Study And Application Of Underground Metal Pipeline Location Technology With Electromagnetic Field Method

With the deepening of China’s urbanization process,urban underground pipe network update and expansion is becoming more and more popular.City’s underground pipeline,all enterprises and institutions of the old pipeline,the new laying pipeline together,each unit of construction management,construction practice each are not identical,repeated construction of underground pipeline layout of chaos,the information management level also have differences,these factors are not conducive to the standardization of the underground pipeline management.Underground pipeline data is incomplete,if improper operation,construction is easy to cause harm to the other line,often in large losses.Strengthen the pipeline detection positioning and census is becoming more and more important.Detection of underground metal pipelines is generally based on the principle of electromagnetic induction to achieve detection.Generally,consists of two parts,the transmitter and the receiver.The transmitter is used to generate the power signal,and the signal is reduced to the metal line.The receiver is used to detect the pipeline,to measure the position of the pipeline,to determine the route of the pipeline,to measure the depth of the pipeline and realize the positioning of the pipeline.Pipeline positioning in general,including the direction of the pipeline routing location and buried depth measurement of the two indicators.Based on the study of electromagnetic field theory,combined with the characteristics of underground metal pipelines,the magnetic field strength distribution characteristics of the long straight conducting wire under the ideal condition are analyzed and studied theoretically.On the basis of this,the key technologies of pipeline location are studied,the principle of route location and buried depth measurement are mainly studied.Several methods of routing location and depth measurement are discussed,and the pipeline positioning technology scheme is designed.According to the technical scheme,design hardware circuit principle diagram,including signal acquisition module,signal prevention module,signal conditioning module,power supply module,digital signal processing module,keyboard control module and display module seven module circuit,completed the hardware circuit printed circuit board layout design,completed the circuit fabrication and debugging,carried out on the circuit testing and technical index verification.In the pipeline location,the transmission distance,measuring depth,in the actual measurement signal is relatively weak,the noise in the signal is also varied,put forward higher requirement for signal processing and calculation.Signal noise reduction includes two aspects,one is the use of analog circuit for signal filtering,another is the use of digital processing algorithms to achieve detection and signal processing;here focuses on the weak signal detection technology,to improve quality of signal detection from two aspects of hardware and software,improve the positioning accuracy.The design ideas and methods of improving test accuracy are analyzed.On the basis of hardware design,the software design of pipeline positioning is completed.Some key algorithms of software design are described,including digital signal processing algorithm,wavelet noise reduction algorithm,left and right position estimation algorithm and depth measurement algorithm.In the study,the use of embedded software modeling method,with the help of LabVIEW and MATLAB on the research of the algorithm has played a very good supporting role,improve the efficiency of the algorithm development.Through the establishment of the software algorithm model,the realization of DSP in MATLAB is realized quickly.On the basis of the software and hardware design,the PCB circuit is designed,the experiment test and verification analysis are carried out,and the manufacture of the prototype is completed.Finally,several typical test experiments are introduced,the data is analyzed,the data analysis conclusion is drawn,and the prototype design and verification test is completed.