A Specific Methodology of Creep Compensation for Piezoelectric Actuators by Open-Loop Control
Piezoelectric actuators exhibit creep behavior in open-loop operation, which may lead to unaffordable errors in high precision static positioning systems. An inversion-based compensation strategy by open-loop control is presented for reducing creep effect. The approach utilizes a nonlinear viscoelastic model to portray creep phenomenon, which consists of a linear spring, a nonlinear dashpot and a series of nonlinear Voigt elements. It is shown that for the presented creep model the step responses are very similar to the piezoelectric actuators. In order to compensate creep effect, a concept of voltage relaxation in piezoelectric actuators is proposed. And the voltage relaxation model tantamount to the inverse creep model is derived using a PID closed-loop control system. Experimental results prove that, by insertion of voltage relaxation model in open-loop operation, creep effect is attenuated markedly in piezoelectric actuators.
Sally Gao and Tina Hu
X. Wang et al., "A Specific Methodology of Creep Compensation for Piezoelectric Actuators by Open-Loop Control", Applied Mechanics and Materials, Vol. 281, pp. 141-145, 2013