Design, Modeling and Control of a New Robotic Module Actuated by Shape Memory Alloy Springs

Modular robotic systems provide attractive benefits in the form of re-configurable robots that can change and adapt for special tasks. Self-reconfigurable is re-configurable robot with the ability to change their framework for different missions. One way to increase robots capabilities and to achieve self-configurable robots is to develop small, powerful and dexterous modules. In this paper, a new mechanism which uses Shape Memory Alloy (SMA) spring actuators is applied to develop a robotic module. Among the proposed modular systems until now, shape memory alloys especially the spring type are rarely used as actuators. The proposed mechanism is based on antagonistic application of SMA springs which provide faster actuation response. It is shown that the module mechanism is suitable for developing modular robotic systems, such as mobile robots, snake robots, and legged robots. The design of mechanical and electrical hardware of the module in addition to the sensing and actuating system is done talented in an optimum space. The same extendable modules communicate through a common bus in order to develop a distributed system. Consequently a proper module is presented to be applied in different robotic systems. Moreover, an effective non-linear control strategy which is variable structure control is applied for controlling the position of the module. Benefits and suitability of this controller for the module different configurations is verified using simulations and experiments.