A Biped Pattern Generation Allowing Immediate Modification of Foot Placement in Real-time

This paper proposes a method of a real-time gait planning for biped robots which can change stride immediately at every step. Based on an analytical solution of an inverted pendulum model, the trajectories of COG (center of gravity) and ZMP (zero-moment point) are parameterized by polynomials. Since their coefficients can be efficiently computed with given boundary conditions, this framework can provide a real-time walking pattern generator for biped robots. To handle the unexpected result caused by immediate changes of foot placement, we made single support periods as an additional trajectory parameter. The effectiveness of our method is shown by simulations of the humanoid robot HRP-2