Navigational Ship Draught Detection System For Upstream Of Xiangjiaba

In recent years,with the development of national economy,inland waterway shipping,especially the Yangtze River shipping,has developed rapidly with its advantages of large volume,environmental protection,energy saving and low cost.The construction of Xiangjiaba Hydropower Station has greatly improved the navigation conditions and navigation efficiency of its watershed.At the same time,the problem of ship overloading and overdraft has become increasingly prominent,which seriously threatens the waterway and navigation facilities.Especially for Xiangjiaba ship lift,Overloading or overdraft of passing ship will not only affect the safety of ship itself,but also pose a major security risk to the safe and stable operation of ship lift facilities.Faced with the requirement of draught detection for Xiangjiaba ship lift navigable ships,aiming at the characteristics of the upstream of Xiangjiaba,such as huge changes in water level,special installation conditions and difficult installation of draft detection equipment,Designed a draft detection system for single floating navigable ship.Make compensation for the change of the attitude and position of the detection gate by water level gauge;Sound velocity compensation of ranging results is carried out by combining water level gauge with ultrasonic ranging sensor.The real-time off-board measurement of the draught of the navigable ship is realized,and the navigation efficiency of the ship lift is improved.The scheme of draught detection based on single floating detection platform puts forward new requirements for the design of the whole system.Firstly,in order to reduce the difficulty of detection door design and system maintenance and installation,it is necessary to reduce the weight of the detection door as much as possible.For this reason,after analyzing the characteristics of ultrasound and ultrasonic transducer,we redesigned the ranging module based on the STM32 to realize the deployment of ranging circuit on the water surface,which reduced the burden of the detection door.At the same time,the efficiency of data acquisition is improved by designing synchronous control and data acquisition module based on FPGA.The problem of blind area in draft detection system is analyzed,A maximum draft fitting algorithm based on least squares method is proposed to eliminate the error caused by the existence of blind zone.The application of the algorithm successfully expands the effective measurement range of the draft detection system and reduces the depth of underwater deployment of the detection gate.After preliminary laboratory experiments,we have carried out a large number of real ship surveying experiments upstream of Xiangjiaba.The analysis results of measurement data show that the error of the system is less than 0.1m,which meets the needs of the project.At present,the draught detection system for navigable ships upstream of Xiangjiaba has entered the trial operation stage.