Health state assessment method for rotary machine based on probability density function

Abstract

The invention relates to a health state assessment method for a rotary machine based on statistical methods such as kernel density estimation and K-L divergence calculation. The method comprises the following steps that 1) original vibration data of a monitored object is collected; 2) time-domain and frequency-domain features are extracted from the original vibration data; 3) the dimensions of the time-domain and frequency-domain features are reduced to obtain sensitive features; 4) a movable sliding window of the width k is used to dynamically select sample sets, and the statistical characteristics of the sample sets are calculated; 5) the probability density function of each sample set under each sensitive feature is calculated; 6) the K-L divergence between the probability density functions of two adjacent sample sets under the same sensitive feature is calculated; and 7) an integrated K-L divergence is calculated and serves as a health assessment index of the monitored object. The health state assessment method has the advantages that the statistical uncertainty of the samples is fully considered, and the accuracy and generalization performance of a health state assessment model are improved.

Description

technical field

[0001] The invention belongs to the field of performance degradation evaluation of mechanical equipment, and in particular relates to a statistical method based on kernel density estimation and K-L divergence to realize health state evaluation of rotating machinery. Background technique

[0002] Rotating machinery is widely used in large-scale manufacturing systems and important technical equipment, such as CNC machine tools, wind power generators, aerospace engines, etc. In these manufacturing systems and equipment, key components in rotating machinery such as rolling bearings and gears play an important role, but rotating machinery parts need to withstand alternating mechanical stress and occasional impact during operation, coupled with inherent manufacturing errors, often There will be some early defects (such as: mild wear, pitting, etc.). If these defects are not diagnosed in time, they will continue to deteriorate over time, eventually leading to syste...

Examples

Embodiment Construction

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0052] like figure 1 As shown, the steps include:

[0053] Step 1: Collect raw vibration data of the detected object.

[0054] The present invention takes the rolling bearing accelerated life test platform of the American Intelligent Maintenance System Center (Intelligent Maintenance System, IMS) as an example, and the specific test parameters are as follows:

[0055] as attached figure 2 As shown, the test rig has four test bearings installed on the same rotating shaft. The shaft is driven by an AC motor through a belt drive. The rotational speed of the rotating shaft is maintained at 2000r / min. A load of 2700Kg is added radially to the rotating shaft, applied by a spring mechanism. All tested bearings are forced to lubricate. A magnetic plunger is added to the feedback oil pipe of the lubricating oil supply system to collect the beari...

technical field

[0001] The invention belongs to the field of performance degradation evaluation of mechanical equipment, and in particular relates to a statistical method based on kernel density estimation and K-L divergence to realize health state evaluation of rotating machinery. Background technique

[0002] Rotating machinery is widely used in large-scale manufacturing systems and important technical equipment, such as CNC machine tools, wind power generators, aerospace engines, etc. In these manufacturing systems and equipment, key components in rotating machinery such as rolling bearings and gears play an important role, but rotating machinery parts need to withstand alternating mechanical stress and occasional impact during operation, coupled with inherent manufacturing errors, often There will be some early defects (such as: mild wear, pitting, etc.). If these defects are not diagnosed in time, they will continue to deteriorate over time, eventually leading to syste...

Examples

Embodiment Construction

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0052] like figure 1 As shown, the steps include:

[0053] Step 1: Collect raw vibration data of the detected object.

[0054] The present invention takes the rolling bearing accelerated life test platform of the American Intelligent Maintenance System Center (Intelligent Maintenance System, IMS) as an example, and the specific test parameters are as follows:

[0055] as attached figure 2 As shown, the test rig has four test bearings installed on the same rotating shaft. The shaft is driven by an AC motor through a belt drive. The rotational speed of the rotating shaft is maintained at 2000r / min. A load of 2700Kg is added radially to the rotating shaft, applied by a spring mechanism. All tested bearings are forced to lubricate. A magnetic plunger is added to the feedback oil pipe of the lubricating oil supply system to collect the beari...

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