A Data Preprocessing Method for Rendezvous and Docking Sensors Based on Absolute Attitude Recursive Correction

Abstract

This invention discloses a recursive correction method for rendezvous and docking sensor data preprocessing. The method utilizes the time-stamped relative measurement data output by the rendezvous and docking sensor mounted on the tracking spacecraft, representing the relative position and attitude between the target and tracking spacecraft. By combining the time-stamped measurement data with the time difference calculated for relative navigation, the absolute attitudes of the tracking and target spacecraft, as well as the transformation matrix from the target spacecraft's orbital frame to its inertial frame, are recursively corrected. Furthermore, the relative measurement data output by the rendezvous and docking sensor undergoes delay compensation preprocessing to reduce the impact of delay on relative navigation accuracy and stability. This recursive correction method for rendezvous and docking sensor data preprocessing can be applied to single-machine data preprocessing of rendezvous and docking sensors in rendezvous and docking missions. The method is simple, the process is clear, it is easy to implement, and it has widespread application value.

Description

Technical Field

[0001] This invention belongs to the field of relative pose measurement and processing technology for space rendezvous and docking missions, specifically involving a recursive correction method for rendezvous and docking sensor data preprocessing. Background Technology

[0002] The prerequisite for successfully completing a space rendezvous and docking mission is to perform relative measurements on the target spacecraft. The tracking spacecraft typically has a specific relative measurement unit. During the long-range and short-range phases, microwave radar can be used to detect the target spacecraft as a point target, thereby achieving relative navigation and hovering. This technology is relatively mature. However, for the ultra-short-range phase, high-precision target relative navigation is required, and microwave radar is no longer sufficient. Therefore, optical rendezvous and docking sensors can be used to obtain relative information between the target spacecraft and the tracking spacecraft, thereby achieving high-precision volume target relative navigation. This method is simple and highly reliable.

[0003] Optical rendezvous and docking sensors use detectors and their optical systems to obtain images or point cloud information of the target spacecraft. They then process the images and point clouds to calculate the relative information between the target and tracking spacecraft. With limited hardware resources, higher measurement accuracy requires more computing power, inevitably leading to greater delays in the relative position and attitude data output by the rendezvous and docking sensors.

[0004] Considering low-Earth orbit rendezvous and docking missions, the impact of the target spacecraft's orbit changing over time cannot be ignored. Therefore, if the relative data delay output by the rendezvous and docking sensor is not processed, the delay between the measurement data and the target spacecraft's orbital information will affect the accuracy and stability of the target's relative navigation, thus adversely affecting the rendezvous and docking mission. Summary of the Invention

[0005] To address the adverse effects of relative data delay output by rendezvous and docking sensors on docking missions, this invention provides a data preprocessing method for rendezvous and docking sensors based on absolute attitude recursive correction. By recursively correcting the relative measurement data of the rendezvous and docking sensors during preprocessing, the data delay is compensated, reducing the impact of data delay on relative navigation accuracy and stability, and providing assurance for rendezvous and docking missions.

[0006] The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction provided by this invention includes the following steps: S1. Install a rendezvous and docking sensor on the tracking spacecraft to obtain information on the relative position and relative attitude between the target spacecraft and the tracking spacecraft. S2. Recursively correct the absolute attitudes of the tracking spacecraft and the target spacecraft to obtain the absolute attitudes of the tracking spacecraft and the target spacecraft at the moment when the rendezvous and docking sensor outputs relative measurement information; S3. The orbital system transformation matrix of the target spacecraft is recursively corrected to obtain the target spacecraft orbital system to inertial system transformation matrix at the time when the rendezvous and docking sensor outputs the relative measurement information; S4. Based on the absolute attitude of the tracking spacecraft, the absolute attitude of the target spacecraft, and the transformation matrix from the target spacecraft's orbital frame to its inertial frame, preprocess the relative position between the tracking spacecraft and the target spacecraft to compensate for and correct the data delay of the rendezvous and docking sensors.

[0007] Optionally, the relative position information between the tracking spacecraft and the target spacecraft output by the rendezvous and docking sensor in step S1 is defined as the three-dimensional coordinates of the origin of the target spacecraft's coordinate system in the measurement coordinate system of the rendezvous and docking sensor, and the output time is set to... .

[0008] Optionally, the rendezvous and docking sensor mentioned in step S1 may be a laser imaging navigation radar, a near-field camera, or a rendezvous and docking imaging radar.

[0009] Optionally, the recursive correction process for tracking the absolute attitude of the spacecraft in step S2 is as follows: Based on the time calculation of relative navigation Tracking spacecraft inertial quaternions Tracking the inertial angular velocity of spacecraft and recursive correction time Calculated using quaternion integration algorithm Inertial quaternions that are constantly tracked by spacecraft and quaternions Convert to a rotation matrix, and obtain Constantly track the absolute attitude of the spacecraft ; The absolute attitude of the tracking spacecraft is the rotation matrix of the tracking spacecraft body to the inertial frame.

