A small and fast piezo-actuated legged robot

摘要

In this paper we present the development of a small and fast LIPCA-actuated mobile robot. LIPCA (Lightweight Piezoceramic Composite curved Actuator) is a piezo-composite actuator that uses a PZT layer sandwiched between composite materials of carbon/epoxy and glass/epoxy layers to amplify the displacement. Three versions of LIPCA robots have been developed thus far to implement a small and autonomous robot. The design of the first prototype was inspired by a six-legged insect like a cockroach. Its maximum speed is 173 mm/sec with the voltage input of 400 Vpp at 40 Hz frequency. As the result of a slight modification in the design, a faster LIPCA robot was developed. However their structures are not strong enough to carry a load heavier than 20 gram, which can be a major obstacle to implementing autonomous robots. By several changes in the mechanism, the LIPCA-actuated robot has been improved such that it is able to carry a weight as much as 60 gram. For all the prototypes we used two LIPCA strips that are placed oppositely in the middle of the robot body. The LIPCA strips are driven by a square signal function of high AC voltage with the phase difference of 180°. All the experimental results show a possibility of a small and fast walking robot actuated by LIPCA without using any conventional electromagnetic actuator.