Design Of Portable Infrared Thermal Imager For Pipeline Inspection

Pipeline transportation plays an important role in the transport of water,oil and gas,so safety testing during piping is particularly important.Buried pipes are often leaked due to corrosion,aging or man-made damage.In the event of a leak alarm,staff need to conduct on-site investigation and maintenance,but because of the buried pipeline leaks are in the ground,the naked eye is not easy to find it,so to find and confirm the leak has brought great trouble,both reduce work efficiency,but also increase the risk of environmental pollution and waste of resources.This paper designs a portable infrared thermal imager for the hot oil pipeline inspection line,which helps the pipeline inspector find the leak position conveniently and quickly,and reduce the risk and loss.This paper analyzes and compares the advantages and disadvantages of three kinds of portable infrared thermal imager design based on onboard BT656 interface,STM32F407 development board and CVBS switch USB module,and determines the system structure of infrared thermal imager based on CVBS to USB module,Based on AM4379 ARM processor and TC388 thermal imaging movement to build a portable infrared thermal imager hardware platform.In the embedded Linux operating system environment,the UVC image acquisition driver is written.The infrared image acquisition program is prepared based on the Qt programming environment,and the infrared image is collected,processed,stored and infrared image via CVBS to USB module.A method of detecting the leakage of buried hot oil pipeline based on SVDD(support vector data description)is proposed to approximate the rectangular area ratio and boundary spacing variance of pipeline contours.The boundary of the infrared image of the buried pipeline is extracted by the image processing method such as histogram equalization,image binarization and edge extraction.The rectangular contour is obtained by using the rectangle to get the rectangular rectangle with the smallest rectangle and the pipe can contain the largest rectangle,and calculate the variance of the distance between the two boundary pixels,the two parameters for the characteristics of the amount of SVDD modeling,to achieve the identification of pipeline leakage occurred.A simulation experiment platform for leak detection of buried thermal oil pipeline was carried out,and the test experiment of normal pipeline false alarm rate was completed.The experimental results show that the contours of the buried pipelines can be effectively extracted by the infrared image acquisition in different depth pipelines.For the same buried pipe,according to the rectangular area ratio and the boundary spacing variance threshold of thermal imaging,Effective detection of pipeline leakage.This paper designs a portable infrared thermal imager for the hot oil pipeline inspection line,providing a time-saving and technical means for the accurate positioning of the leakage point of the buried hot oil pipeline.