A Novel Crawling Robot Based on the Hexagonal Mesh Structure and Enhanced PID Control Strategy

ABSTRACT The locomotion of crawling robots is similar to that of caterpillars, relying on foot adhesion and body contraction to ensure flexible movement without compromising stability. However, most existing pneumatic soft crawling robots are incapable of simultaneously achieving forward, backward, turning, and climbing capabilities. To address this issue, this paper proposes a novel soft crawling robot that combines a hexagonal mesh structure with an adhesion mechanism and the enhanced PID control strategy. The innovative structural design ensures the implementation of the robot's locomotion functions. Notably, this study represents the first application of the Whale Optimization Algorithm to optimize the parameters of a PID controller for crawling robots. The results indicate that the optimized controller achieves significantly shorter rise time, overshoot, peak, and settling time compared to other intelligent optimization algorithms. During the experimental phase, a road circuit consisting of straight movement, lateral parking, reverse entry, and S‐shaped turns successfully validated the robot's capabilities in forward, backward, and turning bending locomotion. Additionally, the robot demonstrated its ability to climb inclined surfaces at angles of 10°, 30°, 45°, and 60°, as well as 90° glass surfaces. Experimental results confirm that the proposed soft crawling robot exhibits exceptional locomotion capabilities and holds significant practical potential. The integration of its unique hexagonal mesh structure with an enhanced PID control strategy enables faster and more precise bending movements, offering both theoretical insights and practical foundations for future research in crawling robot control.