Development of Wheel-leg Hybrid Climbing Robot with Switchable Permanent Magnetic Omni-wheels as Feet

Integrating wheeled and legged locomotion modes is an effective approach for climbing robots improving their mobility. In this paper, we developed a novel wheel-leg hybrid quadruped climbing robot employing permanent magnetic omni wheels with controllable adsorption states as its feet. The magnetic force of each foot (wheel-foot module) can be adjusted between 7N to 71N, which means the wheel-foot module serves as either wheel with adsorption, foot with adsorption and foot without adsorption. This design enables the robot to move omni-directionally with omni-wheels on flat planes or walking with legs on discontinuous surface of steel structures by coordinately switching the adsorption statues of different feet. The design, kinematics and control of the robot was presented. And experiments were conducted to verify the effectiveness and to exhibit the characteristics of our design.