Active Balancing Technology Of Rotor Based On Unbalanced Vibration Signal Extraction

Active balancing of rotor has been becoming the key technology for rotating machinery to develop toward the direction of high speed, high precision. There are two bottlenecks, which are dynamic balancing test and active balancing correction. In program of dynamic balancing test, acquiring precise amplitude and phase of unbalanced vibration signal is necessary. However, a lot of noise mixed with unbalanced, which collected from vibration sensor, makes it complex. Main research works of this thesis include:1. In order to explore the relationship between unbalance mass and vibration response, this thesis takes monitored spindle as example to analyze its unbalanced vibration response in finite element method. The result shows that, at constant speed and damping, unbalanced vibration response under the critical speed is sinusoidal signal, whose amplitude is proportional to the amount of unbalance and whose phase delay a constant value than unbalance.2. In order to extract precisely amplitude and phase of the unbalanced characteristic signal from strong noise and background of heavy nearly frequency interference, and considering both accuracy and efficiency, two kinds of unbalance signal extraction method is put forward. They are single sinusoidal signal cross-correlation method based on two stage filtering and double harmonic signal cross-correlation method based on variable sampling length. The simulation and experiment show that, the proposed two-stage filtering effectively improves the signal-to-noise ratio (SNR) of unbalanced signal and eliminates the influence on phase extraction for phase delay caused by filtering. And error of the proposed variable sampling length method is always significantly lower than the fixed sampling length method under different signal-to-noise ratio and frequency difference between signal and noise, the standard deviation of10unbalanced signal extraction experiments is lower than that of variable sampling length method.3. In order to put rotor active balancing technology based on vibration signal extraction into practice, a set of active balance controller based on TMS320F2812is designed and developed, which aims to Schmitt automatic balancing head. Subsequently, adjustable speed balance test bench is established and active balance controller is produced and debugged on the test bench.