A Generalized Theory of Load Distribution in Redundantly-actuated Robotic Systems

TL;DR

This paper develops a comprehensive theory for load distribution in redundantly-actuated robotic systems, enabling efficient force control and identifying limitations in existing methods.

Contribution

It introduces a generalized, fully characterized model for load distribution, with explicit, scalable solutions and corrections to current approaches.

Findings

Provides explicit solutions for wrench synthesis and analysis.

Identifies shortcomings in current load distribution methods.

Demonstrates advantages through illustrative examples.

Abstract

This paper presents a generalized theory which describes how applied loads are distributed within rigid bodies handled by redundantly-actuated robotic systems composed of multiple independent closed-loop kinematic chains. The theory fully characterizes the feasible set of manipulating wrench distributions for a given resultant wrench applied to the rigid body and has important implications for the force-control of multifingered grippers, legged robots, cooperating robots, and other overconstrained mechanisms. We also derive explicit solutions to the wrench synthesis and wrench analysis problems. These solutions are computationally efficient and scale linearly with the number of applied wrenches, requiring neither numerical methods nor the inversion of large matrices. Finally, we identify significant shortcomings in current state-of-the-art approaches and propose corrections. These are supported by illustrative examples that demonstrate the advantages of the improved methods.