A FREE GAIT PLANNING METHOD BASED ON THE FOOTHOLD SEARCH STRATEGY FOR QUADRUPED ROBOT

Planning a robust free gait is an important thing to improve the terrain adaptability of quadruped robot. By using a robust free gait, quadruped robot can walk through the rough terrains with high complexity. The foothold search method is presented in this paper to search the optimum foothold for the swing foot, and the stability of the robot can be improved by using the proposed foothold search method. Furthermore, in order to ensure that quadruped robot can swing a foot forward with enough stability margin, just before the swing foot lift-off the ground, a four feet phase is added into the walking process of the robot to complete a body sway movement to enlarge the stability margin, and the Cubic Bezier curves are used to construct the COG trajectory. With the proposed free gait, the robot can walk through the rough terrains automatically and successfully. The correctness and effectiveness of the proposed method is verified via simulation.