Fuzzy Logic Controller for a Shape Memory Alloy Tentacle Robotic Structure

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