Camera posture determination method and system

Abstract

The present invention discloses a camera attitude determination method based on the joint processing of on-orbit real-time measurement data of a star sensor, a gyroscope, a star sensor installation angle, and a camera installation angle. The real-time measurement data of the star sensor installation angle is introduced to improve the satellite body attitude determination method. The real-time measurement data of the camera installation angle is introduced to provide a direct determination method for the satellite camera attitude. The present invention proposes a preprocessing and use method of the star sensor installation angle measurement data and the camera installation angle measurement data to improve the determination accuracy of the satellite body attitude and the camera attitude. The present invention is suitable for increasing the star sensor and camera installation angle measurement capabilities on the basis of using star sensors and gyroscopes to complete high-precision attitude determination of the satellite body attitude or the satellite camera attitude.

Description

Technical Field

[0001] The invention relates to a camera posture determination method and system. Background Art

[0002] The satellite body attitude determination method is often obtained by joint filtering of the observation data of the star sensor and the gyroscope. The satellite camera attitude determination method is based on the result of the satellite body attitude determination, using the installation matrix of the camera measurement coordinate system relative to the satellite body coordinate system to obtain the camera attitude quaternion or attitude matrix.

[0003] The result of the star sensor measurement is the attitude quaternion of the star sensor measurement coordinate system relative to the inertial coordinate system. The installation matrix of the star sensor measurement coordinate system relative to the satellite body coordinate system is used to obtain the attitude quaternion or attitude matrix of the satellite body relative to the inertial coordinate system. When there are two or more star sensors, the dual-vector attitude determination method or the QUEST attitude determination method can be used to obtain the attitude quaternion of the star sensor measurement coordinate system relative to the inertial coordinate system. Then, two or more installation matrices between the star sensor measurement coordinate system and the satellite body coordinate system are used to obtain the attitude quaternion or attitude matrix of the satellite body relative to the inertial coordinate system.

[0004] The result of gyro measurement is the angular velocity of the gyro measurement coordinate system relative to the inertial coordinate system. The angular velocity of the satellite body coordinate system relative to the inertial coordinate system is obtained by using the installation matrix of the gyro measurement coordinate system relative to the satellite body coordinate system. Taking advantage of the characteristics of the star sensor measurement results, which have high absolute attitude accuracy but large high-frequency noise, and the gyro measurement results, which have low high-frequency noise but large constant drift, the extended Kalman filter method is used to jointly filter the star sensor and the gyro to obtain the attitude quaternion or attitude matrix of the new satellite body relative to the inertial coordinate system after filtering.

[0005] The above-mentioned star sensor installation matrix and camera installation matrix will produce installation attitude changes of several to dozens of angular components during the launch process due to the vibration of the active segment, and will produce installation attitude changes of several to dozens of arc seconds during the on-orbit operation due to the periodic changes in the thermal environment. The direct use of the above-mentioned star sensor installation matrix and camera installation matrix will lead to inaccurate satellite body attitude determination and inaccurate camera attitude determination. The error reaches the angular component level, which cannot meet the application scenarios requiring camera attitude determination at the arc second level.

[0006] With the successful development of the on-orbit real-time measurement device for the star sensor installation angle and the camera installation angle, the current situation that the on-orbit installation matrix of the star sensor and the camera cannot be directly obtained has been made up. However, it is still necessary to study a camera attitude determination method based on the joint processing of the star sensor, gyroscope, star sensor installation angle and camera installation angle measurement data to realize the direct determination of the satellite camera attitude. Summary of the invention

[0007] In view of the defects existing in the above-mentioned prior art approaches, the present invention discloses a camera attitude determination method based on the joint processing of on-orbit real-time measurement data of star sensors, gyroscopes, star sensor installation angles and camera installation angles, an on-orbit camera attitude determination system and a simulation verification system, introduces the real-time measurement data of the star sensor installation angle, and improves the satellite body attitude determination method. The real-time measurement data of the camera installation angle is introduced to provide a direct determination method for the satellite camera attitude.

[0008] To achieve the above purpose, the technical route adopted by the present invention is as follows:

[0009] A method for determining a camera posture comprises the following steps:

[0010] Step 1, collecting real-time measurement data of the star sensor, the gyroscope, the star sensor installation angle and the camera installation angle;

[0011] Step 2: Using the star sensor data as the reference time, synchronize the gyro, star sensor installation angle, and camera installation angle data to the time when the star sensor data is generated; the specific method is: fit a linear function using the original time data, and then obtain the data at the new time from the fitting function.

