The superior mobility and function of W-Climbot — A bio-inspired modular biped wall-climbing robot

W-Climbot is an inchworm-like biped wall-climbing robot we developed with a modular approach. Consisting of five joint modules and two suction modules, the robot is actually a mobile 5-DoF manipulator with dual sucking end-effectors at the two ends. With this kinematic structure and biped climbing mode, W-Climbot has superior wall-climbing function (great ability to omni-directional locomotion, to negotiate obstacles on the walls and to transit between walls) and manipulation function. In this paper, the robot system is first introduced, suction force in one critical case is analyzed for climbing reliability and safety, and three climbing gaits are presented. To illustrate its superior 3-D mobility, a series of experiments (climbing on a vertical exterior surface with different gaits, negotiating obstacles, and transiting among interior surfaces) are carried out. Performing a pick-and-place task on a wall is also demonstrated as one of its the potential applications. The results show that W-Climbot is a significant advancement in development of wall-climbing robots.