Closed-Chain Manipulation of Large Objects by Multi-Arm Robotic Systems

TL;DR

This paper introduces an innovative regrasping move called 'IK-switch' that enhances multi-arm robotic manipulation of large objects by enabling transitions across disconnected configuration space components, facilitating complex tasks.

Contribution

The paper presents the 'IK-switch' move and associated methods to improve multi-arm manipulation planning for large objects with closed kinematic chains.

Findings

Enables flipping a chair frame using multi-arm robots.

Improves connectivity in configuration space for complex tasks.

Demonstrates successful manipulation of large objects with new planning strategies.

Abstract

Closed kinematic chains are created whenever multiple robot arms concurrently manipulate a single object. The closed-chain constraint, when coupled with robot joint limits, dramatically changes the connectivity of the configuration space. We propose a regrasping move, termed "IK-switch", which allows efficiently bridging components of the configuration space that are otherwise mutually disconnected. This move, combined with several other developments, such as a method to stabilize the manipulated object using the environment, a new tree structure, and a compliant control scheme, enables us to address complex closed-chain manipulation tasks, such as flipping a chair frame, which is otherwise impossible to realize using existing multi-arm planning methods.