Footstep Planning for Rapid Path Following in Humanoid Robots

Rapid path following is an important component of a layered planning framework to improve motion speed. A method of generating a bipedal footstep sequence that follows a designated path and maintains stability in a planar environment is proposed in this paper. It adopts a walking style with a fixed step frequency and adjusts consecutive strides by eliminating irrational stride changes. An omnidirectional moving vehicle model and the deduced inequalities are introduced to theoretically describe the inter-pace constraints. A modified backtrack search is then implemented to solve the resulting constraint satisfaction problem. Both dynamics simulations and real robot experiments show that a humanoid robot is capable of tracking various paths with rapid paces. Comparison with several alternatives verifies the superiority of this novel method in terms of rapidity.