Sliding mode observer based adaptive control of a VGT single acting pneumatic actuator

In this paper, we have considered a novel sliding mode friction observer based control for a servo pneumatic actuator system. The model is obtained to incorporate friction and aerodynamic force related effects, such as hysteresis, using LuGre friction model. A sliding mode observer is proposed to estimate the internal friction state of the LuGre model. In order to compensate for parametric uncertainties and aerodynamic force effects, an adaptive control law for the VGT pneumatic actuator is also designed. The stability of the controller is analyzed with the Lyapunov candidate function. A comparative study with experimental results shows the effectiveness of the proposed controller.