Deformation Modelling and Gripper Contact Simulation of Deformable Objects

Grasping and manipulation of deformable objects is still a challenging problem in industrial automation and robotics. To grasp a deformable object, the right amount of force needs to be used to, on the one hand, have a stable grasp and, on the other hand, prevent damaging the object. Besides, the object will deform when in contact with a grasping finger. Therefore, the behaviour of a deformable object and its contact with a finger needs to be understood.

This presentation proposes a mass-spring-damper model with additional constraints for volume preservation and spring deformation limits and Hunt-Crossley and stick-slip contacts. Experiments with objects made of silicone rubber are conducted to acquire data about the deformation of an object when impacted by an external fingertip. The influence of model parameters on the simulation results is explored and fitted to minimize the error.

The results indicate that the proposed model can predict object deformations with a normalized root mean square error of 2.2% in the explored situations.