Measurement and Calculation of Speed Profile for Rotating Machinery

Abstract The vibration signal angular domain resampling of rotating machinery depends on the speed profile. To obtain the speed profile, n ribbons of uniform width with black and white were pasted along the circumference of the shaft. Key phasor pulses were picked up by photoelectric sensor, and the threshold of the sampling sequence was calculated. Key phasor time vectors were calculated according to the threshold and the sampling sequence. The rotating speed was calculated by the key phasor time vector and the midpoint coefficient of the Lagrange 7 point interpolation differential. The speed profiles of single key phasor pulse, 4 key phasor pulse and digital encoder with 60 pulses per revolution are measured by using LabVIEW program simultaneously. It shows that the smoothness and the calculation accuracy of the speed profile can be improved by using multi key phasor pulse per revolution.