Development and control of new legged robot QUARTET III - from active walking to passive walking

We introduce a newly developed legged robot QUARTET III. Two direct drive motors are mounted on the robot as a main actuator. Therefore, this robot can walk both actively and passively. We also propose a new control law for the robot on a slight slope. The strategy of the control scheme is as follows. At the beginning of the walking, the robot walks with actuator. Then after a while the control input gradually decrease. Finally, the robot walks passively. The effectiveness of the control law is shown through simulations and experiments