Nonlinear Control of a MEMS Optical Switch

This paper presents the development of a dynamical model of a MEMS based optical switch. The model is verified using experimental results. An inherent weakness in the use of the model for control design is the unavailability of position information at all times due to the saturated output characteristics. To counteract this problem, a nonlinear observer is designed for the saturated output system to estimate the states (both inside and outside of the saturation region) for dynamic control of the switch. The nonlinear observer is used to synthesize feedback linearization nonlinear control. The central idea of the feedback linearization control is to compensate for the nonlinearity in the system dynamics. Simulation results show that the proposed nonlinear observer and controller design approaches have not only good tracking ability and convergence but also extremely good parameter variation robustness