An Empirical Study of Static Loading on Piezoelectric Stick-Slip Actuators of Micromanipulators

Piezoelectric stick-slip actuators have become the foundation of modern micromanipulation. Due to difficulty in closed-loop control with manipulators that use piezoelectric stick-slip actuators, methods for open-loop control with a human in the loop have been developed. The utility of such methods depends directly on the accuracy of the open-loop models of the manipulator. Prior research has shown that modeling of piezoelectric actuators is not a trivial task as they are known to suffer from nonlinearities that degrade their performance. In this paper, we study the effect of static (non-inertial) loads on a prismatic and a rotary piezoelectric stick-slip actuator, and obtain a model relating the step size of the actuator to the load. The actuator-specific parameters of the model are calibrated by taking measurements in specific configurations of the manipulator. Results comparing the obtained model to experimental data are presented.