With flying colours: Pilot performance with colour-coded head-up flight symbology

The manipulation of colour in display symbology design has long been recognised as a method to improve operator experience and performance. Recent developments in colour head-up display (HUD) and helmet-mounted display (HMD) technology underline the necessity to understand the human factors considerations of symbology colour coding against conventional monochrome symbology formats. In this low-fidelity desktop human-in-the-loop experiment, the colour of flight symbology on an overlaid symbology set was coded as a redundant cue to indicate the accuracy of professional and non-professional pilots’ flight profile across a range of simulated flight manoeuvres. The main finding of this study was that colour coding flight symbology supported the manual flying performance of both professional and non-professional pilots. Notably, colour-coding of the bank indicator and airspeed tape minimised performance error during turning and altitude change manoeuvres, respectively. The usability of colour coded symbology was also rated higher than the monochrome symbology. We conclude that colour coded HUD/HMD symbology is preferred by the user and may improve performance during low workload manual flying tasks. A fuller understanding of performance and workload effects will require future studies to employ higher workload flying tasks and examine the utility of colour coding within higher fidelity environments.     

Superimposition, symbology, visual attention, and the head-up display

In two experiments we examined a number of related factors postulated to influence head-up display (HUD) performance. We addressed the benefit of reduced scanning and the cost of increasing the number of elements in the visual field by comparing a superimposed HUD with an identical display in a head-down position in varying visibility conditions. We explored the extent to which the characteristics of HUD symbology support a division of attention by contrasting conformal symbology (which links elements of the display image to elements of the far domain) with traditional instrument landing system (ILS) symbology. Together the two experiments provide strong evidence that minimizing scanning between flight instruments and the far domain contributes substantially to the observed HUD performance advantage. Experiment 1 provides little evidence for a performance cost attributable to visual clutter. In Experiment 2 the pattern of differences in lateral tracking error between conformal and traditional ILS symbology supports the hypothesis that, to the extent that the symbology forms an object with the far domain, attention may be divided between the superimposed image and its counterpart in the far domain.     

Workload benefits of colour coded head-up flight symbology during high workload flight

The manipulation of colour in display symbology design has been recognised as a method to improve operator experience and performance. An earlier paper by the authors demonstrated that redundantly colour coding head-up flight symbology supported the manual flying performance of both professional and non-professional pilots during low-workload flying scenarios. In this study the workload and performance of 12 professional airline pilots was evaluated in high workload conditions whilst they flew manoeuvres and an instrument landing system (ILS) approach with and without the presence of colour feedback on a head up display (HUD). Workload was manipulated by presenting pilots with a concurrent auditory n-back task. Colour coded flight symbology reduced the subjective workload of the pilots during high workload conditions. In contrast, manual flying performance during high workload was not improved by the presence of colour coded feedback.     

An eye-tracking study of how color coding affects multimedia learning

Color coding has been proposed to promote more effective learning. However, insufficient evidence currently exists to show how color coding leads to better learning. The goal of this study was to investigate the underlying cause of the color coding effect by utilizing eye movement data. Fifty-two participants studied either a color-coded or conventional format of multimedia instruction. Eye movement data were collected during the study. The results indicate that color coding increased retention and transfer performance. Enhancement of learning by color coding was due to efficiency of locating corresponding information between illustration and text. Color coding also attracted attention of learners to perceptually salient information.     

Comparison of helmet-mounted visual displays for flight simulation

The objective was to determine if there are performance differences among pilots accomplishing simulated aerial refuelling using five different visual display configurations. The displays were all used in the A-10 cockpit of the Advanced Simulator for Pilot Training (ASPT). The configurations were (a) a helmet-mounted binocular display, (b) lead lanthanum zirconate titamate (PLZT) goggles (binocular) used with one channel of the ASPT display, (c) a helmet-mounted biocular display, (d) the ASPT 300° field-of-view (FOV) dodecahedron display, and (e) the ASPT display masked to present an FOV equal to that of the helmet-mounted displays. Forty subjects participated in this effort: eight per display condition. After an initial practice period, the subject's first task was to estimate distances behind the refuelling tanker while the A-10 was flown automatically to the contact position. The pilots then flew the refuelling task three times. Dependent variables measures were the oscillation of the A-10 receiver receptacle around the centre point of the acceptable refuelling boom movement envelope in three dimensions. The results show that the subject's ability to estimate distance does not differ significantly among the display configurations. Although performance measures were recorded during both the approach and contact phase of the refuelling task, a computer malfunction negated the value of the approach measures. Measures obtained during the contact phase clearly indicate the value of a wide FOV and of stereoscopic depth cues. Optics in front of the eyes were shown not to be detrimental, and the helmet-mounted stereoscopic display proved superior to the PLZT goggles.     

