A satellite navigation deception detection method and system based on inertial navigation

Abstract

This invention discloses a satellite navigation spoofing detection method based on inertial navigation, comprising: verifying the validity of received satellite navigation data before the device is aligned; once the data is valid, the device enters a combined navigation state, in which the judgment thresholds for satellite navigation position and velocity are dynamically set by utilizing the divergence characteristic of inertial navigation error over time; by comparing the position and velocity information provided by satellite navigation and inertial navigation in real time, if the difference between the two exceeds a preset dynamic threshold, it is determined that the satellite navigation information may be spoofed; once spoofing is detected, the device exits the combined navigation state; this invention implements satellite navigation spoofing detection through software algorithms, enabling autonomous and accurate judgment and processing of navigation data in complex and harsh navigation environments, preventing navigation errors caused by signal spoofing.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation deception detection technology, specifically to a satellite navigation deception detection method and system based on inertial navigation. Background Technology

[0002] In modern navigation technology, satellite navigation systems are widely used for navigation and surveying on various platforms across sea, land, air, and space due to their advantages such as low cost, high accuracy, and error characteristics close to white noise that do not accumulate over time. However, satellite navigation systems also have the drawback of being easily interfered with or spoofed, which is particularly prominent in high-precision navigation applications. This can lead to errors in navigation information, thereby affecting the accuracy and safety of navigation.

[0003] To ensure the reliability of satellite navigation information, existing technologies employ various measures. On one hand, satellite navigation messages typically include signal availability indicators to show signal validity; on the other hand, anti-interference antennas are configured to enhance signal acquisition and anti-interference capabilities. However, these methods primarily rely on hardware improvements and assessments, lacking a comprehensive approach that integrates software algorithms with other navigation systems for integrated evaluation.

[0004] Furthermore, although inertial navigation systems (INS) are autonomous navigation systems and do not rely on external signals, their errors gradually increase over time. This error characteristic means that traditional static threshold setting methods cannot accurately reflect the real-time changes in INS errors when setting detection thresholds, thus affecting the accuracy of satellite navigation deception detection. Especially during long-term navigation, static thresholds often cannot adapt to the gradual accumulation of errors, leading to an increased risk of misjudgment or missed detection. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a satellite navigation spoofing detection method based on inertial navigation. By implementing satellite navigation spoofing detection through software algorithms, it can autonomously and accurately judge and process navigation data in complex and harsh navigation environments, preventing navigation errors caused by signal spoofing.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A satellite navigation spoofing detection method based on inertial navigation, comprising:

[0008] Before the inertial navigation system has completed alignment, the satellite navigation system receives a new frame of satellite navigation data relayed by the flight control system and performs a validity check on the satellite navigation data.

[0009] If the validity assessment passes, the satellite navigation data is considered valid and can proceed with subsequent satellite navigation anti-fraud assessments.

[0010] Once the device is aligned and enters the integrated navigation state, a satellite navigation anti-spoofing judgment is performed.

[0011] The satellite navigation anti-fraud judgment process includes:

[0012] Based on the characteristic that inertial navigation error diverges over time, dynamic satellite navigation position thresholds and satellite navigation speed thresholds that are related to time are set.

[0013] The satellite navigation position of the new frame is compared with the inertial navigation position. If the difference is greater than or equal to the satellite navigation position threshold, it is determined that the satellite navigation position information has been spoofed.

[0014] The satellite navigation speed is compared with the inertial navigation speed. If the difference is greater than or equal to the satellite navigation speed threshold, it is determined that the satellite navigation speed information has been spoofed.

[0015] If neither the satellite navigation position nor the satellite navigation speed information is spoofed, the device will continue to maintain the integrated navigation state. If either the satellite navigation position or the satellite navigation speed information is spoofed, the device will exit the integrated navigation state.

[0016] Determining the validity of satellite navigation data includes:

[0017] Check the original satellite navigation validity identifier relayed by the flight control system to confirm whether the identifier is valid.

