Ergonomics Research On Application Of LED In Civil Cockpit Lighting

This thesis mainly focuses on ergonomics study of LED’s application in the cockpit lighting environment. We consider about interaction among human (visual characteristics), machine (LED) and environment (cockpit), aiming to get the key factors that would influence visual comfort and performance in the cockpit lighting environment. There are mainly three parts of research work in this thesis. Firstly, the study on light characteristics and visual effects of the new type LED light sources used in the driving cabin helps us know better of how LED would influence people and makes us better evaluating color temperature and color rendering characteristics of LED. Secondly, based on ergonomics research in the laboratory simulated lighting environment, we study visual characteristics of pilots and how it changes with age. Thirdly, based on ergonomics research in the simulated cockpit environment, we comprehensively study effect of luminance, color and contrast on visual comfort and performance, and get the key factors that would influence comfort and performance design in the cockpit lighting environment.This work started by investigating the main researches that have been done in this topic internationally, then discussed the key factors in the cockpit lighting and some existing problems. Through investigation on light sources, domestic and international standards, and survey for relationship among lighting environment, visual comfort and visual performance, we indentified the main problems should be solved in this work.Based on existing LED models, color temperature system, mesopic theory and non-visual biological theory, we make calculation and analysis of LED, and compare with traditional light sources, and then we understand the characteristics of LED. We also work on color rendering property of LED. By discussing on deficiency of traditional CRI model, and studying the main factors that would influence color rending evaluation, like naturalness, vividness and color discrimination, we define a new concept called correlated gamut area (CGA), based on which, we propose a new gamut color rendering index(GCRI). On evaluating color rendering of LEDs and some light sources with special spectrum, GCRI performs well. GCRI model can make objective evaluation of LED light sources. This study is meaningful for evaluating color temperature and color rendering property of light sources used in cockpit, and can be guidance for choosing suitable LED light sources for cockpit design.Based on ergonomics study in the laboratory simulated lighting environment, we study detection threshold of two groups of subjects with different age ranges. Through a systematic study of how luminance threshold and color discrimination threshold is influenced by contrast, color, luminance and target size, we speculate pilots’visual characteristics with different ages. According to statistical analysis, we deduce the exponential fitting function of luminance threshold and color discrimination threshold, and propose relative yellow index (RYI) to describe difference of pilots with different ages on yellow discrimination. This work comprehensively studies the visual characteristics of pilots and how it changes with age.Based on ergonomics research in the simulated cockpit environment, we systematically, study how light color, luminance, illuminance and contrast influence on preference and performance. We also study light panel and display used in the cockpit, and consider about their influence on general evaluation. According to the CIE tri-stimulus values, we define new tri-stimulus values X’, Y’and Z’, and theoretically deduce and evaluate relationship among color temperature, illuminance and comfort. This study provides a basis for LED application in the cockpit design, and can be used to help improve cockpit lighting design considering visual comfort and performance.