Development Of Electromagnetic Flaw Detection Data Analysis System Using Data Compression And Instant Communication Technology

With the rapid development of technologies on G-series high-speed trains and the large promotion in total volume of railway freight,traffic safety of our country needs to meet higher requirements,rail detecting is an important part in the guarantee of driving security of trains,traditional pushing rail detecting dolly can hardly meet the detection demands of rails at present,which will greatly increase the demands of flaw detection equipment with high detecting speed.At present,the main rail detecting method used in our country is the ultrasonic testing,for this method,the coupling agent needs to use on the rails to make them pasted closely,which seriously affects the detecting efficiency and can hardly meet the detection demands of routes for G-series high-speed trains in the future.While eddy current testing is of characteristics like lossless,high speed and non-contact,etc.,but it means that a huge data size will be generated when conducting high-speed flaw detection on the rails through eddy current testing,which will cause a great difficulty for the uploading of data collection.With the electromagnetic rail detecting technology as background,the lossy compression algorithm design for electromagnetic rail detection data and development of electromagnetic detection data analytic system were emphasized on in this thesis.This system can upload the detection data it receives to the server through data compression,and workers can enter the system to check the detection data and damage results.The main researches of this thesis were as follows:(1)The basic principles of eddy current testing was researched,the basic concept of theory of information and main performance indexes of data compression were stated in details and some common lossless and lossy compression algorithms were respectively researched.(2)A simulation model of electromagnetic rail detection was established through software of finite element analysis,detection simulation was conducted on the transverse cracks and scaly figures of the rails respectively to confirm the relationship between the magnetic induction intensity and depth,through demodulation on the data,the relationships between detection values when there was and when there was no damage,with different damages,with the same damage but different depths were acquired.(3)An electromagnetic flaw detecting data compression system and electromagnetic flaw detecting information platform were established.The flaw detecting data compression system realized the functions including control of compression and uploading of electromagnetic flaw detection data,etc.An ECS server was used in the electromagnetic flaw detecting information platform,a database of electromagnetic flaw detecting information platform was designed,which realized the functions of role management,real-time monitoring and historical data check for the platform,and the whole system could be applied to WeChat official accounts.(4)The data compression scheme was acquired based on the characteristics of electromagnetic flaw detection data,and the SDT compression algorithm for rail flaw detecting values were emphasized on.Aimed at the insufficiencies of SDT algorithm in electromagnetic rail detection data compression,an improved SDT compression algorithm was put forward,and the feasibility and effect when processing flaw detection data with the improved SDT compression algorithm were verified.