民机驾驶舱在恶劣光环境下的飞行员视觉工效研究

Visual Ergonomics Research of Civil Aircraft Cockpit in Harsh Iuminous Conditions

科学合理的光环境设计可以优化驾驶舱人机工效、提高飞机的安全可靠性,尤其对飞行员视觉、心理等方面,起到积极的指导作用。驾驶舱光环境在大型飞机人机工效综合设计研究中有重要的地位和意义,该报告首先指出了航空视觉问题的特殊性及其与人—机—环境系统的交互作用。然后从光亮度范围、光色的选择、辅助照明、眩光控制、亮度水平与易读性的关系等方面阐述了驾驶舱光环境设计的研究的意义和现状,并展望了民机驾驶舱光环境的研究方向。其次,介绍了相关的视觉理论,并从视觉工效学和实验心理学角度分析了视锐度的定义及测试手段,以及反应时间的特征及其影响因素。针对闪电、太阳直射等恶劣光环境下飞行员视觉功能受到的影响以及应对措施进行了视觉工效学研究。总结了恶劣自然光环境对飞行员视觉功能的影响,将"雷暴雨"和"穿云层"两种典型恶劣光环境的视觉特点抽象为脉冲型和阶跃型的亮度变化,以不同光环境为自变量,视锐度、反应时间和判读准确率为因变量,在全尺寸模拟驾驶舱中对10名被试进行了视觉工效学实验。以判读准确率作为参数,对视锐度和反应时间进行了速度-准确性平衡修正。数据分析结果表明,两种典型的恶劣光环境对视锐度有显著的负面影响;阶跃型光环境变化场景下的反应时间会显著增加,而脉冲场景下的反应速度会所有提高。这些影响都可以被雷暴雨灯提供的背景亮度所消除。两两对比分析后,建议飞行员应该在遇到恶劣光环境之前打开雷暴灯,这样其视觉功能将始终不受光环境突变的影响。针对夜间飞行眩光对飞行员视觉绩效的影响展开研究,选取探测驾驶舱外界目标的反应时间、对于显示器出现视标的探测和识别的阈值尺寸3个因变量作为视觉绩效的评价指标,研究了眩光源亮度、眩光源立体角,背景亮度3个变量对于反应时间的影响以及眩光源表面亮度、显示器视标亮度两个变量对于显示器视标识别绩效的影响。实验结果显示,眩光源表面亮度的提高会增大显示器视标的探测和识别阈值尺寸,但该增量会随着视标亮度的提高而减小,而视标亮度的升高则会减小对于视标的探测和识别阈值尺寸,当视标亮度大于9 cd/m2,阈值尺寸随眩光源表面亮度和视标亮度的变化率趋近于0。该实验结果可以对驾驶舱和飞机场照明的防眩光设计提供一定的理论依据。

Cockpit luminous environment has a significant status of large aircraft ergonomics design, the present thesis pointed out the specific characteristics of aviation visual problems and the interaction with man-machine-environment system. The significance, research status and future study of cockpit luminous environment was summarized from different aspects, such as brightness range, glare control, relationship between luminance level and legibility. Relative vision theory was introduced,while the definition and measurement method of visual acuity as well as the features and influencing factor of reaction time were analyzed. Negative effects on aviator＇s visual performance of harsh luminous environment emerged in variety of natural and weather conditions were summarized. Visual features in two typical harsh luminous environments, thunderstorm and direct sunlight, were abstracted. Tests in a full-scale simulator cockpit were performed with 10 participants while visual acuity,reaction time and identification accuracy were recorded as dependent variables. IA data was taken as a correction factor to correct RT data for each participant under each experimental situation to minimize testing error, with consideration of the speed-accuracy trade off phenomenon. Data analysis result indicates that standardized VA value decreased significantly in both pulsing and step conditions in comparison with dark condition. Standardized RT value increased significantly in the step condition; on the contrary, less reaction time was obtained in pulsing condition. The results are to be used as principle for optimizing lighting design with thunderstorm light. The influence of the glare on the visual performance of the pilot in nighttime flying is also focused on. Three indicators are selected for evaluating the visual performance which is the reaction time of detecting the target outside the cockpit, the detection and discrimination threshold size of the Landolt ring on the display screen. The detection discrimination threshold size get smaller with increasing target luminance but decreasing glare luminance, the variation of the threshold size because of the change of the glare source will get smaller when the target luminance gets higher. When the target luminance is higher than 9 cd/m2,the variation of the threshold size may be close to zero. The conclusion can provide some recommendation for the lighting design of the cockpits and airport against glare.