Mixed H2/H∞ Self-Adaptive Fuzzy Algorithm to Control Satellite Attitude

The main purpose of this paper is to propose a nonlinear H∞ and mixed 2 / H H∞ self-fuzzy algorithm to solve large-angle robust control problem. The attitude control is one of the studied problems in recent years. Under the space environment, there often exists an unpredictable interference which results some deviations of satellite’s attitude. Therefore, it needs to develop a controller still to keep the control ability to the system with respect to the uncertainty of the satellite system and unpredictable environment interference in order to achieve the required control goal and performance specification. In this paper, consider one ROCSAT-3 hardware structure, and use selffuzzy fuzzy algorithm to perform the attitude control with the time varying and uncertainty parameters. Then, we combine the nonlinear H∞ and mixed 2 / H H∞ control law to reduce the impact of the satellite’s attitude system due to external disturbance. Through simulation results, it is shown that the proposed design method can make the ROCSAT-3 system efficiently achieve the desired stability and reject the external interference. Key-Words: Nonlinear H∞ control, Nonlinear mixed / 2 H H∞ control, Self-fuzzy algorithm, Attitude control, Time varying parameter