[0018] Calculate the PDOP value of the current satellite navigation data and compare it with the preset PDOP threshold. If the PDOP value is too large, the satellite navigation data is considered unreliable.

[0019] Check the satellite navigation solution status to confirm whether the position and velocity information have been successfully calculated.

[0020] Compare the current satellite navigation information with the satellite navigation information from the previous moment to check for any abnormal jumps in the data.

[0021] If any of the above judgments fails, the current satellite navigation data is considered invalid and no further processing will be performed; if all judgments pass, the satellite navigation data is considered valid and subsequent satellite navigation anti-fraud judgments can be performed.

[0022] Based on the characteristic of inertial navigation error diverging over time, time-dependent dynamic satellite navigation position and velocity thresholds are set, including:

[0023] Collect position and velocity data output by the inertial navigation system from actual navigation or simulation experiments;

[0024] For the velocity data at each time point, compare it with the known true velocity, calculate the velocity error, and plot the velocity error as a function of time.

[0025] For the location data at each time point, compare it with the known true location, calculate the location error, and plot the curve of the location error changing over time.

[0026] Based on the velocity error curve and the position error curve, determine the divergence characteristics of velocity error and position error over time;

[0027] Based on the divergence characteristics of speed and position errors in inertial navigation, the navigation time is divided into several time periods, and different speed and position judgment thresholds are set for each time period.

[0028] The navigation time is divided into several time periods, and different satellite navigation position thresholds are set for each time period, including:

[0029] When the navigation time is in the initial stage, i.e. 0≤t0≤t1;

[0030] Let the satellite navigation position threshold be ΔP1, as shown in the following formula.

[0031]

[0032] Where n is the initial position error, t0 is the inertial navigation time, and a is the divergence coefficient;

[0033] When the navigation time is in the middle, i.e., t1 <t0≤t2;

[0034] Let the satellite navigation position threshold be ΔP2, as shown in the following formula.

[0035]

[0036] Where b is the mid-term threshold fine-tuning constant;

[0037] When the navigation time is long, i.e. t2 <t0;

[0038] Let the satellite navigation position threshold be ΔP3, and the calculation formula is as follows.

[0039]

[0040] Where c is the long-term threshold fine-tuning constant.

[0041] The navigation time is divided into several time periods, and different satellite navigation speed thresholds are set for each time period, including:

[0042] When the navigation time is in the initial stage, i.e. 0≤t0≤t1;

[0043] Let the satellite navigation speed threshold be ΔS1, as shown in the following formula.

[0044] ΔS1=m+at0;

[0045] Where n is the initial position error, t0 is the inertial navigation time, and a is the initial divergence velocity of the inertial navigation velocity error;

[0046] When the navigation time is in the middle, i.e., t1 <t0≤t2;

[0047] Let the satellite navigation speed threshold be ΔS2, as shown in the following formula.

[0048]

[0049] Where d is the mid-term velocity threshold fine-tuning constant;

[0050] When the navigation time is long, i.e. t2 <t0;

[0051] The satellite navigation speed threshold is set to ΔS3, and the calculation formula is as follows:

[0052]

[0053] Where e is the long-term velocity threshold fine-tuning constant.

[0054] The satellite navigation spoofing detection method also includes a spoofing termination judgment step, which specifically includes:

[0055] Once the deception state is determined, the satellite navigation speed return threshold and the satellite navigation position return threshold are set according to a predetermined ratio of the current satellite navigation speed threshold and the satellite navigation position threshold, respectively.

[0056] Continuously monitor the speed and position information provided by satellite navigation and compare it with the corresponding information provided by the inertial navigation system;

[0057] If the difference between the satellite navigation speed and the inertial navigation speed is less than the satellite navigation speed regression threshold, and the difference between the satellite navigation position and the inertial navigation position is less than the satellite navigation position regression threshold, and this continues for a predetermined time, then the deception is considered to have ended.

