Cooperative positioning error compensation method and system fused with GPS (Global Positioning System)

Abstract

The invention discloses a GPS-fused cooperative positioning error compensation method and system. The method comprises the following steps: acquiring coordinate information of a GPS receiver and data information of an IMU sensor on a moving body in real time; calculating the actual position of the moving body at the current moment based on the data information; calculating a difference value based on the data information in combination with the coordinate information and the data information; setting a spoofing detection threshold value, and if the difference value is greater than the spoofing detection threshold value, determining that the GPS signal has spoofing; if deception exists, correcting the GPS signal based on the actual position; and according to the correction terminal point after the GPS signal is corrected, judging a target position decoy by the deception signal. According to the invention, the IMU sensor is introduced while the GPS is used for navigation and positioning, so that the positioning precision is improved, the overall robustness and reliability are enhanced, and the system can still work normally in a complex environment; moreover, the method can judge the position of a target which is deception by the deception signal.

Description

Technical Field

[0001] The present invention relates to the field of information processing technology, and in particular to a method and system for fusion GPS collaborative positioning error compensation. Background Art

[0002] In navigation and positioning systems, forwarding spoofing of the Global Positioning System (GPS) is a common threat. A typical deception method is to guide the target to a designated location, away from the original destination. The attacker sends false GPS information to the victim after adding the satellite signal to the deception time, inducing the receiver to misjudge its true location. When faced with this kind of location deception, the common way to deal with it is to perform error correction. This processing method is suitable for most scenarios, but when faced with attacks with obvious intentions such as forwarding spoofing, its work efficiency will be affected, and it will be impossible to determine the location of the target it is deceiving. Summary of the invention

[0003] Purpose of the invention: The first purpose of the present invention is to provide a fused GPS collaborative positioning error compensation method which has high working efficiency and can determine the position of the target being deceived.

[0004] The second object of the present invention is to provide a fusion GPS collaborative positioning error compensation system.

[0005] Technical solution: The present invention discloses a method for fusion GPS collaborative positioning error compensation, comprising the following steps: Obtain the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving object in real time; Based on the data information, the actual position of the moving body at the current moment is calculated; Based on the data information and the coordinate information, the difference between the actual position of the moving body at the current moment and the navigation position determined by the GPS navigation is calculated; Set the spoofing detection threshold. If the difference value is greater than the spoofing detection threshold, the GPS signal is considered to be spoofed, and the start time and duration of the spoofing are calculated. If spoofing is believed to have occurred, the GPS signal is corrected based on the actual location; The target location lured by the deceptive signal is determined based on the corrected end point after the GPS signal is corrected.

[0006] Furthermore, the coordinate information includes the x-axis coordinate and the y-axis coordinate , where t is time, and t represents the time from when the moving body starts to move to when the moving body stops moving; the data information includes the acceleration and angular velocity of the moving body coordinate system , where the acceleration includes the acceleration of the x-axis and the acceleration on the y-axis , where b is the coordinate system identifier of the moving body, is the acceleration of the x-axis in the moving body coordinate system, is the acceleration of the y-axis in the moving body coordinate system.

[0007] Furthermore, the calculation steps of the difference value are as follows: Calculate the heading angle of the moving body based on the angular velocity ; Based on heading angle , convert the acceleration of the moving body coordinate system to the global coordinate system that is the same as GPS, and obtain the acceleration of the moving body in the global coordinate system; The actual position of the moving body at the current moment in the global coordinate system is calculated based on the acceleration of the moving body in the global coordinate system. The actual position includes the x-axis coordinate and the y-axis coordinate ; The final difference value is calculated based on the actual position and the coordinate information of the GPS receiver.

[0008] Furthermore, the heading angle , the calculation formula is as follows: .

[0009] Furthermore, the calculation formula of the acceleration of the moving body in the global coordinate system is as follows: Where n is the global coordinate system identifier, is the acceleration of the x-axis in the global coordinate system, is the acceleration of the y-axis in the global coordinate system.