[0012] Step 3, using a dual vector method or a Quest method, using two or more star sensor optical axis vectors to construct a star sensor attitude matrix;

[0013] Step 4, using the real-time measurement result of the star sensor installation angle, correcting the star sensor constant installation matrix to obtain a new star sensor installation matrix;

[0014] The specific method is: use the Euler rotation method to express the star sensor installation angle into an attitude matrix, and then use the installation matrix multiplication method to complete the star sensor installation matrix correction.

[0015] Step 5, using the star sensor attitude matrix and the star sensor new installation matrix, obtain the attitude matrix and attitude quaternion of the satellite body coordinate system relative to the inertial coordinate system;

[0016] Step 6, using the satellite body attitude quaternion vector part and the gyro constant drift, construct a variable constant extended Kalman filter to obtain the satellite body gyro filtered attitude quaternion;

[0017] Step 7, using the real-time measurement result of the camera installation angle, correct the camera constant installation matrix to obtain a new camera installation matrix;

[0018] The specific method is: use the Euler rotation method to express the camera installation angle in matrix form, and then use the installation matrix multiplication method to complete the correction of the camera constant installation matrix.

[0019] Step 8: Use the attitude quaternion after gyro filtering of the satellite body and the new camera installation matrix to obtain the camera attitude matrix and quaternion.

[0020] The on-orbit camera attitude determination system according to the camera attitude determination method comprises a plurality of star sensors, a gyroscope, a star sensor installation angle measurement device, a camera installation angle measurement device, and a system management unit;

[0021] Each star sensor obtains the attitude quaternion Q of the star sensor measurement coordinate system relative to the inertial coordinate system, the gyroscope obtains the angular velocity of the satellite body, the star sensor installation angle measurement device obtains the change of the star sensor installation matrix, and the camera installation angle measurement device obtains the change of the camera installation matrix;

[0022] The star sensor, the gyroscope, the star sensor installation angle measuring device, and the camera installation angle measuring device respectively send their respective data to the system management unit using their own hardware data interface or bus interface;

[0023] The system management unit synchronizes the star sensor data, gyroscope data, star sensor installation angle, and camera installation angle, calculates the star sensor attitude matrix using the attitude quaternion Q value of the star sensor, calculates the new star sensor installation matrix using the star sensor installation angle and the default installation matrix, and obtains the satellite body attitude matrix; constructs a Kalman filter to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity; calculates the new camera installation matrix using the camera installation angle and the default installation matrix, and obtains the camera attitude matrix; after the system management unit completes the entire camera attitude determination, it transmits the calculation results to the ground through the satellite-to-ground link.

[0024] The simulation verification system of the camera attitude determination method includes: a dynamics simulation simulator, a camera angle simulator, a star sensor angle simulator, a star sensor simulator, a gyro simulator, a system management unit simulator, an attitude control unit simulator, and an attitude control actuator simulator;

[0025] The dynamics simulation simulator obtains dynamics simulation data and builds a closed-loop simulation system by establishing a structural thermodynamics model, an attitude dynamics model, and an orbital dynamics model. The orbital dynamics model is used to establish a satellite orbital dynamics and kinematics model and calculate the change of the satellite orbit over time. The attitude dynamics model is used to establish a satellite attitude dynamics and kinematics model and simulate the satellite attitude change process according to the output torque of the attitude control mechanism. The structural thermodynamics model simulates the satellite structure deformation according to the change of the satellite orbit and attitude and gives the change of the star sensor installation angle and the camera installation angle.

[0026] The dynamics simulation simulator sends the dynamics simulation data to the star sensor simulator and the gyro simulator, generates star sensor data and gyro data and sends them to the attitude control unit simulator, generates control instructions and sends them to the attitude control actuator simulator, and then feeds back to the dynamics simulation simulator to complete the entire closed-loop control process;

[0027] At the same time, the dynamics simulation simulator sends the dynamics simulation data to the camera installation angle simulator and the star sensor installation angle simulator, generates the camera installation angle data and the star sensor installation angle data, and sends them to the system management unit simulator together with the star sensor data and the gyroscope data;

[0028] The system management unit simulator synchronizes the star sensor data, gyroscope data, star sensor installation angle, and camera installation angle, calculates the star sensor attitude matrix using the attitude quaternion Q value of the star sensor, calculates the new star sensor installation matrix using the star sensor installation angle and the default installation matrix, and obtains the satellite body attitude matrix; constructs a Kalman filter to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity; calculates the new camera installation matrix using the camera installation angle and the default installation matrix, and obtains the camera attitude matrix; after the system management unit completes the entire camera attitude determination, it outputs the result.