[0058] Satellite navigation deception detection methods also include a calibration step, specifically including:

[0059] After the deception is complete, both the inertial navigation system and the satellite navigation system are activated simultaneously to ensure time synchronization between the two devices and to collect data separately.

[0060] By comparing the output data of the inertial navigation system and the satellite navigation system, the source and magnitude of the error can be determined.

[0061] Based on the error analysis results, the parameters of the satellite navigation system are calibrated and adjusted;

[0062] The output data of the satellite navigation system is repeatedly checked and adjusted until its data deviation from that of the inertial navigation system is within the predetermined range.

[0063] A satellite navigation spoofing detection system based on inertial navigation, comprising:

[0064] An inertial navigation system is used to provide the position and velocity information of a vehicle.

[0065] Satellite navigation systems are used to receive satellite signals and provide real-time position and velocity information;

[0066] The threshold setting module dynamically sets the satellite navigation position threshold and satellite navigation speed threshold based on the characteristics of the inertial navigation system's error diverging over time.

[0067] The comparison and judgment module compares the inertial navigation position with the satellite navigation position in the new frame to determine whether the position information has been spoofed, and compares the inertial navigation speed with the satellite navigation speed to determine whether the speed information has been spoofed.

[0068] The state management module manages the state of the integrated navigation based on the results of the comparison and judgment module, including maintaining or exiting the integrated navigation.

[0069] A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the above-described method steps.

[0070] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method steps described above.

[0071] Compared with the prior art, the beneficial effects of the present invention are:

[0072] 1. By introducing inertial navigation data as a reference source, deception detection of satellite navigation data is performed. Due to the autonomy of inertial navigation, the dependence on external navigation signals is reduced. In complex or harsh navigation environments, the system can more autonomously judge and process navigation data, enhancing the system's autonomy and controllability.

[0073] 2. Setting time-dependent dynamic satellite navigation position and speed thresholds accurately reflects the characteristics of inertial navigation error divergence over time, improving the accuracy of deception detection;

[0074] 3. By deceiving the judgment process, the entire process of satellite navigation data from normal to deceiving and then back to normal can be monitored, improving the system's flexibility;

[0075] 4. After the deception is completed, the output data of the inertial navigation system and the satellite navigation system are compared through the calibration procedure to accurately determine the source and magnitude of the error. The satellite navigation system is then calibrated and adjusted to eliminate system errors and improve the accuracy and stability of navigation. Attached Figure Description

[0076] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0077] Figure 1 This is a schematic diagram illustrating the principle of the satellite navigation deception detection method in the embodiments of this application;

[0078] Figure 2 This is a flowchart illustrating the satellite navigation data validity determination process in an embodiment of this application.

[0079] Figure 3 This is a flowchart illustrating the satellite navigation anti-spoofing judgment process in the embodiments of this application;

[0080] Figure 4 This is a graph showing the change in position error over time across multiple voyages in the embodiments of this application;

[0081] Figure 5 This is a graph showing the speed error over time during multiple voyages in the embodiments of this application. Detailed Implementation

[0082] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0083] The sequence number of each step in the embodiments of this application does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0084] In the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. It should also be understood that although the terms "first," "second," etc., are used in the text to describe various elements in some embodiments of this application, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first table may be named a second table, and similarly, a second table may be named a first table, without departing from the scope of the various described embodiments. Both the first table and the second table are tables, but they are not the same table.

[0085] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0086] In modern navigation technology, satellite navigation systems are widely used for navigation and surveying on various platforms across sea, land, air, and space due to their advantages such as low cost, high accuracy, and error characteristics close to white noise that do not accumulate over time. However, satellite navigation systems also have the drawback of being easily interfered with or spoofed, which is particularly prominent in high-precision navigation applications. This can lead to errors in navigation information, thereby affecting the accuracy and safety of navigation.

[0087] To ensure the reliability of satellite navigation information, existing technologies employ various measures. On one hand, satellite navigation messages typically include signal availability indicators to show signal validity; on the other hand, anti-interference antennas are configured to enhance signal acquisition and anti-interference capabilities. However, these methods primarily rely on hardware improvements and assessments, lacking a comprehensive approach that integrates software algorithms with other navigation systems for integrated evaluation.