[0010] Optionally, the recursive correction step for the absolute attitude of the target spacecraft in step S2 is as follows: Based on the time calculation of relative navigation Target spacecraft inertial quaternion Target spacecraft inertial angular velocity and recursive correction time Calculated using quaternion integration algorithm Inertial quaternion of the target spacecraft at any time and quaternions Convert to a rotation matrix, and obtain The absolute attitude of the target spacecraft at all times ; The absolute attitude of the target spacecraft is the rotation matrix of the target spacecraft body to the inertial frame.

[0011] Optionally, step S3 specifically includes: calculating the time based on relative navigation. Instantaneous orbital elements of the target spacecraft , , and recursive correction time ,get Instantaneous orbital elements of the target spacecraft , , The specific calculation formula is as follows: (1) (2) (3) Optionally, step S3 further includes: obtaining the quaternion algorithm from the orbital frame to the inertial frame and the quaternion algorithm for solving the rotation matrix, thus obtaining... Transformation matrix from orbital frame to inertial frame for the target spacecraft at any given time .

[0012] Optionally, step S4 specifically includes: according to Constantly tracking the absolute attitude of the spacecraft Transformation matrix from the target spacecraft's orbital frame to its inertial frame The corrected transformation matrix from the tracking spacecraft body to the target spacecraft's orbital system is obtained. The calculation formula is as follows: (4) according to The absolute attitude of the target spacecraft at all times Transformation matrix from the target spacecraft's orbital frame to its inertial frame The transformation matrix from the target spacecraft body to its orbital system after correction is obtained. The calculation formula is as follows: (5) Optionally, step S4 may further include: according to The transformation matrix that continuously tracks the spacecraft's orbital system to the target spacecraft's orbital system. The transformation matrix from the target spacecraft body to its orbital system Under the target spacecraft's orbital system, The relative position of the origin of the active end coordinate system in the passive end coordinate system at any given time : (6) In the formula, The relative position between the tracking spacecraft and the target spacecraft output by the rendezvous and docking sensor is also the three-axis position of the origin of the target spacecraft's target coordinate system in the measurement coordinate system of the rendezvous and docking sensor. The triaxial position of the origin of the rendezvous and docking sensor measurement system in the coordinate system of the active end; The three-axis position of the origin of the target coordinate system in the passive end coordinate system; the three-axis direction of the active end coordinate system is parallel to the three-axis direction of the rendezvous and docking sensor measurement coordinate system, and the three-axis direction of the passive end coordinate system is parallel to the three-axis direction of the target coordinate system.

[0013] This invention presents a data preprocessing method for rendezvous and docking sensors based on recursive correction of absolute attitude. By recursively correcting the absolute attitudes of the tracking and target spacecraft and the transformation matrix from the target spacecraft's orbital frame to its inertial frame, it compensates for the data delay in the relative measurements output by the rendezvous and docking sensors. This solves the problem in low-Earth orbit rendezvous and docking missions where the time-varying orbits of the spacecraft and the output delay of the rendezvous and docking sensors affect relative navigation accuracy and stability. This invention can be applied to single-machine data preprocessing of rendezvous and docking sensors in rendezvous and docking missions. The method is simple, the process is clear, it is easy to implement, and it has widespread application value. Attached Figure Description

[0014] Figure 1 A schematic diagram showing the output data of the rendezvous and docking sensor; Figure 2 This is a flowchart of the rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in this invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and by way of detailed description of preferred embodiments.

[0016] This invention provides a recursive correction method for rendezvous and docking sensor data preprocessing. The method utilizes a rendezvous and docking sensor mounted on the tracking spacecraft to output time-stamped relative measurement data, i.e., the relative position and attitude between the target and tracking spacecraft. By combining the time-stamped measurement data with the time difference calculated for relative navigation, the absolute attitudes of the tracking and target spacecraft and the transformation matrix from the target spacecraft's orbital frame to its inertial frame are recursively corrected. Furthermore, the relative measurement data output by the rendezvous and docking sensor undergoes delay compensation preprocessing to reduce the impact of delay on relative navigation accuracy and stability. The specific steps are as follows.

[0017] S1. Install a rendezvous and docking sensor on the tracking spacecraft to obtain information on the relative position and attitude between the target spacecraft and the tracking spacecraft.

[0018] The relative position information between the rendezvous and docking sensor and the target spacecraft is defined as the three-dimensional coordinates of the origin of the target spacecraft's coordinate system in the rendezvous and docking sensor's measurement coordinate system, such as... Figure 1 Medium vector As shown, the output relative information includes a time stamp. The rendezvous and docking sensor can be a laser imaging navigation radar, a near-field camera, or a rendezvous and docking imaging radar.

