Robust Predictive Controller design using LMI for Satellite Attitude Control System

In this paper, a robust model predictive control (RMPC) is proposed based on model reference adaptive system (MRAS). In this algorithm, using the MRAS a combinational RMPC controller, which is called CRMPC, for three degree freedom satellite is designed such that the effect of moment of inertia uncertainty and external disturbance is compensated on the stability and performance of closed loop system. Control law is a state feedback which its gain is obtained by solving a convex optimization problem subject to several linear matrix inequalities (LMIs). To avoid the actuators saturation a linear matrix inequality is incorporated as LMI in the mentioned optimization problem. The advantages of this algorithm are needless to exact information from system’s model, robustness against model uncertainties and external disturbance. The proposed algorithm is implemented on the satellite attitude control system and the results of them are compared to generalized incremental model predictive control (GIPC) algorithm. The results show that the suggestive controller is more robust than the GIPC method.Keywords: Robust model predictive control; Linear matrix inequality; Model reference adaptive system; Satellite attitude control system.