Dynamic Compliant Walking of a Quadruped Robot: Preliminary Experiments

To increase reliability and decrease cost of legged robotic systems it is advantageous to limit actuated degrees of freedom and instead exploit passive elements, such as springs, to provide compliance. Although literature exists on the design and dynamical control of running gaits for such robotic systems, no work exists for slower modes of locomotion such as walking. This paper presents a walking controller for an under-actuated robot, Scout II, with only one actuator per leg, based on commanding a fixed front hip angle and a constant back hip horizontal velocity during stance. Using this straightforward control strategy, we show that the robot achieves stable walking using only limited feedback. Preliminary experimental results are presented and discussed.