Spacecraft tracking and aiming attitude guidance control quantity calculation method

Abstract

The invention provides a spacecraft tracking and aiming attitude guidance control quantity calculation method, which comprises the following steps of: calculating an angular velocity vertical to a vector of a spacecraft pointing to a target position under an inertial system through the spacecraft pointing to the target position under the J2000 inertial system and a velocity vector; according to a conversion matrix from a spacecraft inertial system to the system, a position vector of a spacecraft pointing target under the inertial system and a pointing axis under the spacecraft system, a tracking and pointing attitude control quantity is calculated; and the tracking and pointing attitude angular velocity control quantity is calculated according to the angular velocity perpendicular to the vector pointing to the target position of the spacecraft and the inertial angular velocity of the spacecraft in the spacecraft body system. The method is suitable for tracking aiming or staring of the spacecraft on the target, the attitude guidance control quantity is directly calculated through the target position and speed information and the attitude information of the spacecraft to be used for attitude maneuver control of the spacecraft, the problem of attitude singularity does not exist, and the tedious target guidance attitude calculation process is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft attitude control, and in particular is a method for calculating a spacecraft tracking and aiming attitude guidance control quantity. Background Art

[0002] The missions and functions of modern spacecraft platforms are becoming increasingly diverse and demanding, placing higher demands on the accuracy and stability of attitude guidance control, and especially on agile maneuverability. However, traditional spacecraft attitude guidance control requires complex target guidance attitude calculations, which are computationally intensive and conflicting with the spacecraft's agile maneuverability requirements. Furthermore, auxiliary vectors must be selected in both the J2000 inertial system and the spacecraft's native system. Improper selection of these auxiliary vectors can lead to erratic target guidance attitudes, making it impossible to effectively calculate the target guidance attitude, potentially causing failure in tracking or staring missions.

[0003] Based on the above reasons, there is an urgent need to propose a simple method for calculating the spacecraft tracking, aiming or staring attitude guidance control quantity to achieve agile maneuvering control of the spacecraft attitude and avoid attitude singularity problems. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a method for calculating the attitude guidance control quantity of spacecraft tracking, aiming or staring, which is suitable for spacecraft tracking, aiming or staring missions. The attitude guidance control quantity is calculated by using the target position and velocity information in the J2000 inertial system and the spacecraft's own attitude information for agile attitude maneuvering control of the spacecraft, avoiding the tedious target guidance attitude calculation and attitude singularity problems.

[0005] The present invention provides a method for calculating a spacecraft tracking and aiming attitude guidance control variable, comprising the following calculation steps: The target's position vector and velocity vector in the J2000 inertial system are obtained based on the longitude, latitude, and altitude information of the surface target point or the target spacecraft's orbital elements. The position vector and velocity vector of the spacecraft pointing to the target in the inertial system are then calculated based on the spacecraft's own position vector and velocity vector in the J2000 inertial system. The angular velocity perpendicular to the spacecraft's position vector pointing to the target in the inertial system is calculated from the spacecraft's position and velocity vector pointing to the target in the J2000 inertial system. The conversion matrix from the inertial system to the local system is calculated from the quaternion of the spacecraft inertial system to the local system, and the angular velocity perpendicular to the spacecraft pointing to the target position vector in the inertial system is projected to the spacecraft local system based on the conversion matrix; The tracking and aiming attitude control quantity is calculated from the conversion matrix from the spacecraft's inertial system to its own system, the position vector of the spacecraft pointing to the target in the inertial system, and the pointing axis in the spacecraft's own system. The tracking and aiming attitude angular velocity control quantity is calculated from the angular velocity perpendicular to the position vector of the spacecraft pointing to the target and the inertial angular velocity of the spacecraft in its own system.

[0006] The beneficial effects of the present invention are: The present invention provides a method for calculating the attitude guidance control quantity for spacecraft tracking, aiming (staring), which is suitable for spacecraft tracking, aiming or staring tasks on targets. The method directly calculates the attitude guidance control quantity for agile maneuvering control of the spacecraft attitude through the position and velocity information of the target in the J2000 inertial system and the spacecraft's own attitude information, thereby avoiding the tedious target guidance attitude calculation process and the attitude singularity problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a flow chart for implementing the method for calculating the spacecraft tracking and aiming attitude guidance control quantity in the present invention. DETAILED DESCRIPTION

[0008] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. Example 1

[0009] The present invention provides a method for calculating the control amount of the tracking, aiming or staring attitude guidance of a spacecraft, which is applicable to the tracking, aiming or staring tasks of a spacecraft on a target, such as Figure 1 As shown, it includes the following steps: Step S1: Obtain the target's position vector and velocity vector in the J2000 inertial system based on the longitude, latitude, and altitude information of the surface target point or the target spacecraft's orbital elements. Then, calculate the spacecraft's position vector and velocity vector pointing to the target in the inertial system based on the spacecraft's own position vector and velocity vector in the J2000 inertial system.

[0010] Furthermore, in the aforementioned S1, the process of calculating the position vector and velocity vector of the spacecraft pointing to the target in the inertial system is as follows:

[0011]

[0012] in, 、 They represent the position vector of the target in the J2000 inertial system and the position vector of the spacecraft in the J2000 inertial system respectively; 、 They represent the velocity vector of the target in the J2000 inertial system and the velocity vector of the spacecraft in the J2000 inertial system respectively; 、 They represent the position vector and velocity vector of the spacecraft pointing to the target in the inertial system respectively.

[0013] Step S2: Calculate the angular velocity perpendicular to the spacecraft-pointing-target position vector in the inertial system based on the spacecraft-pointing-target position and velocity vector in the J2000 inertial system.

