Research on Multi-probe Ultrasonic Automated In-line Inspection System of Pipeline Corrosion

The ultrasonic in-line inspection system for pipeline corrosion features multi-channel, high-speed and bulky storage capability. Its detection circuit is characterized by high integration and low energy consumption. Multi-channel ultrasonic automatic inspection is a key technology to inspect the pipeline. The on-line power spectrum estimation featuring short-time series, high resolution and strong anti-jamming ability is an important algorithm of data-processing for in-line inspection. Based on on-line Burg Maximum Entropy Spectral Estimation (MESE), the digital multi-channel ultrasonic in-line inspection system with 20 probes was developed. The system consisted of main and sub-structure. Inspection board communicated with embedded computer through PCI bus and the number of channels was expanded with high-speed switches. The ultrasonic echo signal-processing adopted on-line mode and this processing algorithm was simple as well as fast and possessed good real-time and strong anti-jamming abilities. The pipeline corrosion could be judged by the residual wall thickness. The experiment of standard pipeline section shows that the inspection system has high precision and accurate orientation to inspect the inner and outer defects. Its data acquisition, processing, storage and image display can satisfy the requirement of in-line inspection. It will be used widely in practice.