A Experimental Platform Of Magnetic Flux Leakage Testing System Based On ARM

In order to find out the relationship between the types of defects in the pipelines and the flaw data, we set up an experimental platform system to detect and analyze the oil pipeline defects. This research is one of the most important parts of the national 863 key project–"Robot and Detection technology in offshore oil pipeline". Its main task is to design a magnetic flux leakage(MFL) online inspection system, create an adaptive filter and apply the adaptive filter in MFL signal processing. This system aims to realize the MFL signal pre-processing, real-time data acquisition, de-noised and data compression.This experimental platform system contains two important theories in this paper: principle of leakage magnetic detection and ARM technology. We design mechanical device, Hall sensor array, conditioning circuit, ARM processor, IDE module, USB module, LCD & keyboard and data analysis module based on the two theories in this paper.The content of platform divided into two parts: hardware and software. The task of hardware is to formulate the data acquisition system, fix out the chip type for each module,draw out the schematic and PCB,joint the chips and dedug the hardware circuits. The hardware circuits consist of the power module, multi channels data acquisition module, IDE module, LCD module, USB module and ARM module. The task of software is to transplant UC/OS-II system into ARM processor, explot IDE,USB,LCD driver program to insure the flaw data well stroaged,displayed and transmited.We processed several defects simulated form ocean pipeline with different sharp and size on steel plate. We analyzed and verified the general rule between the MFL field signal and the different types of flaw according to character of flaw such as depth,width and length based on MATLAB. The conclusion is the range and the strength of MFL field is proportional to the size of flaw, so we can find out the special information about each different flaw.