The Application Research Of The Liquid Level Telemetry On Ship Stowage

According to the statistics of the National Bureau of Statistics,the volume of goods transported on waterways in China has shown a significant growth trend in recent years,which not only promotes the development of the shipping industry but also improves the requirements for ship loading capacity.In addition,in the process of cargo loading,unloading and transportation of ships,the phenomenon that the ship capsized and the hull fracture due to insufficient stability of the ship or the strength of the hull does not meet the specifications frequently occurs,which has caused people to pay attention to the safety of navigation.In the past,in the process of ship cargo transportation and loading,the liquid level data including ballast water and fuel was artificially measured,and then manually input into the loading instruments system for complex calculation including ship stability and strength.Which not only required a large amount of manpower input,but also works very inefficient.Under the above background,the application of liquid level telemetry in ship loading was studied in this paper which based on the regulation and control of oil and water in the ship cargo transportation process and the need for safety monitoring during cargo handling,and also combined with the research projects carried out by the laboratory.The work carried out in this paper mainly consists of the following parts:(1)The ship liquid level telemetry system was studied,After comparing and analyzing the basic structure,function characteristics and working principle of several liquid level telemetry systems,the liquid level measuring instruments studied in this paper were selected,and then the measured liquid level data were preprocessed.A correction method for liquid level telemetry data of arbitrary horizontal and vertical tilting state according to water line surface equation is proposed,and the liquid level data measured in sloshing state were filtered.Finally,the filtering effects of three different filtering methods were compared,which not only improve the accuracy of liquid level data,but also guarantee the accuracy of ship stability and strength based on real-time transmission of liquid level data.(2)The data communication process between the liquid level telemetry system and the loading instruments system was studied.According to the designed system network topology and the working principle of data communication,the communication protocol between the two systems was designed to realize the real-time transmission of liquid level data between the systems.(3)The floating state,initial stability and strength of ships were calculated,including initial metacentric height,righting arm,shear force and bending moment.Then,taking the data from the vessel "MV-M" as an example,the calculation principle of ship initial metacentric and strength was validated by tabular method.Finally,the intact stability and strength of the vessel"MV-Z" based on the calculation of liquid level data in real-time transmission were verified in accordance with the real data from the vessel.And based on the calculation results,the ship state can be safely evaluated to reduce the probability of accidents.(4)Under the different loading conditions of the actual ship "MV-Z",the influence of the changed liquid level data on the stability and strength of the ship was analyzed.The results show that the liquid level telemetry plays an important role in ship stability and strength monitoring,which makes the process of ship cargo loading and unloading more intelligent and ensures the efficiency and safety during loading and transportation.