Fuzzy controller design of a new biomimetic earthworm robot for endoscopy actuated by SMA wires

Shape Memory Alloy (SMA) wires are widely employed in robotics, as actuators of prosthetic limbs and medical equipment. Due to advantages such as reducing the size in the application, high power-to-weight ratio and elimination of complex transmission systems and compatibility with the human body, these materials are used as actuators in different types of medical robots. But hysteresis phenomenon is an unsightly effect of SMAs that its compensation is a momentous task in controlling them. In this paper, a fuzzy control system has been designed for SMA actuators in the endoscope robot with 2 segments. The controller schema is developed on the simulated system, and its efficiency is investigated. The accuracy of robot response to achieve the preferred position is examined and compared with other results. The results have shown the current applied to SMA wires has minimum overshoot and output of system has minimal time to achieve stability.