Humanoid motion generation in a world of stairs

Consider the problem of generating humanoid motions in an environment consisting of horizontal patches located at different heights (world of stairs). To this end, the paper proposes an integrated scheme which combines footstep planning and gait generation. In particular, footsteps are produced by a randomized algorithm that guarantees both feasibility and quality of the plan according to a chosen criterion; whereas for 3D gait generation we devise an ad hoc extension of the Intrinsically Stable MPC scheme. In its basic form, the proposed scheme addresses the off-line case (known environments), but a sensor-based adaptation is developed for the on-line case (unknown environments) based on an anytime version of the footstep planner. In order to validate the proposed approach, we present simulations in CoppeliaSim for the HRP-4 humanoid robot navigating scenarios of different complexity, both in the on-line and off-line case.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).