[0029] The beneficial effects of the present invention compared with the prior art are:

[0030] (1) The present invention proposes a method for preprocessing and using star sensor installation angle measurement data and camera installation angle measurement data to improve the accuracy of determining the satellite body attitude and camera attitude.

[0031] (2) The present invention is suitable for increasing the star sensor and camera installation angle measurement capabilities based on the use of star sensors and gyroscopes, thereby completing high-precision attitude determination of the satellite body attitude or the satellite camera attitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Workflow diagram of the camera pose determination method;

[0033] Figure 2 A block diagram of an on-orbit implementation method for camera attitude determination;

[0034] Figure 3 System block diagram for simulation verification of camera pose determination method. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to the accompanying drawings and examples.

[0036] A method for determining a camera posture comprises the following steps:

[0037] Step 1: Collect real-time measurement data of four instruments, namely, star sensor, gyroscope, star sensor installation angle and camera installation angle, as input. The data are generated at different times, but have time tags to clarify the exact time of the data.

[0038] Step 2: Using the star sensor data as the reference time, the three data, gyro, star sensor installation angle, and camera installation angle, need to be synchronized to the time when the star sensor data is generated to ensure the accuracy of subsequent joint processing. Specifically, the original time data is used to fit the linear function, and then the new time data is obtained from the fitting function.

[0039] Step 3: Use the optical axis vectors of two or more star sensors to construct a star sensor attitude matrix to solve the problem that the optical axis of a single star sensor has high accuracy but the horizontal axis has low accuracy. Specifically, the dual vector method or the Quest method is used.

[0040] Step 4: Use the real-time measurement results of the star sensor installation angle to correct the star sensor constant installation matrix and obtain the new star sensor installation matrix. The real-time measurement results of the star sensor installation angle are small, and are expressed as an attitude matrix using the Euler rotation method, and then the correction is completed using the installation matrix multiplication method.

[0041] Step 5: Use the star sensor attitude matrix and the star sensor new installation matrix to obtain the attitude matrix and attitude quaternion of the satellite body coordinate system relative to the inertial coordinate system.

[0042] Step 6, using the satellite body attitude quaternion vector part and the gyro constant drift, a total of 6 quantities, to construct a variable constant extended Kalman filter to obtain the satellite body gyro filtered attitude quaternion.

[0043] Step 7: Use the real-time measurement result of the camera installation angle to correct the camera constant installation matrix and obtain the new camera installation matrix. The real-time measurement result of the camera installation angle is small, so it is expressed in matrix form using the Euler rotation method, and then the installation matrix multiplication method is used to complete the correction.

[0044] Step 8: Use the satellite body filtered attitude quaternion and the camera new installation matrix to obtain the camera attitude matrix and quaternion.

[0045] Embodiment 1:

[0046] Combination Figure 1 , the camera posture determination method steps are as follows:

[0047] Step 1: Obtain the on-orbit real-time measurement data of the star sensor, gyroscope, star sensor installation angle, and camera installation angle. The quaternions measured by star sensor 1 and star sensor 2 are Q_STS1 and Q_STS2, the gyroscope angular velocity measurement value is wm, and the three-axis installation angle changes of star sensor 1, star sensor 2, and camera are deltaphi_sts1, deltaphi_sts2, and deltaphi_cm, all of which are 3D vectors.

[0048] Step 2: Preprocess the data of star sensor, gyroscope, star sensor installation angle, and camera installation angle. Fit a linear function and take the data at the synchronized time point as the result.

