Soft tactile sensing: Retrieving force, torque and contact point information from deformable surfaces

TY - CHAP

T1 - Soft tactile sensing

T2 - 2019 International Conference on Robotics and Automation, ICRA 2019

AU - Ciotti, Simone

AU - Sun, Teng

AU - Battaglia, Edoardo

AU - Bicchi, Antonio

AU - Liu, Hongbin

AU - Bianchi, Matteo

PY - 2019/5/1

Y1 - 2019/5/1

N2 - Intrinsic Tactile Sensing (ITS) is a well-established technique, relying on force/torque and geometric surface description to find contact centroids. The method works well for rigid surfaces. However, finding a solution for deformable surfaces is an open issue. This work presents two solutions to extend ITS to deformable surfaces, relying on force-deformation characteristics of the surface under exploration: (i) a closed-form approach that calculates the contact centroid using standard ITS, but on a shrunk geometry approximating the deformed surface; (ii) an iterative procedure that takes into account soft surface deformation, and force/torque equilibrium to minimize a cost function. We have tested both using ellipsoid silicone specimens, with different softness levels and indented along different directions. Both linear and quadratic fitting for the force-indentation behavior were employed. The two methods have distinct advantages and limitations. However, a combination of two methods, using one to produce the initial guess for the other, turns out to be very effective. Indeed, in our validation this solution showed convergence under 1ms, attaining errors lower than 1 mm. The proposed approaches were implemented in a ROS-based toolbox, integrating both solutions.

AB - Intrinsic Tactile Sensing (ITS) is a well-established technique, relying on force/torque and geometric surface description to find contact centroids. The method works well for rigid surfaces. However, finding a solution for deformable surfaces is an open issue. This work presents two solutions to extend ITS to deformable surfaces, relying on force-deformation characteristics of the surface under exploration: (i) a closed-form approach that calculates the contact centroid using standard ITS, but on a shrunk geometry approximating the deformed surface; (ii) an iterative procedure that takes into account soft surface deformation, and force/torque equilibrium to minimize a cost function. We have tested both using ellipsoid silicone specimens, with different softness levels and indented along different directions. Both linear and quadratic fitting for the force-indentation behavior were employed. The two methods have distinct advantages and limitations. However, a combination of two methods, using one to produce the initial guess for the other, turns out to be very effective. Indeed, in our validation this solution showed convergence under 1ms, attaining errors lower than 1 mm. The proposed approaches were implemented in a ROS-based toolbox, integrating both solutions.

UR - http://www.scopus.com/inward/record.url?scp=85071442703&partnerID=8YFLogxK

U2 - 10.1109/ICRA.2019.8794087

DO - 10.1109/ICRA.2019.8794087

M3 - Conference paper

AN - SCOPUS:85071442703

VL - 2019-May

SP - 4290

EP - 4296

BT - 2019 International Conference on Robotics and Automation, ICRA 2019

PB - Institute of Electrical and Electronics Engineers Inc.

Y2 - 20 May 2019 through 24 May 2019

ER -