MOCA-S: A Sensitive Mobile Collaborative Robotic Assistant exploiting Low-Cost Capacitive Tactile Cover and Whole-Body Control

TL;DR

This paper introduces MOCA-S, a mobile collaborative robot with a low-cost capacitive tactile cover and advanced whole-body control, enhancing safety during physical human-robot interactions.

Contribution

It presents a novel mobile manipulator with integrated tactile sensing and new control strategies, addressing safety in collaborative mobile robotics.

Findings

Tactile sensors effectively detect interaction forces.

Proposed controllers enable safe loco-manipulation.

MOCA-S demonstrates intrinsic safety during collisions.

Abstract

Safety is one of the most fundamental aspects of robotics, especially when it comes to collaborative robots (cobots) that are expected to physically interact with humans. Although a large body of literature has focused on safety-related aspects for fixed-based cobots, a low effort has been put into developing collaborative mobile manipulators. In response to this need, this work presents MOCA-S, i.e., Sensitive Mobile Collaborative Robotic Assistant, that integrates a low-cost, capacitive tactile cover to measure interaction forces applied to the robot base. The tactile cover comprises a set of 11 capacitive large-area tactile sensors distributed as a 1-D tactile array around the base. Characterization of the tactile sensors with different materials is included. Moreover, two expanded whole-body controllers that exploit the platform's tactile cover and the loco-manipulation features are proposed. These controllers are tested in two experiments, demonstrating the potential of MOCA-S for safe physical Human-Robot Interaction (pHRI). Finally, an experiment is carried out in which an undesired collision occurs between MOCA-S and a human during a loco-manipulation task. The results demonstrate the intrinsic safety of MOCA-S and the proposed controllers, suggesting a new step towards creating safe mobile manipulators.