Design, Calibration, and Control of Compliant Force-sensing Gripping Pads for Humanoid Robots

TL;DR

This paper presents a low-cost, lightweight, compliant force-sensing gripping pad for humanoid robots, featuring calibration and hybrid control methods to enhance manipulation accuracy and prevent slippage.

Contribution

It introduces a novel force-sensing pad with calibration and a hybrid control framework for improved gripping and surface alignment in humanoid robots.

Findings

Effective force measurement and calibration achieved.

Hybrid control improves grip stability and alignment.

Successful demonstration on a NAO robot.

Abstract

This paper introduces a pair of low-cost, light-weight and compliant force-sensing gripping pads used for manipulating box-like objects with smaller-sized humanoid robots. These pads measure normal gripping forces and center of pressure (CoP). A calibration method is developed to improve the CoP measurement accuracy. A hybrid force-alignment-position control framework is proposed to regulate the gripping forces and to ensure the surface alignment between the grippers and the object. Limit surface theory is incorporated as a contact friction modeling approach to determine the magnitude of gripping forces for slippage avoidance. The integrated hardware and software system is demonstrated with a NAO humanoid robot. Experiments show the effectiveness of the overall approach.