[0049] Step 3: Calculate the optical axis pointing r_sts1 of the measurement coordinate system of star sensor 1 in the inertial space coordinate system. And calculate the optical axis pointing r_sts2 of the measurement coordinate system of star sensor 2 in the inertial space coordinate system. Obtain the attitude matrix S of the star sensor. The formula is as follows:

[0050] r_sts1=quat2dcm(Q_STS1)·[0;0;1];

[0051] r_sts2=quat2dcm(Q_STS2)·[0;0;1];

[0052] M=cross(r_sts1,r_sts2) / norm(cross(r_sts1,r_sts2));

[0053] L=(r_sts1+r_sts2) / norm((r_sts1+r_sts2));

[0054] K = cross(M,L);

[0055] S = [KLM];

[0056] Step 4: Use the installation matrix Msts1 of the star sensor 1 measurement coordinate system relative to the satellite body coordinate system, and the installation matrix Msts2 of the star sensor 2 measurement coordinate system relative to the satellite body coordinate system. Calculate the optical axis pointing r_BD1 of the star sensor 1 measurement coordinate system in the satellite body coordinate system, and the optical axis pointing r_BD2 of the star sensor 2 measurement coordinate system in the satellite body coordinate system; finally obtain the new installation matrix Sbase of the star sensor, the formula is as follows:

[0057] Among them, deltaphi_sts1 = [0.00031, 0.00062, 0.00011], deltaphi_sts2 = [0.00032, 0.00042, 0.00025] obtained in real time, and the installation angle accuracy of the corrected new installation matrix of the star sensor is improved by about 1 to 2 arc minutes.

[0058] r_BD1=Msts1·[1 0 0; 0cos(deltaphi_sts1(1))-sin(deltaphi_sts1(1)); 0sin(deltaphi_sts1(1))cos(deltaphi_sts1(1))]·[cos(deltaphi_sts1(2))0sin(deltaphi_sts1(2)); 0 1 0;-sin(deltaphi_sts1(2))0cos(deltaphi_sts1(2))]·[0;0;1];

[0059] r_BD2=Msts2·[1 0 0; 0cos(deltaphi_sts2(1))-sin(deltaphi_sts2(1)); 0sin(deltaphi_sts2(1))cos(deltaphi_sts2(1))]·[cos(deltaphi_sts2(2))0sin(deltaphi_sts2(2)); 0 1 0;-sin(deltaphi_sts2(2))0cos(deltaphi_sts2(2))]·[0;0;1];

[0060] Mbase=cross(r_BD1,r_BD2) / norm(cross(r_BD1,r_BD2));

[0061] Lbase=(r_BD1+r_BD2) / norm((r_BD1+r_BD2));

[0062] Kbase = cross(M,L);

[0063] Sbase=[Kbase Lbase Mbase];

[0064] deltaphi_sts1(i) represents the i-th element in deltaphi_sts1, i=1,2,3;

[0065] deltaphi_sts2(i) represents the i-th element in deltaphi_sts2, i=1,2,3;

[0066] Step 5: Calculate the satellite body attitude matrix;

[0067] Input and variable description:

[0068] Using the star sensor attitude matrix S and the star sensor new installation matrix Sbase, we can obtain the attitude matrix O_BD of the satellite body coordinate system relative to the inertial coordinate system and the corresponding quaternion Q_BD. The formula is as follows:

[0069] O_BD=S·Sbase T ;

[0070] Q_BD=dcm2quat(O_BD);

[0071] Step 6: Use the quaternion measurement value qm of the satellite body coordinate system relative to the inertial coordinate system, i.e., Q_BD, and the angular velocity measurement value wm of the satellite body coordinate system relative to the inertial coordinate system to obtain the quaternion filtered value qEKF and the gyro constant drift estimate bhat of the satellite body coordinate system relative to the inertial coordinate system after filtering.

[0072] Step 7: Use the camera three-axis installation angle change deltaphi_cm and the installation matrix Mf of the camera coordinate system relative to the satellite body coordinate system to obtain the new camera installation matrix Mfnew; the formula is as follows.

[0073] Among them, deltaphi_cm=[0.00012, 0.00031, 0.00015] obtained in real time, and the installation angle accuracy of the corrected camera new installation matrix is ​​improved by about 1 arc minute.

[0074] Mfnew=Mf·[1 0 0; 0cos(deltaphi_cm(1))-sin(deltaphi_cm(1)); 0sin(deltaphi_cm(1))cos(deltaphi_cm(1))]·[cos(deltaphi_cm(2))0sin(deltaphi_cm(2)); 0 1 0; -sin(deltaphi_cm(2))0cos(deltaphi_cm(2))]·[cos(deltaphi_cm(3))-sin(deltaphi_cm(3))0; sin(deltaphi_cm(3))cos(deltaphi_cm(3))0; 0 0 1];

[0075] deltaphi_cm(j) represents the jth element in deltaphi_cm, j = 1, 2, 3;

[0076] Step 8: Use the satellite body coordinate system attitude quaternion qEKF, the satellite body coordinate system attitude matrix O_BDfilter, and the camera new installation matrix Mfnew to obtain the camera attitude matrix O_CM and quaternion Q_CM. The formula is as follows:

[0077] The final obtained Q_CM = [-0.12727493 0.714286049 -0.636473081 -0.261718239], compared with before the installation angle correction, the overall accuracy is improved by about 2 arc minutes.

