System Design And Influencing Factors Of Helmet Imaging For Inland Diving Salvage

In recent years,inland waterway transportation has become the most important part of waterway construction.With the vigorous development of inland waterway transportation in China,various kinds of waterway traffic accidents begin to occur frequently,and the number of victims is also increasing frequently.Therefore,the safety of inland waterway transportation is more and more important.At the same time,the rescue after the accident has become particularly important.It is time to strengthen the research on inland waterway rescue and salvage.It is urgent and necessary.In the process of salvage and rescue of inland rivers,because of the large amount of suspended sediment,the water permeability and visibility of inland rivers are low.It is impossible to use light equipment for underwater rescue,which seriously affects the efficiency of underwater rescue.Under such conditions,the effect of ultrasound imaging is particularly prominent.Therefore,this paper proposes to use sonar and diving salvage helmet together,and launches the research on image display of inland river diving salvage helmet sonar.The specific research contents are as follows:1)Based on ergonomics,the requirement analysis of the design of inland diving salvage helmet is carried out.Since the design of the helmet is based on human beings,the problem of screen contrast in the design of the helmet is analyzed from the perspective of human eyes,as well as the distance relationship between the projected virtual image and the diver.The overall framework design of the inland diving salvage helmet is completed.2)On the premise of the Yangtze River water transport,the sediment composition in the Yangtze River waters is analyzed experimentally,and the law of sediment diameter distribution is obtained.Under this sediment distribution,the light attenuation is analyzed.The theoretical property of serious light attenuation in the experiment and the contrast are combined to provide guidance for the design of diving helmet.3)To study the influencing factors of sonar imaging in acoustic imaging,firstly,to study the influence of sonar frequency on sonar imaging,secondly,to determine the number of array elements in sonar probe,to analyze the mechanism of inland river sediment on sonar imaging,to find out how to avoid the influence of sediment on sonar imaging,secondly,to study the influence of detection distance on sonar imaging,and finally to verify it by designing simulation experiments.4)The integration of diving salvage helmet is carried out,and the pressure and function experiments are carried out on the diving salvage helmet through experiments.Each index shows that the diving salvage helmet can meet the requirements of rescue salvage;the underwater illumination survey of Moon Bay in Wuhan is carried out,and the theoretical knowledge of human eye contrast is combined to analyze the use of acoustic imaging and optical imaging in different situations for rescue salvage salvage.The contrast experiment of ultrasonic imaging effect in sediment environment is carried out.The results show that in inland waters with less sediment and smaller sediment particle size,the 3.5MHz ultrasonic system can obtain clear underwater images within 0.5m.However,in the inland waters with larger sediment particle size,the ultrasonic frequency should be chosen between 0.375 MHz and 0.75 MHz.The innovations of this paper include:1)Man-machine engineering mechanism analysis of visible helmet with low visibility in underwater optics and acoustics has been completed.The influence of sediment particle size on light attenuation has been analyzed from optics.The situation of using acoustic imaging in underwater salvage with different ground illumination has been obtained.The influence of sediment on sound attenuation has been studied from acoustics,and the sonar frequency and equipment suitable for different environments when optical imaging is not available have been obtained.2)Complete the integration of sonar and diving salvage helmet,complete the design of digital circuit of sonar system,complete the production and research of physical objects.Through this study,technical support is provided for the development of the ultimate rescue and salvage helmet,so that in the low visibility inland river rescue and salvage operations,the scope of vision of rescue workers is increased,thus improving the efficiency of inland river rescue and salvage.