Application Of Signal Resampling Method In Gearbox Fault Diagnosis

Planetary gearboxes are the core mechanism in the shifting phase of modern rotary mechanical transmission systems,so they are widely used in many fields.Planetary gearboxes are mainly composed of ring gears,sun gears,planetary gears and bearings.When planetary gearboxes are used in actual engineering,they often work in harsh timevarying environments,so it is necessary to troubleshoot planetary gearboxes in such harsh environments.The acoustic emission detection technology used in this dissertation has stronger anti-interference ability than the commonly used vibration detection technology,and then is used for the non-stationary time domain signal generated by the planetary gear box under complicated variable working conditions.The frequency domain data analysis method can not accurately determine the fault type,so it is necessary to convert the nonstationary signal in the original time domain into a stationary signal by the signal resampling method.For the signal resampling method adopted in this dissertation,the speed signal of the planetary gear box is first obtained,and then the non-stationary signal is converted into a stationary signal by the angle resampling method according to the speed signal.The research ideas of this dissertation are as follows:Firstly,this dissertation introduces the background and significance of the research,and deeply understands the working principle and internal structure of the planetary gearbox.At the same time,it briefly analyzes the planetary gearbox fault signal.;After that,the dissertation studies and compares the principles of acoustic wave detection technology and vibration detection technology;In addition,the research status of nonstationary signal processing methods is also introduced in the dissertation,and the general processing methods of non-stationary signals are summarized and analyzed.Then,we designed and produced an FPGA-based acoustic emission data acquisition system and a vibration signal acquisition system based on the NI 9234.The acoustic emission signal data acquisition system includes an analog front end acoustic emission signal conditioning circuit,an ADC sampling circuit,a data transmission circuit,and a power supply circuit;Vibration signal acquisition system includes NI 9234 and host computer design on Labview.The dissertation also gives the selection of key components and the design points of two different acquisition systems.In addition,the acquisition of the speed signal is designed.The air-coupled sensor is used to acquire the speed signal of the planetary gearbox in real time.Finally,in the experimental part of this dissertation,the acoustic emission data acquisition system and the vibration signal acquisition system are used in the planetary gearbox fault diagnosis platform,and the acoustic emission signals and vibration signal data acquisition experiments are carried out under different speeds and different gear failures.And complete the comparison of the acoustic emission signal and the vibration signal in the time domain;Then,according to the speed signal,the original acoustic emission signal is resampled,and the gear fault feature extraction of the planetary gearbox acoustic emission signal is completed,and the scientific verification of the signal resampling method is finally verified.