The PHANToM is a multi-axis feed back system. By holding a pen with a stylus at the end of the PHANToM articulated robot, and moving the pen over a constructed surface in the virtual space, a feed back response can be felt on the hand. The limitation of the device is that the contact with the virtual surface is over a line. However, Katz in his study of surface texture perception noted that it was possible to gain considerable information about a surface by moving a pencil-point across the surface. In the case of fabrics, the contact is over a surface. The PHANToM device, as it exists today, is designed for force feed back applications and does not provide a tactile feeling; we understand this limitation and accordingly designed our own haptic device.

Apart from PHANToM, the PhilaU Haptic Device is designed as a combination force feed back and a tactile display. The device consists of a feeler pad at the end of an articulated arm. The feeler pad consists of an array of pins (tactors) with a horizontal spacing of 0.6 mm and a vertical spacing of 0.3 mm. This resolution is adequate to simulate most fabric textures. The bandwidth is 10 Hz which again satisfies the requirement for the simulation of most apparel fabrics. The articulated arm joints are equipped with magnetic brakes that apply a force feed back to the hand holding the feeler pad assembly. The magnetic brakes get their input voltage proportional to surface friction of the fabric, while the tactor pins follow the contour. Together, the device provides a virtual fabric touch and feel.

The PhilaU Haptic Device is being improved to include the feeling of compress ional compliance of a fabric. Also, an opposing thumb configuration is being designed for the feeler pad so that a fabric can be felt between the index and thumb of a person. Subjective evaluation of the PhilaU Haptic Device is in progress and initial results are encouraging.

Feel the 'Fabric': An Audio-Haptic Interface

An objective fabric modeling system should convey not only the visual but also the haptic and audio sensory feedbacks to remote/internet users via an audio-haptic interface. A fabric surface property modeling system consisting of a stylus based fabric characteristic sound modeling, and an audio-haptic interface.

The Stylus Based Fabric Sound Experiment Setup

By using a stylus, people can perceive fabrics surface roughness, friction, and softness though not as precisely as with their bare fingers. The audio-haptic interface is intended to simulate the case of "feeling a virtually fixed fabric via a rigid stylus" by using the PHANToM haptic interface. A DFFT based correlation-restoration method is developed to model the surface roughness and friction coefficient of a fabric, and a physically based method to model the sound of a fabric when rubbed by a stylus. The audio-haptic interface, which renders synchronized auditory and haptic stimuli when the virtual stylus rubs on the surface of a virtual fabric, is developed in VC++6.0 by using OpenGL and the PHANToM GHOST SDK.

Conclusion

The KES-F system and SiroFAST are a set of instruments and test methods for the measurement of those properties that relate to the performance The greatest value of the system may prove to be in encouraging communication between fabric and garment manufacturers by allowing the exchange of objective information on performance of fabrics and removing some of the subjectivity from discussions and disagreements of fabrics in garment manufacture and appearance of garments after manufacture and in wear. The various applications like PHANToM and the PhilaU Haptic Device are the efficient tools for fabric objective measurement in today's world.