Research Of Worm-Like Robot Based On SMA

Worm-like robot is a biomimetic robot which is widely used in industrial production, fire department and daily life. Worm-like robot based on SMA, due to their small size, modular, cold-resistant, easy to seal and other characteristics, can troubleshoot in a very narrow occasions, pipeline inspection status; as the hidden nature, it is also a good prospect in the field of counter-terrorism and the military. Accordingly, our research has practical value and social significance.Firstly, overall design and plan gait for the worm-like robot. After studies of the low biological mechanism of movement, we make the worm-like robot similar to biological geometrid and preliminary plan its gait. According to the design, main structure of the worm-like robot includes boards and bias-SMA two-way actuator. Bias-SMA two-way actuator consists of four SMA springs and a biasing spring. Its design method is to determine SMA springs at first, then design bias spring under the SMA springs'characteristic curves. It can work with two-way: contraction or elongation.Secondly, design the control system for the worm-like robot. The control system consists of hardware and software components. Using pulse width modulation control SMA springs electric heating or cooling methods of combining control strategy. Control system uses SCM system, to generate certain cyclical dutyfactor pulse signals, which output to FET controlling SMA springs energized or not.Thirdly, use ADAMS to establish the robot model, to make the gait simulation to validate the wiggling-gait feasibility, and to optimize its gait through parametric analysis to maximize the moving displacement.Finally, manufacture the single joint worm-like robot, and then do the dutyfactor test and wiggling experiment. Through the dutyfactor test, single joint worm-like robot determines four SMA springs'contraction time against dutyfactor. Through the wiggling experiment, the average velocity of the robot comes to 0.52mm/s.