Soft Rod-Climbing Robot Inspired by Winding Locomotion of Snake

Soft climbing robots have attracted much attention of researchers for their potential applications on the wall or inside the tube. However, making a soft robot climb on the outer surface of a rod or tube by agile and efficient motion has long been a challenge. Inspired by the winding climbing locomotion of arboreal snakes, a tethered pneumatic-actuated winding-styled soft rod-climbing robot that consists of two winding actuators and a telescopic actuator is proposed in this work. Based on constant curvature assumption, we develop a theoretical model to analyze the linear and bending motion of the actuators. We demonstrate that our robot can perform climbing locomotion similar to snakes, including turning around a corner along a rod, climbing a vertical rod with a maximum speed of 30.85 mm/s (0.193 body length/s), and carrying a larger payload (weight, 500 g, more than 25 times its self-weight) than existing soft climbing robots do on a vertical surface. In addition, the experimental tests exhibit the potential applications of the robot in special environments such as high-voltage cables, nuclear power plants, and underwater sites.