A Multi-Source Cooperative Navigation Method Based on Inertial Navigation State Awareness

Abstract

This invention belongs to the field of inertial astronomical integrated navigation technology, specifically relating to a multi-source cooperative integrated navigation method based on inertial navigation system state awareness, comprising: S1, setting a main inertial navigation system and at least one sub-inertial navigation system in the integrated navigation system; S2, performing main-sub-inertial navigation system communication state detection, and adopting different processing strategies according to the length of the interruption when the main-sub-inertial navigation system communication is detected to be interrupted; S3, performing main-sub-inertial navigation system communication state detection, and performing fault self-reconstruction after the main-sub-inertial navigation system communication is restored; S4, performing main inertial navigation system navigation state detection within the sub-inertial navigation system, and designing filters within the sub-inertial navigation system based on the main inertial navigation system state, thereby enabling a multi-source cooperative integrated navigation method that can dynamically respond to the main-sub-inertial navigation system communication state, possesses fault self-reconstruction capability, and adaptability to state switching.

Description

Technical Field

[0001] This invention belongs to the field of inertial astronomical integrated navigation technology, specifically relating to a multi-source cooperative integrated navigation method based on inertial navigation state perception. Background Technology

[0002] Inertial navigation systems (INS) are widely used in aviation, aerospace, marine, and land-based mobile platforms due to their advantages such as high autonomy, good stealth, and high short-term accuracy. However, the navigation accuracy of a single INS gradually decreases over long periods of operation due to the accumulation of errors in inertial components, making it difficult to meet the requirements of high-precision, long-duration navigation tasks. Therefore, multi-source information fusion combined navigation technology has become an important means to improve the performance of INS.

[0003] In existing integrated navigation schemes, a primary inertial navigation system (INS) is typically used to fuse data with multiple secondary INS or other sensors (such as GNSS, odometry, magnetometers, etc.), and estimation methods such as Kalman filtering are employed to achieve optimal estimation of the navigation state. The primary INS usually serves as the core navigation source of the system, while secondary INS or auxiliary sensors provide measurement information to correct errors in the primary INS, thereby improving overall navigation accuracy and reliability.

[0004] However, in practical applications, data interaction between the master and slave inertial navigation systems (INS) may be unstable due to communication interruptions, sensor failures, environmental interference, etc., leading to performance degradation or even failure of the integrated navigation system. Existing technologies typically employ simple data preservation or system degradation handling methods when master-slave INS communication is interrupted, lacking a tiered processing mechanism for different interruption durations and self-reconfiguration capabilities after recovery. Furthermore, existing solutions often fail to effectively manage the integrated navigation filter during master INS state switching (such as alignment, zero-velocity correction, etc.), resulting in discontinuous system state estimation and affecting navigation accuracy and stability.

[0005] Meanwhile, in terms of altitude channel processing, traditional methods are weak in suppressing altitude errors. Especially after a long period of communication interruption, the altitude error of the sub-inertial navigation system is prone to divergence, and there is a lack of effective damping and reconstruction mechanisms. Summary of the Invention

[0006] This invention provides a multi-source cooperative integrated navigation method based on master inertial navigation system (INS) state awareness, which solves many shortcomings of existing integrated navigation systems in terms of master-sub-INS communication state changes, master INS state switching, and altitude channel processing. This multi-source cooperative integrated navigation method can dynamically respond to the master-sub-INS communication state, has fault self-reconfiguration capability, and state switching adaptability.

[0007] This invention provides a multi-source cooperative navigation method based on master inertial navigation system state awareness, comprising the following steps: S1. Set up a main inertial navigation system and at least one sub-inertial navigation system in the integrated navigation system; S2. Perform master-slave inertial navigation communication status detection. When a master-slave inertial navigation communication interruption is detected, different processing strategies are adopted according to the length of the interruption: S3. Perform master inertial navigation communication status detection, and perform fault self-reconfiguration after the master inertial navigation communication is restored; S4. Perform main inertial navigation state detection within the sub-inertial navigation system, and design filters within the sub-inertial navigation system based on the main inertial navigation state.

[0008] Furthermore, in step 1, within the sub-inertial navigation system, the combined navigation filter transfer and filtering calculations are performed using the main inertial navigation data and the sub-inertial navigation data. The measurement used for filtering is the difference between the longitude, latitude, east speed, and north speed of the main and sub-inertial navigation systems. Within the main inertial navigation system, the combined navigation transfer calculations are performed using the main inertial navigation data, but no filter calculations are performed.

