A Study on the Attitude Determination of the KOMPSAT

다목적 실용 위성의 자세결정에 관한 연구

In this paper, an efficient attitude determination algorithm based on the Kalman Filter which combines earth/sun sensor data with gyro data in a mutually compensating manner is presented. Quaternion is used as the attitude state to save computation time and to prevent the gimbal-lock situation associated with Euler angles. Gyro data allows the use of the kinematic equation instead of space vehicle's dynamic equation which is usually based on approximation of the actual dynamics and inaccurate torque information. The gyro data are used to propagate the attitude through kinematic equation and the earth/sun sensor data are used to update the attitude and estimate the gyro bias. Simulation results for the KOMPSAT attitude determination system are presented.