A Morphing Wing used Shape Memory Alloy Actuators New Control Technique with Bi-positional and PI Laws Optimum Combination - Part 1: Design Phase

The paper presents the design phase of the actuators control system development for a morphing wing application. Some smart materials, like Shape Memory Alloy (SMA), are used as actuators to modify the upper surface of the wing made of a flexible skin. The actuations lines control is designed and validated using a numerical simulation model developed in Matlab/Simulink. The finally adopted control law is a combination of a bi-positional law and a PI law; the control must behave like a switch between cooling phase and heating phase, situations where the output current is 0 A, or is controlled by a law of PI type. The PI controller, for the heating phase, is optimally tuned using the Ziegler-Nichols criterion and the linear model obtained using the System Identification Toolbox of Matlab. The controlled linearized system for heating phase is numerically tested in terms of time response, stability, controllability and the observability. In the actuation control design final phase, numerical simulations, based on SMA non-linear analytical model, were used for validation.