[0009] Furthermore, in step 2, If the interruption time is less than or equal to 30 seconds, the sub-inertial navigation filter calculation is paused, and the sub-inertial navigation data is used to replace the main inertial navigation data for transfer calculation. The sub-inertial navigation data used includes at least: sub-inertial velocity, position, attitude, geographic frame ratio, and machine frame angular rate. If the interruption time exceeds 30 seconds, the filtering and transfer calculation of the sub-inertial navigation filter will be paused, and the combination validity will be marked as invalid. If the communication interruption between the master and slave inertial navigation systems exceeds 30 seconds, the slave inertial navigation system maintains its altitude unchanged from the last frame, and its azimuth velocity is reset to zero. When communication is restored, the slave inertial navigation system's altitude and azimuth velocity are assigned values ​​using the master inertial navigation system's altitude and azimuth velocity.

[0010] Furthermore, in step 3, the elements related to the main inertial navigation system in the filter covariance matrix of the sub-inertial navigation system are dynamically and in real time assigned values ​​using the covariance matrix updated in real time within the main inertial navigation system. After the assignment is completed, the filtering and transfer calculations of the sub-inertial navigation system filter continue.

[0011] Furthermore, in step 4, When the main inertial navigation system is detected to be entering the realignment state, the combined validity is invalidated; when the main inertial navigation system transitions from the realignment state to the navigation state, the combined navigation filter is reinitialized.

[0012] Furthermore, in step 4, When the main inertial navigation system is detected to have entered the delayed alignment state, the corresponding elements of the main inertial navigation system in the covariance matrix and noise matrix are all set to 0, the filter transfer calculation proceeds normally, and the measurement used for filtering is the difference between the east and north velocities of the main inertial navigation system.

[0013] Furthermore, in step 4, When the main inertial navigation system is detected to enter the zero-speed correction state, the filter transfer and filtering calculation proceed normally; when the main inertial navigation system is detected to exit the zero-speed correction state, the corresponding elements of the main inertial navigation system in the covariance matrix are reinitialized.

[0014] Advantages and beneficial effects of this invention 1. Improve system robustness and reliability By introducing a master-slave inertial navigation communication state detection mechanism and adopting a graded processing strategy for different communication interruption durations, the stability and fault tolerance of the system in complex communication environments are effectively improved. During short interruptions, slave inertial navigation data is switched to maintain navigation continuity; during long interruptions, invalid calculations are paused and the system state is marked to avoid error propagation.

[0015] 2. Achieve self-reconfiguration capability after fault recovery After communication is restored, the system can use the covariance matrix updated in real time by the main inertial navigation system to dynamically assign values ​​to the state of the sub-inertial navigation filter, thereby realizing rapid reconstruction of the filter state. This ensures that the integrated navigation system can quickly restore its high-precision navigation capability after the fault is recovered, and enhances the system's adaptability and continuity.

[0016] 3. Optimize the stability of the altitude channel and the adaptability of the main inertial navigation system state. To address the issue of easy divergence in the altitude channel, an altitude damping protection mechanism is proposed. At the same time, the filter parameters and combination strategy are dynamically adjusted according to different operating states of the main inertial navigation system (such as alignment, zero-speed correction, etc.), which effectively improves the navigation accuracy and stability of the system during dynamic operation and state switching. Attached Figure Description

[0017] 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. 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.

[0018] Figure 1 This is a flowchart illustrating a multi-source cooperative navigation method based on master inertial navigation state awareness provided by the present invention. Figure 2 This is a schematic diagram of the process for master-slave inertial navigation communication status detection according to the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0020] This invention proposes a multi-source cooperative integrated navigation method based on master inertial navigation system (INS) state awareness, which is used to maintain the stability and accuracy of integrated navigation under special conditions such as master INS communication interruption, realignment, delayed alignment, and zero-velocity correction. It is applicable to the field of astronomical integrated navigation technology.

[0021] This invention provides a multi-source cooperative navigation method based on master inertial navigation system state awareness, with reference to... Figure 1 The method includes: S1. Set up a main inertial navigation system and at least one sub-inertial navigation system. Within the sub-inertial navigation system, use the main inertial navigation data and the sub-inertial navigation data to perform integrated navigation filter transfer and filtering calculations. The measurement used for filtering is the difference between the longitude, latitude, east speed, and north speed of the main and sub-inertial navigation systems. Within the main inertial navigation system, use the main inertial navigation data to perform integrated navigation transfer calculations, but do not perform filter calculations.

