Ladder Climbing Motion

Abstract

The pitch and roll joints which is used for this ladder climbing locomotion are shown in Fig. 6.1(a). The idlling arm and leg motion are designed in sagittal plane for avoiding the collision with any rungs.

$$ (y_{a} - y_{pos})^{2} + (z_{a}-z_{pos})^{2} = s^{2},x_{a} = 0~~~~(6.1)$$

x _a ,y _a , z _a are the reference trajectory of the hand and the foot, s is the trajectory parameter which is the half distance of climbing and y _pos , z _pos is the center of trajectory circle. The robot keeps the climbing motion with a constant distance between the torso and the ladder. The foot on the ladder has the gradient which the reaction force directs to COG and avoids sliding into the back of a ladder.