Grasping Point Estimation for EA Suction Cup Grippers on Curved Objects
Angelo Catalano, Simone De Carolis, Gennaro Vitucci, Giuseppe Carbone, Mariagrazia Dotoli, Vito Cacucciolo
AI summary
Problem
Electroadhesion suction cups rely on a zipping mechanism to conform to objects, but grasp feasibility is highly sensitive to local surface curvature, making automatic selection of viable contact points challenging.
Approach
The authors derive a closed-form equation that balances electrostatic work and elastic deformation energy to predict the minimum activation voltage needed for full zipping at any contact point based on its local mean and Gaussian curvatures.
Key results
- Closed-form voltage prediction model mapping local curvature invariants to zipping thresholds
- Experimental validation on cylinders, spheres, and ellipsoids confirming predicted voltage thresholds
- Successful robotic pick-and-place demonstrations on everyday objects using curvature-driven voltage commands
- Identification of bending-dominated versus stretching-dominated conformation regimes
Why it matters
Enables reliable, energy-efficient robotic grasping of diverse curved objects by automating safe voltage selection, advancing soft gripper deployment in logistics and handling.
Abstract
Electroadhesion suction cup (EASC) are fully- electrical grippers (no air flow needed) with very low power consumption that can grasp flat to curved objects from the top. They conform to the shape of the object by zipping from the central contact point to their edges, driven by Electroadhesion forces. Zipping requires deforming elastically the EASC membrane. The object surface curvature at contact point strongly affects zipping ability, and therefore grasp feasibility. We developed a model for grasping point selection that predicts the voltage required for full zipping on a point of given local curvature. Feasible points are the ones where the estimated zipping voltage is lower than the breakdown voltage of the EASC. The model is based on an energy balance between electrostatic work and elastic deformation, explicitly including in-plane stretching on doubly curved surfaces. Experiments on cylinders, spheres, and ellipsoids validate the predicted thresholds and curvature-dependent trends.