[0022] S2. Perform master-slave inertial navigation communication status detection, referencing... Figure 2 When a communication interruption between the master and slave inertial navigation systems is detected, different handling strategies are adopted based on the duration of the interruption: If the interruption time is less than or equal to 30 seconds, the filter calculation is paused, and the sub-inertial navigation data is used to replace the main inertial navigation data for transfer calculation, which includes at least: sub-inertial navigation velocity, position, attitude, geographic frame ratio, and machine frame angular rate. If the interruption time exceeds 30 seconds, the filter filtering and transfer calculation will be paused, and the combination validity will be marked as invalid. S3. Perform master-sub-inertial navigation communication status detection. When the master-sub-inertial navigation communication is restored, perform fault self-reconstruction: use the real-time updated covariance matrix in the master inertial navigation to dynamically assign values ​​to the elements related to the master inertial navigation in the filter covariance matrix in the sub-inertial navigation. After the assignment is completed, continue to perform filter filtering and transfer calculation.

[0023] The system performs altitude damping protection and reconfiguration. If the communication interruption between the master and slave inertial navigation systems exceeds 30 seconds, the slave inertial navigation system maintains its altitude unchanged from the last frame, while its azimuth velocity is reset to zero. Once communication is restored, the master inertial navigation system's altitude and azimuth velocity are used to dampen the slave inertial navigation system's altitude and azimuth velocity.

[0024] S4. Perform main inertial navigation state detection. When the main inertial navigation system is detected to have entered the realignment state, the combined validity is invalidated. When the main inertial navigation system transitions from the realignment state to navigation, the combined navigation filter is reinitialized based on the initial values. When the main inertial navigation system enters the delayed alignment state, the corresponding elements of the main inertial navigation system in the P and Q matrices are all set to 0, the filter transfer calculation proceeds normally, and the measurement used for filtering is the difference between the east and north velocities of the main inertial navigation system.

[0025] The main inertial navigation system (INS) is detected to be in a state of zero velocity correction. When the INS is detected to be in a state of zero velocity correction, the filter transfer and filtering calculation proceed normally. When the INS is detected to be exiting the state of zero velocity correction, the corresponding elements of the INS in the covariance matrix are reinitialized.

[0026] In one possible embodiment: In step 1, a main inertial navigation system and at least one sub-inertial navigation system are set up in the integrated navigation system. Within the sub-inertial navigation system, integrated navigation filter transfer and filtering calculations are performed using data from the main inertial navigation system and data from the sub-inertial navigation system. The measurements used for filtering are the differences in longitude, latitude, east velocity, and north velocity between the main and sub-inertial navigation systems. Within the main inertial navigation system, integrated navigation transfer calculations are performed using data from the main inertial navigation system, but no filter calculations are performed.

[0027] In step 2, the master inertial navigation communication status is detected. When a master inertial navigation communication interruption is detected, different processing strategies are adopted according to the length of the interruption, specifically: If the interruption time is less than or equal to 30 seconds, the filter calculation is paused, and the sub-inertial navigation data is used to replace the main inertial navigation data for transfer calculation, which includes at least: sub-inertial navigation velocity, position, attitude, geographic frame ratio, and machine frame angular rate. If the interruption lasts longer than 30 seconds, filter filtering and transfer calculations will be paused, and the combination validity will be marked as invalid. In step 3, the communication status of the master and slave inertial navigation systems is detected. When the communication between the master and slave inertial navigation systems is restored, fault self-reconstruction is performed: the covariance matrix updated in real time in the master inertial navigation system is used to dynamically assign values ​​to the elements related to the master inertial navigation system in the filter covariance matrix of the slave inertial navigation system. After the assignment is completed, the filtering and transfer calculation of the filter continues.

[0028] Perform master-slave inertial navigation communication status detection, and execute altitude damping protection and reconfiguration. If the master-slave inertial navigation communication interruption time exceeds 30 seconds, the slave inertial navigation altitude remains unchanged from the last frame, and the azimuth velocity is reset to zero. When communication is restored, the slave inertial navigation altitude and azimuth velocity are damped using the master inertial navigation altitude and azimuth velocity.

[0029] In step 4, the main inertial navigation system (INS) is detected to be in a realignment state. When the INS is detected to be entering a realignment state, the combined validity is invalidated. When the INS transitions from the realignment state to navigation, the combined navigation filter is reinitialized based on the initial values.

