Motion Pattern Planning of a Quadruped Robot Based on Parallel Kinematics

In this paper, kinematic analysis and motion planning of a quadruped robot are presented by regarding the robot as an equivalent parallel platform-type mechanism with RRRS limb structure. Based on screw theory, the mobility of the quadruped robot with different touchdown legs is analyzed, and proves that the design for degree of freedom (DOF) is available. Base on the established kinematic model of a single leg in terms of POE formula of screw theory, several typical patterns of walking motion planning are implemented and verified by the ADAMS-based simulation. In order to show a good maneuverability and potential manipulation capability of the quadruped robot as a parallel manipulator, the gait planning reflecting two rotating motion patterns (including the rotating motion and walking motion) is modeled and simulated by kinematics of the equivalent parallel manipulators. Finally, a prototype of the quadruped robot has been built. Experimental test shows the practical walking and rotating ability as desired.