25 initializes parameters necessary for calculating the speed of the deception detection device 10 at the start of monitoring (step S40). Next, the velocity information monitoring unit 25 acquires acceleration from the acceleration sensor 41 and acquires angular velocity from the angular velocity sensor 42 (step S42). You may perform the timing which acquires the detected value of the acceleration sensor 41 and the angular velocity sensor 42 at a predetermined time interval.

  Next, the speed information monitoring unit 25 calculates the attitude of the deception detection device 10 using the acquired angular velocity, and corrects the direction of the acquired acceleration (step S44). Next, the speed information monitoring unit 25 calculates the speed from the time integration of acceleration (step S46).

  Next, the speed information monitoring unit 25 determines whether the positioning at the GNSS receiving unit 11 is in the Fix state (step S48). The speed information monitoring unit 25 waits until the positioning is in the Fix state. When the positioning is in the Fix state, the speed information monitoring unit 25 acquires speed information that is an example of the positioning information of the GNSS satellite 1 from the GNSS receiving unit 11 (Step S50). Next, the speed information monitoring unit 25 compares the acquired GNSS speed information with the speed calculated from the detection value of the acceleration sensor 41, and calculates the difference (step S52).

  Next, the detection unit 14 determines whether or not the difference between the speed information of the GNSS and the speed obtained from the detection value of the acceleration sensor 41 is equal to or greater than a fifth threshold (step S54). In the fifth threshold value, an allowable value of a deviation between the GNSS speed information and the speed calculated by time-integrating the acceleration detected by the acceleration sensor 41 is set in advance.

  When the detection unit 14 determines that the difference between the speed information of the GNSS and the speed that is the time integral of the acceleration is less than the fifth threshold, the speed information monitoring unit 25 returns to step S42 and performs the processing after step S42. repeat. As a result, new GNSS speed information is acquired, and deception monitoring is continued.

  On the other hand, when the detection unit 14 determines in step S54 that the difference between the speed information of the GNSS and the speed that is the time integral of the acceleration of the acceleration sensor 41 is equal to or greater than the fifth threshold, the speed information of the GNSS is deceptive. It is determined that there is. In this case, the alarm control unit 15 outputs an alarm notifying deception detection to the display unit 16, and then outputs an off signal to the GNSS reception unit 11 so as to stop receiving the positioning signal (step S22). finish. Thereby, reception of the positioning signal with the possibility of deception can be stopped.

  As described above, according to the deception detection process according to the third embodiment, the speed information of the positioning information received from the GNSS is compared with the speed obtained from the integrated value of the data of the acceleration sensor 41 and the like. When the difference exceeds a set threshold value, it is determined to be fraud and an alarm is output. According to this, since the target to be compared with the GNSS speed information is the speed calculated from the detected value of the acceleration sensor 41 or the like, and not the GNSS speed information that may be deceived, the reference speed becomes a more probable value. As a result, the accuracy of deception detection can be improved based on the speed information of GNSS in real time.

<Fourth embodiment>
[Deception detection processing]
The deception detection process according to the fourth embodiment is performed using the position information obtained from the positioning signal, the acceleration sensor 41, and the angular velocity sensor 42. FIG. 7 is a flowchart illustrating an example of the deception detection process according to the fourth embodiment. Of the steps of the deception detection process according to the fourth embodiment shown in FIG. 7, the same step number is assigned to the step that performs the same process as the flowchart of the deception detection process according to the first embodiment shown in FIG. By attaching, the processing of the same step will be omitted or simplified.

  When this processing is started, first, the position information monitoring unit 26 initializes parameters necessary for calculating the movement amount of the deception detection device 10 at the start of monitoring (step S60). Next, the position information monitoring unit 26 acquires acceleration from the acceleration sensor 41 and acquires angular velocity from the angular velocity sensor 42 (step S42). You may perform the timing which acquires the detected value of the acceleration sensor 41 and the angular velocity sensor 42 at a predetermined time interval.

  Next, the position information monitoring unit 26 calculates the attitude of the deception detection device 10 using the acquired angular velocity, and corrects the direction of the acquired acceleration (step S44). Next, the position information monitoring unit 26 calculates a speed from the time integral of acceleration, and calculates the position by time-integrating the calculated speed (step S62).

