Control method for floating-base robots including generating feasible motions using time warping

摘要

A control method, and a robot controller implementing the method, is provided that adapts human motions to floating-base humanoid robots with time warping techniques. The method of modifying a set of reference motions modifies the timeline of a reference motion so as to speed up or slow down one or more of the motions or motion segments. Through the use of time warping, the velocity and acceleration profiles of the motion are changed to turn an infeasible motion into a feasible one. The optimal time warping is obtained through a generalized motion feasibility index that quantifies the feasibility of a motion considering the friction constraint as well as the center-of-pressure (CoP) constraint. Due to the use of the motion feasibility index, the proposed motion adaptation method taught herein can be applied to motions on arbitrary terrains or with any number of links in contact with the environment.

主权项

1. A method for controlling a floating-base robot to track given reference motions, comprising:
with a tracking controller, receiving as input a set of poses that define a motion for the floating-base robot at a time along a performance timeline; determining, with the tracking controller, whether the defined motion is infeasible for the floating-base robot; based on the determining, modifying, with the tracking controller, the set of poses whereby the defined motion becomes feasible for performance by the floating-base robot when the floating-base robot is moved through each of the poses; and after the modifying, controlling the floating-base robot with the modified set of poses, wherein the modifying comprises changing the time for performing at least one of the poses from a first time to a second time within the performance timeline, wherein the determining whether the defined motion is infeasible comprises calculating a motion feasibility index, and wherein the calculating of the motion feasibility index comprises determining whether contact forces satisfying a friction constraint generate a required wrench.