Dynamic simulation and virtual control of a deformable fingertip

An efficient computational model for the dynamics of a deformable robot fingertip is presented. The dynamic model is based on a discretization of the fingertip´s volume into a lattice of masses locally interconnected by damped springs. The lattice´s parameters are adjusted in correspondence with bulk properties of the fingertip´s deformable material (rubber). In the task studied, the fingertip moves toward a rigid flat surface, contacts it, and presses against it. This motion is commanded by an external feedback controller which communicates with the dynamic model through a virtual control interface: The controller applies forces and torques to the dynamic model and the dynamic model responds in real-time with position/velocity/force feedback information. In this fashion, the controller interacts with the fingertip´s model in the same way it would interact with the actual physical system. This type of paradigm is envisioned as a prototyping/testing tool in the design of control systems for deformable objects as well as for applications involving the haptic (i.e., sensorially realistic) interaction between a human and a virtual (deformable) object. Graphical snapshots of a real time simulation of the task under study are presented which reveal the physical and computational plausibility of the model