Ultrasonic In-line Inspection System of Pipeline Corrosion Based on Maximum Entropy Spectrum Estimation

Ultrasonic detection is one of the important ways to inspect the wall-loss defects on-line for pipeline.The on-line power spectral estimation that characterized short time serial,higher resolution and anti-noise was a key technology to in-line inspect the pipeline.Based on maximum entropy spectral estimation on-line,the multi-channels ultrasonic inspection system with 20 probes was developed.The system consists of main and sub-structure.Inspection board communicated with embedded computer with PCI bus and the numbers of channel was expended by means of high-speed switch.The ultrasonic echo signal was processed with Burg maximum entropy spectrum estimation on-line.The test shows that the inspection system could inspect the inner and outer defects and is suitable for on-line detection of pipeline corrosion.