A method for combined navigation of rejecting false satellite signals

Abstract

The application provides a combined navigation method for eliminating false satellite signals, comprising: acquiring position difference and speed difference output by an inertial navigation device and a satellite device in each cycle; calculating position difference gradient and speed difference gradient output by the inertial navigation device and the satellite device in each cycle according to the position difference and the speed difference; configuring a counter, when the position difference gradient and the speed difference gradient are simultaneously lower than a threshold value, the counter accumulates, when any one of the position difference gradient and the speed difference gradient is higher than the threshold value, the counter resets; detecting the accumulated value of the counter in real time, judging whether to adopt the data output by the satellite device according to the size of the accumulated value and a counting threshold, when judging that the data output by the satellite device is credible, fusing and resolving the satellite device data and the inertial navigation device data to output combined data; when judging that the data output by the satellite device is not credible, eliminating the data output by the satellite device, and only fusing and resolving the data output by the inertial navigation device to output combined data.

Description

Technical Field

[0001] This application belongs to the field of aircraft navigation technology, and specifically relates to a combined navigation method for eliminating false satellite signals. Background Technology

[0002] Inertial / satellite integrated navigation is currently the most common integrated navigation method on aircraft. It can take advantage of the high short-term accuracy of inertial navigation equipment and the long-term stability of satellite signals.

[0003] Because satellite data is stable over a long period of time, existing integrated navigation methods typically use the difference between satellite data and inertial navigation data as measurement information when combining inertial navigation equipment data and satellite data. They then use filtering algorithms to fuse the inertial and satellite data and perform optimal estimation to output combined data with smaller errors after fusion.

[0004] Filtering algorithms typically set thresholds for the position difference and velocity difference between inertial and satellite data. When the inertial and satellite data meet the position or velocity threshold decision conditions, the system performs combined filtering on the inertial and satellite data and outputs the combined result.

[0005] If the satellite signal is deceived or interfered with and outputs incorrect data, but at the same time the position difference and velocity difference between the inertial data and the satellite data do not exceed the set threshold, the combined data will be merged with the deceived satellite data, which will lead to the output of incorrect combined data. Summary of the Invention

[0006] The purpose of this application is to provide a combined navigation method for eliminating spurious satellite signals, in order to solve or mitigate at least one of the problems in the prior art.

[0007] The technical solution of this application is: a combined navigation method for eliminating false satellite signals, the method comprising:

[0008] Acquire the position and velocity differences output by the inertial navigation system and satellite equipment in each cycle;

[0009] Calculate the position difference gradient and velocity difference gradient output by the inertial navigation device and the satellite device in each cycle based on the position difference and velocity difference;

[0010] Configure a counter and set its initial value to 0. When the position difference gradient and velocity difference gradient are both lower than the set threshold, the counter increments by 1. When either the position difference gradient or the velocity difference gradient is higher than the set threshold, the counter is reset to 0.

[0011] The system continuously monitors the accumulated value M of the counter. Based on the magnitude of the accumulated value and the counting threshold, it determines whether to accept the data output by the satellite equipment. When the data output by the satellite equipment is deemed reliable, it uses the data output by the satellite equipment as the measurement value to correct the data output by the inertial navigation equipment. The combined data is then output after fusing and solving the data from the satellite equipment and the inertial navigation equipment. When the data output by the satellite equipment is deemed unreliable, it discards the data output by the satellite equipment and outputs the combined data only based on the data output by the inertial navigation equipment.

[0012] In the preferred embodiment of this application, time T n The position difference output by the inertial navigation system and the satellite equipment at that time is The speed difference is ;

[0013] Time T n+1 The position difference output by the inertial navigation system and the satellite equipment at that time is speed difference ;

[0014] The position difference within each period is P. n+1 -P n The speed difference is V n+1 -V n ,

[0015] In the above formula, P g(n) For time T n The position output by the inertial navigation system at that time;

[0016] P w(n) For time T n The location output by the satellite equipment at that time;

[0017] V g(n) For time T n The speed output by the inertial navigation system at that time;

[0018] V w(n) For time T n The speed at which the satellite equipment outputs at that time;

[0019] P g(n+1) For time T n+1 The position output by the inertial navigation system at that time;

[0020] P w(n+1) For time T n+1 The location output by the satellite equipment at that time;

[0021] V g(n+1) For time T n+1 The speed output by the inertial navigation system at that time;

[0022] V w(n+1) For time Tn+1 The speed at which satellite equipment outputs data.

