A Piezoelectric Unimorph Actuator Based Precision Positioning Miniature Walking Robot

Abstract

This paper proposes a precision positioning miniature walking robot using piezoelectric unimorph actuators. The theoretical working equations of a uniform piezoelectric unimorph beam are derived based on the linear piezoelectric relations, Hamilton’s principle, and Euler-Bernoulli beam equation. The modal superposition method is used to determine the response of the forced transverse vibration of the beam under the effect of electrical signal inputs to the patterned piezoelectric element. Two standing waves corresponding to the third and fourth bending vibration modes are utilized to achieve the bi-directional walking mechanism for a miniature positioning robot. Design strategies and the fabrication method for the proposed walking robot are introduced. Preliminary performance tests of the robot prototype are carried successfully, and the robot can move forward with the speed of 5.86 cm/sec velocity and backward with 3.37 cm/sec.