Multi-contact haptic interaction with deformable objects: a multi-rate approach

This paper describes anew solution for stable haptic interaction with deformable object simulations featuring low servo rates and computational delays. The proposed solution is a combination of the local model and the virtual coupling concepts proposed in the past. More specifically we propose a local model structure that adapts to the deformable object local geometry and impedance characteristics. By doing so we are able to run a haptic interaction loop at high update rates,thus maximizing the Z–width of the simulation, while obtaining overall stable behavior without using any added damping. Furthermore the local model is always computed using the current deformable object surface, thus allowing for real multi-point contact interaction. The proposed solution is presented and analyzed in a multi-rate setting. Some experimental results employing a PHANTOM haptic interface are proposed for a simple one-dimensional example.