Water Supply Pipeline Leak Detection Based On Piezoelectric Sensors And Signal Processing Technology Research

The rate of urban water supply pipeleak in the developed countries is from 7% to 9%,and it is from 20% to 30% in China.In recent years,due to the pipeline aging,engineering construction,etc,the water supply pipeline leaks frequently incidents result in a tremendous waste of water resources.The leak detection technology of water-supply interprises in our country is out of date,it is an urgent task to search an method to quickly and accurately find the leak point to improve the efficiency of pipeline network.With piezoelectric sensors to detect the vibration signals which generates when water supply cast iron pipe leaks,studied a signal processing technology for water supply pipeline leak detection.The study of the main contents include:First,designed a piezoelectric acceleration sensor signal conditioning circuit.Designed a charge-conversion circuit due to the vibration signals of water supply pipeleak are very weak;According to vibration signals frequency range of water supply pipeline leaks designed switched-capacitor band-pass filter based on the MAX266.Second,used the low-power C8051F020 processor to acquisition and storage the data of the vibration signals and control the whole system during work.Set the internal timer 2 of the C8051F020 to start ADC for acquisition signal,according to a low-power requirements and the amount of data needed to locate leakpipe,set up each signal acquisition time for 15 minutes between 2 o'clock to 3 o'clock at night.As the internal data memory of C8051F020 is limited, we used the AT45DB081 FLASH data memory. Used USB interface as the channel to send commands and data, sents the vibration signals which be stored in external memory to the host computer, provided the necessary data basis for follow-up leak detection and location. Finally, used the data collected to the location processing, test verification, using this signal processing technology in a distance of more recent and more distant points in the leak can be more precise positioning,it can satisfy the practical demands of pipeline leak detection and location.