Multizone proximity sensing improves robot grasping and insertion accuracy
Exploring Proximity and Tactile Sensing for Robotic Manipulation
Robotics
Summary
Robots that pick up and place objects often struggle to know exactly when and how to touch things safely. The authors created a new sensor called ToFTouch that lets a robot sense how close an object is before actually touching it, plus feel pressure when it makes contact. This helps the robot adjust its grip earlier and better handle tricky tasks like pulling out items from clutter or inserting them into tight spaces. Tests showed the robot works faster and more reliably with this sensing technology.
What this means in practice
- •For robotic system designers: Enable robots to adjust their grasping approach earlier using proximity sensing to reduce task time and improve handling accuracy.
- •For industrial automation engineers: Improve robot item retrieval and insertion performance in cluttered or tight spaces by integrating multizone time-of-flight and pressure sensing.
Authors
Eric T. Chang, Bianca Aumann, Zhanpeng He, Mohamed Elnoor, Thomas Liang, Matei Ciocarlie, Nima Fazeli, Joshua Migdal, Tye Brady, Taskin Padir
Abstract
Pre-touch sensing, or sensing information about an object before contact, is an attractive modality for robot hands as it can allow a robot to anticipate and respond to a contact before it happens. In this work, we introduce ToFTouch, a multimodal tactile sensor combining three multizone (4$\times$4 resolution) time-of-flight sensors with an optics-based pressure sensing array. We mount this sensor on a parallel jaw gripper and demonstrate its utility on three distinct tasks: (i) pre-grasp adjustment, (ii) item extraction from clutter, and (iii) item insertion into tight spaces. For pre-grasp adjustment, ToF feedback reduced cycle time by 7.4$\%$ by enabling anticipatory gripper closure during approach. For extraction, ToF sensing enabled successful retrieval across all tested depth offsets ($\pm$2 cm) deviating from the nominal pick point, including conditions where baseline approaches failed, with standard deviations below 0.4 cm. For insertion into dense clutter, we explore the proximity and tactile information provided from ToFTouch during an insertion trajectory. The results demonstrate the utility of multizone ToF sensing in a manipulation environment.