Developing a bio inspired steerable robot actuated by shape memory alloy springs

Shape memory alloy (SMA) actuators are good candidates for actuators of mechatronic systems because they can minimize the size and weight of system. In addition, developing small robots which mimic the behavior of animals in movement has been under study in recent decade. The properties of shape memory alloys make them suitable candidates for substitution of animal muscle. In this paper a solution for active locomotion of a robot is described. Inspired by inchworm locomotion, the authors present the design, development, simulation and testing of a small robot actuated by a pair of shape memory alloy springs. In contrast to other presented works in recent years, the developed mechanism is able to steer in addition to move forward. The actuation and transmission mechanisms are described in detail which shows applicability of the design. The robot is placed on a four wheels able to rotate only in one direction. Through the activation of SMAs in a pre defined plan, the robot´s configuration changes and locomotion happens. A simulation platform for observing the robot´s behavior in addition to optimizing the robot parameters has been provided. Using the platform, a plan for activation of SMAs for forward motion or steering is extracted. In order to investigate the motion ability of the robot, a set of experiments has been carried out. Experimental results verified the robot ability to move straight or steer on a common plane.