A method for on-orbit measurement and calibration of space tracking and aiming equipment

Abstract

The present invention relates to an on-orbit measurement calibration method for space tracking and aiming equipment, comprising the following steps: Step 1: Controlling a tracking satellite to form a companion flight relationship with a non-cooperative target satellite, wherein two tracking and aiming devices on the tracking satellite respectively measure the line-of-sight distance, line-of-sight pitch angle, and azimuth angle data of the target satellite; Step 2: Calculating first and second target position vectors based on the measurement values ​​of the two tracking and aiming devices; Step 3: Calculating the cross product vector of the first target position vector and the second target position vector, and using the cross product vector to establish an observation equation; Step 4: Using a filtering algorithm, recursively estimating the three-axis installation deviation angle of the second tracking and aiming device; Step 5: Correcting the second target position vector to obtain a third target position vector; Step 6: Using the third target position vector to recalculate the line-of-sight distance, line-of-sight pitch angle, and azimuth angle data of the second tracking and aiming device and outputting them. The present invention can effectively improve the consistency of measurement data from two sets of tracking and aiming devices.

Description

Technical Field

[0001] The present invention relates to the field of space relative measurement, and specifically designs an on-orbit measurement calibration method for space tracking and aiming equipment. Background Art

[0002] As a relative measurement device, space tracking and pointing equipment is used to search, capture, and track target satellites in space, obtaining relative angle and distance information for relative navigation. When a satellite carries two tracking and pointing devices, due to factors such as vibration during launch or thermal deformation in orbit, the measurements of the same target by the two devices will inevitably deviate. To eliminate this deviation, one tracking and pointing device is used as a reference to calibrate the other, thereby improving its measurement accuracy and the consistency of the measurement data from the two devices, achieving stable, high-precision relative navigation. Summary of the Invention

[0003] In order to eliminate the measurement deviation caused by installation deviation or thermal deformation of two sets of space tracking and pointing equipment under the requirement of high-precision relative measurement, the present invention proposes an on-orbit measurement calibration method for space tracking and pointing equipment.

[0004] The present invention comprises the steps of:

[0005] Step 1: Control the tracking satellite to form a stable accompanying flight relationship with the non-cooperative target satellite in space. The first tracking and second tracking devices on the tracking satellite work simultaneously to stably track and observe the non-cooperative target satellite. At the same time, the tracking satellite's attitude is controlled to perform small back-and-forth scans on the pitch and azimuth axes to obtain the line-of-sight distance, line-of-sight pitch angle, and azimuth angle data measured by the two tracking and pointing devices.

[0006] Step 2: Calculate the three-axis target position vector of the target star relative to the tracking star in the tracking star system based on the measurement data of the two tracking and aiming devices, which are the first target position vector calculated by the first tracking and aiming device and the second target position vector calculated by the second tracking and aiming device;

[0007] Step 3: Using one of the tracking and aiming devices as a reference, in this example, the first tracking and aiming device is used as the measurement reference, and the cross product vector of the first target position vector and the second target position vector is calculated. The coordinate value of the cross product vector in the reference plane established with the first target position vector as the normal vector is used to establish the observation equation;

[0008] Step 4: Use a filtering algorithm to recursively estimate the three-axis installation deviation angles of the roll axis, pitch axis, and yaw axis of the second tracking device;

[0009] Step 5: Calculate the installation deviation correction matrix using the three-axis installation deviation angle of the second tracking and pointing device, and use the correction matrix to correct the second target position vector of the target star in the satellite system calculated by the second tracking and pointing device to obtain the third target position vector in the satellite system after installation correction;

[0010] Step 6: Use the third target position vector to recalculate the sight distance, sight pitch angle and azimuth angle data of the second tracking device, and use the recalculated data as the measurement output of the second tracking device.

[0011] Furthermore, in the step three, the first target position vector and the second target position vector are normalized before the cross product vector is calculated.

[0012] Furthermore, the step three also includes the following contents:

[0013] Calculate the first target position vector perpendicular reference vectors;

[0014]

[0015] Establish observation equations and calculate observation quantities

[0016]

[0017]

[0018] in is the normalized first target position vector, is the normalized second target position vector.

