Miniature resonant ambulatory robot

This article describes the design, manufacture and performance of a prototype miniature resonant ambulatory robot (MinRAR V1) that uses piezoelectric actuators to achieve locomotion. Each leg is comprised of two piezoelectric bimorph benders, joined at the tip by a flexure and end-effector. Combinations of amplitude and phase can be used to produce a wide range of motions including swinging, and lifting. A lumped mass model previously developed is described as a design tool to tune the resonance modes of the end-effector. The completed robot was driven with frequencies up to 500 Hz resulting in a maximum forward velocity of approximately 520 mm/s at 350 Hz. A frequency analysis was also performed to determine the effects of ground contact on the performance of the robot. This analysis showed a significant reduction in the resonance gain and frequency.