Display Method for Roughness Sensation

This equation presents the information detected by FA I and shows that both the amplitude and the frequency change in response to the velocity, v. Based on this assumption, the roughness sensation can be presented by changing both the frequency and the amplimde of stimulation in accordance with hand velocity. In this manner, the roughness sensation can be defined by the wavelength, X. For practical use of this method, we applied phase adjustments to produce smooth outputs in response to changing frequencies with respect to each sampling time. 

The frequencies generated by the proposed method depend on the wavelength and hand movements. However, usual hand movement on the surface of several millimeter wavelengths generates the suitable frequency range for FA 1 consequently. 

From the results, it was confirmed that roughness sensation could be expressed by the parameter of the wavelength in the case of relatively short wavelengths. In addition to the wavelength, it is confirmed that the maximum amplitude of stimulus affects the amount of the subjective sensation of roughness. 

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