[0010] Furthermore, the calculation formula of the actual position is as follows: in represents the speed of the moving body along the x-axis, represents the speed of the moving body along the y-axis, represents the x-axis coordinate of the moving body, Indicates the y-axis coordinate of the moving body.

[0011] Furthermore, the calculation formula of the difference value is: .

[0012] Furthermore, the steps for correcting the GPS signal are as follows: Calculate the position offset of the GPS signal, the calculation formula is as follows: Offset in the x-axis direction: , Offset in the y-axis direction: ; Based on the position offset statistics, the statistical formula is as follows: Offset characteristics in the x-axis direction: , Y-axis offset characteristics: ,in refers to the time interval when deception is considered to exist, and N refers to the total number of position points in the time interval when deception is considered to exist; The x-axis trend is calculated based on the least squares method and the y-axis trend ;in and is the slope, b x and b y is a constant; The calculation formula for the corrected endpoint is: End point x-axis offset value: , End point y-axis offset value: , where t end It refers to the end time of the moving body's movement, and t0 refers to the start time of the moving body's movement.

[0013] Furthermore, the steps for determining the target position lured by the deceptive signal are as follows: first determine the offset direction based on the positive and negative attributes of the offset feature, and then combine the corrected offset value to obtain the target position lured by the deceptive signal.

[0014] Based on the same inventive concept, the present invention also provides a fusion GPS collaborative positioning error compensation system, comprising: A data acquisition module is used to obtain the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving body in real time; A calculation module is used to combine the coordinate information and the data information and calculate the difference between the actual position of the moving body and the navigation position determined by the GPS navigation; The spoofing judgment module can judge whether the GPS signal is spoofed based on the difference value; A correction module, which corrects the GPS signal based on the actual location if the judgment module determines that there is deception; The target judgment module can judge the target position lured by the deceptive signal according to the corrected end point after the GPS signal is corrected.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the present invention introduces IMU sensors while utilizing GPS navigation and positioning, and can maintain positioning capability even when the GPS signal is damaged, and the synergistic effect of GPS and IMU sensors not only improves positioning accuracy, but also enhances overall robustness and reliability, ensuring normal operation in complex environments; the present invention can correct the drift error of the IMU sensor in real time, reduce the impact of error accumulation, and is beneficial to improving positioning accuracy; the present invention sets a deception detection threshold to determine whether there is forwarding deception, and if there is deception, calculates the position offset of the GPS signal and obtains a corrected endpoint prediction result, which is used to determine the target position deceived by the deception signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of the method of the present invention; Figure 2 A motion trajectory diagram of a certain object of the present invention; Figure 3 IMU error and GPS error result diagram of a certain target of the present invention; Figure 4 Calculate error-corrected GPS trajectory diagram for a certain objective of the present invention; Figure 5 It is a schematic diagram of the structure of the system of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0018] Example 1

[0019] The present invention discloses a method for compensating for GPS-integrated collaborative positioning errors. Figure 1 As shown, the following steps are included: Get the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving object in real time. The coordinate information includes the x-axis coordinate and the y-axis coordinate , where t is time, and t represents the time from when the moving body starts to move to when the moving body stops moving. The data information includes the acceleration and angular velocity of the moving body coordinate system , where the acceleration includes the acceleration of the x-axis and the acceleration on the y-axis , where b is the coordinate system identifier of the moving body, is the acceleration of the x-axis in the moving body coordinate system, is the acceleration of the y-axis in the moving body coordinate system.

[0020] Based on the data information and combined with the coordinate information, the difference between the actual position of the moving body at the current moment and the navigation position determined by the GPS navigation is calculated.

[0021] Calculate the heading angle of the moving body based on the angular velocity , the calculation formula is: .

