Biped walking and stairs climbing using reconfigurable adaptive motion primitives

Humans can reliably walk in dynamic and unstructured environments, simultaneously handle stairs and obstacles, as well as the transition from one gait to another. Despite the outstanding progress in the last decades, today's robots are still far from attaining that level of performance. This paper presents a new way of walk and stair climbing realization with a smooth transition between two types of gait. The gaits are composed of Reconfigurable Adaptive Motion Primitives (RAMPs), which serves as building blocks for any walking pattern. A human locomotion experiment is conducted to better understand how human approaches and positions the foot in front of the stairs with respect to the overall walk characteristics. These findings are used to compare the results of a simulation experiment with humanoid robot performing same locomotion as the human subject. It is shown that the robot's path or gait shape can be modified by the set of overall gait parameters that can be changed at any time instance. The robot can approach stairs with a variable number of half-steps, switch smoothly to stair climbing, and back to walking on flat surface, and modify walking speed and direction on-line as humans can do.