| 摘要 |
PURPOSE:To obtain the information about the amount of unbalance that is always stable and informaion about phase from unbalance signals even if revolution of a rotary body to be measured varies, by using a digital; filter provided with a prescribed transfer function. CONSTITUTION:A tire 4 to be measured is rotated via a motor 5, etc., and unbalance signals of the faces 4a, 4b of the tire 4 are detected with vibration detecting elements 11, 12 provided on bearings 2, 3. These detected signals are sampled by digital filters 18, 19 when sampling pulses are applied from a sampling pulse generator 7 at each time interval T. At the same time, with the execution of inpulse response of a filter function and convolution, a signal proportional to amplitude and phase of the amount of unbalance is generated. In that case, when a transfer function of each of the filters 18, 19 is selected such that it satisfies a formula I where each coefficient becomes a constant with respect to the sampling time interval T, unbalance information that is always stable is obtained even if revolution of the rotary shaft varies. |