  Next, the position information monitoring unit 26 determines whether the positioning at the GNSS receiving unit 11 is in the Fix state (step S64). The position information monitoring unit 26 waits until the positioning is in the Fix state. When the positioning is in the Fix state, the position information monitoring unit 26 acquires position information at the current time, which is an example of the positioning information of the GNSS satellite 1 (Step S66). The position information monitoring unit 26 calculates a movement amount (movement distance amount) based on the GNSS position information, which is the difference between the acquired GNSS position information at the current time and the GNSS position information at the past time (step S68). .

  Next, the position information monitoring unit 26 calculates the amount of movement by the sensor from the amount of movement distance that is the difference between the position information of the current time and the past time calculated from the detected value of the acceleration sensor 41 (step S70).

  Next, the detection unit 14 determines whether or not the difference between the movement amount by the GNSS and the movement amount by the sensor is equal to or greater than a fourth threshold (step S72). In the fourth threshold, an allowable value of a deviation between the movement amount of the GNSS and the movement amount by the sensor is set in advance.

  When the detection unit 14 determines that the difference between the movement amount by the GNSS and the movement amount by the sensor is less than the fourth threshold, the detection unit 14 updates the GNSS position information at the past time with the value of the GNSS position information at the current time. Then, the position information of the GNSS by the sensor at the past time is updated (replaced) with the value of the position information by the sensor at the current time (step S74). Thereafter, the position information monitoring unit 26 returns to step S42 and repeats the processing after step S42. Thereby, the position information of a new GNSS is acquired, and deception monitoring is continued.

  On the other hand, when the detection unit 14 determines in step S72 that the difference between the movement amount by the GNSS and the movement amount by the sensor is equal to or greater than the fourth threshold value, the position information of the GNSS is determined to be deception. In this case, the alarm control unit 15 outputs an alarm notifying deception detection to the display unit 16, and then outputs an off signal to the GNSS reception unit 11 so as to stop receiving the positioning signal (step S22). finish. Thereby, reception of the positioning signal with the possibility of deception can be stopped.

  As described above, according to the deception detection process according to the fourth embodiment, the movement amount (movement distance amount) from the position information obtained based on the information received from the GNSS and the movement obtained from the acceleration sensor or the like. The amount (movement distance amount) is compared, and if the set threshold value is exceeded, it is judged as deception and an alarm is output. According to this, the object to be compared with the GNSS position information (movement amount) at the current time and the past time is the position (movement amount) calculated from the detection values detected by the acceleration sensor 41 and the like at the current time and the past time. Since the position information of the GNSS is not likely to be deceived, the reference position becomes a more reliable value. As a result, the accuracy of deception detection can be improved based on the position information of the GNSS in real time.

<Fifth Embodiment>
[Deception detection processing]
The deception detection process according to the fifth embodiment is performed using visible satellite position information obtained from a positioning signal. FIG. 8 is a flowchart illustrating an example of the deception detection process according to the fifth embodiment. FIG. 9 is a diagram for explaining the azimuth angle and the elevation angle, and FIG. 10 is a diagram for explaining deception detection based on visible satellite position information according to the fifth embodiment.

  Of the steps of the deception detection process according to the fifth embodiment shown in FIG. 8, the same step numbers are assigned to the steps that perform the same process as the flowchart of the deception detection process according to the first embodiment shown in FIG. By attaching, the processing of the same step will be omitted or simplified.

  When this process is started, first, the visible satellite position information monitoring unit 27 acquires visible satellite position information, which is an example of positioning information of the GNSS satellite 1, from the GNSS receiving unit 11 (step S80). The visible satellite position information includes satellite number, elevation angle, and azimuth information.

  As shown in FIG. 9A, the azimuth is an angle that is swung clockwise with the north azimuth as 0 degrees. For example, the azimuth is 90 degrees in the east, the azimuth is 180 degrees in the south, and the azimuth is in the west. 270 degrees. As shown in FIG. 9B, the elevation angle is an angle that is directed upward from the horizontal (the ground surface) by that angle, for example, the vertical elevation angle from the ground surface is 90 degrees. The satellite number is identification information assigned to each GNSS satellite 1.

