Research On The Evaluation Method Of Legibility And Readability Of Fonts On Aircraft Cockpit Interfaces

Flight safety and efficiency are the eternal goals in the aviation field.In the cockpit,the crew can obtain information and realize human-computer interaction through the cockpit interface.Text is the most basic,intuitive and important unit in man-machine interface.The speed and accuracy of pilots’ interpretation of flight information are closely related to flight safety,especially under extremely harsh conditions.For improving the quality of information display and ensuring flight safety,the research on the evaluation method of legibility and readability of fonts on cockpit interface is of great significance.The main research work is as follows:(1)The concepts of legibility and readability are defined,and the levels of relevant influencing factors are divided.From the demand of aircraft cockpit,the content of man-machine interface and the particularity of cockpit environment are analyzed.The typical flight missions in which the pilot interacts with the text on the interface are extracted and the textual information is classified.(2)On the basis of comprehensive literature,according to the principle of "scientific,goal-oriented,structured and all-round",a legibility evaluation system including two stages,four attribute categories and 22 indicators is constructed.A readability evaluation system including two stages,four attribute categories and 20 indicators has also been established.It interprets the selection of evaluation indicators,measurement methods and the judgment of measurement results.It can provide evaluation tools for professionals and help designers choose,modify and design fonts with high legibility and readability.(3)According to the evaluation system and the analysis of special environment of the cockpit,five design requirements are put forward.Referring to the font design theory and high-quality fonts,11 specific principles guiding font design are proposed.Following the above design specifications,a new font Air was created for the cockpit interface.In terms of legibility and readability,the crew can obtain textual information efficiently and safely.(4)The experiment of measuring font contrast threshold was designed to evaluate the legibility of fonts.The eye movement experiment of visual search of target characters was designed to evaluate the readability of text.Comparing the Air with Futura and Helvetica,the experimental results show that the new font has excellent overall performance,especially for the readability of confusing characters.Futura and Helvetica produce similar results,but perform better on individual characters than Air.It basically verifies the feasibility of the new font and shows the working method of the evaluation system.