[0078] O_BDfilter=quat2dcm(qEKF);

[0079] O_CM=Mfnew·O_BDfilter;

[0080] Q_CM=dcm2quat(O_CM);

[0081] The basic functions used in the above embodiments are all general functions, which are briefly described as follows:

[0082] cross() is the vector cross multiplication function;

[0083] norm() is the modulus function of the vector;

[0084] quat2dcm() is the quaternion to attitude matrix function;

[0085] dcm2quat() is a function that converts attitude matrix to quaternion.

[0086] Combination Figure 2 , an on-orbit attitude determination system of a camera attitude determination method, comprising:

[0087] The star sensor can obtain the attitude quaternion Q of the star sensor measurement coordinate system relative to the inertial coordinate system, the gyroscope can obtain the angular velocity of the satellite body, the star sensor installation angle measurement device can obtain the change of the star sensor installation matrix, and the camera installation angle measurement device can obtain the change of the camera installation matrix. The above four devices use their own hardware data interface or bus interface to send to the system management unit. In the system management unit, various types of data are first pre-processed by time synchronization. Then the star sensor attitude matrix is ​​calculated using the star sensor Q value, and the new installation matrix is ​​calculated using the star sensor installation angle and the default installation matrix, so as to obtain the satellite body attitude matrix. The Kalman filter is constructed to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity. The new installation matrix is ​​calculated using the camera installation angle and the default installation matrix, so as to obtain the camera attitude matrix. After the system management unit completes the entire camera attitude determination, the calculation result is transmitted to the ground through the satellite-to-ground link.

[0088] Combination Figure 3 ,The simulation verification system of the camera attitude determination method is as follows:

[0089] A closed-loop simulation system is constructed by establishing three main simulation models, namely, a structural thermodynamic model, an attitude dynamics model, and an orbital dynamics model. The orbital dynamics model is used to establish orbital dynamics and kinematics models, that is, a calculation model of the satellite orbit change over time. The attitude dynamics model is used to establish dynamics and kinematics models, and simulate the satellite attitude change process according to the output torque of the attitude control mechanism. The structural thermodynamics model is used to simulate the structural deformation in combination with the changes in orbit and attitude, and give the changes in the installation angle of the star sensor and the camera.

[0090] The dynamic simulation data is given to the star sensor simulator and gyro simulator to generate star sensor data and gyro data. It is further given to the attitude control unit simulator to generate control instructions and send them to the attitude control actuator simulator to complete the entire closed-loop control process.

[0091] At the same time, the dynamic simulation data is also given to the camera installation angle simulator and the star sensor installation angle simulator to generate the camera installation angle data and the star sensor installation angle data. Together with the star sensor data and the gyroscope data, they are sent to the system management unit simulator;

[0092] The system management unit simulator synchronizes the star sensor data, gyroscope data, star sensor installation angle, and camera installation angle, calculates the star sensor attitude matrix using the attitude quaternion Q value of the star sensor, calculates the new star sensor installation matrix using the star sensor installation angle and the default installation matrix, and obtains the satellite body attitude matrix; constructs a Kalman filter to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity; calculates the new camera installation matrix using the camera installation angle and the default installation matrix, and obtains the camera attitude matrix; after the system management unit completes the entire camera attitude determination, it outputs the result.

[0093] Parts of the present invention that are not described in detail belong to the well-known technologies of those skilled in the art.

