Feel the 'fabric' via the PHANToM.

摘要

This dissertation presents the research work on the fabric surface property simulation, the stylus based fabric characteristic sound simulation, and the haptic-audio interface design. By using a stylus people could perceive the fabric surface roughness and friction, instead of directly touching the fabric with their bare fingers. Our haptic-audio interface is intended to simulate the case “feeling a virtually fixed fabric via a rigid stylus” by using the PHANToM 1.5—a force/torque feedback device by SensAble Technologies. Four cotton fabrics, which are different in terms of yarn and weaving pattern, were chosen. The surface roughness and friction force profiles of each fabric were measured by using the KES FB4 surface tester. Because of the stochastic and periodic aspects of each profile, a FFT based correlation-restoration method is developed and implemented to analyzed the characteristic frequencies, amplitudes, and initial phases of the surface roughness and friction coefficient of the fabric. By using the characteristic parameters, we simulate the surface roughness and friction coefficient profiles for each fabric. The fabric characteristic sound when a stylus rubs a fabric were generated and recorded by a system developed by us. The frequencies of the fabric characteristic sound were obtained from the DFFT spectral analysis on the sound profile of each fabric. By using the frequencies, we developed a physically based method to simulated the sound of a fabric when a stylus is rubbing it. The haptic-audio interface, which renders synchronized auditory and haptic stimuli when the PHANToM endpoint—the virtual stylus—rubs on the surface of a virtual fabric, was developed in Visual C++ 6.0 by using OpenGL and PHANToM GHOST SDK. Finally, subjects were asked to test our haptic-audio interface. From the user evaluation, we conclude that the surface roughness and friction of the four different virtual fabrics can be perceived haptically and ordered by the subjects. Comparing with the recorded sound, subjects satisfy the simulated sound when a stylus rubs a virtual fabric.