Change blindness in pilot perception of METAR symbology

ObjectiveTo assess General Aviation (GA) pilots' perception of changes in aviation routine weather report (METAR) symbols.MethodSixty instrument-rated GA pilots were randomly assigned to one of three METAR symbology groups. We assessed pilots' ability to detect changes to the METAR symbols during a simulated flight, and examined the relationship between detection performance and pilots' flight behavior, cognitive engagement, and decision making.ResultsDepending on the symbology, pilots varied considerably in their overall detection of METAR symbol change during flight. Pilots who detected the METAR-symbol changes differed in their cognitive engagement compared to pilots who did not detect the changes.ConclusionWeather presentation symbology affects pilots' perception of symbol change and cognitive engagement.Relevance to industryThe simulation outcome provides important data on the perception of weather-presentation symbology important to the design and optimization of cockpit weather displays.     

Target cuing in visual search: the effects of conformality and display location on the allocation of visual attention

Two experiments were performed to examine how frame of reference (world-referenced vs. screen-referenced) and target expectancy can modulate the effects of target cuing in directing attention for see-through helmet-mounted displays (HMDs). In the first experiment, the degree of world referencing was varied by the spatial accuracy of the cue; in the second, the degree of world referencing was varied more radically between a world-referenced HMD and a hand-held display. Participants were asked to detect, identify, and give azimuth information for targets hidden in terrain presented in the far domain (i.e., the world) while performing a monitoring task in the near domain (i.e., the display). The results of both experiments revealed a cost-benefit trade-off for cuing such that the presence of cuing aided the target detection task for expected targets but drew attention away from the presence of unexpected targets in the environment. Analyses support the observation that this effect can be mediated by the display: The world-referenced display reduced the cost of cognitive tunneling relative to the screen-referenced display in Experiment 1; this cost was further reduced in Experiment 2 when participants were using a hand-held display. Potential applications of this research include important design guidelines and specifications for automated target recognition systems as well as any terrain-and-targeting display system in which superimposed symbology is included, specifically in assessing the costs and benefits of attentional cuing and the means by which this information is displayed.     

Effect of visual field asymmetries on performance while utilizing aircraft attitude symbology

This research explores the effect of symbology placement on human performance for users of head-mounted augmented reality displays. A pair of experiments examined the impact on visual performance asymmetries when perceiving complex, meaningful visual stimuli, such as the Arc Segment Attitude Reference (ASAR). The ASAR symbology represents an aircraft’s vertical flight path and roll angles. Experiment 1 examined participants’ performance in making categorical and coordinate judgments regarding various attitudes of the ASAR and a Gabor patch which were briefly presented in the peripheral visual field. The results were consistent with the horizontal-vertical anisotropy literature, which implies that performance would be better for stimuli placed on the horizontal than the vertical meridian. Experiment 2 assessed asymmetries for continuously presented stimuli in a dual-task environment which involved a centrally located, demanding visual psychomotor task and monitoring of the ASAR or Gabor stimuli at the same peripheral locations as Experiment 1. No performance differences were found as a function of peripheral stimulus placement. However, eye tracking, particularly for a subset of the participants suggest they employed a more efficient visual process to monitor the peripheral stimuli when the stimuli were placed on the horizontal meridian.     

A control theoretic model for piloted approach to landing

A previously developed, optimal control model for manned-vehicle systems analysis is extended to analyze a piloted approach to landing task. The system model that is developed is used to investigate pictorial display requirements for a light aircraft. The effects, on system performance, of different display symbology are predicted by the model and are compared with data obtained in an independent experimental study. The comparison demonstrates the validity of our pilot model and its utility in manned vehicle analysis and synthesis.     

Effects on visual functions during tasks of object handling in virtual environment with a head mounted display

This study examined the effects on visual functions of a prolonged handling task within the helmet-mounted display environment. Both version eye movement and accommodative response became gradually slower during the 40-min task. Although delayed presentation of display after head movement noticeably worsened both visual responses, presentation delay after hand movement did not significantly change the sluggishness of responses. Therefore it is suggested that decreasing time delay after head movement is a more important factor in order to improve human performance of handling tasks within the HMD environment.     

Weather display symbology affects pilot behavior and decision-making

ObjectiveTo examine the basic discriminability of weather display symbols and to assess the effects of weather display symbology on pilot behavior and decision-making.MethodDuring a cockpit simulation, 24 instrument-rated general aviation (GA) pilots were randomly allocated to one of three simulation groups. Pilots flew a Cessna 172 single-engine GA aircraft under Visual Meteorological Conditions (VMC) and Instrument Meteorological Conditions (IMC) while avoiding hazardous weather. We manipulated the weather display so that each pilot group used a different weather symbology (i.e., symbols and colors). We measured dependent variables for weather avoidance, communication, weather display usage, and cognitive engagement (i.e., oxygenation from Functional Near-Infrared [fNIR] measures). During a change-detection experiment, 20 naïve participants performed a detection task of changes in Aviation Routine Weather Reports (METARs), precipitation, Significant Meteorological Information (SIGMET), lightning, and time-stamp images.ResultsThe simulation outcome showed credible pilot group differences in weather deviations, cognitive engagement, and weather display usage. The change-detection experiment revealed credible differences in discriminability of METAR, SIGMET, and lightning symbols.ConclusionSymbol and color variations in weather displays contribute to perceptual asymmetries which affect pilot behavior and decision-making. We recommend the development of cockpit applications that use weather data to automatically track hazardous conditions and alert the pilot of potential weather conflicts or weather changes.     