Claims

1. A camera posture determination method, characterized in that: The steps include: Step 1, collecting real-time measurement data of the star sensor, the gyroscope, the star sensor installation angle and the camera installation angle; Step 2, using the star sensor data as the reference time, synchronizing the gyro, star sensor installation angle, and camera installation angle data to the time when the star sensor data is generated; Step 3, using a dual vector method or a Quest method, using the optical axis vectors of two or more star sensors to construct a star sensor attitude matrix; Step 4, using the real-time measurement result of the star sensor installation angle, correcting the star sensor constant installation matrix to obtain a new star sensor installation matrix; Step 5, using the star sensor attitude matrix and the star sensor new installation matrix, obtain the attitude matrix and attitude quaternion of the satellite body coordinate system relative to the inertial coordinate system; Step 6, using the satellite body attitude quaternion vector part and the gyro constant drift, construct a variable constant extended Kalman filter to obtain the satellite body gyro filtered attitude quaternion; Step 7, using the real-time measurement result of the camera installation angle, correct the camera constant installation matrix to obtain a new camera installation matrix; Step 8, using the attitude quaternion after gyro filtering of the satellite body and the new camera installation matrix, obtain the camera attitude matrix and quaternion; In step 2: fit the linear function using the original time data, and then obtain the data at the new time from the fitting function; In step 4: the star sensor installation angle is expressed as an attitude matrix using the Euler rotation method, and then the star sensor constant installation matrix correction is completed using the installation matrix multiplication method; In step 7: Use the Euler rotation method to express the camera installation angle in matrix form, and then use the installation matrix multiplication method to complete the correction of the camera constant installation matrix.

2. An on-track camera attitude determination system using the camera attitude determination method according to claim 1, characterized in that: It includes several star sensors, gyroscopes, star sensor installation angle measurement devices, camera installation angle measurement devices, and a system management unit; Each star sensor obtains the attitude quaternion Q of the star sensor measurement coordinate system relative to the inertial coordinate system, the gyroscope obtains the angular velocity of the satellite body, the star sensor installation angle measurement device obtains the change of the star sensor installation matrix, and the camera installation angle measurement device obtains the change of the camera installation matrix; The star sensor, the gyroscope, the star sensor installation angle measuring device, and the camera installation angle measuring device respectively send their respective data to the system management unit using their own hardware data interface or bus interface; The system management unit synchronizes the star sensor data, gyroscope data, star sensor installation angle, and camera installation angle, calculates the star sensor attitude matrix using the attitude quaternion Q value of the star sensor, calculates the new star sensor installation matrix using the star sensor installation angle and the default installation matrix, and obtains the satellite body attitude matrix; constructs a Kalman filter to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity; calculates the new camera installation matrix using the camera installation angle and the default installation matrix, and obtains the camera attitude matrix; after the system management unit completes the entire camera attitude determination, it transmits the calculation results to the ground through the satellite-to-ground link.

3. The simulation verification system of the camera posture determination method according to claim 1, characterized in that: include: Dynamics simulation simulator, camera angle simulator, star sensor angle simulator, star sensor simulator, gyroscope simulator, system management unit simulator, attitude control unit simulator, attitude control actuator simulator; The dynamics simulation simulator obtains dynamics simulation data and builds a closed-loop simulation system by establishing a structural thermodynamics model, an attitude dynamics model, and a track dynamics model; The orbital dynamics model is used to establish the satellite orbital dynamics and kinematics model and calculate the change of the satellite orbit over time. The attitude dynamics model is used to establish the satellite attitude dynamics and kinematics model and simulate the satellite attitude change process according to the output torque of the attitude control mechanism. The structural thermodynamics model simulates the satellite structure deformation according to the change of the satellite orbit and attitude and gives the change of the star sensor installation angle and the camera installation angle. The dynamics simulation simulator sends the dynamics simulation data to the star sensor simulator and the gyro simulator, generates star sensor data and gyro data and sends them to the attitude control unit simulator, generates control instructions and sends them to the attitude control actuator simulator, and then feeds back to the dynamics simulation simulator to complete the entire closed-loop control process; At the same time, the dynamics simulation simulator sends the dynamics simulation data to the camera installation angle simulator and the star sensor installation angle simulator, generates the camera installation angle data and the star sensor installation angle data, and sends them to the system management unit simulator together with the star sensor data and the gyroscope data; The system management unit simulator synchronizes the star sensor data, gyroscope data, star sensor installation angle, and camera installation angle, calculates the star sensor attitude matrix using the attitude quaternion Q value of the star sensor, calculates the new star sensor installation matrix using the star sensor installation angle and the default installation matrix, and obtains the satellite body attitude matrix; constructs a Kalman filter to complete the joint filtering of the attitude quaternion and the gyroscope angular velocity; calculates the new camera installation matrix using the camera installation angle and the default installation matrix, and obtains the camera attitude matrix; after the system management unit completes the entire camera attitude determination, it outputs the result.

Images