Mechanism Design and Leg Kinematics Analysis of Four-Legged Robot

Aiming at the shortcomings of serial quadruped robot, such as small load/dead weight ratio and large moment of inertia of the legs, a new quadruped robot with serial-parallel coupling mechanism is designed. The hybrid leg mechanism can realize the change in rotating pair to moving pair through redundant drive, and has the characteristics of stable movement, large work space range, strong bearing capacity and large stiffness. Firstly, the degree of freedom of the mechanism is analyzed, and its position and velocity kinematics are analyzed. The foot position of the leg was analyzed by positive and negative kinematics solutions. MATLAB and SOILDWORKS software are used for theory and simulation verification of the foot movement space; the kinematics simulation of the leg mechanism is carried out by ADAMS software, and the displacement, velocity and acceleration curves of the foot end are obtained. The results show that the motion speed of the mechanism is stable and there is no obvious mutation. This study has important guiding significance for the dynamics and gait planning of the follow-up leg mechanism.