A Step-Climbing Strategy of Hexapod Robot with Eccentric Wheel Legs

In this paper, a design of simple and highly hexapod robot is described and a method of step-climbing is proposed. The robot structure is inspired by cockroach and it has six eccentric wheeled legs contacting with six motors through hips made by fiberglass. Its discretized gaits differ from wheeled and tracked robots who are good at flat terrain or sloping area which makes it obstacle navigation such as stairs or ditches more convenient. Gait comes from learning of six-legged insects (i.e. locomotion of cockroach) including the well-known tripod gait and the way of climbing in the outdoor environment. The process of step-climbing is described in detail and we designed an open-loop control of the gait for eccentric wheel type legs without any terrain sensing or actively controlled adaptation. In our experiment the eccentric robot performs well like the cockroaches do by achieving stable and robust locomotion traveling.