Lightweight robotic arm actuated by shape memory alloy (SMA) wires

The current paper discusses the design, modeling and control of a Light weight robotic arm actuated by Shape Memory Alloy (SMA) actuators, usable for applications such as Aerial Manipulator. Compared to servo motor based robotic arm the proposed design has an added advantage of light weight and high force to mass ratio, but further introduces the problem of nonlinearities such as Hysteresis into the system. A nonlinear dynamic model of the hysteretic robotic arm is systematically developed to perform closed loop simulations. A Joint Space control is performed using Variable Structure Control and the closed loop performance is successfully verified by simulation studies.