Abstract
This paper discusses two high-speed and high-accuracy positioning actuators for magnetic recording test stands. Both actuators consist of two multilayer piezoelectric elements (PZTs) and a displacement amplifier which amplifies the displacement of the PZT. One of them has been designed with a diamond-shaped link mechanism with flexure hinges which is adopted as the displacement amplifier. The other one has been designed with a shape optimization method in which the shape of the displacement amplifier is defined like as a skeleton and meats and a genetic algorithm (GA) is used to search the combination of the skeleton and meats. Both structures are axisymmetrical to two orthogonal axes. In previous studies, the effectiveness of the axisymmetrical structures has been verified in high-speed positioning actuators. The actively controlled mechanical system of each actuator has been designed by using the integrated design concept of plant and controller. In this paper, the fundamental characteristics of the two actuators are experimentally tested, and it is shown that the robustness of the actuator designed with a shape optimization method is superior to that of the actuator designed with a diamond-shaped-link mechanism.