[0088] Furthermore, although inertial navigation systems (INS) are autonomous navigation systems and do not rely on external signals, their errors gradually increase over time. This error characteristic means that traditional static threshold setting methods cannot accurately reflect the real-time changes in INS errors when setting detection thresholds, thus affecting the accuracy of satellite navigation deception detection. Especially during long-term navigation, static thresholds often cannot adapt to the gradual accumulation of errors, leading to an increased risk of misjudgment or missed detection.

[0089] In response to the above issues, such as Figures 1 to 3 As shown, a first aspect of this application provides a satellite navigation spoofing detection method based on inertial navigation, comprising the following steps:

[0090] S1. Before the inertial navigation system has completed alignment, the satellite navigation system receives a new frame of satellite navigation data forwarded by the flight control system and performs a validity check on the satellite navigation data.

[0091] S2. If the validity judgment is passed, the satellite navigation data is considered valid and subsequent satellite navigation anti-fraud judgment can be carried out.

[0092] S3. After the device is aligned and enters the integrated navigation state, a satellite navigation anti-spoofing judgment is performed.

[0093] The satellite navigation anti-fraud judgment process includes:

[0094] S4. Based on the characteristics of inertial navigation error diverging over time, set time-dependent dynamic satellite navigation position thresholds and satellite navigation speed thresholds.

[0095] S5. Compare the satellite navigation position of the new frame with the inertial navigation position. If the difference is greater than or equal to the satellite navigation position threshold, it is determined that the satellite navigation position information has been spoofed.

[0096] S6. Compare the satellite navigation speed with the inertial navigation speed. If the difference is greater than or equal to the satellite navigation speed threshold, it is determined that the satellite navigation speed information has been spoofed.

[0097] S7. If neither the satellite navigation position nor the satellite navigation speed information is spoofed, the integrated navigation state will continue. If either the satellite navigation position or the satellite navigation speed information is spoofed, the device will exit the integrated navigation state.

[0098] In this embodiment, by introducing inertial navigation data as a reference source, deception detection of satellite navigation data is performed. Due to the autonomy of inertial navigation, the dependence on external navigation signals is reduced. In complex or harsh navigation environments, the system can more autonomously judge and process navigation data, thereby enhancing the system's autonomy and controllability.

[0099] By setting dynamic satellite navigation position and velocity thresholds that are related to time, the divergence characteristics of inertial navigation errors over time can be reflected more accurately, thereby improving the accuracy of satellite navigation deception judgment.

[0100] like Figure 2 As shown, in step S1, the determination of the validity of satellite navigation data includes:

[0101] S1.1 Check the original satellite navigation validity identifier relayed by the flight control system to confirm whether the identifier is valid;

[0102] S1.2 Calculate the position accuracy dilution PDOP value of the current satellite navigation data and compare it with the preset PDOP threshold. If the PDOP value is too large, the satellite navigation data is considered unreliable.

[0103] S1.3 Check the satellite navigation solution status to confirm whether the position and velocity information have been successfully calculated;

[0104] S1.4 Compare the current satellite navigation information with the satellite navigation information at the previous moment to check for any abnormal jumps in the data;

[0105] S1.5 If any of the above judgments fails, the current satellite navigation data is considered invalid and no further processing will be performed; if all judgments pass, the satellite navigation data is considered valid and subsequent satellite navigation anti-fraud judgments can be performed.

[0106] By following the steps in the above embodiments, the validity of satellite navigation data is determined before spoofing detection. This allows for the rapid identification and removal of obviously abnormal or invalid data, ensuring the reliability of the data entering the spoofing detection process.

