A low rotational inertia reconfigurable 3D thrust vector leg mechanism for legged robot capable of omnidirectional legged locomotion

The structure design of the robotic leg is a core and hot research area for legged robots. In this paper, we report a series-parallel reconfigurable 3D thrust vector leg mechanism with 3 degree-of-freedom (DOF). Upper leg is a spatial dual-parallelogram-linkages parallel mechanism, lower leg is a spatial closed-loop eight-bar mechanism. The kinematic model of the mechanism is built based on the screw theory, and the mechanism's control complexity is examined and contrasted. The kinematic performance and static performance of the leg mechanism are analyzed. A quadruped robot is built based on the proposed leg mechanism., and the omnidirectional legged locomotion is verified by simulation.