An improved method for joint filtering of star sensor and gyroscope

Abstract

The invention discloses a method for improving star sensor-gyro federated filtering. The method comprises the following steps: step 1, constructing an extended Kalman filter and implementing an extended Kalman filtering algorithm; step 2, determining the jumping time of a measured quaternion value q<s>, i.e., an input of the xtended Kalman filtering algorithm, wherein the scalar part of the measured quaternion value is smaller than a threshold, and the current beat and the previous beat of a vector part with a greatest absolute value in the measured quaternion value have opposite signs; step 3, resetting a reference quaternion value q<^><R> at the jumping time so as to obtain a reference quaternion value fitting with the measured quaternion value at the jumping time; and step 4, continuing implementation of the extended Kalman filtering algorithm by using the reset q<^><R>. According to the invention, the reference quaternion value at the jumping time is reset so as to overcome the problem that an estimated quaternion value needs convergence anew caused by jumping of the measured quaternion value, so stable continuous high-precision attitude information is provided for an attitude determination system; and the method is simple in the algorithm, can be easily implemented by spaceborne software and has high reliability.

Description

technical field [0001] The present invention relates to an improved method of extended Kalman filtering for star sensors and gyroscopes, specifically a method for resetting the quaternion reference value when the quaternion measurement value of the filtering algorithm jumps, which belongs to satellite attitude Identify technical areas. Background technique [0002] Both the star sensor and the gyroscope are the most important sensor stand-alone in the satellite attitude control system. The measurement value of the star sensor is the quaternion of the star sensor measurement coordinate system relative to the inertial coordinate system, and the quaternion of the satellite body coordinate system relative to the inertial coordinate system can be obtained from the star sensor installation matrix; the measurement value of the gyro is The projection of the angular velocity of the gyro measurement coordinate system relative to the inertial coordinate system in the gyro measurement ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide an improved method for the combined filtering of star sensors and gyroscopes to solve the problem that the quaternion estimated value needs to re-converge when the quaternion measured value of the existing extended Kalman filter algorithm jumps

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