[0030] When the main inertial navigation system enters the delayed alignment state, the corresponding elements of the main inertial navigation system in the P and Q matrices are all set to 0, the filter transfer calculation proceeds normally, and the measurement used for filtering is the difference between the east and north velocities of the main inertial navigation system.

[0031] The main inertial navigation system (INS) is detected to be in a state of zero velocity correction. When the INS is detected to be in a state of zero velocity correction, the filter transfer and filtering calculation proceed normally. When the INS is detected to be exiting the state of zero velocity correction, the corresponding elements of the INS in the covariance matrix are reinitialized.

[0032] This invention employs a sub-inertial navigation system and at least one master inertial navigation system for integrated navigation fusion and altitude damping. When communication between the master and sub-inertial navigation systems is interrupted, different processing strategies are adopted based on the duration of the interruption. Upon resumption of communication, the filter covariance matrix is ​​dynamically updated to ensure continuous system operation during short interruptions and after recovery. When the master inertial navigation system is in a delayed alignment or zero-velocity correction state, filter parameters are dynamically adjusted to guarantee system accuracy and convergence. This invention significantly improves the fault tolerance and adaptability of integrated navigation systems in complex environments through mechanisms such as multi-source data collaboration, state management, and dynamic adjustment of the covariance matrix. It is suitable for application fields with high requirements for navigation reliability, such as high-precision navigation.

[0033] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A multi-source cooperative navigation method based on inertial navigation state awareness, characterized in that, Includes the following steps: S1. Set up a main inertial navigation system and at least one sub-inertial navigation system in the integrated navigation system; S2. Perform master-slave inertial navigation communication status detection. When a master-slave inertial navigation communication interruption is detected, different processing strategies are adopted according to the length of the interruption: S3. Perform master inertial navigation communication status detection, and perform fault self-reconfiguration after the master inertial navigation communication is restored; S4. Perform main inertial navigation state detection within the sub-inertial navigation system, and design filters within the sub-inertial navigation system based on the main inertial navigation state.

2. The method according to claim 1, characterized in that, In step 1, within the sub-inertial navigation system, the combined navigation filter transfer and filtering calculations are performed using the main inertial navigation data and the sub-inertial navigation data. The measurements used for filtering are the differences between the longitude, latitude, east speed, and north speed of the main and sub-inertial navigation systems. Within the main inertial navigation system, the combined navigation transfer calculations are performed using the main inertial navigation data, but no filter calculations are performed.

3. The method according to claim 1, characterized in that, In step 2, If the interruption time is less than or equal to 30 seconds, the sub-inertial navigation filter calculation is paused, and the sub-inertial navigation data is used to replace the main inertial navigation data for transfer calculation. The sub-inertial navigation data used includes at least: sub-inertial velocity, position, attitude, geographic frame ratio, and machine frame angular rate.

4. The method according to claim 3, characterized in that, In step 2, If the interruption time exceeds 30 seconds, the filtering and transfer calculation of the sub-inertial navigation filter will be paused, and the combination validity will be marked as invalid. If the communication interruption between the master and slave inertial navigation systems exceeds 30 seconds, the slave inertial navigation system maintains its altitude unchanged from the last frame, and its azimuth velocity is reset to zero. When communication is restored, the slave inertial navigation system's altitude and azimuth velocity are assigned values ​​using the master inertial navigation system's altitude and azimuth velocity.

5. The method according to claim 1, characterized in that, In step 3, the elements related to the main inertial navigation system in the filter covariance matrix of the sub-inertial navigation system are dynamically and in real time assigned values ​​using the covariance matrix updated in real time within the main inertial navigation system. After the assignment is completed, the filtering and transfer calculations of the sub-inertial navigation system filter continue.

6. The method according to claim 1, characterized in that, In step 4, When the main inertial navigation system is detected to be returning to alignment, the combination validity is invalidated. When the main inertial navigation system returns to the alignment state and enters the navigation state, the combined navigation filter is reinitialized.

7. The method according to claim 6, characterized in that, In step 4, When the main inertial navigation system is detected to have entered the delayed alignment state, the corresponding elements of the main inertial navigation system in the covariance matrix and noise matrix are all set to 0, the filter transfer calculation proceeds normally, and the measurement used for filtering is the difference between the east and north velocities of the main inertial navigation system.

8. The method according to claim 7, characterized in that, In step 4, When the main inertial navigation system is detected to enter the zero-speed correction state, the filter transfer and filtering calculation proceed normally; when the main inertial navigation system is detected to exit the zero-speed correction state, the corresponding elements of the main inertial navigation system in the covariance matrix are reinitialized.

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