Active position control of a shape memory alloy wire actuated compositebeam

Abstract

This paper presents the design and the experimental result of theactive position control of a shape memory alloy (SMA) wire actuated compositebeam. The composite beam has a honeycomb structure with SMA wires embedded inone of its face sheets for the active actuation. The potential applications ofthis experiment include thermo-distortion compensation for precision spacestructure, stern shape control for submarines, and flap shape control foraeronautical applications. SMA wires are chosen as the actuating elements dueto their high recovery stress ({>}500 MPa) and tolerance to highstrain (up to 6%). However, SMA wires are inherently nonlinear and pose achallenge for control design. A robust controller is designed and implementedto actively control the tip position of the composite beam. The experimentset-up consists of the composite beam with embedded SMA wires, a programmablecurrent/voltage amplifier to actuate the SMA wires, an infrared laser rangesensor to detect the beam tip displacement, and a real-time data acquisitionand control system. The experimental result demonstrates the effectiveness ofthe robust control.