Improved self-adaptive frequency modulation mode decomposition time-frequency analysis method

Abstract

The invention discloses an improved self-adaptive frequency modulation mode decomposition time-frequency analysis method. According to the improved self-adaptive frequency modulation mode decomposition, a conditional entropy optimization self-adaptive frequency modulation mode decomposition threshold value and a polynomial frequency modulation transformation estimation initial instantaneous frequency method are adopted to process relatively close and weak signal components. Compared with a traditional time frequency detection method, the improved self-adaptive frequency modulation mode decomposition can effectively solve the problem that interference exists between gear box vibration signal components under the strong interference condition. The improved self-adaptive frequency modulation mode decomposition can effectively extract fault characteristics and generate a high-resolution time-frequency representation result, clearly represent characteristic components related to faults in vibration signals, and effectively identify local faults of the planetary gearbox. The effectiveness of the method is verified through simulation analysis of fault signals of the variable-speed gearbox. Experimental data analysis results also show that the method can effectively diagnose faults in the variable-speed gearbox.

Description

technical field [0001] The invention relates to a gearbox fault diagnosis method, in particular to an improved self-adaptive frequency modulation mode decomposition variable speed gearbox fault diagnosis method, which belongs to the technical field of fault diagnosis. Background technique [0002] In the planetary gearbox fault diagnosis, the key to fault diagnosis is to extract the fault characteristic frequency and its amplitude variation of the signal. Due to the changes in the operating conditions, load and speed of the planetary gearbox, the fault characteristic frequency and amplitude of the planetary gearbox also change with the load and speed, and the mechanical system will produce non-stationary signals whose fault characteristics change with time. In addition, the early fault features are weak and susceptible to environmental noise interference, so it is difficult to extract the fault characteristic frequency by traditional time domain and frequency domain methods....

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a gear box fault diagnosis method based on improved adaptive frequency modulation mode decomposition, to solve the problem of low time-frequency aggregation and over-decomposition of the variable speed gear box signal by the adaptive frequency modulation mode decomposition algorithm in variable speed gears Technical Problems in Box Fault Diagnosis

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