  Returning to FIG. 8, the visible satellite position information monitoring unit 27 then knows the known orbit information (for example, almanac data), the current position, and the current time (position and time information from the orbit information DB 22 at the GNSS system level. The positioning accuracy is not required), and the elevation angle and azimuth angle of the satellite are calculated from the orbit information (step S82). Next, the visible satellite position information monitoring unit 27 compares the obtained elevation angle and azimuth angle with the elevation angle and azimuth angle calculated from the orbit information, and calculates the difference in elevation angle and the difference in azimuth angle (step S84). .

  Next, the detection unit 14 determines whether or not the difference in elevation angle is equal to or greater than a predetermined threshold value for elevation angle, and whether or not the difference in azimuth angle is equal to or greater than a threshold value for azimuth angle. (Step S86). The threshold for elevation and the threshold for azimuth are collectively referred to as a third threshold. The third threshold indicates an allowable value for each deviation of the elevation angle and the azimuth angle. The third threshold value may be set in advance, or may be dynamically set using the elevation angle and azimuth angle of the satellite.

  When the detection unit 14 determines that the elevation angle difference is less than the elevation angle threshold value and the azimuth angle difference is less than the azimuth angle threshold value, the visible satellite position information monitoring unit 27 returns to step S80. Then, the processing after step S80 is repeated. Thereby, the visible satellite position information of new GNSS is acquired, and deception monitoring is continued.

  On the other hand, in step S86, the detection unit 14 determines that the elevation angle difference is equal to or greater than a predetermined elevation angle threshold value, or that the azimuth angle difference is equal to or greater than a predetermined azimuth angle threshold value. In the case of determination, or in both cases, it is determined that the visible satellite position information is deception. In this case, the alarm control unit 15 outputs an alarm notifying deception detection to the display unit 16, and then outputs an off signal to the GNSS reception unit 11 so as to stop receiving the positioning signal (step S22). finish. Thereby, reception of the positioning signal with the possibility of deception can be stopped.

  For example, in FIG. 10, when the visible satellite position information is received from the GNSS satellites with satellite numbers 1 to 5, the difference between the elevation angle and azimuth angle of satellite numbers 1 to 4 and the elevation angle and azimuth angle obtained from the orbit information is the first. It is assumed that the threshold value is less than 3. In this case, deception is not detected. On the other hand, it is assumed that the difference between the elevation angle and azimuth angle of satellite number 5 and the elevation angle and azimuth angle obtained from orbit information is equal to or greater than the third threshold. For example, this is a case where the GNSS satellite with the satellite number 5 is arranged at a position where it cannot be seen from the deception detection device 10. In this case, deception is detected and reception of the positioning signal from the GNSS satellite is stopped. The signal to be stopped may be a positioning signal transmitted from a GNSS satellite in which deception is detected, or may be a positioning signal received from all GNSS satellites including a GNSS satellite in which deception is detected. . In addition, when the number of GNSS satellites for which deception is detected exceeds a preset number, reception of positioning signals may be stopped.

  As described above, according to the deception detection process according to the fifth embodiment, from the visible satellite position information (satellite number, elevation angle, azimuth angle) obtained based on the information received from GNSS and the known orbit information. The calculated reception position and the elevation angle and azimuth angle of the satellite at the reception time are compared. When the set threshold value is exceeded, it is determined to be a deception and an alarm is output. Thereby, the precision of deception detection can be improved based on visible satellite position information in real time.

  The fraud detection process according to the first to fifth embodiments has been described above. The deception detection process according to the first to fifth embodiments can be executed independently. However, it is preferable to execute two or more processes among the deception detection processes according to the first to fifth embodiments in parallel. By detecting a deception of a positioning signal in each of two or more deception detection processes executed in parallel, the accuracy of deception detection can be further improved.

