A vertical jump optimization strategy for one-legged robot with variable reduction ratio joint

This paper proposes a vertical jump optimization strategy for a one-legged robot with consideration of its variable reduction ratio joints. Firstly, the characteristic of the joint is derived to obtain its influence on jump motion, which is similar to the reduction ratio. Secondly, referring to the joint’s characteristic, the initial posture of jumping is optimized to maximize the initial acceleration of jumping. Then, to generate the trajectory of the center of mass (CoM) and make the jump motion more efficient, nonlinear optimization of CoM is adopted with respect to human jumping data. Full-body dynamics is considered to track the trajectory with virtual force control. For flight phase, joint PD controller is adopted to decelerate and maintain the posture. A contrast simulation is implemented to demonstrate the characteristics of the variable reduction ratio joint. Vertical jump experiment on a one-legged robot platform is realized with a height of 30 cm.