DESIGN AND DYNAMICS OF A SHAPE MEMORY ALLOY WIRE BUNDLE ACTUATOR

Abstract

In this paper, the design and dynamics of a new Shape Memory Alloy (SMA) actuator that possesses impressive payload lifting capabilities are presented. This actuator consists of 48 SMA wires mechanically bundled in parallel forming one powerful muscle. The new actuator can lift up to 100 lbs., which is approximately 300 times its weight. This actuator was tested in open loop experiments with different weights and different inputs, such as step, ramp, sinusoid, and half sinusoid, and its dynamic characteristics were evaluated. Of special importance is the observed unpredictability of the actuator's response when low voltages are applied. This characteristic suggests possible chaotic behavior of the actuator, potentially causing control difficulties in fine and high accuracy tasks. 1. Introduction Robotic systems have been proposed to perform important tasks in the nuclear industry such as hazardous waste removal and decommissioning of nuclear sites [1, 2]. Since these tasks occur in a...