Design and Analysis of a Snake-Inspired Crawling Robot Driven by Alterable Angle Scales

Inspired by the anisotropic friction of snakes' scales, many snake-like robots actuated by scales have been developed. However, these robots' scales' angle is unalterable, causing them to crawl in only one direction. Moreover, these robots typically require complex controllers to control their locomotion. To address these limitations, the letter proposes a crawling robot with alterable angle scales, a soft actuator, and an autonomous vibrating valve. All scales are strung on a spring wire and can rotate freely, and an airbag can easily control the rotation. The robot can crawl backward after flipping the scales' orientation. A piston located inside the vibrating valve can be periodically pushed by a reset spring and air pressure to achieve reciprocating motion, which results in periodic inflating and deflating of the soft actuator. Such that the crawling robot can move automatically. The locomotion mechanism was analyzed, and a dynamic model was built. The locomotion performance was tested by experiments. The experimental results show that both the forward and backward locomotion speed can be improved by increasing the driving pressure. When the driving pressure is 195 kPa, the robot can crawl forward and backward at the speed of 49.0 mm/s and 38.2 mm/s, respectively.