Research On New Method Of Ship Weighting Based On Ultrasonic Phase Control Technology

With the rapid development of China’s foreign economic and trade,the import and export of bulk marine bulk cargoes,which are related to national economy and people’s livelihood,are increasing rapidly year by year,and the existing ship weighting methods are gradually unable to meet the increasing weighting requirements.Existing ship weights are calculated by reading the draft lines on the six sides of the ship to be tested,and then combining the accurate chart of the ship to calculate the weight of the cargo carried.There are inevitably some defects.The underwater hull before and after the additional load is scanned by phase control,the three-dimensional model of the underwater hull is reconstructed and the volume is calculated,and then the weight of the cargo is obtained using Archimedes’ theorem.The specific research contents are as follows:First of all,through the analysis of the current status of ship water gauge weighting and ultrasonic phased array technology,the research route of the subject was planned.The principle of sound field radiation,ultrasonic focusing technology,phase control technology,acoustic lens focusing technology and water gauge weighting of ultrasonic array transducer related to this subject are studied,and the method is verified by theoretical analysis.Then set up a set of ultrasonic water gauge weighing test system,including ultrasonic array transducer,FPGA-based signal transceiver system and weighing software,in addition to the analog load device and traction device for testing.Then by analyzing the echo signal,the factors that affect the signal-to-noise ratio of the echo signal are studied.Afterwards,the ultrasonic echo time delay estimation method was studied,and the matched filter algorithm was used to improve the signal-to-noise ratio of the signal.On this basis,a scanning point space calculation model was established,and point cloud data processing methods and Delaunay were studied for point cloud data.Triangulation algorithm to realize the three-dimensional reconstruction of the hull.Finally,a sound field test experiment is performed on the transducer to analyze the radiation performance of the array transducer;and a small load ship model is used as the measurement object to calculate the error magnitude at different loads,and at the same time,the uncertainty analysis of the weighted results is performed.The results show that when the load is within 10 kg,the weight error of this method does not exceed 2%,and the relative measurement uncertainty is less than 0.5%.