Research On Earthworm-like Peristaltic Micro In-pipe Robot Driven By SMA

As effective detection tools for small pipelines, micro in-pipe robots have much broader application space in the industry and medical fields. Peristaltic robots have been the hotspot in the micro in-pipe robot fields in the recent years because of their various driving modes, strong load capacity, reliable action and easy miniaturization. However, the traditional SMA peristaltic micro in-pipe robots have some disadvantages such as small pace, low velocity, not able to move in the curving pipes and so on.According to the problems existed, a new type of peristaltic micro in-pipe robot based on Shape Memory Alloy actuator is designed in this paper. The robot is made up of many same modules and can realize the peristaltic motion mechanism imitating earthworm through the regular expansions between different modules and frictions on the moving surface. The robot is driven by parallel Shape Memory Alloy actuator which is made up of three SMA springs. It can supply bigger pace, draft load and move in both horizontal pipe and curving pipe. It is suitable for the soft and narrow environment. The robot adopts improved controlling method. It can overcome the shortcomings of low extension velocity in the traditional SMA peristaltic robots and enhance the motion performance.The main work of this paper are the motion mechanism determination, comparison of different driving modes in peristaltic robots; analysis of SMA actuator characteristics and SMA spring actuators design; robot fabrication, driving circuit design and controlling method improvement. The last part of this paper is a series of experiments for the robot performance including motions on flat surface, on inclined plane and in the pipeline. It can conclude that the robot designed and fabricated in this paper has good motion performance.