Semi-Passive Walk and Active Walk by One Bipedal Robot

We developed a robot which can do both of active walking (all joints are actively controlled by actuators) and semi-passive walking (hip joints are passive and spring attached). In this paper, we summarize three technologies to achieve the development. The first one is small and high-strength clutch mechanism to sustain massive weight of lifesize robot. The second one is semi-passive walk controller to consider passive joint dynamics. The last one is model parameter identification considering not only body parameters but also environment ones such as ground slope to achieve unstable motion similar to simulated result in real world.