Design of squeezing-tube-driven pump for soft pneumatic robotics based on spiral spring winding

Aiming at the demand for high-speed, easy-controllability, and integration of pneumatic soft robots and elastomer actuators, this study presents a squeezing-tube-driven pump (STDP) for soft pneumatic robotics based on spiral spring winding. This concept contains a customized spiral spring and a pneumatic tube with high-elasticity. The spiral spring is driven by an electric motor and coerced into winding deformation. Furthermore, the pneumatic tube is extruded by the spring and then the air in the tube is fast compressed to drive soft pneumatic grippers. The mechanical model and simulation are utilized to explain the operating principle of STDP. The air pressure and rotation angle of the spring under various rotation speeds are in a close linear correlation verified by the experimental results, which provides feasibility for easy controlling and rapid actuation. Finally, fast-gripping tests with an integrated gripper-pump system and a pneumatic muscle actuation test are presented to show the advantages of the proposed pump, respectively.