[0019] Furthermore, the filtering estimation algorithm used in step 4 is as follows:

[0020] Fai(k)=H T (k)·H(k)+Fai(k-1)

[0021]

[0022] in, Δθ(k) and Δψ(k) are the installation deviation angles of the roll axis, pitch axis, and yaw axis respectively; Fai(0)=zeros(3,3), Y(0)=[0 0 0] T , Fai -1 (k) is the inverse matrix of the matrix Fai(k).

[0023] Furthermore, the step five includes the following:

[0024] Calculate the installation deviation correction matrix ΔA(k)

[0025]

[0026] Calculate the third target position vector

[0027]

[0028] in is the second target position vector.

[0029] Furthermore, in step six, the third target position vector Recalculate the sight distance ρ2′(k), sight elevation angle θ2′(k), and azimuth angle ψ2′(k) of the second tracking device using the following formula:

[0030]

[0031] The present invention can effectively reduce measurement deviations between two tracking and aiming devices caused by installation deviations or thermal deformation, thereby improving the consistency of measurement data from the two tracking and aiming devices. Furthermore, when one tracking and aiming device is used as the measurement reference, the measurement values ​​of the other tracking and aiming device can be calibrated and corrected, thereby improving the angle measurement accuracy. The present invention is suitable for satellites carrying two tracking and aiming devices for relative measurement. It is simple to implement and has already been applied on satellites currently under development. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the calibration method of the present invention. DETAILED DESCRIPTION

[0033] The following is a further detailed description of the on-orbit measurement and calibration method of a space tracking and aiming device proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present invention, so they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0034] In order to eliminate the measurement deviation caused by installation deviation or thermal deformation of two sets of space tracking and pointing equipment under the requirement of high-precision relative measurement, the present invention proposes an on-orbit measurement calibration method for space tracking and pointing equipment.

[0035] like Figure 1 As shown, the method includes the following steps:

[0036] Step 1: Control the tracking satellite to form a stable accompanying flight relationship with the non-cooperative target satellite in space. The first tracking and second tracking devices on the tracking satellite work simultaneously to stably track and observe the non-cooperative target satellite. At the same time, the tracking satellite's attitude is controlled to perform small back-and-forth scans on the pitch and azimuth axes to obtain the line-of-sight distance, line-of-sight pitch angle, and azimuth angle data measured by the two tracking and pointing devices.

[0037] Step 2: Calculate the three-axis target position vector of the target star relative to the tracking star in the tracking star system based on the measurement data of the two tracking and aiming devices, which are the first target position vector calculated by the first tracking and aiming device and the second target position vector calculated by the second tracking and aiming device;

[0038] Step 3: Using one of the tracking and aiming devices as a reference, in this example, the first tracking and aiming device is used as the measurement reference, and the cross product vector of the first target position vector and the second target position vector is calculated. The coordinate value of the cross product vector in the reference plane established with the first target position vector as the normal vector is used to establish the observation equation;

[0039] Furthermore, in the step three, the first target position vector and the second target position vector are normalized before the cross product vector is calculated.

[0040] Furthermore, the step three also includes the following contents:

[0041] Calculate the first target position vector perpendicular reference vectors;

[0042]

[0043] Establish observation equations and calculate observation quantities

[0044]

[0045] in is the normalized first target position vector, is the normalized second target position vector.

[0046] Step 4: Use a filtering algorithm to recursively estimate the three-axis installation deviation angles of the roll axis, pitch axis, and yaw axis of the second tracking device;

[0047] Furthermore, the filtering estimation algorithm used in step 4 is as follows:

[0048] Fai(k)=H T (k)·H(k)+Fai(k-1)

[0049]

[0050] in, Δθ(k) and Δψ(k) are the installation deviation angles of the roll axis, pitch axis, and yaw axis respectively; Fai(0)=zeros(3,3), Y(0)=[0 0 0] T , Fai -1 (k) is the inverse matrix of the matrix Fai(k).

[0051] Step 5: Calculate the installation deviation correction matrix using the three-axis installation deviation angle of the second tracking and pointing device, and use the correction matrix to correct the second target position vector of the target star in the satellite system calculated by the second tracking and pointing device to obtain the third target position vector in the satellite system after installation correction;

[0052] Furthermore, the step five includes the following:

[0053] Calculate the installation deviation correction matrix ΔA(k)

[0054]

[0055] Calculate the third target position vector

[0056]

[0057] in is the second target position vector.