[0107] In step S4, based on the characteristic of inertial navigation error diverging over time, time-dependent dynamic satellite navigation position thresholds and satellite navigation velocity thresholds are set, including:

[0108] S4.1 Collect position and velocity data output by the inertial navigation system from actual navigation or simulation experiments;

[0109] S4.2 For the velocity data at each time point, compare it with the known true velocity, calculate the velocity error, and plot the velocity error as a function of time;

[0110] S4.3 For the location data at each time point, compare it with the known true location, calculate the location error, and plot the curve of the location error changing over time;

[0111] S4.4. Based on the velocity error curve and the position error curve, determine the divergence characteristics of velocity error and position error over time;

[0112] S4.5 Based on the divergence characteristics of speed and position errors in inertial navigation, the navigation time is divided into several time periods, and different speed and position judgment thresholds are set for each time period.

[0113] By following the steps in the above embodiments, velocity error curves and position error curves are obtained, which can accurately reflect the changing pattern of inertial navigation error over time. Furthermore, a dynamic threshold set based on this changing pattern can more accurately determine whether satellite navigation data has been spoofed, thereby improving the accuracy of spoofing detection.

[0114] like Figure 4 As shown, the position error varies with time across multiple voyages, as follows: Figure 5 As shown, this is the curve of speed error changing over time during multiple voyages.

[0115] The divergence trend of inertial navigation position and velocity errors can be summarized as follows:

[0116] Within the first 15 minutes of navigation, the velocity error exhibits a linear growth trend, primarily due to factors such as sensor noise. As time progresses, entering the 15-40 minute range, the velocity error begins to be affected by Schula oscillations, exhibiting significant oscillations. Schula oscillations are a unique error manifestation of inertial navigation systems, related to the Earth's rotation and the internal dynamics of the navigation system. During this stage, the oscillations of the velocity error gradually intensify, reaching a peak. After 40 minutes, the velocity error begins to gradually converge, and the accumulated error reaches a dynamic equilibrium. When pure inertial navigation time exceeds one hour, the pattern of velocity error becomes less pronounced, and the differences between multiple voyages become larger.

[0117] Within the first 10 minutes of navigation, the relationship between position error and time is roughly quadratic, as position error is the integral of velocity error, and velocity error initially increases linearly. Between 10 and 40 minutes, although position error continues to increase, the rate of increase in velocity error slows, thus the divergence of position error also becomes relatively slow. Between 40 minutes and 1 hour, the divergence of position error further slows, gradually reaching a peak. Similar to velocity error, when pure inertial navigation time exceeds 1 hour, the pattern of position error becomes less pronounced, and the differences between multiple voyages increase.

[0118] In step S4.5, the navigation time is divided into several time periods, and different satellite navigation position determination thresholds are set for each time period, including:

[0119] When the navigation time is in the initial stage, i.e. 0≤t0≤t1;

[0120] Let the satellite navigation position threshold be ΔP1, as shown in the following formula.

[0121]

[0122] Where n is the initial position error, t0 is the inertial navigation time, and a is the initial divergence velocity of the inertial navigation velocity error, which is used as the divergence coefficient;

[0123] When the navigation time is in the middle, i.e., t1 <t0≤t2;

[0124] Let the satellite navigation position threshold be ΔP2, as shown in the following formula.

[0125]

[0126] Where b is the mid-term threshold fine-tuning constant;

[0127] When the navigation time is long, i.e. t2 <t0;

[0128] Let the satellite navigation position threshold be ΔP3, and the calculation formula is as follows.

[0129]

[0130] Where c is the long-term threshold fine-tuning constant.

[0131] In step S4.5, the navigation time is divided into several time periods, and different satellite navigation speed judgment thresholds are set for each time period, including:

[0132] When the navigation time is in the initial stage, i.e. 0≤t0≤t1;

[0133] Let the satellite navigation speed threshold be ΔS1, as shown in the following formula.

[0134] ΔS1=m+at0;

[0135] Where m is the initial velocity error, t0 is the inertial navigation time, and a is the initial divergence velocity of the inertial navigation velocity error, which serves as the divergence coefficient.

