Bridge Monitoring System Based on Distribution Network Sensor

Large span bridge must be monitored to avoid the paroxysmal accident during their constructing and using. The deflection is the most important factor among all these parameters which can indicate the safety conditions of bridge. According to the theory of the liquid connectivity, the change of the bridge deflection can be obtained by recognizing the liquid level change in the connecting pipe installed on the bridge by optical imaging. The PLLD sensors are designed to compose a distribution network sensor system on the bridge. The method that RS-485 bus is transformed to Ethernet is used to implement the long distance data transmission. The upper computer gets the healthy state by analyzing and processing the credible and stable data it gets. This system can achieve long time online monitoring, non-contact measuring and it can control any sensor unit´s data collection automatically. The improvement of the optical imaging precision will lead to further improvement of the monitoring system precision.