Optimization-Based wearable tactile rendering

Novel wearable tactile interfaces offer the possibility to simulate tactile interactions with virtual environments directly on our skin. But, unlike kinesthetic interfaces, for which haptic rendering is a well explored problem, they pose new questions about the formulation of the rendering problem. In this work, we propose a formulation of tactile rendering as an optimization problem, which is general for a large family of tactile interfaces. Based on an accurate simulation of contact between a finger model and the virtual environment, we pose tactile rendering as the optimization of the device configuration, such that the contact surface between the device and the actual finger matches as close as possible the contact surface in the virtual environment. We describe the optimization formulation in general terms, and we also demonstrate its implementation on a thimble-like wearable device. We validate the tactile rendering formulation by analyzing its force error, and we show that it outperforms other approaches

Efficient nonlinear skin simulation for multi-finger tactile rendering

Recent advances in tactile rendering span, among others, wearable cutaneous interfaces, tactile rendering algorithms, or nonlinear soft skin models. However, the adoption of these advances for multi-finger tactile rendering of dexterous grasping and manipulation is hampered by the computational cost incurred with nonlinear skin models when applied to the full hand. We have observed that classic constrained dynamics solvers, typically designed for contact mechanics, fail to perform efficiently on deformation constraints of nonlinear skin models. In this paper, we propose a novel constrained dynamics solver designed to perform well with highly nonlinear deformation constraints. In practice, we achieve more than 10x speed-up over previous approaches, and as a result we enable multi-finger tactile rendering of manipulation actions that capture the nonlinearity of skin