Dual-axis optical mirror positioning using a nonlinear closed-loop controller

This paper describes tilt angle control of a dual-axis optical mirror from the perspective of a fully integrated solution. Economical integration of the entire control system and high voltage drivers on-chip forces the use of simplified controllers that are realizable using standard small circuit blocks. Despite these constraints, the controller must guarantee fast 10 millisecond performance in the face of cross-axis coupling, electrostatic nonlinearity, nonlinear damping, higher order modes, and process variation. Following a brief description of mirror dynamics, a control solution conducive to integration is presented with experimental proof of concept using microprocessor control to emulate on-chip circuits.