Design of new quadruped robot with SMA actuators for dynamic walking

Abstract

This paper presents a small-sized dynamic walking quadruped robot that uses SMA actuators. Conventional dynamic walking robots have a bulky body and are usually driven by large and heavy electrical motors or hydraulic actuators in order to produce a high output torque. Thus, to resolve this problem, a new SMA actuator is proposed with attractive features, such as a high power density, small size, and light weight. To improve the small ratio of deformation and slow response time of an SMA, the proposed actuator also has a unique winding structure for the SMA wire and reversed gear mechanism. As such, a quadruped robot for dynamic walking is introduced that is equipped with twelve SMA actuators, four 3-DOF leg mechanisms, and a rigid body. The control system for the proposed robot consists of a main control board, PWM generator board, SMA driver board, and sensor interface board