Safe Human Robot-Interaction using Switched Model Reference Admittance Control

TL;DR

This paper introduces a novel switched model reference admittance control method to ensure safe and compliant physical human-robot interaction by maintaining safety constraints and trajectory compliance in manipulators.

Contribution

It develops a switched reference model with stability analysis using CQLF, ensuring safe and compliant pHRI, validated through simulation on a two-link robot.

Findings

Effective safety constraint enforcement in pHRI

Stable trajectory tracking with the proposed controller

Validated approach through simulation results

Abstract

Physical Human-Robot Interaction (pHRI) task involves tight coupling between safety constraints and compliance with human intentions. In this paper, a novel switched model reference admittance controller is developed to maintain compliance with the external force while upholding safety constraints in the workspace for an n-link manipulator involved in pHRI. A switched reference model is designed for the admittance controller to generate the reference trajectory within the safe workspace. The stability analysis of the switched reference model is carried out by an appropriate selection of the Common Quadratic Lyapunov Function (CQLF) so that asymptotic convergence of the trajectory tracking error is ensured. The efficacy of the proposed controller is validated in simulation on a two-link robot manipulator.