Novel algorithm of gait planning of hydraulic quadruped robot to avoid foot sliding and reduce impingement

In order to solve kinematic redundancy problems of a hydraulic quadruped walking robot, which include leg dragging, sliding, impingement against the ground, an improved gait planning algorithm for this robot is proposed in this paper. First, the foot trajectory is designated as the improved composite cycloid foot trajectory. Second, the landing angle of each leg of the robot is controlled to satisfy friction cone to improve the stability performance of the robot. Then with the controllable landing angle of quadruped robot and a geometry method, the kinematic equation is derived in this paper. Finally, a gait planning method of quadruped robot is proposed, a dynamic co-simulation is done with ADAMS and MATLAB, and practical experiments are conducted. The validity of the proposed algorithm is confirmed through the co-simulation and experimentation. The results show that the robot can avoid sliding, reduce impingement, and trot stably in trot gait.