Abstract: On-orbit identification of the moment of inertia parameters is an important prerequisite to achieve high-precision attitude control of the combination which is combined by the active spacecraft and non-cooperative space target.With that combination,a method for on-orbit identification of inertia parameters in two steps was proposed.The first step,making the moment of inertia of X axis as a benchmark normalized the spacecraft moment of inertia matrix in order to get the special combination of inertia ratio matrix.Then the spacecraft combination attitude dynamics model was established.Based on the angular rate measurement information given by a star gyro,the extended Kalman filter method was proposed to identify all the inertia ratio parameters in about 100s and overcome the shortcomings which the simple model cannot completely identify the rotational inertia parameters information.The second step,according to the identification of the inertia ratio matrix in the first step and using the least squares algorithm,the X axis moment of inertia was obtained.The simulation example verifies the effectiveness of the method,and the identification accuracy is about 1%.

Key words: Combination spacecraft, Moment of inertia, On-orbit identification, Extended Kalman filter, Least squares