Feedforward and feedback dynamic trot gait control for a quadruped walking vehicle

To realize dynamically stable walking for a quadruped walking robot, the combination of the trajectory planning of the body and leg position (feedforward control) and the adaptive attitude control using sensory information (feedback control) is indispensable. In this paper, we initially propose a new trajectory planning for the stable trot gait named 3D sway compensation trajectory, and show that this trajectory has lower energy consumption than the conventional sway trajectory that the authors have proposed. Next, as the adaptive attitude control method used during the 2- leg supporting phase of the trot gait, we consider four methods: a) rotation of body along the diagonal line between supporting feet, b) translation of body along the perpendicular line between supporting feet, c) vertical swing motion of recovering legs, and d) horizontal swing motion of recovering legs. The stabilization efficiency of each method is verified through computer simulation and the damping experiment using a quadruped wal king robot, TITAN-VIII. Furthermore, the dynamic trot gait control that combines the feed- forward control based on the proposed 3D sway compensation trajectory and the adaptive feedback control using body translation and vertical motion of swing legs is developed, and the walking experiment on rough terrain using TITAN-VIII is carried out.