  For example, in a positioning signal transmitted by a GNSS satellite, speed information and position information are acquired as separate information. Therefore, in the deception detection process based on the GNSS speed information according to the third embodiment and the deception detection process based on the GNSS position information according to the fourth embodiment, separate positioning obtained from a signal transmitted from the GNSS satellite. It becomes detection of deception using information. Therefore, the accuracy of deception detection can be further improved by executing these two processes in parallel and detecting the deception of the positioning signal in each of the two or more deception detection processes executed in parallel.

  Further, in this case, in the deception detection process based on the GNSS position information according to the fourth embodiment, if the movement distance amount calculated from the GNSS current time and the position information of the past time is short, the movement distance amount is long. The deception detection accuracy is lower than the case. Therefore, particularly when executing the deception detection process according to the fourth embodiment, it is possible that the accuracy of the deception detection is higher when the third embodiment or other deception detection processes are executed in parallel.

  As described above, according to the deception detection processing according to the first to fifth embodiments, the time information monitoring, the C / N information monitoring, the speed information monitoring, the position information monitoring, the visible satellite position information monitoring and the like are performed independently. By the deception detection method or the combination of a plurality of deception detection methods, it is possible to improve the accuracy of deception detection for the reception information of the GNSS positioning signal which is not encrypted in real time. In addition, it is possible to ensure the validity of positioning information such as position and time obtained from the positioning signal of GNSS.

  As described above, the deception detection program, the deception detection method, and the deception detection device have been described in the above embodiment. However, the deception detection program, the deception detection method, and the deception detection device according to the present invention are not limited to the above embodiment. Various modifications and improvements are possible within the scope of the invention. In addition, when there are a plurality of the above-described embodiments and modifications, they can be combined within a consistent range.