[0058] Step 6: Use the third target position vector to recalculate the sight distance, sight pitch angle, and azimuth angle data of the second tracking device, and use the recalculated data as the measurement output of the second tracking device.

[0059] Furthermore, in step six, the third target position vector Recalculate the sight distance ρ2′(k), sight elevation angle θ2′(k), and azimuth angle ψ2′(k) of the second tracking device using the following formula:

[0060]

[0061] In summary, the present invention has the following beneficial effects:

[0062] The present invention can effectively reduce measurement deviations between two tracking and aiming devices caused by installation deviations or thermal deformation, thereby improving the consistency of measurement data from the two tracking and aiming devices. Furthermore, when one tracking and aiming device is used as the measurement reference, the measurement values ​​of the other tracking and aiming device can be calibrated and corrected, thereby improving the angle measurement accuracy. The present invention is suitable for satellites carrying two tracking and aiming devices for relative measurement. It is simple to implement and has already been applied on satellites currently under development.

[0063] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for on-orbit measurement and calibration of space tracking and aiming equipment, characterized in that: The following steps are involved: Step 1: Control the tracking satellite to form a stable accompanying flight relationship with the non-cooperative target satellite in space. The first tracking and second tracking devices on the tracking satellite work simultaneously to stably track and observe the non-cooperative target satellite. At the same time, the tracking satellite's attitude is controlled to perform small back-and-forth scans on the pitch and azimuth axes to obtain the line-of-sight distance, line-of-sight pitch angle, and azimuth angle data measured by the two tracking and pointing devices. Step 2: Calculate the three-axis target position vector of the target star relative to the tracking star in the tracking star system based on the measurement data of the two tracking and aiming devices, which are the first target position vector calculated by the first tracking and aiming device and the second target position vector calculated by the second tracking and aiming device; Step 3: Calculate the cross product vector of the first target position vector and the second target position vector, and use the coordinate value of the cross product vector in the reference plane established with the first target position vector as the normal vector to establish an observation equation; Step 4: Use a filtering algorithm to recursively estimate the three-axis installation deviation angles of the roll axis, pitch axis, and yaw axis of the second tracking device; Step 5: Calculate the installation deviation correction matrix using the three-axis installation deviation angle of the second tracking and pointing device, and use the correction matrix to correct the second target position vector of the target star in the satellite system calculated by the second tracking and pointing device to obtain the third target position vector in the satellite system after installation correction; Step 6: Use the third target position vector to recalculate the sight distance, sight pitch angle, and azimuth angle data of the second tracking device, and use the recalculated data as the measurement output of the second tracking device.

2. The on-orbit measurement calibration method for space tracking and aiming equipment according to claim 1, characterized in that: In the step three, the first target position vector and the second target position vector are normalized before calculating the cross product vector.

3. The on-orbit measurement calibration method for space tracking and aiming equipment according to claim 2, characterized in that: The step three also includes the following contents: Calculate the first target position vector perpendicular reference vectors; Establish observation equations and calculate observation quantities in is the first target position vector, is the second target position vector.

4. The on-orbit measurement calibration method for space tracking and aiming equipment according to claim 3, characterized in that: The filtering estimation algorithm used in step 4 is as follows: Fai(k)=H T (k)·H(k)+Fai(k-1) in, Δθ(k) and Δψ(k) are the installation deviation angles of the roll axis, pitch axis, and yaw axis respectively; Fai(0)=zeros(3,3), Y(0)=[0 0 0] T , Fai -1 (k) is the inverse matrix of the matrix Fai(k).

5. The on-orbit measurement calibration method for space tracking and aiming equipment according to claim 4, characterized in that: The step five includes the following contents: Calculate the installation deviation correction matrix ΔA(k) Calculate the third target position vector in is the second target position vector.

6. The on-orbit measurement calibration method for space tracking and aiming equipment according to claim 5, characterized in that: In step six, the third target position vector is used Recalculate the sight distance ρ2′(k), sight elevation angle θ2′(k), and azimuth angle ψ2′(k) of the second tracking device using the following formula:

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