Vibration and Position Tracking Control of a Flexible Beam Using SMA Wire Actuators

Abstract

This paper presents vibration and position control of a flexible beam structure by adopting shape memory alloy (SMA) wire actuators. The governing equation of motion of the proposed flexible structure is obtained via Hamilton's principle. The dynamic characteristics of the SMA wire actuator are experimentally identified and incorporated with the governing equation to furnish a control system model in the state space. Subsequently, a sliding mode controller which has inherent robustness to external disturbances and parameter uncertainties is formulated. The controller is then empirically realized for vibration control with relatively large tip displacement. In addition, tip position tracking control to follow desired trajectories with low-frequency sine and square waves is undertaken. Control performances such as tracking error are evaluated through both computer simulation and experimental investigation in time domain.