Research On Wireless Intelligent Monitor Unit Of Pump Based On ZigBee

The current on-line diagnosis systems usually rely on traditional sensors and local area network, to realize distributed data collection and transmission. The installation and implementation of systems are limited by the field conditions and it is difficult to change and expand testing points. Wireless transmission technology can solve this problem, and promote the usage in dangerous environment, especially in hazardous chemical production systems. Research on wireless sensor network (WSN) with capabilities of perception, computation and communication is concerned by more and more technical staff and academics. WSN based on ZigBee protocol has a high density of network nodes, a large number of sensor nodes, and the data transmission has the property of exigency and discontinuity. Meanwhile, its network nodes can self-organize and the network topology can change frequently. At present, ZigBee is mainly used in temperature, pressure and other low-frequency signal acquisition and transmission. Due to the restriction of bandwidth, it still has shortage in acquisition of high-frequency signals such as those from vibration and acoustic emission, which constrains the application of ZigBee in diagnosis system.This paper researches building and optimizing technology of the WSN based on ZigBee. Intelligent node of wireless sensor network with functions such as signal acquisition, data processing, feature recognition and data transmission, etc. is developed. Vibration sensor of intrinsic safety is designed with two accelerometers in different range to keep the high resolution with broad range. FPGA and ARM is used to make WSN unit has function of data storage, data processing and characteristic parameters extraction. There are two modes in data transmission, transmission of characteristic parameters or waveform data. The former can reduce the network load and energy consumption obviously, and effectively improve the transmission efficiency. WiFi as connector between the WSN coordinator and server, overcomes the cost of wiring and the tedious work, as well as provides higher access bandwidth for simultaneous existence of multiple ZigBee networks.Finally, this WSN is tested in on-line fault diagnosis system of pump. Experimental results show that the system can implement signal acquisition and transmission, recognize abnormal state of rotating machinery timely and effectively.