Design of a robust PID-control switching scheme for an electrostatic micro-actuator

In this article, a robust switching PID controller coupled to a feedforward compensator is designed for set-point regulation of an electrostatic micro-actuator. The nonlinear model of the actuator is linearized at multiple operating points and based on LMI-theory stabilizing optimal PID controllers are designed. The parameters of the PID controllers vary according to the neighborhood of the operating point and switch between the sets of the locally stabilizing PID controllers. Each PID controller stabilizes the convex hull formed by the current and neighboring linearized subsystems of the electrostatic micro-actuator indexed according to the operating point. Simulation studies are used for testing the efficiency of the suggested scheme.