Attitude Estimation Method for Spinning Spacecraft Using Markley Variables and Optical Flow of Stars

摘要

Markley variables has the advantages of slow varying, easy calculation and high-precision on the attitude estimation of spinning spacecraft. Most of the previous methods for spinning spacecraft using Markley variables employ the star vector or the angular velocity from gyro as the measurement. Different from the previous methods, this paper proposes an attitude estimation method for spinning spacecraft using Markley variables and optical flow of stars directly from star images of star sensor. This method makes full use of the advantages of Markley variables on the attitude estimation of spinning spacecraft, and it is computationally efficient since the optical flow of stars directly comes from star image. In addition, the star sensor has the higher accuracy of attitude estimation than the traditional sun sensor and magnetometer. Simulations using FY-2 meteorological satellite show that the estimation precision of the spin axis is 0.091° and the estimation precision of spin angular velocity is 1.72×10-4°/s when the star location error is 0.05pixels.