Structure design and motion analysis of waist of humanoid robot for jumping and crawling

It is a new research hotspot to improve the jumping and crawling ability of humanoid robot. A novel anti-impact and lightweight humanoid waist joint structure is presented. The degree of freedom of roll and pitch is provided by sphere-pin pair, and driven by two lead screws in the back. When the robot is in the upright state, the rotation axis of DoF of roll is not in the horizontal direction. It is vertical to the rotation axis of DoF of pitch, but not vertical to that of yaw. A kinematic model and corresponding rotation matrix calculation method is proposed for this structure. The motion space and attitude changes are numerically analyzed. The lengths of the screw rod with different attitudes are calculated by inverse kinematics calculation using the rotation matrix. The numerical results show that the structure can adapt to the requirements of the robot jumping and crawling on the motion space and attitude, and all the poses can be smoothly controlled.