Improving the Performance of an Electrostatically Actuated MEMS by Nonlinear Control: Some Advances and Comparisons

Though certain control schemes, such as charge control and capacitive feedback, can extend the stable travelling range of electrostatically actuated micro-devices to the full gap, the transient behavior of actuators is dominated by their mechanical dynamics. Thus, the performance may be poor if the natural damping of the devices is too low or too high. The presented work aims at improving the performance of a parallel-plate electrostatic micro-actuator by nonlinear control. Three control schemes, based on differential flatness, control Lyapunov functions, and backstepping, are considered, which are capable of stabilizing the system while ensuring desired performances. The simulation results demonstrate the efficiency of the considered control schemes and provide some comparisons on their performance.