A unified framework for virtual passive bipedal gait generation

It is well known a fine tuned unpowered biped machine can passively walk down a gentle slope. The in-depth understanding of the passivity is helpful to design more efficient bipedal gaits. In this paper, we investigate the principle mechanism of passive dynamic walking and propose a unified framework for virtual passive bipedal gait generation. The framework shows the physical system´s kinetic energy varies inversely proportional to the imitated virtual system´s potential energy. Based on this property we propose a kinetic energy tracking control law to realize virtual passive dynamic walking on any slopes in any virtual gravity fields. Numerical simulations are given to support our proposal.