State-Space Control of a H-Bridge-Based Switching Driver with Energy Recovery for MEMS Actuators

Growing interest for piezoelectric MEMS actuators lead to the design of novel driver topologies along with proper control loops. In this work a state-space based control for an energy-recovery, switching driver is presented, considering its multivariable, non-linear, and discontinuous nature. To track large-dynamic references (e.g., 100-V, 200-Hz waveforms), four driver working-modes, and therefore four plant models, are derived. For each one, a triplet of LQR controllers is designed, linked through a gain-scheduling methodology. A Discontinuity Handler is implemented to manage the working phase change. The closed-loop system, along with most of the relevant non-idealities, is implemented and tested in Simulink, tracking a 56-V peak reference signal with 2.9-mV RMS error for the 10%-90% of the full-scale which represents a harsh scenario for continuous-time topologies.