Stable running with a two-segment compliant leg

This research presents a two-segment compliant leg model for understanding fast running locomotion of animals and extending to quadruped robot later. We introduce an approach toward a full understanding of the model by investigating the energy of the system and constructing a set of data, called Limit Cycle Set. The set is computed via optimization procedures and includes all the configurations of the model that contribute to its periodic, stable running locomotion. By introducing the creative design of the configurations, the two-segment compliant model is sufficiently general to be extended to other similar two-segment leg models. Along with the computation, we investigate the system stability and discover that it is possible to achieve stability of a compliant leg in real environments with a simple control strategy. The stable motion is successfully validated in real experiments.