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 computer-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 piezoceramic actuator is modeled in the feedforward loop by using the classical Preisach model. Experiments were performed on a stacked piezoceramic actuator for tracking sinusoidal waveforms with signal frequencies ranging from 0.1-20 Hz. A comparison was made between a feedforward control scheme, a regular PID feedback control scheme, and a PID feedback control scheme with hysteresis modeling in the feedforward loop. The results show that the tracking control performance is greatly improved by augmenting the feedback loop with a model of hysteresis in the feedforward loop. The maximum error in tracking a sinusoidal waveform is about half that obtained using a regular PID controller