Robots safely grasp fragile objects with adaptive force control
Control Architecture for Safe Grasping of Fragile Objects Using a Coarse Position-Controlled Gripper
Robotics
Summary
Handling delicate objects can be tricky because robots might squeeze too hard and break them or too softly and drop them. The authors present a method that lets robots sense how much pressure they are applying and adjust it in real time. Their system uses force and shape information to grip objects gently but firmly, even when the object is unknown in size or softness. This approach helps robots avoid dropping or damaging fragile things during grasping.
What this means in practice
- •For industrial automation teams: Improve robot grippers to safely handle fragile products of varying shapes and textures without causing damage.
- •For warehouse robotics operators: Enable robots to pick and move unknown objects gently to prevent breakage during sorting or packaging tasks.
Authors
Marko Pavlic, Moritz Geier, Timo Markert, Darius Burschka
Abstract
Robots are increasingly used in unstructured environments. The need for them to safely grasp unknown objects without damaging them becomes crucial. Humans achieve this by sensing and quickly responding by adjusting their grasping force. Similarly, effective grasp acquisition in robots requires compliant interaction strategies that can adapt to uncertain object properties and adjust to any instabilities during manipulation. We present a geometry-aware force/torque-based contact estimation method for a coarse position-controlled gripper, combined with an adaptive admittance controller for safe grasp acquisition. The desired contact forces are estimated online to keep stable contact with objects of unknown properties. This enables compliant and stable grasps while avoiding excessive forces. Experiments with objects of different sizes, shapes, stiffnesses, and weights show that the proposed algorithm not only prevents slippage but also applies minimal force to safely grasp an object without causing excessive deformation.