Development Of Real Time Clearance Height Measurement System For Bridges Based On Pulse Radar Level Gauge

With the rapid development of China's transportation industry,the large-scale ship has become the main trend of water transport.Due to the high water level of large-scale transport ships,it will bring certain security risks when passing bridges.At present,due to the lack of real-time clearance height data of bridges,when a ship driver navigates through the bridge hole,it is easy to cause a shipping accident because of the misjudgment of the headroom,which not only seriously damages the hull,but also jeopardizes the safety of people and vehicles on the bridge.Therefore,it is particularly important to monitor the headroom of large bridges in real time.Based on the investigation and analysis of the clearance height measurement and water level monitoring technology of China's major river systems,this paper proposes a method for real-time measurement of bridge clearance altitude based on pulse radar level gauge.The main research contents and conclusions are as follows:The GNSS-RTK technology was used to measure the height of the installation platform of the pulse radar level gauge.The principle of elevation measurement by GNSS-RTK is described,and the implementation method of platform elevation measurement using GNSS-RTK technology is analyzed.The accuracy that can be achieved is analyzed.The principle and method of real-time measurement of bridge headroom based on pulse radar level gauge are presented.The principle and disadvantages of high-precision trigonometric height measurement and dynamic GNSS-RTK elevation measurement method for bridge bottom height are studied and analyzed.The measurement principle of the pulse radar level gauge analyzes the causes of its measurement error.By improving the radar level gauge measurement implementation scheme,the measurement accuracy is improved,and the accuracy of the pulse radar level gauge to measure the clearance height of the bridge in real time is ensured.According to the requirements of navigation channel management and navigational safety requirements,a real-time measurement system for the clearance height of the channel bridge area based on pulse radar level gauge was designed and developed.The system is divided into three parts: the clear space standard monitoring subsystem,the bridge culvert standard monitoring subsystem and the supervision center subsystem.Through real-time data transmission between the sensor and the management platform,the system can accurately determine the clearance height of the bridge in real time,and can monitor the running status of the bridge and culvert,monitor and forecast the system in real time.The actual engineering application shows that the system can not only meet the requirements of real-time monitoring and forecasting of the clearance height of the fairway bridge area,but also can effectively guarantee the navigation safety and bridge safety of ships.