Robust adaptive tracking control of electrostatic micro-actuators with uncertainty

In this paper, a novel adaptive robust tracking control scheme for a class of single-degree-of-freedom (1DOF) electrostatic micro-actuator systems with constant parameter uncertainties and external disturbances is addressed. This control method is based on backstepping control technique and Nussbaum gain function. The derived adaptive robust controller guarantees that the closed-loop system is globally and uniformly bounded, and the tracking error is convergent to a small neighbourhood of zero. In addition, the desired performance can be achieved by an appropriate choice of design parameters of the controller, and the singular problem can be avoided. Simulation results demonstrate that the developed adaptive nonlinear tracking controller can always drive the electrostatic micro-actuator systems into prescribed orbits with good robustness and adaptability.