Robust Cooperative Manipulation without Force/Torque Measurements: Control Design and Experiments

TL;DR

This paper introduces two decentralized, robust control methods for cooperative robotic manipulation that do not require force/torque sensors, ensuring reliable object handling with experimental validation.

Contribution

The paper proposes novel adaptive and performance-guaranteed control protocols for multi-robot manipulation without force/torque measurements, incorporating quaternion feedback and load distribution.

Findings

Control protocols are robust to disturbances and uncertainties.

Experimental results validate the control strategies.

Decentralized control without communication is effective.

Abstract

This paper presents two novel control methodologies for the cooperative manipulation of an object by N robotic agents. Firstly, we design an adaptive control protocol which employs quaternion feedback for the object orientation to avoid potential representation singularities. Secondly, we propose a control protocol that guarantees predefined transient and steady-state performance for the object trajectory. Both methodologies are decentralized, since the agents calculate their own signals without communicating with each other, as well as robust to external disturbances and model uncertainties. Moreover, we consider that the grasping points are rigid, and avoid the need for force/torque measurements. Load distribution is also included via a grasp matrix pseudo-inverse to account for potential differences in the agents' power capabilities. Finally, simulation and experimental results with two robotic arms verify the theoretical findings.