Research On Fault Diagnosis System Of Rolling Bearing Based On DSP

Rolling bearing is one of the most familiar components in the machine equipments, its operation state influences the whole running of the machine directly. Therefore, carrying on the condition monitor and fault diagnosis for rolling bearings are seemed to be particularly important and meaningful.To the expensive large machine equipments, the domestic enterprise usually adopts the on-line condition monitor system to carry on the real-time condition monitor. But the on-line fault diagnosis system doesn't apply to the medium and small equipments because of its expensive cost and fussy installation. In the view of this condition to developing a kind of off-line fault diagnosis equipment will have its applied importance.The researching object of this thesis are rolling bearings. According to the structure of the rolling bearings, the mechanism of the fault is analyzed, the basic modality of the fault and its monitoring method are discussed, and the calculation method of the natural frequency and the fault characteristic frequency of each parts are introduced. In the thesis, the design of the resonance demodulator is also introduced in detail.The schematic circuit diagram is given, the hardware circuit design and the system which based on the DSP are completed, and the software code of the system is compiled.Resonance demodulation is a kind of technique that the high frequency resonance wave which is activized by low frequency impact should be envelope-demodulated and low-pass filtered, and would judge the type and value of fault by the analyses of amplitude and frequency spectrum that from the resonance demodulation wave which is more ampliative than the low frequency impact. Resonance demodulation can be divided into the hardware resonance demodulation and software resonance demodulation according to the realized method. This thesis adopts resonance demodulation technique that based on hardware for the theories basis to analyses and judge the fault of rolling bearings. The vibration signal that collected by the IC acceleration sensor would get though a series of hardware signal processing method, such as signal amplification, band-pass filter, envelope demodulation and low-pass filter that made by resonance demodulator, then entering the A/D to carry on a analog/digital conversion, finally entering the DSP to carry on the FFT operation. According to the data that analyzed after FFT operation, adjusting the fault and finding the fault components will become clear and easy, then attaining to the purpose of diagnosing the fault of rolling bearings. The experiments prove that the system can draw the fault signals availably, adjust the fault and the fault's concrete place of the rolling bearing's exactly, and the system can satisfy the design requirements that framed at the beginning.