Human Interaction with Small Haptic Effects

This research investigated the ability of subjects to detect small haptic effects, and the associated gains in task performance with various configurations of haptic stimulus. Variations in amplitude, shape, and pulse duration were studied. An adaptive thresholding method was used to obtain detection thresholds for actively explored haptic icons ranging in size from 3 to 5 mm, smooth vs rough actively explored icons, and force pulses of 100 to 150 ms pulse duration. Using Fitts’ law. Rough (saw-tooth) haptic icons are more easily detected by a human subject than smooth (sinusoidal) icons of the same size, by almost a factor of two. Mean subject performance, as measured by Fitts’ information processing rate and clicks-per-minute, improved with the amplitude of haptic stimulus.