Hall signal based accurate fault diagnosis method for variable-speed working condition motor bearing

Abstract

The invention discloses a Hall signal based accurate fault diagnosis method for a variable-speed working condition motor bearing. The method comprises the steps of: 1) performing polynomial fitting ona motor rotating speed signal acquired by a Hall sensor to obtain a roughly estimated rotating speed function; 2) optimizing a polynomial coefficient of the rotating speed function obtained in the step 1) within a certain range, performing equal-angle sampling on a fault signal by using the rotating speed function determined by the polynomial during optimization, and taking a spectral kurtosis ofthe obtained equal-angle sampling signal as an optimization index; and 3) performing equal-angle sampling on the fault signal according to the optimal estimated rotating speed function obtained in the step 2), and obtaining a diagnosis conclusion through envelope spectrum analysis. The method is suitable for variable speed fault diagnosis for the bearing of a motor which is provided with a Hall sensor or is inconvenient to install an encoder but can be provided with the Hall sensor, and compared with a traditional method, the anti-noise capability is better, and accurate fault diagnosis can be realized without additionally installing the encoder.

Description

technical field [0001] The invention is applied to the technical field of precise fault diagnosis of motor bearings under variable speed conditions, and in particular relates to a precise fault diagnosis method for motor bearings under variable speed conditions based on Hall signals. Background technique [0002] The fault signal of the motor bearing (such as vibration, sound, etc.) contains a wealth of operating status information of the bearing, and the effective health monitoring and fault diagnosis of the motor bearing can be carried out through signal processing methods. Spectrum analysis is one of the common means of fault diagnosis, but frequency aliasing will occur in the frequency spectrum of the bearing fault signal of the motor under the condition of variable speed, which reduces the accuracy of the diagnosis result. At present, the main technical means to solve this problem is to perform equal-angle resampling on the fault signal, and the premise of equal-angle r...

AI Technical Summary

Problems solved by technology

However, the angular resolution of the Hall sensor is poor, and only a few speed pulses can be obtained for one revolution of the motor shaft. Under the condition of variable speed, the speed measurement accuracy it can provide is far from meeting the needs of accurate fault diagnosis.

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