Hysteresis Compensation of a Piezoelectric-Stack-Actuator-Driven System
What is it about?
This paper compares tracking performances of the inverse hysteresis model-based feedforward compensator and the feedback-feedforward combined controller for the time-varying hysteresis nonlinearity of a piezoelectric-stack-actuator-driven (PSA-driven) system.
Why is it important?
Three different inverse hysteresis models, including Bouc-Wen, polynomial, and Prandtl-Ishlinskii (PI), are adopted to design feedforward compensator for the PSA-driven compliant system. Particle swarm optimization (PSO) scheme is employed to estimate model parameters of the Bouc-Wen and PI hysteresis models, respectively, whereas the least-mean-square-error based criterion is utilized in identifying the polynomial-based hysteresis model. Although solely feedforward compensation approach seems workable for systems with rate-independent hysteresis or slow tracking trajectories, large modeling errors are inevitable when fast trajectory or rate-dependent hysteresis is facing. To improve tracking performances, conventional PID control is augmented to the feedforward controllers. The resultant scheme is denoted as the feedback-feedforward combined control.