[0022] Based on heading angle , convert the acceleration of the moving body coordinate system to the global coordinate system that is the same as GPS, and obtain the acceleration of the moving body in the global coordinate system. The calculation formula is as follows: , where n is the global coordinate system identifier, is the acceleration of the x-axis in the global coordinate system, is the acceleration of the y-axis in the global coordinate system; The actual position of the moving body in the global coordinate system at the current moment is calculated based on the acceleration of the moving body in the global coordinate system. The calculation formula is as follows: ,in represents the speed of the moving body along the x-axis, represents the speed of the moving body along the y-axis, represents the x-axis coordinate of the moving body, Indicates the y-axis coordinate of the moving body.

[0023] The final difference value is calculated based on the actual position and the coordinate information of the GPS receiver.

[0024] Combine the actual position of the moving body at the current moment with the coordinate information of the GPS receiver at the current moment, and calculate the difference between the actual position of the moving body and the navigation position determined by GPS navigation. , the calculation formula is: .

[0025] Setting the spoof detection threshold ,like , the GPS signal is considered to be deceptive, and the start time and duration of the deception are calculated. If deception is considered to exist, the GPS signal is corrected based on the actual position.

[0026] The steps to correct the GPS signal are as follows: Calculate the position offset of the GPS signal, the calculation formula is as follows: Offset in the x-axis direction: , Offset in the y-axis direction: ; Based on the position offset statistics, the statistical formula is as follows: Offset characteristics in the x-axis direction: , Y-axis offset characteristics: ,in refers to the time interval when deception is considered to exist, and N refers to the total number of position points in the time interval when deception is considered to exist; The x-axis trend is calculated based on the least squares method and the y-axis trend ;in and is the slope, b x and b y is a constant; that is, based on the least squares method , 、b x and b y ; The calculation formula for the corrected endpoint is: End point x-axis offset value: , End point y-axis offset value: , where t end It refers to the end time of the moving body's movement, and t0 refers to the start time of the moving body's movement.

[0027] The target location lured by the deceptive signal is determined based on the corrected end point after the GPS signal is corrected.

[0028] First, the offset direction is determined based on the positive and negative attributes of the offset feature, and then the target position lured by the deceptive signal is obtained by combining the corrected offset value. The positive and negative values ​​of determine the east-west direction, positive for east, negative for west; based on The positive and negative value of determines the north-south direction, positive for north and negative for south.

[0029] The method of this embodiment is used to obtain the coordinate information of the GPS receiver of a target (a moving body) moving from the origin and the data information of the IMU sensor on the moving body, and then the following is obtained based on the coordinate information and the data information: Figure 2 GPS trajectory and IMU integrated trajectory shown.

[0030] Combine the coordinate information and data information to calculate the difference between the actual position of the target at the current moment and the navigation position determined by GPS navigation, and obtain the following: Figure 3The GPS error and IMU error shown in the figure refer to the errors between the two and the real motion trajectory of the target. When calculating the difference between the actual position of the target at the current moment and the navigation position determined by GPS navigation, it is assumed that the actual position calculated by the data information of the IMU sensor is correct. In fact, there is a certain error when calculating the actual position by the data information of the IMU sensor. The error is calculated based on the IMU position. Therefore Figure 3 There is also IMU error in the calculation. The difference between GPS error and IMU error is used as the basis to calculate the distance between the corresponding two points on the two trajectories.

[0031] Set the spoofing detection threshold to 5, from Figure 3 It can be concluded that deception occurs from 0.2 seconds onwards.

[0032] Then the GPS signal is corrected, and the corrected result is as follows Figure 4 shown.

[0033] Predicted endpoint offset: -22.70 meters in X direction, 21.34 meters in Y direction. Finally, based on the corrected endpoint corrected according to the GPS signal, the target position deceived by the deceptive signal is judged, and the target position deceived by the target is obtained: guide the target to the endpoint X-23 meters Y+21 meters.

[0034] The deceptive intent is summarized as follows: Number of cheating points: 81%; refers to the ratio of the number of position points in the time interval when cheating is considered to exist to the total number of points; Average offset: 12.11 meters in the X direction (west), 11.23 meters in the Y direction (north); Deviation trend: -22.70 m / s in the X direction, 21.34 m / s in the Y direction; Deceptive target position: Try to guide the target to the end point X-23m Y+21m.

