Adaptive Vision-Based Control of Redundant Robots with Null-Space Interaction for Human-Robot Collaboration

TL;DR

This paper introduces an adaptive vision-based control scheme for redundant robots that enhances human-robot collaboration by enabling autonomous task execution and safe interaction without prior environment calibration.

Contribution

It proposes a novel control approach combining task space and null space control for redundant robots, improving safety and adaptability in human-robot collaboration.

Findings

The control scheme ensures stable and convergent task execution.

Experimental validation with AR-guided robots demonstrates effectiveness.

The method handles unknown environments and human interactions safely.

Abstract

Human-robot collaboration aims to extend human ability through cooperation with robots. This technology is currently helping people with physical disabilities, has transformed the manufacturing process of companies, improved surgical performance, and will likely revolutionize the daily lives of everyone in the future. Being able to enhance the performance of both sides, such that human-robot collaboration outperforms a single robot/human, remains an open issue. For safer and more effective collaboration, a new control scheme has been proposed for redundant robots in this paper, consisting of an adaptive vision-based control term in task space and an interactive control term in null space. Such a formulation allows the robot to autonomously carry out tasks in an unknown environment without prior calibration while also interacting with humans to deal with unforeseen changes (e.g., potential collision, temporary needs) under the redundant configuration. The decoupling between task space and null space helps to explore the collaboration safely and effectively without affecting the main task of the robot end-effector. The stability of the closed-loop system has been rigorously proved with Lyapunov methods, and both the convergence of the position error in task space and that of the damping model in null space are guaranteed. The experimental results of a robot manipulator guided with the technology of augmented reality (AR) are presented to illustrate the performance of the control scheme.