Study On The Impacts Of Sea-ships' Visual Display Units On Navigating Safety At Night

Navigation equipments are important means to ensure the navigation safety of ships,Visual Display Units is the main way of human-computer interaction of equipments.With the deepening of ships intelligence and information,the quantity of equipment in the bridge is gradually increasing.While the Visual Display Units provides the man-machine interface,its influence on shipping safety under night navigation conditions should not be ignored.This thesis mainly focuses the influences of uncomfortable glare and dark adaptation on WWO's navigation vision at night,some measures to reduce the influence on Visual Display Units layout and brightness control are proposed.This thesis aimed to reduce the influence of Visual Display Units on night lookout and promote the safety of night navigation under the premise of ensuring the efficiency of man-machine information interaction.Basing on the basic theories of vision,the Visual Display Units affects the WWOs lookout during night is pointed out at two aspects,namely visual efficacy and visual psychological comfort.The main factors include uncomfortable glare,porthole reflection,contrast sensitivity,screen color,color temperature,light color and light source position.Based on the influencing factors,the indicator system for the visual evaluation of the WWOs by Visual Display Units are constructed.Basing on the characteristics of ships' actual work,this thesis explores more applicable ways of Delphi method,aimed to study the main factors of the WWOs' visual influence in the bridge.At first,basing on the improved Delphi method,the weight function of visual impact index is constructed,and based on the weight of visual impact index,the comprehensive evaluation of the visual effects of Visual Display Units on night WWOs are conducted,assess the degree to which Visual Display Units affects the WWOs' vision.The most important factor of visual impacts on WWOs are obtained,the causes of this factor are explored and lays a theoretical foundation for further management of the light environment on the bridge.The brightness of Visual Display Units is not only the main cause of uncomfortable glare,but also the cause of dark adaptation to WWOs' vision.This thesis study the brightness change of Visual Display Units at two aspects,Visual Display Units and background light source.Firstly,the main factors affecting the brightness of the terminal and the spatial distribution of the background light source are studied,and the Visual Display Units brightness model is proposed basing on the background light source.Then,depend on the Visual Display Units brightness model of background light source,MATLAB is used to simulate ECDIS and the radar Visual Display Units to influence the brightness of the bridge in any space.Basing on the achievement of the brightness of the bridge anywhere in space,the influence of uncomfortable glare and dark adaptation on the WWOs' vision are studied further,which purpose is to reverse the reasonable interval of the brightness of the bridge by controlling the two factors.Firstly,based on the evaluation of uncomfortable glare on ships,the luminance interval of controlling uncomfortable glare is obtained,and the control effect of variable control table types on uncomfortable glare is verified.Then,basing on the experiment on ships,the optimal luminance interval to reduce the influence of dark adaptation is obtained.Finally,basing on the results of uncomfortable glare and dark adaptation,the optimization measures of the interior light environment of the bridge is put forward.