A comparative study of position control of a SMA actuated manipulator

This paper investigates an upstanding nonlinear controller for controlling a single-degree-of-freedom shape memory alloy (SMA) actuated manipulator and proposes a novel nonlinear PID (NPID) controller suitable for real time manipulator control applications. The salient features of this controller are that it has significant effects in reducing overshoot and settling time of position tracking system. A series of experiments have been performed in tracking both stationary and periodically varied reference signals. Experimental results are presented to show the effectiveness of the proposed controller in real time applications. A linear PID and a nonlinear PID-P³ controller are also applied to the system to compare the performance.