Regarding the above description, the following items are further disclosed.
(Appendix 1)
Among the positioning information obtained from positioning signals received from GNSS (Global Navigation Satellite System), statistical information of time information, statistical information of ratio information of carrier wave to noise ratio, statistical value of visible satellite position information, positional information and acceleration Calculating at least one of the shift amount of the movement amount based on the position information obtained from the detection value of the sensor and the shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Detecting a deception of the positioning signal based on the calculated result;
A deception detection program for causing a computer to execute processing.
(Appendix 2)
If the difference between the time information and the monitoring time information of the deception detection device deviates from a first threshold value indicating an allowable value of the deviation, an alarm for notifying deception of the positioning signal is output.
The deception detection program according to attachment 1.
(Appendix 3)
When the statistical value of the ratio information between the carrier wave and the noise ratio deviates from a second threshold value indicating a normal statistical value, the alarm is output.
The deception detection program according to attachment 2.
(Appendix 4)
When the deviation between the elevation angle and azimuth angle of the visible satellite position information and the elevation angle and azimuth angle calculated from the orbit information deviates from a third threshold value indicating an allowable deviation value, the alarm is output.
The deception detection program according to any one of Appendix 2 or 3.
(Appendix 5)
When the deviation between the movement distance amount calculated from the position information and the movement amount calculated from the position information obtained from the acceleration sensor provided in the deception detection device deviates from a fourth threshold value indicating a deviation allowable value, Output an alarm,
The deception detection program according to any one of appendices 2 to 4.
(Appendix 6)
When the deviation between the velocity information and the velocity information obtained from the acceleration sensor provided in the deception detection device deviates from the fifth threshold value indicating the deviation tolerance, the alarm is output.
The deception detection program according to any one of appendices 2 to 5.
(Appendix 7)
When deception of the positioning signal is detected from each of two or more of the time information, the ratio information between the carrier wave and the noise ratio, the visible satellite position information, the position information, and the speed information, Output an alarm,
The deception detection program according to any one of appendices 2 to 6.
(Appendix 8)
Stop receiving the positioning signal from the GNSS after outputting the alarm, or all the time information, the ratio information of the carrier wave to the noise ratio, the visible satellite position information, the position information, and the speed information. Continue outputting the alarm until no deception of the positioning signal is detected from the calculation result,
The deception detection program according to any one of appendices 2 to 7.
(Appendix 9)
Among the positioning information obtained from the positioning signal received from GNSS, it is obtained from the statistical value of the time information, the statistical value of the ratio information between the carrier wave and the noise ratio, the statistical value of the visible satellite position information, the position information and the detection value of the acceleration sensor. Calculating at least one of the shift amount of the movement amount based on the position information and the shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Detecting a deception of the positioning signal based on the calculated result;
A deception detection method in which processing is performed by a computer.
(Appendix 10)
If the difference between the time information and the monitoring time information of the deception detection device deviates from a first threshold value indicating an allowable value of the deviation, an alarm for notifying deception of the positioning signal is output.
The deception detection method according to attachment 9.
(Appendix 11)
When the statistical value of the ratio information between the carrier wave and the noise ratio deviates from a second threshold value indicating a normal statistical value, the alarm is output.
The deception detection method according to attachment 10.
(Appendix 12)
When the deviation between the elevation angle and azimuth angle of the visible satellite position information and the elevation angle and azimuth angle calculated from the orbit information deviates from a third threshold value indicating an allowable deviation value, the alarm is output.
The deception detection method according to any one of Appendix 10 or 11.
(Appendix 13)
When the deviation between the movement distance amount calculated from the position information and the movement amount calculated from the position information obtained from the acceleration sensor provided in the deception detection device deviates from a fourth threshold value indicating a deviation allowable value, Output an alarm,
The deception detection method according to any one of appendices 10 to 12.
(Appendix 14)
When the deviation between the velocity information and the velocity information obtained from the acceleration sensor provided in the deception detection device deviates from the fifth threshold value indicating the deviation tolerance, the alarm is output.
The deception detection method according to any one of appendices 10 to 13.
(Appendix 15)
When deception of the positioning signal is detected from each of two or more of the time information, the ratio information between the carrier wave and the noise ratio, the visible satellite position information, the position information, and the speed information, Output an alarm,
The deception detection method according to any one of appendices 10 to 14.
(Appendix 16)
Stop receiving the positioning signal from the GNSS after outputting the alarm, or all the time information, the ratio information of the carrier wave to the noise ratio, the visible satellite position information, the position information, and the speed information. Continue outputting the alarm until no deception of the positioning signal is detected from the calculation result,
The deception detection method according to any one of appendices 10 to 15.
(Appendix 17)
Among the positioning information obtained from positioning signals received from GNSS (Global Navigation Satellite System), statistical information of time information, statistical information of ratio information of carrier wave to noise ratio, statistical value of visible satellite position information, positional information and acceleration A monitoring unit that calculates at least one of a shift amount of the movement amount based on the position information obtained from the detection value of the sensor and a shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Based on the calculated result, a detection unit for detecting deception of the positioning signal,
A deception detection device having
(Appendix 18)
When the deviation between the time information and the monitoring time information of the deception detection device deviates from a first threshold value indicating an allowable deviation value, the alarm control unit outputs an alarm notifying the deception of the positioning signal,
The deception detection device according to appendix 17.
(Appendix 19)
The alarm control unit outputs the alarm when a statistical value of the ratio information between the carrier wave and the noise ratio deviates from a second threshold value indicating a normal statistical value.
The deception detection device according to appendix 18.
(Appendix 20)
When the deviation between the elevation angle and azimuth angle of the visible satellite position information and the elevation angle and azimuth angle calculated from the orbit information deviates from a third threshold value indicating a deviation tolerance, the alarm control unit Output,
The deception detection device according to any one of appendix 18 or 19,
(Appendix 21)
In the alarm control unit, a difference between a movement distance amount calculated from the position information and a movement amount calculated from position information obtained from an acceleration sensor provided in the deception detection device indicates a tolerance value of a deviation. If the threshold value is exceeded, the alarm is output.
The deception detection device according to any one of appendices 18 to 20.
(Appendix 22)
The alarm control unit outputs the alarm when the deviation between the speed information and the speed information obtained from the acceleration sensor provided in the deception detection device deviates from a fifth threshold value indicating a deviation allowable value.
The deception detection device according to any one of appendices 18 to 21.
(Appendix 23)
The alarm control unit is configured to detect the deception of the positioning signal from each of two or more of the time information, the ratio information of the carrier wave and the noise ratio, the visible satellite position information, the position information, and the speed information. If detected, output the alarm,
The deception detection device according to any one of appendices 18 to 22.
(Appendix 24)
The alarm control unit stops receiving the positioning signal from the GNSS after outputting the alarm, or the time information, the ratio information of the carrier wave to the noise ratio, the visible satellite position information, the position information, and Continue outputting the alarm until no deception of the positioning signal is detected from all the calculation results of the speed information,
The deception detection device according to any one of appendices 18 to 23.

