Research On An Automatic Wear Debris Parameters Measurement System On Microscope For Ferrogram Of Rotary Ferrograph

As one of the important branches of oil analysis technology,ferrographic quantitative analysis technology is widely used in condition monitoring and fault diagnosis of large mechanical equipment.Among them,the ferrogram made by rotary ferrograph contains a large amount of information about mechanical wear,which is more significant for mining machinery in harsh environment.However,there are still some problems such as low efficiency of manual analysis,large workload and incomplete analysis results.Therefore,according to the requirement of ferrographic quantitative analysis,an automatic wear debris parameters measurement system based on microscope for ferrogram of rotary ferrograph is designed.According to the structure of magnetic head of rotary ferrograph,forces on wear debris in the process of making ferrogram are analyzed,and factors that affect deposition position of wear debris on the surface of magnetic head are analyzed.The magnetic field on the surface of magnetic head is analyzed by ANSYS magnetic field simulation,and the equal probability deposition law of wear debris on the surface of magnetic head is deduced.Based on the theory of wear debris group,the debris group suitable for detection and analysis on ferrogram is established,and the mesurement paths and quantitative analysis parameters are determined.According to the quantitative analysis parameters and mesurement paths of ferrogram,an automatic mesurement system composed of wear debris optical density collection module,image collection module and carrier driving module is designed.Among them,the optical density collection module is composed of a light source,a photoelectric sensor,a signal processing module and a data acquisition card,to realize the collection of wear debris coverage rate.The wear debris image collection module collects real-time images through a micro-camera.The carrier driving module is composed of an automatic carrier,a motion control card and a driver,to realize automatic positioning of view field.At the same time,the magnetic head and the carrier are improved through designing positioning column on magnetic head and the positioning slot on the carrier.Based on the center of wear debris deposition ring on ferrogram,the view field is positioned.The mesurement system software based on Labview is developed.According to mesurement paths of wear debris information on ferrogram,multithread technology is adopted to realize movement of the carrier,and collection,processing,analysis of the wear debris coverage rate and images.Trend analysis and wear degree judgment of wear debris are automatically completed.The wear debris image processing of MATLAB is integrated into the system software by transmitting parameter method with intermediate fiies to calculate wear debris size and quantity.The mesurement system is calibrated experimentally.The static characteristics of the system are evaluated from linearity and resolution,and the comprehensive performance of the system is tested by repetitive experiments.On this basis,the system is used to monitor the oil samples obtained from the simulated experiment of working conditions.The results show that,the automatic mesurement system can automatically collect and process the wear debris coverage rate and images on ferrogram of rotary ferrograph,effectively and accurately judge the wear degree of mechanical equipment,and effectively monitor the friction and wear conditions of mechanical equipment.