Reality-based models for vibration feedback in virtual environments

Reality-based modeling of vibrations has been used to enhance the haptic di splay of virtual environments for impact events such as tapping, although t he bandwidths of many haptic displays make it difficult to accurately repli cate the measured vibrations. We propose modifying reality-based vibration parameters through a series of perceptual experiments with a haptic display . We created a vibration feedback model, a decaying sinusoidal waveform, by measuring the acceleration of the stylus of a three degree-of-freedom hapt ic display as a human user tapped it on several real materials. For some ma terials, the measured parameters (amplitude, frequency, and decay rate) wer e greater than the bandwidth of the haptic display; therefore, the haptic d evice was not capable of actively displaying all the vibration models. A se ries of perceptual experiments where human users rated the realism of vario us parameter combinations, were performed to further enhance the realism of the vibration display for impact events given these limitations. The resul ts provided different parameters than those derived strictly from accelerat ion data. Additional experiments verified the effectiveness of these modifi ed model parameters by showing that users could differentiate between mater ials in a virtual environment.