TRACKING CONTROL OF A PIEZOCERAMIC ACTUATOR

The tracking control accuracy of piezoceramic actuators is limited due to their inherent hysteresis nonlinearity, This paper presents a comp uter-based tracking control approach for a piezoceramic actuator based on incorporating a feedforward loop with a PID (proportional integral derivative) feedback controller. The hysteresis nonlinearity of the p iezoceramic actuator is modeled in the feedforward loop by using the c lassical Preisach model. Experiments were performed on a stacked piezo ceramic actuator for tracking sinusoidal waveforms with signal frequen cies ranging from 0.1-20 Hz. A comparison was made between a feedforwa rd control scheme, a regular PID feedback control scheme, and a PID fe edback control scheme with hysteresis modeling in the feedforward loop . The results show that the tracking control performance is greatly im proved by augmenting the feedback loop with a model of hysteresis in t he feedforward loop. The maximum error in tracking a sinusoidal wavefo rm is about half that obtained using a regular PID controller.