用于相贯线焊缝检测机器人的图像处理算法

针对管道相贯线焊缝难以检测的问题,提出了一种用于管道相贯线焊缝自动检测机器人轨道识别和定位的图像处理算法.在颜色空间转换和彩色边缘检测基础上,引入图像金字塔方法的Hough变换直线检测算法,快速识别磁性色码条并实现机器人自身姿态和运动轨迹的实时控制,将多阈值处理引入区域生长算法分割人工标识点,对人工标识点进行计数从而实现定位.实验结果验证了提出的图像处理算法的有效性.     

Color and defective color vision as factors in the conspicuity of signs and signals

The conspicuity of road traffic signs and signals for a group of observers with the color vision defect of deuteranopia is compared with that for a control group of observers with normal color vision. Conspicuity was measured by the proportion of reports of target objects detected in 300-ms presentations of projected slides of road scenes. There were two instructions, one designed to measure attention conspicuity and the other, search conspicuity. The attention conspicuity of red, orange, and green color-coded traffic control devices was significantly less for deuteranopes than for the observers with normal color vision, but this was not true for yellow and blue color-coded signs. This result is consistent with our understanding of the color perceptions of deuteranopes. The reduction of conspicuity was not so great for the search conspicuity condition. We conclude that redundant color coding does contribute to the conspicuity of signs and signals and that deuteranopes--and probably those with other severe forms of defective color vision--have a significantly reduced ability to notice colored targets, such as road signs and signals, in complex visual environments. The actual and potential application of this work is in the design of signs so they are conspicuous, especially when the user group includes people with defective color vision.     

Maintaining the level of operational effectiveness of a CSOC under adverse conditions

International Journal of Information Security - The level of operational effectiveness (LOE) is a color-coded performance metric that is monitored by the cybersecurity operations center (CSOC). It...     

Imagery for a virtual cockpit

The paper describes an example of the type of image that is required for a helmet-mounted system that displays a complex mixture of sensor and synthetic imagery. Some of the factors to be studied are discussed, and the paper outlines some potential processing architectures for achieving image generation and combination in a virtual cockpit.     

Interactive design system application

An interactive design system for the drawing office is described that should provide better control and standardization of drafting procedures, electrical and electronic symbology, repeatable designs and manufacturing processes, thus making it possible to produce higher-quality drawing documents in a shorter time and to increase the capacity of the drawing office.     

Earmuff effectiveness against chainsaw noise over a 12-month period

A study measuring the ability of new Peltor H7P3 Grade 4 helmet-mounted earmuffs to reduce the level of chainsaw noise reaching forestry workers' ears was undertaken over a one-year period. The objective was to establish effective replacement guidelines for earmuffs. The results showed that the earmuffs provided effective hearing protection for the subjects over the one-year test period. There were no statistically significant changes in field attenuation levels during the first 9 months. While the following three-month period (9-12 months) did experience a significant 3 dB(A) decrease, mean inside microphone noise level measured at the 12-month stage was 78.8 +/- 3.0 dB(A). This level is well under the damage risk criterion of Leq (8 hour) not exceeding 85 dB(A). It was noted during the study that a large proportion of the earmuffs would normally have been replaced before the 12-month stage owing to the discomfort associated with cushion deterioration. Results suggest that Peltor H7P3 grade 4 helmet-mounted earmuffs could be safely used as an effective form of chainsaw noise protection in a production forestry environment for a maximum period of 12 months before cushion replacement.     

Head Orientation Prediction: Delta Quaternions Versus Quaternions

Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.     

Experimental studies of the use of phase lead filters to compensatelags in head-coupled visual displays

Display lags degrade performance when using the head to track a target presented on a helmet-mounted display. These lags originate from delays in measuring the position of the head and the time required to generate the image of the target. This paper presents two laboratory studies on the use of phase lead filters to improve head tracking performance in the presence of display lags. In the preliminary study, the benefits of lag compensation by a phase lead filter were impeded by associated changes in filter gain. The frequency responses of two phase lead filters were then optimized to have near unity gain at frequencies below 0.7 Hz where there was most head motion. The main study showed that these optimized filters significantly improved head tracking performance with a system having a total lag of 140 ms. At frequencies above about 0.7 Hz, a greater than unity filter gain caused jittery image movement. Although this jittering degraded head tracking performance it was removed by an alternative lag compensation technique involving `image deflection'. This deflection shifted the displayed image to its correct horizontal and vertical position relative to the head. Image deflection, combined with the phase lead filters, produced a tracking performance unaffected by lag     

立体视频传输与再现研究

在分析人的立体视觉原理基础上,设计了一种立体视频传输方案:用两个摄像头代替人的双眼采集远端场景,采用RTP传输两路视频,为了确保两路视频同步,提出了时间戳匹配算法.最后介绍了使用头盔显示器立体显示方法.