Fuzzy Sliding Mode Control for Hypersonic Re-entry Vehicles

This paper developed a fuzzy sliding mode controller for the attitude control of hypersonic re-entry vehicles.First,the control-oriented model of vehicles is given.Then,by combining fuzzy control theory and sliding mode control technique,a fuzzy sliding mode control method is proposed.The design of fuzzy sliding mode controller is based on a pre-designed sliding surface in the stable error phase plane.The output of the fuzzy controller is accordingly adjusted with respect to the distances between the error state and the sliding surface,which could force the system state to reach the sliding surface,in turn lead error to converge to the origin along it.Furthermore,this control design method is applied to the attitude control problem of hypersonic re-entry vehicles.Three independent fuzzy sliding mode controllers are designed for the control of angle of attack,sideslip and bank.In addition,a practical piecewise linear control allocation scheme is introduced.Finally,the simulation results show that the proposed method is feasible.