Bimorph-Type Optical Actuator Using PLZT Elements Position Control of Optical Actuator by On-Off Control.

Abstract

An optical actuator consisting of PLZT elements is a new type of actuator that makes active use of energy and information of light, and is inherently robust to electromagnetic noise. PLZT is an element that produces mechanical strain by the photostrictive effect when irradiated by ultraviolet light. Since displacement of the element is very small, we adopt a bimorph structure for the optical actuator to increase the displacement. In this paper, we propose an effective position control method for the bimorph-type optical actuator ; its validity is confirmed by experiments. A simple on-off control is insufficient to control the optical actuator because the mechanical shutters controlling light irradiation have a large time lag. A new control method, taking into account the dynamic responses of the optical actuator and the shutters, is introduced into the system, and improves the precision and response speed of the optical actuator.