MANEUVERING OPERATIONS OF A QUADRUPED WALKING ROBOT ON A SLOPE

We discuss how to prevent a quadruped walking robot from tumbling over when operating on a slope. In the process of tumbling, the potential energy of the center of gravity goes through a maximum. The larger the difference between the potential energy of the center of gravity of t he initial position and that of this maximum, the less the robot tumbl es. So this difference can be regarded as the stability margin and a n ovel gait to obtain the largest stability margin is mentioned here. It is nothing but the intermittent crawl gait whose posture is illustrat ed in this paper. In addition, the energy stability contour, drawn by connecting equal stability points on the inclined plane, is also expla ined in this paper and it is a helpful tool for designing standard foo t trajectories. An optimal posture on the slope designed in this way r esults in an inverse trapezoid shape, which means that the upper two l egs are located wider than lower two ones. This form worked for the ex perimental machine, TITAN VII. Furthermore, if the standard trajectory for one direction is combined with another direction trajectory, the quadruped robot can easily change directions, maintaining a sufficient stability margin. This sequence is shown in the last part of this pap er.