Underground Metal Pipe Detector Developed

With the development of modern city, the underground pipeline has become the infrastructure of the city's survival and development. For some reason, the underground pipeline's information of our country is incomplete.and the underground pipeline is usually destroyed.It not only causes great loss of the country,but also seriously affects the people's daily life and brings some difficulties in the excavation and maintenance of the underground pipeline, so designing the underground metal pipeline detector of high-performance and high-precision is significant to provide portable pipeline detection tools for city builder and ensure people's daily life.Nowadays there are lots of companies which produce metal pipeline detector, but their products have certain defects, some have larger detection errors, some have single working mode and can not adapt to different environment,etc. In order to solve these problems, considering the basic theory of the electromagnetic method,we designed a set of high-performance metal pipeline detector which can be used to positione and detect the underground pipeline from the detector's actual function demand. The specific work mainly includes the following aspects:First, the designing of transmitter's system of the detector.The transmitter's RF signal uses direct digital frequency synthesizer (Direct Digital Synthesizer, DDS) technology and intergrated chip AD9833 to avoid the inconvenience of using divided components, and the signal produced is strictly verificated,this is one of the innovations of this study. It provides the guarantee for the long-distance exploration by realizing the high power output and multi-stage adjustable power through using the push-pull power amplifier circuit in power amplifier part. the whole transmitter's operation system is controlled by the MCU STC12C5410AD and the whole system operates reasonable and orderly. The advanced integrated chip technology and the traditional matched harmonic capacitance technology are used in transmitter module. Launching the four different frequency is realized,the noise is readuced effectively,and the whole transmitter has achieved optimum performance. The measure and control system of the transmitter software is written.Second,the designing of receiver's system of the detector. The receiver adopt three detection modes by using different detection modes for the transmitter's work.In order to improve the sensitivity of receive coil, the double-wire high magnetic permeability magnetic cores is used in the receiver module as receiving antenna, receiving module consists two groups of horizontal coil and one group of vertical coil,and detecting the pipeline with three methods--- peaks,throughs and sounding is realized, made t to some extend and the sensitivity of the receiver coil is improved by enlarging the receiving weak signals with the programmable amplifier and preamplifier circuit module considering the system's resolution and different detection environments. Frequency selective filtering module extracts the useful signal and eliminate the noise with the switched capacitor filter MAX262. The core module of receiver is controlled by the Silicon labs C8051F020,it achieved efficient detection for the entire system. The measure and control system of the receiver software is written.Finally, the actual system of detector is briefly introduced and measured, our designed underground metal pipeline is of high sensitivity, high precision and multi-working mode, it is easy to carry and operate in different environment and is very useful in the application of engineering practice.