Safe Force/Position Tracking Control via Control Barrier Functions for Floating Base Mobile Manipulator Systems

TL;DR

This paper presents a real-time, robust control strategy for free-floating mobile manipulators that ensures safe force and position tracking during contact with surfaces, integrating control barrier functions to handle safety constraints and uncertainties.

Contribution

It introduces a novel control approach combining control barrier functions with force/position tracking for MMSs, addressing safety and robustness under uncertainties and constraints.

Findings

Enhanced safety during contact operations

Robustness to dynamic uncertainties and disturbances

Real-time implementation demonstrated in simulations

Abstract

This paper introduces a safe force/position tracking control strategy designed for Free-Floating Mobile Manipulator Systems (MMSs) engaging in compliant contact with planar surfaces. The strategy uniquely integrates the Control Barrier Function (CBF) to manage operational limitations and safety concerns. It effectively addresses safety-critical aspects in the kinematic as well as dynamic level, such as manipulator joint limits, system velocity constraints, and inherent system dynamic uncertainties. The proposed strategy remains robust to the uncertainties of the MMS dynamic model, external disturbances, or variations in the contact stiffness model. The proposed control method has low computational demand ensures easy implementation on onboard computing systems, endorsing real-time operations. Simulation results verify the strategy's efficacy, reflecting enhanced system performance and safety.