[0035] Example 2

[0036] The present invention discloses a fusion GPS collaborative positioning error compensation system, such as Figure 5 As shown, it includes a data acquisition module, a calculation module, a deception judgment module, a correction module and a target judgment module.

[0037] The data acquisition module is used to obtain the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving body in real time. The coordinate information includes the x-axis coordinate and the y-axis coordinate , where t is time, and t represents the time from when the moving body starts to move to when the moving body stops moving. The data information includes the acceleration and angular velocity of the moving body coordinate system , where the acceleration includes the acceleration of the x-axis and the acceleration on the y-axis , where b is the coordinate system identifier of the moving body, is the acceleration of the x-axis in the moving body coordinate system, is the acceleration of the y-axis in the moving body coordinate system.

[0038] The calculation module is used to combine the coordinate information and the data information and calculate the difference between the actual position of the moving body and the navigation position determined by the GPS navigation. Calculate the heading angle of the moving body , the calculation formula is: .

[0039] Based on heading angle , convert the acceleration of the moving body coordinate system to the global coordinate system that is the same as GPS, and obtain the acceleration of the moving body in the global coordinate system. The calculation formula is as follows: , where n is the global coordinate system identifier, is the acceleration of the x-axis in the global coordinate system, is the acceleration of the y-axis in the global coordinate system; The actual position of the moving body in the global coordinate system at the current moment is calculated based on the acceleration of the moving body in the global coordinate system. The calculation formula is as follows: ,in represents the speed of the moving body along the x-axis, represents the speed of the moving body along the y-axis, represents the x-axis coordinate of the moving body, Indicates the y-axis coordinate of the moving body.

[0040] The final difference value is calculated based on the actual position and the coordinate information of the GPS receiver.

[0041] Combine the actual position of the moving body at the current moment with the coordinate information of the GPS receiver at the current moment, and calculate the difference between the actual position of the moving body and the navigation position determined by GPS navigation. , the calculation formula is: .

[0042] The deception judgment module can judge whether the GPS signal is deceptive based on the difference value, and calculate the start time and duration of the deception. Preferably, a deception detection threshold is set. ,like , then it is considered that there is deception.

[0043] The correction module, if the judgment module determines that there is deception, corrects the GPS signal based on the actual location. The steps for correcting the GPS signal are as follows: Calculate the position offset of the GPS signal. The calculation formula is as follows: Offset in the x-axis direction: , Offset in the y-axis direction: ; Based on the position offset statistics, the statistical formula is as follows: Offset characteristics in the x-axis direction: , Y-axis offset characteristics: ,in refers to the time interval when deception is considered to exist, and N refers to the total number of position points in the time interval when deception is considered to exist; The x-axis trend is calculated based on the least squares method and the y-axis trend ;in and is the slope, b x and b y is a constant; that is, based on the least squares method , , b x and b y ; The calculation formula for the corrected endpoint is: End point x-axis offset value: , End point y-axis offset value: , where t end It refers to the end time of the moving body's movement, and t0 refers to the start time of the moving body's movement.

[0044] The target judgment module can judge the target position lured by the spoof signal based on the corrected end point of the GPS signal. First, the offset direction is judged based on the positive and negative attributes of the offset feature, and then the target position lured by the spoof signal is obtained by combining the corrected offset value. Preferably, based on The positive and negative of determines the east-west direction, positive for east and negative for west; based on The positive and negative value of determines the north-south direction, positive for north and negative for south.

Claims

1. A method for fusion GPS collaborative positioning error compensation, characterized in that: The following steps are involved: Obtain the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving object in real time; Based on the data information and the coordinate information, the difference between the actual position of the moving body at the current moment and the navigation position determined by the GPS navigation is calculated; Set the spoofing detection threshold. If the difference value is greater than the spoofing detection threshold, the GPS signal is considered to be spoofed, and the start time and duration of the spoofing are calculated; If spoofing is believed to have occurred, the GPS signal is corrected based on the actual location; The target location lured by the deceptive signal is determined based on the corrected end point after the GPS signal is corrected.

