A Stable Trot Strategy of Quadruped Robot Based on Capture Point

摘要

Trotting is a kind of dynamic moving style for quadrupedal robot, which can make the robot move in fast and efficient way. However, the posture balance and the walking stability are two difficult problems for the robot control. In this paper, the dynamic model of the robot is obtained by Lagrange method. Based on the QR decomposition of the external force mapping matrix of the support leg, the constraints consistent dynamic model is obtained. The process of the quadruped robot trot is approximated as the locomotion of the linear inverted pendulum(LIPM). Based on the principle of the capture point for the biped robot, the trajectory of the swing leg during the trot is calculated. Through the method of joint torque optimization, inverse dynamic of robot is calculated, and each joint torque is obtained. The simulation results show that the method proposed in this paper can make the quadrupedal robot trot in a stable style.