Research On The Motion Mechanism And Structure Of Aerodynamic Worm-like Flexible Crawling Robot

As the technology of bionic robots and materials develops, much attention of researchers all over the world is drawn to a novel kind of robot—soft robot. Soft robots have the ability to adapt to load and obstacles by changing their sizes and shapes at enormous range. They have an excellent flexibility to adapt to different kinds of narrow and irregular surroundings. So, soft robots have broad prospects of application in the fields of industry, military, healthcare and rescue.The existing soft robots have the problem that deformability is still not enough, response speed is slow, construction is complicated. In this paper, as the key technology, soft actuation is studied by analyzing the movement pattern of soft robot, then the characteristics of different kinds of soft actuation are compared, the structures of soft robot and actuator are designed, and the kinetic characteristics and influencing factors are studied by testing.The main research work in this paper includes:1. By studying the structures and motion mechanism of worm and analyzing the movement pattern of peristalsis,?-type and rolling type, a kinematic model was established, and influencing factors of locomobility were studied.2. A novel pneumatic soft actuator was designed which had simple structure and greate deformability by simplifying the structure model of a worm. Using the finite element analysis software, influences of the thickness of main body and rigidity of silicon rubber were studied, the parameters of actuators were optimized, so the soft actuator had greater deformability at lower air pressure.3. The mould was designed to shape the soft actuator, and influencing factors on deformability and response speed of soft actuators were studied by testing. The results showed that as the main body was thinner and the silicon rubber was softer, soft actuators had greater deformability. The variation tendencies of inflating and deflating deformation response were the same at the effective range of deformation. At the same actuating air pressure, as the main body was thicker, the deformation response speed was slower, but the increase of response time was little; for the same soft actuator, as the actuating air pressure was higher, the deformation response speed was slower. Based on the testing data, a deformation model was established.4. Using four soft actuators, a prototype of earthworm-like soft robot system was fabricated, and a velocity model was established. By testing the locomobility of soft robot, the influence of friction coefficient on speed and efficiency was analyzed. The results showed that the speed of earthworm-like soft robot was faster and the efficiency of locomotion was higher when the robot moved on more rough surface.