Safe Adaptive Switching among Dynamical Movement Primitives: Application to 3D Limit-Cycle Walkers

TL;DR

This paper introduces a control-theoretic framework for safely switching among dynamical movement primitives in robotic systems, demonstrated on a 3D walking robot that adapts to external disturbances.

Contribution

It presents a novel safety-aware planning method for dynamical primitives, ensuring safe execution under disturbances, with application to 3D limit-cycle walking robots.

Findings

Successfully generated safe motion plans for a 3D walking robot.

Demonstrated adaptation to persistent external forces.

Enhanced safety in primitive switching under disturbances.

Abstract

Complex motions for robots are frequently generated by switching among a collection of individual movement primitives. We use this approach to formulate robot motion plans as sequences of primitives to be executed one after the other. When dealing with dynamical movement primitives, besides accomplishing the high-level objective, planners must also reason about the effect of the plan's execution on the safety of the platform. This task becomes more daunting in the presence of disturbances, such as external forces. To alleviate this issue, we present a framework that builds on rigorous control-theoretic tools to generate safely-executable motion plans for externally excited robotic systems. Our framework is illustrated on a 3D limit-cycle gait bipedal robot that adapts its walking pattern to persistent external forcing.