2. The method for fusion GPS collaborative positioning error compensation according to claim 1, characterized in that: The coordinate information includes the x-axis coordinate and the y-axis coordinate , where t is time, and t represents the time from when the moving body starts to move to when the moving body stops moving; the data information includes the acceleration and angular velocity of the moving body coordinate system , where the acceleration includes the acceleration of the x-axis and the acceleration on the y-axis , where b is the coordinate system identifier of the moving body, is the acceleration of the x-axis in the moving body coordinate system, is the acceleration of the y-axis in the moving body coordinate system.

3. The method for fusion GPS collaborative positioning error compensation according to claim 2, characterized in that: The steps for calculating the difference value are as follows: Calculate the heading angle of the moving body based on the angular velocity ; Based on heading angle , convert the acceleration of the moving body coordinate system to the global coordinate system that is the same as GPS, and obtain the acceleration of the moving body in the global coordinate system; The actual position of the moving body at the current moment in the global coordinate system is calculated based on the acceleration of the moving body in the global coordinate system. The actual position includes the x-axis coordinate and the y-axis coordinate ; The final difference value is calculated based on the actual position and the coordinate information of the GPS receiver.

4. The method for fusion GPS collaborative positioning error compensation according to claim 3 is characterized in that: The heading angle , the calculation formula is as follows: 。 5. The method for fusion GPS collaborative positioning error compensation according to claim 3 is characterized in that: The calculation formula of the acceleration of the moving body in the global coordinate system is as follows: Where n is the global coordinate system identifier, is the acceleration of the x-axis in the global coordinate system, is the acceleration of the y-axis in the global coordinate system.

6. The method for fusion GPS collaborative positioning error compensation according to claim 5, characterized in that: The actual position is calculated as follows: in represents the speed of the moving body along the x-axis, represents the speed of the moving body along the y-axis, represents the x-axis coordinate of the moving body, Represents the y-axis coordinate of the moving body.

7. The method for fusion GPS collaborative positioning error compensation according to claim 3 is characterized in that: The calculation formula of the difference value is: 。 8. The method for fusion GPS collaborative positioning error compensation according to claim 3 is characterized in that: The steps to correct the GPS signal are as follows: Calculate the position offset of the GPS signal, the calculation formula is as follows: Offset in the x-axis direction: , Offset in the y-axis direction: ; Based on the position offset statistics, the statistical formula is as follows: Offset characteristics in the x-axis direction: , Y-axis offset characteristics: ,in refers to the time interval when deception is considered to exist, and N refers to the total number of position points in the time interval when deception is considered to exist; The x-axis trend is calculated based on the least squares method and the y-axis trend ;in and is the slope, b x and b y is a constant; The calculation formula for the corrected endpoint is: End point x-axis offset value: , End point y-axis offset value: , where t end It refers to the end time of the moving body's movement, and t0 refers to the start time of the moving body's movement.

9. The method for fusion GPS collaborative positioning error compensation according to claim 8, characterized in that: The steps for determining the target position lured by the deceptive signal are as follows: first determine the offset direction based on the positive and negative attributes of the offset feature, and then combine the corrected offset value to obtain the target position lured by the deceptive signal.

10. A GPS-integrated collaborative positioning error compensation system, characterized in that: include, A data acquisition module is used to obtain the coordinate information of the GPS receiver and the data information of the IMU sensor on the moving body in real time; A calculation module is used to combine the coordinate information and the data information and calculate the difference between the actual position of the moving body and the navigation position determined by the GPS navigation; The deception judgment module can judge whether the GPS signal is deceptive based on the difference value, and calculate the start time and duration of the deception; A correction module, which corrects the GPS signal based on the actual location if the judgment module determines that there is deception; The target judgment module can judge the target position lured by the deceptive signal according to the corrected end point after the GPS signal is corrected.

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