[0019] S2. The absolute attitudes of the tracking spacecraft and the target spacecraft are recursively corrected to obtain the absolute attitudes of the tracking spacecraft and the target spacecraft at the moment when the rendezvous and docking sensor outputs relative measurement information.

[0020] First, a recursive correction process is performed on the absolute attitude of the tracked spacecraft: based on the time calculated by relative navigation... Tracking spacecraft inertial quaternions Tracking the inertial angular velocity of spacecraft and the calculated recursive correction time Calculated using quaternion integration algorithm Inertial quaternions for tracking spacecraft in real time , further quaternion Convert to a rotation matrix, and obtain Constantly track the absolute attitude of the spacecraft Among them, tracking the absolute attitude of the spacecraft. This refers to the rotation matrix that tracks the spacecraft body to the inertial frame.

[0021] Secondly, the absolute attitude of the target spacecraft is recursively corrected: based on the relative navigation solution time... Target spacecraft inertial quaternion Target spacecraft inertial angular velocity and the calculated recursive correction time Calculated using quaternion integration algorithm Inertial quaternion of the target spacecraft at a given time , further quaternion Convert to a rotation matrix, and obtain The absolute attitude of the target spacecraft at all times Among them, the absolute attitude of the target spacecraft This is the rotation matrix from the target spacecraft body to the inertial frame.

[0022] S3. The orbital system transformation matrix of the target spacecraft is recursively corrected to obtain the target spacecraft orbital system to inertial system transformation matrix at the time when the rendezvous and docking sensor outputs the relative measurement information.

[0023] Based on the time calculation of relative navigation Instantaneous orbital elements of the target spacecraft , , and the calculated recursive correction time ,get Instantaneous orbital elements of the target spacecraft , , The specific calculation formula is as follows: (1) (2) (3) Further utilizing the quaternion algorithm for converting the orbital frame to the inertial frame, and the quaternion algorithm for solving the rotation matrix, we obtain... Transformation matrix from orbital frame to inertial frame for the target spacecraft at any given time .

[0024] S4. Based on the absolute attitude of the tracking spacecraft, the absolute attitude of the target spacecraft, and the transformation matrix from the target spacecraft's orbital frame to its inertial frame, preprocess the relative position between the tracking spacecraft and the target spacecraft to compensate for and correct the data delay of the rendezvous and docking sensors.

[0025] Considering the changes in the target spacecraft's orbit and the delay in the output data of the rendezvous and docking sensor, the delay in the data of the rendezvous and docking sensor is compensated.

[0026] Using the recursion obtained in step S2 Constantly tracking the absolute attitude of the spacecraft And the result obtained by recursion in step S3 Transformation matrix from orbital frame to inertial frame for the target spacecraft at any given time. The corrected transformation matrix from the tracking spacecraft body to the target spacecraft's orbital system is obtained. The calculation formula is as follows: (4) Using the recursion obtained in step S2 absolute attitude of the target spacecraft And the result obtained by recursion in step S3 Transformation matrix from orbital frame to inertial frame for the target spacecraft at any given time. The transformation matrix from the target spacecraft body to its orbital system after correction is obtained. The calculation formula is as follows: (5) Since the relative position measured by the rendezvous and docking sensor is the three-axis position of the origin of the target spacecraft coordinate system in the measurement system within the rendezvous and docking sensor's measurement coordinate system. Relative navigation requires the three-axis positions of the origin of the active end coordinate system in the target spacecraft's orbital system and the passive end coordinate system. .

[0027] Combined with recursive correction The transformation matrix that continuously tracks the spacecraft's orbital system to the target spacecraft's orbital system. and the transformation matrix from the target spacecraft body to the target spacecraft orbital system. Under the target spacecraft's orbital system, The relative position of the origin of the active end coordinate system in the passive end coordinate system at any given time : (6) in, The relative position between the tracking spacecraft and the target spacecraft output by the rendezvous and docking sensor is also the three-axis position of the origin of the target spacecraft's target coordinate system in the measurement coordinate system of the rendezvous and docking sensor. To determine the triaxial position of the origin of the rendezvous and docking sensor measurement system in the coordinate system of the active end, The three-axis position of the origin of the target coordinate system in the passive end coordinate system is defined. By default, the three-axis directions of the active end coordinate system are parallel to the three-axis directions of the rendezvous and docking sensor measurement coordinate system, and the three-axis directions of the passive end coordinate system are parallel to the three-axis directions of the target coordinate system.

[0028] The recursive correction-based rendezvous and docking sensor data preprocessing method provided by this invention can be applied to the single-machine data preprocessing of rendezvous and docking sensors in rendezvous and docking missions. The method is simple, the process is clear, it is easy to implement, and it has promotional value.

