Fuzzy PID controller design for snake robot based SMA actuators

Shape Memory Alloy (SMA) wires are currently employed in robotics, rescue operations and medical equipments. Due to advantages such as reducing the size in the application, high power-to-weight ratio, elimination of complex transmission systems and noiseless actuation, and human-machine interface, these materials are used as actuators in robotics such as snake robot. Because of hysteresis property and nonlinear behavior of SMA, control of these actuators is very complicated. In this paper, the design of control algorithms has been discussed for SMA actuators in the snake robot with 3 links, which includes PID-fuzzy controller. Gains of controllers are set so that the voltage applied to SMA wires has minimum overshoot and output of system has minimal time to achieve stability.