Fig. 11

Temporal course of physical quantities observed during experiments. Left Those when the intended finger velocity was 0.1 m/s and the relative velocity was constantly positive while touching the contactor. Right Those when the intended finger velocity was 0.04 m/s. Stimulus condition was #2 for which the frequency and amplitude were 6 Hz and 0.625 mm, respectively. While the normal force was nearly zero, the finger was not touching the contactor and the finger velocity is not shown. Because the finger movement was reciprocating, its velocity was alternately positive and negative. The contactor was being touched only when the finger velocity was positive. The sinusoidal vibration of the contactor was largely maintained while it was being touched. The relative velocity is the difference between the finger velocity and that of the contactor