Analysis of gait and mechanical property of wall-climbing caterpillar robot

In order to demonstrate the validity and the benefit of the closed-chain kinematics of four-link motional method for the gait of wall-climbing caterpillar robot, the mathematical model and the relation of kinematical parameters were built. The caterpillar robot can climb on the wall by coordinated rotation of one active joint and three passive joints. The mechanical property of the closedchain kinematics of four-link method is analyzed. And the relation of the driving joint torque and joint angle in wallclimbing process is deduced based on coplanar arbitrary force system. The coordinated control of multiple joints and the basis for selecting driving joints were discussed for developing the wall-climbing caterpillar robot. To testify the availability of the closed-chain kinematics of four-link method, a prototype of wall-climbing caterpillar robot with three kinds of adhesion modules based on vibrating suction method is designed. A successful wall-climbing test confirms both the principles of the closed-chain kinematics of fourlink method and the validity of the adhesion modules based on vibrating suction method. The results show that the basis for selecting driving joints was reasonable and that the adhesion module based on vibrating suction method can produce powerful adsorption force with small weight and volume to ensure the safety and reliability of wall-climbing.