Design and structure analysis of multi-legged bionic soft robot

Inspired by the crawling behavior of crabs and their structural characteristics, this work investigates a four-legged soft robot which can climb over obstacles. Fabricating by the rubber material with super-elastic characteristics, the leg joint of the soft robot is driven to bend through the wire drawing mechanism. The leg structure of the soft robot can produce spatial motion and the four legs of the robot can move alternately through the periodic bending of the leg joint. The bending behaviors with large angle of leg joint is achieved due to different degrees of tension through the wire drawing mechanism. The hyper-elastic constitutive model is used to analyze the mechanism of the rubber part of the main body of the robot and we analyze the relationship between the pulling force of the wire drawing structure and the bending angle of the leg. Thus, the relationship between the steering gear angle and the quadruped position of the robot is obtained through the geometry. The simulation provides a simple way to optimize the main body of the robot to achieving performances such as stress, strain, and fatigue life. This work further helps in the development of soft robots which can deliver items over obstacles.