Abstract
It is necessary to examine what kind of vibration and swinging is comfortable, in order to develop the comfortable human-machine interface using vibration or swinging. This study is focusing on the fluctuation in the period on the rhythm produced by the human; especially the stroke interval of the air stick is examined. The air stick is a simple version of the devil stick which is a kind of the main street art. First, the portable measuring system of the stroke interval is developed by sticking two strain gauges on each hand stick and putting a wired battery driven strain amplifier and a portable data recorder in a knapsack which the performer wears. Then, the fluctuation is measured and the power spectrum is examined. As the result, it is clarified that the power spectrum shows the tendency of downward-sloping in the low frequency range, and it shows the relation of about 1/f averagely.
