Abstract: Combining the characteristics of redundant configuration of attitude sensors and unknown inertia parameters of the on orbit assembled satellites, in order to suppress the influence of sensor measurement errors and parameter uncertainty disturbance on satellite attitude, firstly a gyroscope/GPS/star sensor multisensor federal filtering algorithm is established and the residual chi square test method is used to achieve the detection, isolation and reconstruction of sensor faults, by which the attitude determination precision and result reliability are improved. On this basis, the parameter identification algorithm is used to estimate the assembly satellite inertia parameters, and the adaptive fixed time sliding mode control algorithm is proposed to improve the control precision of the sliding mode control under unknown disturbance and reduce the parameter selection range to attenuate the chattering phenomenon. Finally, the algorithm effectiveness is verified by numerical simulation, and the attitude precision and attitude stability of the assembled satellite are within 0.000 2° and 0.000 3(°)/s, respectively, indicating that the proposed algorithm can achieve high precision and high stability attitude control of the assembled satellites.

Key words: adaptive fixed time sliding mode control, federal filtering, on orbit assembled satellite