Internal force compensating method for wall-climbing caterpillar robot

The redundant driving problem is an inherent phenomenon existing in a modular caterpillar robot. To limit the internal forces arising from the redundant driving, this paper proposes a joint torque control method, which is based on an assumption that there is only one active joint in the four-link mechanism driving the climbing gait. Except the active joint, the other three joints are all considered as passive joints, whose torques tend to be zero, although they are driven by motors in reality. According to the analyses of static forces in the closed chain state, the ideal torque of named active joint is calculated, and will be followed by the joint in real climbing locomotion. The experiments reveal the reasonability and feasibility of the proposed joint control method, as well as the limitations of current prototype and control algorithm.