Robot adjusts grip force to gently handle various objects
How Firm Should a Grasp Be?
RoboticsComputer Vision and Pattern Recognition
Summary
Gripping objects too tightly can cause damage, while too loose a grip can make them slip. The authors developed a method for robots to estimate how heavy and squishy an object is using visual and touch sensors during grasping. This helps the robot decide the lightest grip force needed to hold the object safely without damage. They created a dataset of real fruits and vegetables with their physical properties to train their system. The robot tested can gently and securely pick up many different items by adjusting its grip in real time.
What this means in practice
- •For robotics engineers: Create robots that can safely handle delicate or varied objects by estimating their physical properties during grasping.
- •For agriculture automation teams: Design robotic pickers that can adapt grip force to different fruits and vegetables to minimize damage during harvest and packing.
Authors
Matthew Beveridge, Shree K. Nayar
Abstract
An ideal robot grasp is firm enough to securely handle an object, yet gentle enough to avoid damaging it. Achieving this balance requires knowledge of the object's material properties, such as its mass, elasticity, and surface friction. These properties, however, are seldom precisely known a priori. In this work, we propose a visuotactile approach to estimating material properties in real time, during the process of grasping. Our method uses these estimated properties to determine the minimum grasp force required to handle the object. We contribute a new dataset of real-world objects (fruits and vegetables) with measured physical properties (shape, mass, elasticity, and friction), which we use to construct our force estimation model via simulations. We experimentally validate our approach to grasp force control using a robot with a parallel-jaw gripper. We demonstrate our system's ability to gently grasp a wide variety of objects, in each case adapting to their unique physical properties.