Driven by advances in aviation technology, the operational performance of fighter aircraft is constantly improving, making the future aerial battlefield increasingly complex. Looking back at the development of head down display interfaces in fighter aircraft, from the earliest mechanical instruments to modern electronic displays, integrated large-screen displays have become the trend for future development. As the performance of fighter aircraft improves, the amount of information pilots face is rapidly increasing, with 70% of the information coming from visual sources. Therefore, it is of practical significance to explore the interaction layout design of head down display interfaces based on visual attention mechanisms to enhance pilots’ information acquisition capabilities.
Visual attention mechanisms refer to the selective concentration of attention in visual information processing, allocating limited cognitive resources to areas of interest to improve information processing efficiency and accuracy. Visual attention mechanisms possess characteristics of initiative, passivity, selectivity, and allocative, as well as visual cognition forms based on space, features, and objects. Interface layout refers to placing the information to be arranged within the interface according to design goals, ensuring that the information does not interfere with each other under certain constraints. The head down display interface is mainly divided into two parts: the navigation area integrated with display control information and the task display area, displaying operational information using different spatial configurations.
Based on the characteristics of the aforementioned visual attention mechanisms, this study proposes four design principles for fighter aircraft head-down display interface layout: uniqueness, specificity, objectivity, and robustness. The principle of uniqueness requires ensuring the uniqueness of the initial state, visual attention focus, functional display state, and feature form; the principle of specificity emphasizes displaying information distinct from uniqueness in special situations, effectively utilizing visual passivity to attract attention and appropriately using prompting information to inform changes in advance; the principle of objectivity requires matching with the aircraft environment, being task-oriented, and allowing pilots to autonomously set the interface layout form after familiar operation; the principle of robustness requires accurately conveying information in emergency situations, using backup information to reduce error rates, and presenting information in an appropriate manner according to needs. These four principles are not independent but complementary in application.
To verify the effectiveness of these design principles, this study systematically sorted out the interface display information and aircraft tasks and extracted the priority of the display information. The information display priorities of different classic aircraft stages of fighter aircraft vary, and the emphasis can be emphasized and expressed through interface layout. Therefore, this study conducted layout design for the interface based on aircraft tasks in the takeoff, cruise, combat, and mountain cruise stages. Then, a 4DVR aircraft simulation system was built using a two degree of freedom platform, HTC Vive Pro VR head mounted display device, and Lesida dual wing PXN-2119 aircraft joystick, and developed using the cross platform engine Unity. In the aircraft simulation system, the fighter aircraft takes off, reaches a certain height above the ground, and sequentially reaches the cruise target points, completing the cruise task. Subsequently, enemy aircraft are encountered in the air, entering combat mode. As a cruise oriented fighter, it does not carry offensive weapons and needs to enter the mountains, using mountain residual waves to interfere with enemy aircraft radar and evade pursuit.
This study conducted two experiments to verify the design principles. Experiment 1 aimed to investigate the correlation between head down display interface layout design and visual attention, verifying that the design principles can improve information acquisition efficiency. The experimental setting was that the fighter aircraft experienced engine abnormalities during aircraft, requiring the display of engine abnormality information. Through experiments with 60 subjects, quantitative data on reaction time and accuracy were obtained. T-test analysis of the data showed that there were significant differences in reaction time between the two groups, but not in accuracy, and the interface with the specificity principle had higher information acquisition efficiency.
Experiment 2 was based on the previous interface layout and 4DVR aircraft simulation system, aiming to verify that the interface layout based on design principles can effectively control information acquisition efficiency. Alarms, as special situations, can both display the classic interface layout and reasonably present alarm information, making them suitable for exploring information acquisition efficiency. The experiment used task performance measurement and subjective evaluation measurement methods, supplemented by semi-structured interviews for evaluation. 23 subjects were tested, and data were automatically recorded when operating the interface task. After completion, the subjects filled out questionnaires and participated in interviews. The experiment was conducted in two groups for comparison, with data collection and analysis methods similar to Experiment 1. The experimental data analysis showed that the first group had significant differences in global warning and local prompt, while the second group did not have significant differences in detail attention and pop up attention. The questionnaire results showed that using detail attention had a smaller cognitive load than pop up attention. Using global warning, subjects were more satisfied with the task, but frequent use would increase cognitive load. Local prompts are suitable for prompt-type information that does not need to be processed immediately. The interview results indicated that information prompts should also propose solutions and provide feedback after resolution.
In summary, this study verified through two experiments that the design principles of fighter aircraft head-down display interfaces based on visual attention mechanisms can effectively control information acquisition efficiency. Then, based on the design principles and experimental results proposed in this study, the layout of the fighter aircraft’s downward display interface was designed from a conceptual design perspective and loaded onto a 4DVR aircraft simulation system. Designing the layout of the fighter aircraft head down display interface from the perspective of visual attention mechanisms can provide meaningful insights for the future design of fighter aircraft cockpit head down interfaces.