Dynamic stabilization and rapid motion control system driven by antagonistic shape memory alloy actuators

Abstract

The frequency response analysis of antagonistic shape memory alloy actuators and the influence of temperature, stress and strain on its speed of operation are studied and presented. Based on the decisive results an interesting servo control application is designed and tested such that the operating angle utilizes only partial strain of shape memory alloy (SMA) wire. The application developed is an open loop unstable, under actuated, a renowned highly dynamic ball balancing beam system driven by antagonistic SMA wires. The control scheme of proportional derivative controller cascaded with sliding mode controller is designed in order to demonstrate the tracking control capability of SMA wires under partial transformation. Experimental results show the motion control with significantly faster response of SMA under partial transformation. The robustness of the control system for disturbance rejection is also tested. The implication is that this design scheme can be extended to all other dynamic applications including robotics, automotive, aerospace, etc.