This paper puts forward a kind of gearbox fault diagnosis methods which based on empirical mode decomposition (EMD), Hilbert transform, Fast Fourier Transform (FFT) and spectrum refined techniques. This method is applicable to the analysis of the nonlinear unsteady signal. First of all used wavelet denoising to the acquisition of gearbox vibrate signal, again carries on the empirical mode decomposition (EMD), than get a certain number of intrinsic mode function (imf); Choose the specific imf, based on kurtosis value, after the Hilbert transform and Fast Fourier Transform is done, the corresponding power spectrum can be obtained; To refine the power spectrum and extract the gearbox fault characteristic frequency; Then in pattern recognition and diagnosis of the gearbox fault, and compared with the normal signal characteristics. The analysis results show that the proposed method can effectively detect the gearbox fault characteristics.
Through the visual inspection, the appearance of size measurement, crimping size measurement, the steel core crimping length measurement and steel core tensile strength test of tension crimp barrel on 220kV transmission line. Made a detail analysis on test results combined with wire crimping theory. Pointed out the wire crimping defects caused by crimping irregularities. Analyzed the main causes of rupture accident, and made recommendations for improvement. Provides a reference to wire crimp and wire accident analysis.
In this paper, Based on GIS pipeline internal inspection difficult problem, according to the special structure of GIS pipeline internal proposed using testing equipment such as the mobile manipulator and image acquisition method of GIS pipeline internal components for testing. According to the job requirements of the mobile manipulator inside the pipeline, determine the specific parameters of the mechanical arm, and the mechanical arm was established based on Matlab toolbox robot model, and has carried on the kinematics simulation of mechanical arm. The use of mobile manipulator and vehicle test prototype of mobile manipulator movement characteristics and stability are verified.
Acoustics vibration detection is detected the displacement of post insulator by inspection the change of vibration state. Hoe to indentify the situation of insulator accurately from vibration signal is fate for acoustics vibration detection. According to analyzing the vibration date with statistics method, it is proved that the vibration frequency distribution of the same type of insulator follow normal distribution. Based on this conclusion, the identification frequency section has been set for identifying breached insulators.
Composite insulators suspension clamp fractured of a high-voltage transmission lines in Yunnan. Through the broken suspension clamp conducted visual inspection, fracture examination, material analysis, finite element simulation to determine the cause of the accident and proposed improvements. For the electrical fittings defect detection and accident analysis provide reference.
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