A SMA HIGH PERFORMANCE ACTUATOR FOR ROBOT HANDS

Abstract

Proposes a prototype of a high performance robotic actuator, based on shape memory alloys. The actuator prototype was designed for generating a torque of 75 Nmm. It consists of a wire with rectangular section which is driving a pulley system. A bias spring is used to preload the system. This design is to be used within the links of a human-sized multi-fingered robot hand. Therefore a highly miniaturised actuator had to be built. Resistive heating and oil cooling are used to obtain the necessary transformations. Due to the low electrical resistance of the SMA, a specially designed power amplifier has been developed. A real time position controller for this device is proposed, taking into account the hysteresis behaviour of the SMA material.