Fuzzy Logic Controller for a Shape Memory Alloy Tentacle Robotic Structure

Abstract

This paper presents a fuzzy logic controller for a shape memory alloy (SMA) tentacle robotic structure. A tentacle manipulator is a manipulator with a great flexibility and a distributed mass and torque that can take any arbitrary shape. Technologically, such systems can be obtained by using a cellular structure for each element of the arm. In the first part of the paper, the mathematical model of single unit SMA actuator and conventional PI controller are presented. Secondly, a mathematical model for the proposed SMA tentacle module is described. In the final part, a fuzzy controller is developed and applied to the SMA tentacle structure. The fuzzy control strategy is based on the so-called direct sliding mode control (DSMC). A fuzzy controller is proposed and the fuzzy rules are established by using the DSMC procedures. Conventional control structures offer better performance in term of time response, but they don't guarantee repeatability without ambient temperature control