[0023] In a preferred embodiment of this application, the position P output by the inertial navigation device g Including longitude L g Latitude λ g Height H g The output speed V g Including northbound speed V xg Eastward speed V yg Horizontal velocity V zg ,Right now:

[0024] , .

[0025] In a preferred embodiment of this application, the position P output by the satellite device w Including satellite longitude Lw, satellite latitude λ w Satellite altitude Hw, output speed V w Including satellite northward velocity V xw Satellite eastward velocity V yw Satellite celestial velocity V zw ,Right now: , .

[0026] In a preferred embodiment of this application, the position difference gradient output by the inertial navigation device and the satellite device in each cycle is: velocity difference gradient .

[0027] In a preferred embodiment of this application, the method for determining whether the data output by the satellite equipment is acceptable is as follows:

[0028] If the counter's accumulated value M is greater than or equal to the counting threshold N, then the data output by the satellite equipment is deemed reliable.

[0029] If the counter's accumulated value M is less than the counting threshold N, the data output by the satellite equipment is determined to be deceptive and is not accepted. When outputting combined data, only the data output by the inertial navigation equipment is used.

[0030] The navigation method of this application eliminates false satellite signals by setting counters that satisfy the velocity difference gradient and position difference gradient, thereby ensuring the accuracy and reliability of the combined data. This solves the problem of incorrect output of the combined data after fusion due to satellite signal deception and improves the accuracy when using inertial / satellite combined navigation. Attached Figure Description

[0031] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0032] Figure 1 This is a flowchart of the combined navigation method of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0034] To address the problem of erroneous output of fused combined data due to satellite signal deception, this application provides a combined navigation method that eliminates false satellite signals.

[0035] like Figure 1 As shown, the integrated navigation method for eliminating spoof satellite signals provided in this application includes the following steps:

[0036] Step 1: Calculate the position difference and velocity difference output by the inertial navigation equipment and the satellite equipment in each cycle.

[0037] For example, in this embodiment of the application, the position output by the inertial navigation device is P. g The output speed is V g The location output by the satellite equipment is P. w The output speed is V w It calculates the position and velocity differences between the inertial navigation system and the satellite equipment in real time within each cycle ∆T. (Time T) n The positional difference at time is P n The speed difference is V n Then the position difference speed difference Time T n+1 The positional difference at time is P n+1 The speed difference is V n+1 Then the position difference speed difference .

[0038] It should be noted that the position P output by the inertial navigation device g Including longitude L g Latitude λ g Height H g The output speed V g Including northbound speed V xg Eastward speed V yg Horizontal velocity V zg ,Right now:

[0039] , .

[0040] Similarly, the location P output by the satellite equipment w Including satellite longitude Lw, satellite latitude λ w Satellite altitude Hw, output speed V w Including satellite northward velocity V xw Satellite eastward velocity V yw Satellite celestial velocity V zw ,Right now:

[0041] , .

[0042] Step 2: Calculate the position gradient of the inertial navigation equipment and the velocity gradient of the velocity difference between the inertial navigation equipment and the satellite equipment in each cycle.

[0043] For example, time T n The position difference gradient at time is ∆P n ,but The velocity gradient is ∆V n ,but .

[0044] Step 3: Configure a counter and set its initial value to 0. When the position difference gradient and velocity difference gradient in Step 2 are both lower than the set threshold, the counter increments by 1. When either the position difference gradient or the velocity difference gradient is higher than the set threshold, the counter is reset to 0.

[0045] In some embodiments of this application, the threshold value satisfies: ∆V n ≯Am / s, ∆P n ≯B m / s 2 .

[0046] Step 4: Real-time detection of the accumulated value M of the counter. Based on the magnitude of the accumulated value and the counting threshold, determine whether to accept the data output by the satellite equipment. If the data output by the satellite equipment is deemed reliable, use the data output by the satellite equipment as the measurement value to correct the data output by the inertial navigation equipment, and output the combined data after fusing and solving the data from the satellite equipment and the inertial navigation equipment. If the data output by the satellite equipment is deemed unreliable, discard the data output by the satellite equipment, and output the combined data by fusing and solving the data from the inertial navigation equipment alone.

