Kinematics of 3-UPU Parallel Leg Mechanism Used for a Quadruped Walking Robot

Compared with series mechanism, the parallel mechanism has many advantages. Using the parallel mechanism as the basic leg mechanism of a walking robot, not only the payload-weight ratio can be improved, but also the robot walking stability and security performance can be enhanced. This paper proposes the application of a typical 3-UPU parallel mechanism in a quadruped walking robot. The inverse and forward position solutions of 3-UPU parallel mechanism as standing leg are obtained. Based on the first order kinematics influence coefficient matrix, the corresponding global velocity performance index of the 3-UPU parallel mechanism is analyzed. This research provides a theoretical basis of further investigation for the quadruped walking robot with parallel leg mechanism.