Flatness-based control of an electrostatic torsional micro-mirror with voltage feedback

Electrostatic micro-mirrors are typically modelled in terms of the tilt angle, the angular velocity, and the electrical charge on the device. Although from a theoretical point of view this is a convenient choice, it is not practical due to the ensuing low resolution and the complexity of implementation related to charge measurement. The present paper addresses the practical control of a micro-mirror with the voltage across the device as a state variable. The technique of flat systems is employed to construct a closed-loop scheme for tracking control. Experimental testing results conducted on a scanning micro-mirror demonstrate that the developed control scheme can achieve good performance.