Sliding mode variable structure control study of ram-air servo system

This paper deals with the ram-air servo system, a control methodology based on the model-based control of pulse is present, which can linearize the nonlinear servo system. Pneumatic actuators exhibit highly nonlinear characteristics due to the compressibility of air, the complicity of friction and the nonlinearity of valves. To solve these problems, an integral sliding mode variable structure control scheme is proposed. An integral controller is introduced to avoid the assumption that the derivative of desired signal must be known in conventional sliding mode variable structure control. And the state observer is designed. The proposed method is verified through simulation.