Pipe Corrosion With Ultrasonic Detection Signal Processing Research

Safety inspection of oil and gas pipeline has been paid more and more attention. For the sake of guaranteeing their safe movement and prolonging their life, the pipelines should be inspected periodically in order to discover the problem and take the measure timely. In-line pipeline inspection with Ultrasonic is one of the most important ways for the safe inspection. Pipeline orientation and ultrasonic echo signal processing are the key technologies of pipe inspection. It is needed to know the real-time locations when scanning and record them in order to locate corrosions from the ground after the detection is completed. Therefore, the accurate orientation is the key technology to pipeline inspection.In this paper, the four-step comprehensive method which contains course wheel orientation, welding lines modification, outer orientation modification and revolving angle orientation applies to locating pipeline corrosions. At the same time, outer orientation modification usually use the way of low-frequency electromagnetic wave to modify the course wheel's count, for improving the precision. This article establishes the out orientation model of in-line pipeline inspection, deduces the formula of the magnetic strength in the pipeline, uses ANSYS software to simulate the model. Compared with experimental data, simulation results show that different parameter values would affect the magnetic strength in the pipeline.Based on in-depth analysis, the ultrasonic echo signals are processed by "radial-base-kernel function" SVM, using two ways of "one to many "and the layer (tree) classification to achieve automated classification of the corrosion levels of pipeline. Experimental results show that the method improves the classification accuracy, and processing speed, and better classification results are achieved.The corrosion processing software achieves detecting orientation and multi-channel signal operation.