Research On Measurement System For Seafloor Sediment Pressure Environment Simulation And Acoustic Test

In the underwater acoustic exploration of the ocean,the area between the surface and the seabed constitutes the measurement range,among which the seabed sediment is taken as the bottom boundary,and its acoustic characteristics are one of the important research contents of the ocean acoustic exploration,which is closely related to the development of Marine science,as well as the development and construction of the ocean.At present,the research on the acoustic characteristics of seabed sediments is mainly based on laboratory acoustic measurements,but due to the separation from the in-situ environment,the measurement results are biased compared with in-situ measurements,and the variation mechanism and degree of such deviation are still unsolved.Therefore,it is necessary to develop a measurement system for seafloor sediment pressure environment simulation and acoustic test,in order to research the influence of pressure factors on the acoustic characteristics of the seafloor sediments,and to establish a link between laboratory measurement and in-situ measurement.The main contents of this paper are as follows:1.Design the pressure environment simulation scheme,and design the pressure method and the overall structure scheme of the system accordingly.2.Design the mechanical structure of the system and its simulation analysis,check its strength and analysis of the impact of deformation on the measurement accuracy.3.Design the hardware of the electronic control device of the system,including the hardware circuit design of the servo system,the input circuit design of the sensor and the hardware design of the PLC.4.According to the control requirements of the system,the T-chart program of safety control,analog quantity processing,automatic pressure,manual control,shaft position initialization,shear failure inspection and other functions is designed,and the upper computer software is designed based on Win CC.5.debug the system,test its performance and correct the displacement measurement.Based on the system,carry out acoustic-pressure characteristics test of water and sediment,the results show that the function and performance of the system meet the expected requirements,and verify the influence of different pressure factors in the in-situ pressure environment on the acoustic characteristics of seabed sediment.The system can simulate the pressure environment(including water depth pressure and buried depth pressure)and measure the acoustic characteristics of the sediment.The system is based on PLC,servo pressure control,multi-sensor measurement,Win CC interaction to achieve in-situ pressure environment simulation and pressure automatic control,can simulate the water depth pressure up to 10 MP and horizontal buried depth pressure,pressure control accuracy 0.02MPa;The maximum axial force of 50 k N can be applied to the sample to simulate the vertical buried depth pressure,and the control accuracy is 0.2k N.At the same time,the displacement control and length measurement of the sample during the experiment can be realized with an accuracy of 0.1mm.