I will describe the application of a 6 degree-of-freedom magnetic levitation haptic device to the exploration of human texture perception. The device simulates virtual textures and allows a correlation between their physical and psychophysical properties.
Studies of the psychophysics of texture perception have previously been hampered by the need for the expensive manufacture of finely textured physical surfaces. These physical surfaces provide only discrete levels of experimental variables for study and are time-consuming to present to subjects. Virtual haptic textures, on the other hand, provide continuous control of variables and are quick and easy to use.
Unfortunately, previous psychophysics experiments have demonstrated differences between real and virtual textures. I will describe a new texture rendering algorithm which carefully models probe and texture geometry. Subjective magnitude estimates by subjects reveal that the roughness of this rendered virtual haptic texture is perceptually the same as real texture.
The effects of changing probe geometry, surface friction and compliance are also investigated. Measurements of device position and force, made during the psychophsical experiments, reveal a relationship between force variability and the perception of roughness. Roughness detection thresholds are documented and their relationship to probe geometry and compliance is examined.
This work provides significant new insight into the perception of roughness and its relationship to texture geometry, compliance and friction. It also establishes an experimental platform and framework which should expedite future studies of texture perception.