[0136] When the navigation time is in the middle, i.e., t1 <t0≤t2;

[0137] Let the satellite navigation speed threshold be ΔS2, as shown in the following formula.

[0138]

[0139] Where d is the mid-term velocity threshold fine-tuning constant;

[0140] When the navigation time is long, i.e. t2 <t0;

[0141] The satellite navigation speed threshold is set to ΔS3, and the calculation formula is as follows:

[0142]

[0143] Among them, e is the fine-tuning constant of the long-term speed threshold.

[0144] Exemplarily, the navigation time is divided into three time periods: the initial period, the middle period, and the long-term period. It is set that the initial period is 0 ≤ t0 ≤ 600 s, the middle period is 600 < t0 ≤ 2400 s, and the long-term period is t0 > 2400 s.

[0145] When the navigation time is in the initial period, that is, 0 ≤ t0 ≤ 600 s.

[0146] According to the divergence characteristic that the position error shows a quadratic function with time, the position error threshold is set as ΔP1 = 80 + 0.001t

[0151] ,

[0156] ,

[0152] ,

[0154] ,

[0155] ,

[0153] , , , , , , .

[0147] According to the linear divergence of the speed error with time, the speed error threshold is set as ΔS1 = 0.5 + 0.002t.

[0148] When the navigation time is in the middle period, that is, 600 < t0 ≤ 2400 s.

[0149] According to the Schuler oscillation characteristic of the inertial navigation error, the position error threshold is set as ΔP2 = 180 + 0.00066t 2 , and the speed error threshold is set as ΔS2 = 1.7 + 0.0013t.

[0150] When the navigation time is in the long-term period, that is, t0 > 2400 s

[0151] According to the Schuler oscillation characteristic of the inertial navigation error, the position error threshold is set as a fixed value of 4000, and the speed error threshold is set as a fixed value of 4.82.

[0152] This embodiment takes into account the divergence characteristics of the inertial navigation error in different stages. By introducing the divergence coefficient a, the middle-period threshold fine-tuning constant, and the long-term threshold fine-tuning constant, the system can flexibly adjust the threshold according to the error conditions in different stages, and can better cope with various complex navigation environments and interference sources.

[0153] The satellite navigation spoofing detection method of this application further includes a spoofing end judgment step S8, which specifically includes:

[0154] S8.1. When it is determined to enter the spoofing state, set the satellite navigation speed regression threshold and the satellite navigation position regression threshold respectively at a predetermined ratio of the current satellite navigation speed threshold and the satellite navigation position threshold;

[0155] S8.2. Continuously monitor the speed information and position information provided by the satellite navigation, and at the same time compare them with the corresponding information provided by the inertial navigation system;

[0156] S8.3 If the difference between the satellite navigation speed and the inertial navigation speed is less than the satellite navigation speed regression threshold, and the difference between the satellite navigation position and the inertial navigation position is less than the satellite navigation position regression threshold, and this continues for a predetermined time, then the deception is determined to have ended.

[0157] By setting up a deception termination judgment step, the entire process of satellite navigation data from normal to deception and back to normal can be monitored. This not only allows for timely detection of deception behavior but also accurately determines whether the deception has ended, thus improving the completeness of deception detection.

[0158] The satellite navigation deception detection method of this application also includes a calibration step S9, which specifically includes:

[0159] S9.1 After the deception ends, simultaneously activate the inertial navigation system and the satellite navigation system to ensure time synchronization of the two devices and collect data separately;

[0160] S9.2 Compare the output data of the inertial navigation system and the satellite navigation system to determine the source and magnitude of the error;

[0161] S9.3. Based on the error analysis results, calibrate and adjust the parameters of the satellite navigation system;

[0162] S9.4 Repeatedly verify and adjust the output data of the satellite navigation system until its data deviation from that of the inertial navigation system is within the predetermined range.

[0163] After the deception ends, by comparing the output data of the inertial navigation system and the satellite navigation system, the source and magnitude of the error can be accurately determined, and the parameters of the satellite navigation system can be calibrated and adjusted. By eliminating system errors, navigation accuracy is improved.

