A method to reduce the sliding force on adhering points of caterpillar climbing robot

Due to the sliding force arising from the closed chain mechanism among the adhering points of a climbing caterpillar robot (CCR), a sliding phenomenon will happen at the adhering points, e.g. the vacuum pads or claws holding the surface. This sliding force makes the attachment of the robot unsteady and reduces the motion efficiency. According to the results of the bionic research, some flexible structures based on natural rubber bars are applied in the CCR, which was originally composed of only rigid parts. This paper establishes the static model of the sliding forces, the distortion of flexible bars and the driving torques of joints firstly. Then, the paper designs a method to reduce the sliding force by exerting a compensating angle to an active joint of the CCR. The analyses and experimental results indicate that the flexible structure and the compensating angle method can reduce the sliding forces remarkably.