DESCRIPTION OF SYMBOLS 10 Deception detection apparatus 11 GNSS receiving part 12 Storage part 13 Monitoring part 14 Detection part 15 Alarm control part 16 Display part 17 Acceleration sensor 18 Angular velocity sensor 21 Positioning information DB
22 Orbit information DB
23 Time information monitoring unit 24 C / N information monitoring unit 25 Speed information monitoring unit 26 Position information monitoring unit 27 Visible satellite position information monitoring unit 41 Acceleration sensor 42 Angular velocity sensor

Claims (10)

Among the positioning information obtained from positioning signals received from GNSS (Global Navigation Satellite System), statistical information of time information, statistical information of ratio information of carrier wave to noise ratio, statistical value of visible satellite position information, positional information and acceleration Calculating at least one of the shift amount of the movement amount based on the position information obtained from the detection value of the sensor and the shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Detecting a deception of the positioning signal based on the calculated result;
A deception detection program for causing a computer to execute processing. If the difference between the time information and the monitoring time information of the deception detection device deviates from a first threshold value indicating an allowable value of the deviation, an alarm for notifying deception of the positioning signal is output.
The deception detection program according to claim 1. When the statistical value of the ratio information between the carrier wave and the noise ratio deviates from a second threshold value indicating a normal statistical value, the alarm is output.
The deception detection program according to claim 2. When the deviation between the elevation angle and azimuth angle of the visible satellite position information and the elevation angle and azimuth angle calculated from the orbit information deviates from a third threshold value indicating an allowable deviation value, the alarm is output.
The fraud detection program as described in any one of Claim 2 or 3. When the deviation between the movement distance amount calculated from the position information and the movement amount calculated from the position information obtained from the acceleration sensor provided in the deception detection device deviates from a fourth threshold value indicating a deviation allowable value, Output an alarm,
The deception detection program as described in any one of Claims 2-4. When the deviation between the velocity information and the velocity information obtained from the acceleration sensor provided in the deception detection device deviates from the fifth threshold value indicating the deviation tolerance, the alarm is output.
The deception detection program according to any one of claims 2 to 5. When deception of the positioning signal is detected from each of two or more of the time information, the ratio information between the carrier wave and the noise ratio, the visible satellite position information, the position information, and the speed information, Output an alarm,
The deception detection program according to any one of claims 2 to 6. Stop receiving the positioning signal from the GNSS after outputting the alarm, or all the time information, the ratio information of the carrier wave to the noise ratio, the visible satellite position information, the position information, and the speed information. Continue outputting the alarm until no deception of the positioning signal is detected from the calculation result,
The deception detection program as described in any one of Claims 2-7. Among the positioning information obtained from the positioning signal received from GNSS, it is obtained from the statistical value of the time information, the statistical value of the ratio information between the carrier wave and the noise ratio, the statistical value of the visible satellite position information, the position information and the detection value of the acceleration sensor. Calculating at least one of the shift amount of the movement amount based on the position information and the shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Detecting a deception of the positioning signal based on the calculated result;
A deception detection method in which processing is performed by a computer. Among the positioning information obtained from positioning signals received from GNSS (Global Navigation Satellite System), statistical information of time information, statistical information of ratio information of carrier wave to noise ratio, statistical value of visible satellite position information, positional information and acceleration A monitoring unit that calculates at least one of a shift amount of the movement amount based on the position information obtained from the detection value of the sensor and a shift amount of the speed information and the speed information obtained from the detection value of the acceleration sensor;
Based on the calculated result, a detection unit for detecting deception of the positioning signal,
A deception detection device having

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