Concept and Design of a Lightweight Biped Robot for Walking on Rough Terrain

Long-term evolvement enables human to achieve various locomotion on different terrains. But it is still a challenge for biped robots to walk stably on rough terrain. The purpose of this paper is to develop a lightweight biped robot adaptable to uneven ground, by integrating the inspirations obtained from human into its structure design and realization. The main design concepts of the biped robot include compliance, combination of active and passive actuation, as well as electric-pneumatic hybrid actuation. On this basis, a prototype of the biped robot which is composed of hip joints with unidirectional series elastic actuator, biomimetic knee joints, semi-passive ankle joints and stiffness adjustable feet is developed. Walking experiments on the biped robot shows that it has the ability to adapt to uneven ground with small-sized bumps in maximum height of 8 mm.