Modified feedback linearization controller for Pneumatic System

This paper presents an approach to design a nonlinear controller for a pneumatic cylinder system for which the connection port comprises a non-negligible restriction. The pressure chamber of this system is difficult to control because the servo valve and the connection port form a double restriction. This double restriction causes a singularity in the feedback linearization controller. To avoid this singularity, a modified feedback linearization controller is proposed. The Linear Matrix Inequality (LMI) approach is then used to calculate the controller gains which ensure the stability of the tracking error and the non-singularity of the control law. Simulation results show good performance of the proposed controller.