Dense Tactile Force Distribution Estimation using GelSlim and inverse FEM

TL;DR

This paper introduces GelSlim 2.0, a vision-based tactile sensor capable of real-time contact force distribution estimation using inverse FEM, with improved hardware design and high spatial resolution.

Contribution

The paper presents a new rugged, adjustable GelSlim 2.0 sensor and applies inverse FEM for accurate, real-time force distribution estimation from marker displacements.

Findings

High spatial density of force distribution estimation.

Physically reasonable and accurate force reconstructions.

Enhanced hardware robustness and illumination.

Abstract

In this paper, we present a new version of tactile sensor GelSlim 2.0 with the capability to estimate the contact force distribution in real time. The sensor is vision-based and uses an array of markers to track deformations on a gel pad due to contact. A new hardware design makes the sensor more rugged, parametrically adjustable and improves illumination. Leveraging the sensor's increased functionality, we propose to use inverse Finite Element Method (iFEM), a numerical method to reconstruct the contact force distribution based on marker displacements. The sensor is able to provide force distribution of contact with high spatial density. Experiments and comparison with ground truth show that the reconstructed force distribution is physically reasonable with good accuracy.