| In traditional bridge monitoring system, sensor complicated in practical application is cable. In order to process and diagnose signals, each sensor transmits signals to central processing unit through wires which requires lots of wires. This will not only increase costs, but also make installation more difficult, it is unsuitable for bridge monitoring system. Compared to traditional bridge monitoring system, wireless bridge monitoring system has great advantages. The key technology is completing information wireless transmission. Wireless stress sensor based on ZigBee presents in this paper can dispose and achieve signals conveniently and fast.Having studied the structure of wireless bridge monitoring system and analyzed the demands of wireless stress sensor, on the basis of researching current wireless communication technologies, wireless bridge monitoring system acquisition terminal and wireless stress sensor composition based on ZigBee have been proposed in this thesis. In order to achieve accurate stress strain parameter, resistance strain gage is used for measuring strain signals in the coupling produced from the stress response. Having analyzed the working principles and structures of resistance strain gage, it comes out that resistance strain gage is suitable for this system. From the view of low-power, low cost and character of wireless sensor network, modular pattern is proposed to create the acquired stress sensor node. Based on the comparison of several short-range wireless communication modes, ZigBee wireless transceiver module based on CC2430 has been selected to complete signalsNtransmission. WhatN more, this thesis has analyzed communication protocols and designed data transmission frame. Data acquisition and signal transmission of wireless stress sensor have been achieved on the IAR development platform. Experimental results have shown that the sensitivity of wireless stress sensor is 1με, and the transmission distance can up to 80 meters. |
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