Research On Light Source Power Stability Control And Optical Signal Amplification Technology In Steel Ball Surface Defect Detection

Rolling bearing is a basic shafting component and indispensable in modern mechanical equipment.As a common rolling element in rolling bearing,the quality and grade of steel ball directly affect the service performance of rolling bearing.The defects and surface roughness of the steel ball surface are the main factors that cause the failure of the ball bearing.The scrap rate of the bearing caused by the defects of the steel ball surface reaches 65%.The quality of the steel ball surface has a decisive impact on the quality of the bearing.The detection of steel ball surface defects is of great significance for improving the quality of ball bearing,the safe operation of mechanical equipment and the improvement of steel ball production technology in enterprises.There are many steel ball production enterprises in China,and the annual output of steel ball is large.However,nowadays,the detection effect and stability of steel ball surface defect detection equipment independently developed in China are poor,which cannot meet the needs of enterprises for normal production of steel ball.Therefore,our country urgently needs to develop automatic inspection equipment for surface quality of steel ball with high detection accuracy and stable system.By studying and analyzing the appearance geometric features of standard defects and surface roughness of steel ball surface,five detection parameters of defect height,depth,length,width and reflectivity are extracted;The displacement defects on the surface of steel balls are detected by the dual-beam comparison measurement method,and the surface roughness defects of steel balls are detected by the Beckmann-Kirchhoff scattering model and dual-wavelength method;The reflective intensity modulated optical fiber sensor,the end structure of the optical fiber probe and the distribution of the outgoing light field at the end of the optical fiber are studied;Combined with the sensor structure of single fiber transmission and three loop fiber bundles reception,the general structure of the steel ball surface defect detection system is designed.The mathematical model of RIM-FOS for detecting the surface defects of steel balls is established.The received reflected light area and light intensity modulation function under the reflected light spot with different radii are analyzed;According to the Beckmann-Kirchhoff random surface scattering model,the received reflected light power under rough surface is derived;Considering the spherical factor of the steel ball,the light intensity modulation function under the spherical convex surface is calculated and derived;The mathematical model of RIM-FOS for detecting displacement and roughness defects on the surface of steel ball is established.The detection scheme using the first and second loops of receiving optical fiber bundles with a detection distance of 0.9mm was determined through simulation analysis.The power stability control system of RIM-FOS light source is designed,and the power feedback control and temperature control circuits of single-chip microcomputer are designed.The circuits are simulated;The production and harm of reverse light in the detection system were studied,and a light isolator was used to suppress the reverse light.A method of amplifying the reflected light signal power of the detection system using doped fiber amplifiers is proposed.The relationship between the structural parameters and the gain of the erbium doped fiber amplifier is simulated and analyzed using Optisystem software.The test results show that the long-term instability of the output optical power of 1310 nm and 1550 nm lasers in this experiment is 1.4% and 1.7% respectively,and the optical power is relatively stable;The detection system was calibrated using roughness comparison samples to simulate displacement and roughness defects;Conduct testing experiments on surface defects of steel balls,collect a large amount of data,and after processing the data,it is found that the designed detection system has good defect detection effect;The detection optical signal is amplified by the EDFA and then received by the optical receiver,which improves the performance of the optical fiber sensing detection system.It provides an idea for developing a high accuracy and high stability steel ball surface defect detection equipment.