Design And Realization Of Real-Time Monitoring System For Bridge Alignment Based On Inclinometer

Bridge construction and service implement in an open environment, in addition to the weight of the bridge structure, material aging and other self-factors, the continuing effects of natural environment and human factors result in the bridge producing damages and deteriorations of various degrees. The absence of timely maintenance for these risks will shorten the bridge’s service time and effect driving experience, what’s worse, it will lead to the bridge collapse accident which endanger life and health, so the real-time health monitoring is an essential part for bridge. Bridge alignment, calculated by the deflection of bridge’s key section, is an important index to evaluate the bridge health status, which reflects the overall working condition of the bridge.Combined with the needs of Tianjin Haihe River Bridge health monitoring project, a system solution of bridge alignment monitoring is proposed in this paper after large analysis of deflection measurement method, furthermore, this paper complete the design of a high precision inclinometer and a data collection terminal with multiple types of interfaces. By using tilt sensor, the inclinometer realizes differential measurement of angle and filter out the common mode noise, moreover, the oversampling and temperature compensation in microcontroller further improve the measurement accuracy, and its design of isolation and anti lightning in communication interface circuit can inhibit the high energy transient interference effectively. Integrated a variety of analog and digital signal interface, data collection terminal can implement the data acquisition of various sensors in the monitoring system on the bridge, and through the wireless network the GPRS/CDMA module can upload the collected data to the monitoring center for data analysis and safety assessment.According to the actual contrast test, the measuring accuracy of the inclinometer is 0.005 degrees and the effective measurement range is 15 degrees, which can meet the actual demand of bridge alignment measurement.