| In recent years, pipeline accidents have frequently occurred, which caused a great deal of concern. In the fields of shipping oil, leak detection research has made a breakthrough, but is lack of active protecting. Pipeline Inspection Technology,which guarantees the safe operation of pipelines,is a multi-field, interdisciplinary topics. It involved technologies such as hydrodynamics, thermodynamic, sensor technology, weak signal detection, signal processing, etc . This paper focus on the weak signal detection and processing .The main efforts accomplished can be summed up as the following aspects:1. According to the theoretical and practical analysis of signal attenuation in pipe, the longitudinal wave of the fluid dominated wave is proved can be long-distanced transmitted,and it is chosen as the origin signal used in oil pipeline inspection .2. Framework of pipe inspection system has been structured,and the design of the wave sensor suitable for high-pressure pipeline in China is completed.3. Wavelet analysis is practically applicated in signal feature extraction under the strong noise pollution.4. The feature of signal is characterized by LPCC as parameters,and Hmm model is used for pattern recognition.Creative points are as followed:1. A kind of dynamic wave sensor, which inspects the longitudinal wave of the fluid dominated wave, has been designed, and it's suitable for high-pressure pipeline in China.2. DB4 has been chosen as the wavelet basis function, and been confirmed effective in feature extraction under strong noise pollution. Hmm model is used in the pattern recognition and the establishment of model library. |