[0014] Furthermore, in the aforementioned S2, the process of calculating the angular velocity of the vector perpendicular to the spacecraft pointing to the target position in the inertial system is:

[0015] in, represents the two-norm of a vector; It represents the angular velocity of the vector perpendicular to the spacecraft pointing to the target position in the inertial system.

[0016] Step S3: Calculate the quaternion from the spacecraft inertial system to the local system to obtain the inertial system to local system conversion matrix, and project the angular velocity perpendicular to the spacecraft target position vector in the inertial system to the spacecraft local system according to the conversion matrix.

[0017] Furthermore, in the aforementioned S3, the angular velocity perpendicular to the spacecraft's target position vector in the inertial system is projected onto the spacecraft's own system:

[0018] in, It represents the conversion matrix from the inertial system to the spacecraft system, which is usually obtained by integrating the inertial angular velocity of the star sensor or gyroscope; is the angular velocity of the spacecraft in its own system perpendicular to the vector pointing to the target position of the spacecraft.

[0019] Step S4: Calculate the tracking and aiming attitude control value based on the conversion matrix from the spacecraft's inertial system to the current system, the position vector of the spacecraft pointing to the target in the inertial system, and the pointing axis in the current system of the spacecraft. Calculate the tracking and aiming attitude angular velocity control value based on the angular velocity perpendicular to the position vector of the spacecraft pointing to the target and the inertial angular velocity of the spacecraft in the current system of the spacecraft.

[0020] Furthermore, in the aforementioned S4, the process of calculating the tracking and aiming attitude control amount and the tracking and aiming attitude angular velocity control amount is as follows:

[0021]

[0022] in, Represents vector cross product operation; 、 They represent the tracking attitude control value and the tracking attitude angular velocity control value respectively; represents the unit vector of the pointing axis in the spacecraft system; It represents the inertial angular velocity of the spacecraft system, which is generally measured by a combination of gyroscopes.

[0023] The method for calculating the spacecraft tracking, aiming or staring attitude guidance control quantity provided by the present invention based on the above-mentioned embodiment can avoid attitude singularity, avoid complex target guidance attitude calculation, and achieve the purpose of agile maneuvering compared with the existing technology. It has the advantages of high reliability, simple algorithm, and easy software programming.

[0024] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for calculating the control amount of a spacecraft tracking and aiming attitude guidance, characterized in that: The following steps are involved: S1. Obtain the target's position vector and velocity vector in the J2000 inertial system based on the longitude, latitude, and altitude information of the surface target point or the target spacecraft's orbital elements. Calculate the spacecraft's position vector and velocity vector pointing toward the target in the inertial system based on the spacecraft's own position vector and velocity vector in the J2000 inertial system. S2. Calculate the angular velocity perpendicular to the spacecraft's position vector pointing to the target in the inertial system based on the spacecraft's position and velocity vector pointing to the target in the J2000 inertial system. S3. Calculate the inertial system to local system conversion matrix based on the quaternion from the spacecraft inertial system to the local system, and project the angular velocity perpendicular to the spacecraft target position vector in the inertial system to the spacecraft local system based on the conversion matrix; S4. The tracking and aiming attitude control quantity is calculated based on the conversion matrix from the spacecraft's inertial system to the current system, the position vector of the spacecraft pointing to the target in the inertial system, and the pointing axis in the current system of the spacecraft. The tracking and aiming attitude angular velocity control quantity is calculated based on the angular velocity perpendicular to the position vector of the spacecraft pointing to the target and the inertial angular velocity of the spacecraft in the current system of the spacecraft.

2. A method for calculating a spacecraft tracking and aiming attitude guidance control variable according to claim 1, characterized in that: In S1, the process of calculating the position vector and velocity vector of the spacecraft pointing to the target in the inertial system is as follows: ； ； in, 、 They represent the position vector of the target in the J2000 inertial system and the position vector of the spacecraft in the J2000 inertial system respectively; 、 They represent the velocity vector of the target in the J2000 inertial system and the velocity vector of the spacecraft in the J2000 inertial system respectively; 、 They represent the position vector and velocity vector of the spacecraft pointing to the target in the inertial system respectively.

3. The method for calculating a spacecraft tracking and aiming attitude guidance control variable according to claim 1, wherein: In S2, the process of calculating the angular velocity of the vector perpendicular to the spacecraft pointing to the target position in the inertial system is: ； in, represents the two-norm of a vector; It represents the angular velocity of the vector perpendicular to the spacecraft pointing to the target position in the inertial system.

4. The method for calculating a spacecraft tracking and aiming attitude guidance control variable according to claim 1, wherein: In S3, the angular velocity perpendicular to the spacecraft's target position vector in the inertial system is projected onto the spacecraft's own system: ； in, It represents the conversion matrix from the inertial system to the spacecraft system, which is obtained by integrating the inertial angular velocity of the star sensor or gyroscope; is the angular velocity of the spacecraft in its own system perpendicular to the vector pointing to the target position of the spacecraft.

5. The method for calculating a spacecraft tracking and aiming attitude guidance control variable according to claim 1, wherein: In S4, the process of calculating the tracking and aiming attitude control amount and the tracking and aiming attitude angular velocity control amount is as follows: ； ； in, Represents vector cross product operation; 、 They represent the tracking attitude control value and the tracking attitude angular velocity control value respectively; represents the unit vector of the pointing axis in the spacecraft system; It represents the inertial angular velocity of the spacecraft system, which is measured by the gyroscope combination.

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