Dynamic modeling and controller design for a piezoelectric actuation system used for machine tool control

The dynamic model of a commercially available piezoelectric actuation system intended for use in a machine tool position control system is presented, and its fidelity to observed behavior evaluated. The components of the actuation system are presented and an available nonlinear dynamic model form for piezoelectric actuators, capable of representing actuator hysteresis, used as the basis for the system dynamic model. Parameters in the dynamic model are obtained from manufacturer's specifications. The resulting actuator model is combined with a nonlinear model of the amplifier, the resulting system model forming the basis of a SIMULINK simulation. System responses based on the simulation are compared with experimentally measured responses. The agreement between simulation and experimental responses is reasonably good at low frequencies, and the model is used for preliminary closed loop position control system evaluations. Specific recommendations for improvement in model accuracy are also made.