Research On Composite Detection Technology Of Aluminum Plate Defect Based On ACFM And EMAT

Aiming at the demand of aluminum plate defect detection in the aspect of comprehensiveness and defect quantification,this paper puts forward the composite aluminum plate detection technology,which combines the advantages of ACFM and EMAT detection technology and achieve comprehensive,intelligent classification and high-precision quantitative detection of aluminum plate defects.The theory and simulation model of ACFM/EMAT composite detection technology are established.The mechanism of defect disturbance under complex field is analyzed,the defect complex characteristic signal is extracted,and the defect detection mechanism of composite detection technology is constructed.Through the combination of simulation and experiment,the key technical parameters of composite detection technology are optimized.Based above parameters,the composite detection probe is designed and optimized,and the hardware system of composite detection technology is built.In order to realize the intelligent and comprehensive evaluation of aluminum plate detection by the composite detection technology,a multi-type intelligent classification and defect size quantization algorithm.Finally,a more perfect composite detection theory system and detection system are formed to realize the comprehensive detection and evaluation of aluminum plate defects.The thesis mainly carries out the research from the following four aspects:(1)Theory and Simulation Modeling of composite Detection TechnologyBased on the theoretical model of ACFM/EMAT composite detection technology,the finite element simulation model of composite detection technology is established,and the composite mechanism is analyzed,especially the surface defect detection mechanism and internal defect detection mechanism of composite detection technology.The corresponding defect feature signals are extracted,which lays a foundation for the optimization of system parameters and the study of quantitative methods.(2)Parameter optimization and system development of composite detection technologyBased on the finite element simulation model of composite detection technology,the rectangular excited-lift height and permanent magnet height are simulated and optimized in the design of composite probe,and the excitation parameters of the system are optimized.It provides the basis for the development of the probe and system of composite detection technology,and carries on the experimental research to the permanent magnet self-excited vibration suppression method.At the same time,combined with the optimization parameters,the component of the composite detection probe and the signal conditioning circuit are designed,the probe shell is made,and the composite detection system is built.(3)Data fusion classification and quantization algorithm and defect detection experiment of composite detection technologySupport vector machine data fusion classification algorithm and defect quantization algorithm are constructed to realize the classification recognition and quantization inversion of surface defect and bottom defect.The experimental study of compound detection system is carried out to identify different types of defects and to carry out quantitative inversion.The results show that the designed compound detection system can effectively detect the defects on the surface and inside of aluminum plate,and the data fusion classification and quantization algorithm can effectively realize the intelligent classification and high precision quantification of the defects.