[0029] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A recursive correction method for rendezvous and docking sensor data preprocessing, characterized in that, Includes the following steps: S1. Install a rendezvous and docking sensor on the tracking spacecraft to obtain information on the relative position and relative attitude between the target spacecraft and the tracking spacecraft. S2. Recursively correct the absolute attitudes of the tracking spacecraft and the target spacecraft to obtain the absolute attitudes of the tracking spacecraft and the target spacecraft at the moment when the rendezvous and docking sensor outputs relative measurement information; wherein, the absolute attitude of the tracking spacecraft is the rotation matrix of the tracking spacecraft body to the inertial frame, and the inertial frame is represented by i. S3. The orbital system transformation matrix of the target spacecraft is recursively corrected to obtain the target spacecraft orbital system to inertial system transformation matrix at the time when the rendezvous and docking sensor outputs the relative measurement information; S4. Based on the absolute attitude of the tracking spacecraft, the absolute attitude of the target spacecraft, and the transformation matrix from the target spacecraft's orbital frame to its inertial frame, preprocess the relative position between the tracking spacecraft and the target spacecraft to compensate for and correct the data delay of the rendezvous and docking sensors.

2. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 1, characterized in that, In step S1, the relative position information between the tracking spacecraft and the target spacecraft output by the rendezvous and docking sensor is defined as the three-dimensional coordinates of the origin of the target spacecraft's coordinate system in the measurement coordinate system of the rendezvous and docking sensor, and the output time is set to... .

3. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 1, characterized in that, The rendezvous and docking sensor mentioned in step S1 is a laser imaging navigation radar, a near-field camera, or a rendezvous and docking imaging radar.

4. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 2, characterized in that, The recursive correction process for tracking the absolute attitude of the spacecraft in step S2 is as follows: Based on the time calculation of relative navigation Tracking spacecraft inertial quaternions Tracking the inertial angular velocity of spacecraft and recursive correction time Calculated using quaternion integration algorithm Inertial quaternions that are constantly tracking spacecraft and quaternions Convert to a rotation matrix, and obtain Constantly track the absolute attitude of the spacecraft ; The absolute attitude of the tracking spacecraft is the rotation matrix of the tracking spacecraft body to the inertial frame.

5. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 4, characterized in that, The recursive correction steps for the absolute attitude of the target spacecraft in step S2 are as follows: Based on the time calculation of relative navigation Target spacecraft inertial quaternion Target spacecraft inertial angular velocity and recursive correction time Calculated using quaternion integration algorithm Inertial quaternion of the target spacecraft at any time and quaternions Convert to a rotation matrix, and obtain The absolute attitude of the target spacecraft at all times ; The absolute attitude of the target spacecraft is the rotation matrix of the target spacecraft body to the inertial frame.

6. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 5, characterized in that, Step S3 specifically includes: calculating the time based on relative navigation. Instantaneous orbital elements of the target spacecraft , , and recursive correction time ,get Instantaneous orbital elements of the target spacecraft , , The specific calculation formula is as follows: (1) (2) (3) 7. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 6, characterized in that, Step S3 also includes: obtaining the quaternion algorithm from the orbital frame to the inertial frame and the quaternion algorithm for solving the rotation matrix, thus obtaining... Transformation matrix from orbital frame to inertial frame for the target spacecraft at any given time .

8. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 7, characterized in that, Step S4 specifically includes: according to Constantly tracking the absolute attitude of the spacecraft Transformation matrix from the target spacecraft's orbital frame to its inertial frame The corrected transformation matrix from the tracking spacecraft body to the target spacecraft's orbital system is obtained. The calculation formula is as follows: (4) according to The absolute attitude of the target spacecraft at all times Transformation matrix from the target spacecraft's orbital frame to its inertial frame The transformation matrix from the target spacecraft body to its orbital system after correction is obtained. The calculation formula is as follows: (5) 9. The rendezvous and docking sensor data preprocessing method based on absolute attitude recursive correction as described in claim 8, characterized in that, Step S4 also includes: according to The transformation matrix that continuously tracks the spacecraft's orbital system to the target spacecraft's orbital system. The transformation matrix from the target spacecraft body to its orbital system Under the target spacecraft's orbital system, The relative position of the origin of the active end coordinate system in the passive end coordinate system at any given time : (6) In the formula, The relative position between the tracking spacecraft and the target spacecraft output by the rendezvous and docking sensor is also the three-axis position of the origin of the target spacecraft's target coordinate system in the measurement coordinate system of the rendezvous and docking sensor. The three-axis position of the origin of the rendezvous and docking sensor measurement system in the coordinate system of the active end; The three-axis position of the origin of the target coordinate system in the passive end coordinate system; the three-axis direction of the active end coordinate system is parallel to the three-axis direction of the rendezvous and docking sensor measurement coordinate system, and the three-axis direction of the passive end coordinate system is parallel to the three-axis direction of the target coordinate system.

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