[0164] For example, comparing the positioning data of the two systems revealed that the satellite navigation system's positioning result was approximately 10 meters further north than that of the inertial navigation system. Further analysis determined that this was due to atmospheric delay affecting the satellite signal transmission. Based on the error analysis results, the tracking loop parameters of the satellite navigation receiver were adjusted to adapt to the atmospheric delay. The adjusted output data of the satellite navigation system was repeatedly verified until the positioning deviation was reduced from 10 meters to less than 1 meter, achieving the expected calibration effect.

[0165] A second aspect of this application provides a satellite navigation deception detection system based on inertial navigation, comprising:

[0166] An inertial navigation system is used to provide the position and velocity information of a vehicle.

[0167] Satellite navigation systems are used to receive satellite signals and provide real-time position and velocity information;

[0168] The threshold setting module dynamically sets the satellite navigation position threshold and satellite navigation speed threshold based on the characteristics of the inertial navigation system's error diverging over time.

[0169] The comparison and judgment module compares the inertial navigation position with the satellite navigation position in the new frame to determine whether the position information has been spoofed, and compares the inertial navigation speed with the satellite navigation speed to determine whether the speed information has been spoofed.

[0170] The state management module manages the state of the integrated navigation based on the results of the comparison and judgment module, including maintaining or exiting the integrated navigation.

[0171] A third aspect of this application provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the above-described method steps.

[0172] A fourth aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method steps described above.

[0173] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A satellite navigation deception detection method based on inertial navigation, characterized in that, include: Before the inertial navigation system has completed alignment, the satellite navigation system receives a new frame of satellite navigation data and determines the validity of the satellite navigation data. If the validity assessment passes, the satellite navigation data is considered valid and can proceed with subsequent satellite navigation anti-fraud assessments. Once the inertial navigation system has completed alignment and entered the integrated navigation state, it will perform satellite navigation anti-spoofing judgment. The satellite navigation anti-fraud judgment process includes: Based on the characteristic that inertial navigation error diverges over time, dynamic satellite navigation position thresholds and satellite navigation speed thresholds that are related to time are set. The satellite navigation position of the new frame is compared with the inertial navigation position. If the difference is greater than or equal to the satellite navigation position threshold, it is determined that the satellite navigation position information has been spoofed. The satellite navigation speed is compared with the inertial navigation speed. If the difference is greater than or equal to the satellite navigation speed threshold, it is determined that the satellite navigation speed information has been spoofed. If neither the satellite navigation position nor the satellite navigation speed information is spoofed, the integrated navigation state will continue. If either the satellite navigation position or the satellite navigation speed information is spoofed, the device will exit the integrated navigation state. Determining the validity of satellite navigation data includes: Check the original satellite navigation validity identifier relayed by the flight control system to confirm whether the identifier is valid. Calculate the PDOP value of the current satellite navigation data and compare it with the preset PDOP threshold. If the PDOP value is too large, the satellite navigation data is considered unreliable. Check the satellite navigation solution status to confirm whether the position and velocity information have been successfully calculated. Compare the current satellite navigation information with the satellite navigation information from the previous moment to check for any abnormal jumps in the data. If any of the above checks fails, the current satellite navigation data is considered invalid and no further processing will be performed; if all checks pass, the satellite navigation data is considered valid and subsequent satellite navigation anti-spoofing checks can be performed. Based on the characteristic of inertial navigation error diverging over time, dynamic satellite navigation position and velocity thresholds that are time-dependent are set, including: Collect position and velocity data output by the inertial navigation system from actual navigation or simulation experiments; For the velocity data at each time point, compare it with the known true velocity, calculate the velocity error, and plot the velocity error as a function of time. For the location data at each time point, compare it with the known true location, calculate the location error, and plot the curve of the location error changing over time. Based on the velocity error curve and the position error curve, determine the divergence characteristics of velocity error and position error over time; Based on the divergence characteristics of speed and position errors in inertial navigation, the navigation time is divided into several time periods, and different speed and position judgment thresholds are set for each time period.

