Quadruped robots are very popular because of their good terrain adaptability

but the poor battery life is also prominent due to high energy consumption. Wheel-footed robots are just the opposite

so wheel-legged robots came into being. The leg structure of a wheeled-legged quadruped robot is innovatively designed

which can switch freely between the wheel and foot movements according to different terrain

and it can consider the terrain adaptability and energy consumption optimization. The stable leg triangle support structure and independent suspension device are designed for the movement

which enhances the stability of the wheeled movement and the flexibility of the legs. The force analysis of the leg structure is carried out

and the key parameters of the joint motor are selected; the finite element analysis and lightweight design of the leg structure are carried out according to the output torque of the joint motor

and the inertia of the leg is well controlled. The kinematic models of the robot's foot and wheel are established. Finally

the feasibility and rationality of the wheel-foot motion of the leg structure design are verified by using the kinematics simulation.