Search

The electrovibration tactile display could render the tactile feeling of different textured surfaces by generating the frictional force through voltage modulation. When a user is sliding his/her finger on the display surface, he/she can feel the frictional texture. However, it is not trivial to prepare and fine-tune the appropriate frictional signals for haptic design and texture simulation. In this paper, we present a deep-learning-based framework to generate the frictional signals from the textured images of fabric materials. The generated frictional signal can be used for the tactile rendering on the electrovibration tactile display. Leveraging GANs (Generative Adversarial Networks), our system could generate the displacement-based data of frictional coefficients for the tactile display to simulate the tactile feedback of different fabric materials. Our experimental results show that the proposed generative model could generate the frictional-coefficient signals visually and statistically close to the ground-truth signals. The following user studies on fabric-texture simulation show that users could not discriminate the generated and the ground-truth frictional signals being rendered on the electrovibration tactile display, suggesting the effectiveness of our deep-frictional-signal-generation model. [Display omitted] • The deep-learning-based image-to-friction generation framework for tactile simulation of fabric material. • The augmented visual-to-frictional database based on HapTex for image-to-friction generation. • The technical experiment of frictional-coefficient signal generation evidencing the performance of the proposed generative model. • The user-perception experiment validating the effectiveness of generated signals for tactile simulation of fabrics on the electrovibration tactile display. [ABSTRACT FROM AUTHOR]

• Hyper-elastic material model is identified using object deformation data. • Real-time FEM simulation for haptic rendering. • Realistic haptic rendering using FEM simulation. This paper presents a measurement-based FEM (finite element method) modeling and haptic rendering framework for objects with hyper-elastic deformation property. A complete set of methods covering the whole process of the measurement-based modeling/rendering paradigm is newly designed and implemented, with a special emphasis on haptic feedback realism. To this end, we first build a data collection setup that accurately captures shape deformation and response forces during compressive deformation of cylindrical material samples. With this setup, training and testing sets of data are collected from four silicone objects having various material profiles. Then, an objective function incorporating both shape deformation and reactive forces is designed and used to identify material parameters based on training data and the genetic algorithm. For real-time haptic rendering, an optimization-based FEM solver is adopted, ensuring around 500 Hz update rate. The whole procedure is evaluated through numerical and psychophysical experiments. The numerical rendering error is calculated based on the difference between simulated and actually measured deformation forces. The errors are also compared to the human perceptual threshold and found to be perceptually negligible. Overall realism of the feedback from the system is also assessed through the psychophysical experiment. A total of twelve participants rated similarity between real and modeled objects, and the results reveal the rendering quality to be at a reasonable level of realism with positive user feedback. [ABSTRACT FROM AUTHOR]

Common approaches for the haptic rendering of complex scenarios employ multi-rate simulation schemes. Here, the collision queries or the simulation of a complex deformable object are often performed asynchronously at a lower frequency, while some kind of intermediate contact representation is used to simulate interactions at the haptic rate. However, this can produce artifacts in the haptic rendering when the contact situation quickly changes and the intermediate representation is not able to reflect the changes due to the lower update rate. We address this problem utilizing a novel contact model. It facilitates the creation of contact representations that are accurate for a large range of motions and multiple simulation time-steps. We handle problematic geometrically convex contact regions using a local convex decomposition and special constraints for convex areas. We combine our accurate contact model with an implicit temporal integration scheme to create an intermediate mechanical contact representation, which reflects the dynamic behavior of the simulated objects. To maintain a haptic real time simulation, the size of the region modeled by the contact representation is automatically adapted to the complexity of the geometry in contact. Moreover, we propose a new iterative solving scheme for the involved constrained dynamics problems. We increase the robustness of our method using techniques from trust region-based optimization. Our approach can be combined with standard methods for the modeling of deformable objects or constraint-based approaches for the modeling of, for instance, friction or joints. We demonstrate its benefits with respect to the simulation accuracy and the quality of the rendered haptic forces in several scenarios with one or more haptic proxies. [ABSTRACT FROM AUTHOR]

Abstract: In many haptic applications, the user interacts with the virtual environment through a rigid tool. Tool-based interaction is suitable in many applications, but the constraint of using rigid tools is not applicable to some situations, such as the use of catheters in virtual surgery, or of a rubber part in an assembly simulation. Rigid-tool-based interaction is also unable to provide force feedback regarding interaction through the human hand, due to the soft nature of human flesh. In this paper, we address some of the computational challenges of haptic interaction through deformable tools, which forms the basis for direct-hand haptic interaction. We describe a haptic rendering algorithm that enables interactive contact between deformable objects, including self-collisions and friction. This algorithm relies on a deformable tool model that combines rigid and deformable components, and we present the efficient simulation of such a model under robust implicit integration. [ABSTRACT FROM AUTHOR]

Abstract: Incorporating the sense of touch brings a new level of realism to human–computer interaction and this is particularly important for virtual reality systems attempting to simulate physical environments. Haptic Feedback devices are able to produce force and tactile feedback, which enables the sense of touch to be exploited. In this paper a novel approach to the simulation of interactions between deformable tools and rigid objects, utilizing haptic feedback, is presented. As the deformable tool makes contact with the virtual environment the forces are computed and transmitted to the user via the Phantom Desktop device produced by SensAble Technologies. A haptic update rate of 1000Hz can be obtained with a simple scene object and a deformable tool representing a flexible rod. The deformations of the rod are modelled using the finite element method. [Copyright &y& Elsevier]