Design, fabrication, and nonlinear control of a flexible minirobot module by using shape memory alloy actuators

Recently, the increasing need for performing intricate operations in small dimensions has motivated many researchers and industrialists to focus on minirobots. Different types of minirobots with diverse locomotive mechanisms have been designed for various applications. Modular design is a new method which is employed to fabricate small robots with more flexibility and capability. In many works, each module of modular minirobots has rotational displacement. In this article, a flexible minirobot module is developed and manufactured which can produce controlled rotational displacement. Shape memory alloy springs are applied as the actuators to provide impressively large strokes. The final fabricated flexible minirobot module is verified by the open-loop experimental tests. In order to achieve the desired maneuvers and have a perfect tracking of reference input, a nonlinear fuzzy controller is developed and implemented to control the maneuvers of flexible minirobot module. Finally, the results are discussed which show good agreement between the simulations and experimental tests.