Developing a novel SMA-actuated robotic module

Unstructured environments and task based goals require varying robot configurations to fulfill the missions. Modular robotic systems are fast growing solutions for this purpose, where the robot configuration may quickly and easily be changed by connecting or disconnecting different modules. Flexibility of the modules and their degrees of freedom directly affect the overall robot agility and performance. In this paper a novel robotic module, FlexiBot (Flexible Robotic Module) with two degrees of freedom is introduced. The module incorporates shape memory alloy (SMA) springs to create relative motion between two parallel plates hinged to each other. Furthermore the module is developed in an embedded package including a moving mechanism, an electronic driver hardware, and a sensory system. SMA springs are used as the module actuators due to their ability in providing larger displacements, which make them more suitable for robotic applications. Further, the modeling of a SMA spring actuator is introduced along with the dynamic model of the FlexiBot. The model is verified against experimental results. (C) 2010 Elsevier B.V. All rights reserved.