Study On Eye Movement Characteristics Of Operators In The Digital Control System During Target-searching And The Safety Influence

With the Nuclear Power Safety being paid much more attention in our country,the DCS, short of Digital Control System, tends to be used in the Main Control Roomof a new-built Nuclear Power Plant. Since the DCS advancing the system automationlevel, the apparatus reliability have been developed greatly as well as the cognitivepressure, in contrast, human error has been a main course leading to an accident. Theaccident consequence in a complicated man-machine system is usually extremelyserious, causing a great economic loss, or even worse making casualties and socialinstability. In order to improve the system safety and decrease the probability ofhuman error, it is appropriate to analyses the reliability of operators’ behavior.According to the video material analysis and visit about the Main Control Room of aNuclear Power Plant, it comes out that monitor is one of main operation for a operator,while visual search is a monitor activity and as a main path to obtain information, forthis reason, the paper consider the eye movement characteristic during a taskexecution as a beginning to explore visual eye movement characteristic during atarget-searching, which provides a foundation to make a deeper research on operators’monitor behavior law.On the basis of Safety Engineering, human factors, cognitive psychology and aneye tracker tool, the paper takes the SOP electronic operation procedures of a DCSNuclear Power Plant as the experiment material; chose four typical operationinterfaces—RCP, RCV, REA, TEP, what’s more, in each interface set up fouroperation task—Click, Close, Open, Auto, in a all16task interface; utilize thevisual-tracking system composed of eye tracker and computer to design and conduct atarget-searching experiment; use the SPSS and MATLAB to make a deeper dataanalysis on the eye movement data and make some conclusions as bellow:During a target-searching, target position, color character and shape character affect the eye movement situation, besides the un-target information sources will beobtained and processed by consciously or unconsciously. When searching the targetinformation sources, it is influenced by the searching background’s target position,color character and shape character, and the influence degree in turn is targetposition, color character and shape character. The clearer the target position, colorcharacter and shape character are, the easier the information sources will berecognized. It means that it is influenced by both top to bottom-target driven andbottom to top-data driven during target searching progress, under a certain task, taskdriven influences much greater than data driven. The eye movement fixation iscentered on the target position, diminished in the rim land. When divided thesearching background into four quadrants equally, the fixation time and the counts ofthe target quadrants are the most dominance classes, those of un-target quadrants areless and another quadrant gets the least. It explains deeply that during atarget-searching progress, the task position has a leading function and thoseinformation sources which close to the target can be achieved easily.Nuclear power accidents make people take nuclear safety seriously. HumanReliability Analysis (HRA) is inseparable. It turns out the HRA research has made agreat contribution to system safety. Only if knowing and grasping the law betweenboth, it will guide the people’s production and living which is the social developmenttrend. This research is a part of HRA, which is from the visual eye movement toexplore the way to improve the human reliability during target-searching activities,and the conclusions can assist to design a better man-machine interface, which willprovide a base to research the operators’ monitor behavior law and guarantee thesafety work much more smoothly.