[0047] In this application, if the counter accumulation value M ≥ the counting threshold N, the data output by the satellite equipment is deemed credible; if the counter accumulation value M < the counting threshold N, the data output by the satellite equipment is deemed to be deceptive and is not credible. When outputting combined data, only the data output by the inertial navigation equipment is used.

[0048] The navigation method of this application eliminates false and deceptive satellite signals by setting counters that satisfy the velocity difference gradient and position difference gradient, thus ensuring the accuracy and reliability of the combined data. This solves the problem of errors in the output of the combined data after fusion due to satellite signal deception and improves the accuracy when using inertial / satellite combined navigation.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for integrating navigation that eliminates false satellite signals, characterized in that, The method includes: Acquire the position and velocity differences output by the inertial navigation system and satellite equipment in each cycle; Calculate the position difference gradient and velocity difference gradient output by the inertial navigation device and the satellite device in each cycle based on the position difference and velocity difference; Configure a counter and set its initial value to 0. When the position difference gradient and velocity difference gradient are both lower than the set threshold, the counter increments by 1. When either the position difference gradient or the velocity difference gradient is higher than the set threshold, the counter is reset to 0. The system continuously monitors the accumulated value M of the counter. Based on the magnitude of the accumulated value and the counting threshold, it determines whether to accept the data output by the satellite equipment. When the data output by the satellite equipment is deemed reliable, it uses the data output by the satellite equipment as the measurement value to correct the data output by the inertial navigation equipment. The combined data is then output after fusing and solving the data from the satellite equipment and the inertial navigation equipment. When the data output by the satellite equipment is deemed unreliable, it discards the data output by the satellite equipment and outputs the combined data only based on the data output by the inertial navigation equipment.

2. The integrated navigation method for eliminating false satellite signals as described in claim 1, characterized in that, Time T n The position difference output by the inertial navigation system and the satellite equipment at that time is The speed difference is ; Time T n+1 The position difference output by the inertial navigation system and the satellite equipment at that time is speed difference ; The position difference within each period is P. n+1 -P n The speed difference is V n+1 -V n , In the above formula, P g(n) For time T n The position output by the inertial navigation system at that time; P w(n) For time T n The location output by the satellite equipment at that time; V g(n) For time T n The speed output by the inertial navigation system at that time; V w(n) For time T n The speed at which the satellite equipment outputs at that time; P g(n+1) For time T n+1 The position output by the inertial navigation system at that time; P w(n+1) For time T n+1 The location output by the satellite equipment at that time; V g(n+1) For time T n+1 The speed output by the inertial navigation system at that time; V w(n+1) For time T n+1 The speed at which satellite equipment outputs data.

3. The integrated navigation method for eliminating false satellite signals as described in claim 2, characterized in that, The position P output by the inertial navigation device g Including longitude L g Latitude λ g Height H g The output speed V g Including northbound speed V xg Eastward speed V yg Horizontal velocity V zg ,Right now: ， 。 4. The integrated navigation method for eliminating false satellite signals as described in claim 3, characterized in that, The position P output by the satellite equipment w Including satellite longitude Lw, satellite latitude λ w Satellite altitude Hw, output speed V w Including satellite northward velocity V xw Satellite eastward velocity V yw Satellite celestial velocity V zw ,Right now: , .

5. The integrated navigation method for eliminating false satellite signals as described in any one of claims 2 to 4, characterized in that, The position difference gradient output by the inertial navigation system and the satellite system in each cycle is: velocity difference gradient .

6. The integrated navigation method for eliminating false satellite signals as described in claim 5, characterized in that, The method for determining whether data output by satellite equipment is reliable is as follows: If the counter's accumulated value M is greater than or equal to the counting threshold N, then the data output by the satellite equipment is deemed reliable. If the counter's accumulated value M is less than the counting threshold N, the data output by the satellite equipment is determined to be deceptive and is not accepted. When outputting combined data, only the data output by the inertial navigation equipment is used.

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