2. The satellite navigation deception detection method based on inertial navigation according to claim 1, characterized in that, The navigation time is divided into several time periods, and different satellite navigation position thresholds are set for each time period, including: When the navigation time is in the initial stage, i.e. 0≤t0≤t1; Let the satellite navigation position threshold be ΔP1, as shown in the following formula. ； Where n is the initial position error, t0 is the inertial navigation time, and a is the divergence coefficient; When the navigation time is in the middle, i.e., t1 <t0≤t2; Let the satellite navigation position threshold be ΔP2, as shown in the following formula. ； Where b is the mid-term threshold fine-tuning constant; When the navigation time is long, i.e. t2 <t0; Let the satellite navigation position threshold be ΔP3, as shown in the following formula. ； Where c is the long-term threshold fine-tuning constant.

3. The satellite navigation deception detection method based on inertial navigation according to claim 2, characterized in that, The navigation time is divided into several time periods, and different satellite navigation speed thresholds are set for each time period, including: When the navigation time is in the initial stage, i.e. 0≤t0≤t1; Let the satellite navigation speed threshold be ΔS1, as shown in the following formula. ； Where m is the initial velocity error, t0 is the inertial navigation time, and a is the initial divergence velocity of the inertial navigation velocity error; When the navigation time is in the middle, i.e., t1 <t0≤t2; Let the satellite navigation speed threshold be ΔS2, as shown in the following formula. ； Where d is the mid-term velocity threshold fine-tuning constant; When the navigation time is long, i.e. t2 <t0; The satellite navigation speed threshold is set to ΔS3, and the calculation formula is as follows: ； Where e is the long-term velocity threshold fine-tuning constant.

4. The satellite navigation deception detection method based on inertial navigation according to claim 1, characterized in that, It also includes the steps for determining the end of the deception, specifically including: Once the deception state is determined, the satellite navigation speed return threshold and the satellite navigation position return threshold are set according to a predetermined ratio of the current satellite navigation speed threshold and the satellite navigation position threshold, respectively. Continuously monitor the speed and position information provided by satellite navigation and compare it with the corresponding information provided by the inertial navigation system; If the difference between the satellite navigation speed and the inertial navigation speed is less than the satellite navigation speed regression threshold, and the difference between the satellite navigation position and the inertial navigation position is less than the satellite navigation position regression threshold, and this continues for a predetermined time, then the deception is considered to have ended.

5. The satellite navigation deception detection method based on inertial navigation according to claim 1, characterized in that, It also includes calibration steps, specifically: After the deception is complete, both the inertial navigation system and the satellite navigation system are activated simultaneously to ensure time synchronization between the two devices and to collect data separately. By comparing the output data of the inertial navigation system and the satellite navigation system, the source and magnitude of the error can be determined. Based on the error analysis results, the parameters of the satellite navigation system are calibrated and adjusted; The output data of the satellite navigation system is repeatedly checked and adjusted until its data deviation from that of the inertial navigation system is within the predetermined range.

6. A system for detecting satellite navigation deception based on inertial navigation as described in any one of claims 1-5, characterized in that, include: An inertial navigation system is used to provide the position and velocity information of a vehicle. Satellite navigation systems are used to receive satellite signals and provide real-time position and velocity information; The threshold setting module dynamically sets the satellite navigation position threshold and satellite navigation speed threshold based on the characteristics of the inertial navigation system's error diverging over time. The comparison and judgment module compares the inertial navigation position with the satellite navigation position in the new frame to determine whether the position information has been spoofed, and compares the inertial navigation speed with the satellite navigation speed to determine whether the speed information has been spoofed. The state management module manages the state of the integrated navigation based on the results of the comparison and judgment module, including maintaining or exiting the integrated navigation.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the method steps of any one of claims 1 to 5.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method steps of any one of claims 1 to 5.

Images