The Design Of Monitor Node For Water-supply Pipeline Based On ZigBee

Along with rapid development of economy and urbanization process accelerated of our country, people’s demand on water resource continuously increases. People are paying more and more attention to water security problems, for which water-supply pipeline safety is proposed higher requirements. However, our country’s water supply pipeline transportation still exist a lot of leakage problems because of pipeline corrosion and aging, technology immature or other accidents.There are a lot of security risks. Therefore, it is very necessary to develop a safe,reliable and low-cost water supply pipeline monitor node for safe operation of the water-supply pipeline networks and to avoid the waste of water resources.Through the comparison of the leakage detection and location technologies and examples of their practical applications, we chooses the negative pressure wave method to detect the leakage by detect the pressure transient change of pipeline. When it is determined that a leakage has happened, the node begin to gather the acoustic signal in pipelines, which is prepare for the latter positioning of the leakage by acoustic method. At the same time, we also detect p H value change in pipeline, as a basis for leakage detection and monitoring of water quality. This paper analyzed the generation mechanism of negative pressure wave and acoustic wave in pipelines. The principle to detect leakage by using negative pressure wave method, the principle to locate leakage by sound wave method, and signal characteristics of leakage sound wave in pipelines are introduced in detail. The principle to detect the p H value is also described. A water supply pipeline monitor node based on Zig Bee is designed on the basis of the above study, the hardware of the node is made up of the pressure sensor, the pressure signal acquisition module, acoustic sensor, acoustic signal conditioning module, p H sensor, p H value acquisition module, time synchronization module, power supply module and other components. In the node, in order to solve the problem of complex pipeline acoustic environment noise signal and great acoustic attenuation after long distance transmission, the sound conditioning module has the function of amplification and filtering. The simulation of amplitude frequency and phase frequency characteristics to the circuit is done by Multisium. The software is divided into node software and PC software. The node software is compiled with the IAR embedded workbench software with C language. The program of each node is written on the basis of Z-stack. In this paper, the overall process of the monitoring of pipeline leakage and p H value anomaly by node and the overall process of leakage positioning by the computer data processing center is given. thesoftware process of the coordinator, router and terminal nodes which are the composition of wireless sensor network is also described. The PC software is compiled by Lab VIEW, which achieves the function of serial port communication, leakage data display, leakage acoustic signal waveform display, data storage and data setting. This paper gives the program block diagram of each function module of serial port communication, leakage data display, data storage and data setting.By experiment, it is verified that the water-supply pipeline monitor node can be used to detect the leakage of water supply pipelines and to detect the water quality change. Experimental simulation and practical experiments proved the effectiveness of the acoustic signal conditioning circuit in this paper. The experiment proved the validity and reliability of the wireless sensor network combined by water supply pipeline monitoring nodes. The nodes have important reference meaning in detecting leakage and water quality in pipeline, and it realized the expected goal of the design.