Development of a compact and bidirectional mechanism to amplify the displacement of piezoelectric actuator

Abstract

This paper proposes a compact and bidirectional mechanism to amplify the displacement of the piezoelectric actuator. The piezoelectric actuator is compact, fast, and precise, but its small displacement limits its application. Although the displacement amplification mechanism is often used to obtain large displacement, its output is one-directional. In the conventional studies, bidirectional motion was achieved by antagonistic arrangement of this mechanism after displacement amplification. However, this design make the whole mechanism bulky. To realize the compact design, this paper applies the displacement amplification mechanism after antagonistic arrangement of the actuators. To control the mechanism’s displacement, we constructed the feed-forward controller by using a polynomial function. Through experiments, the complementary input voltage reduces the effect of dead zone due to the clearance at the attachment of the actuators. Additionally, we validated that our design enables bidirectional motion.