Design of saturating attitude controller for microsatellites based on H₂/H_∞ optimization

This paper concerns the robust performance and input saturation problem for attitude control of a microsatellite, and presents a novel method for design of PID saturation attitude controllers for microsatellites based on the mixed H₂/H_∞ optimization. The method takes account of the problem that the pointing accuracy of microsatellites is vulnerable to space environmental disturbances and the internal uncertainty of moment-of-inertia variation due to its smaller size and weight, and considers the saturation problem of control actuators for its physical configuration and energy confinement, and the input uncertainty for the installation error of the actuator could also deteriorate the performance of the attitude control system, so the anti-interference performance of the attitude control system can be effectively improved. For a PID controller is feasible for spacecraft attitude control, the mixed H₂/H_∞ performance index was used to optimize the parameters of robust anti-interferential PID saturation attitude controller for microsatellites. The simulation results demonstrate that the presented controller can improve the robustness and the dynamic response performance, and the input saturation can be effectively refused.