Figure 6 - uploaded by Christopher D Wickens
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Representation of the display size (small: 23° VAD and large: 33° VAD) and field of view (30° and 60°) conditions. The visual angle on the display depends on the viewing distance, and this was maintained relatively constant for all pilots.
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Two experiments conducted in a high-fidelity flight simulator examined the effects of guidance symbology, display size, and field of view (FOV) on flight performance and situation awareness within a Synthetic Vision System (SVS). In Experiment 1, 18 pilots flew highlighted and lowlighted tunnel-in-the-sky displays and a less-cluttered follow-me-air...
Citations
... Research was first carried out on the best symbology to display the attitude of fighter planes on Head-Up-Displays [9]. More complex symbologies depicting flight path later demonstrated their relevance for upgrading flight path guidance and reducing workload [10]. However, display modality is only one amongst many ergonomic considerations, and relevant information also had to be provided to users to improve performance. ...
Helicopter landing on a ship is a visually regulated "rendezvous" task during which pilots must use fine control to land a powerful rotorcraft on the deck of a moving ship tossed by the sea while minimizing the energy at impact. Although augmented reality assistance can be hypothesized to improve pilots’ performance and the safety of landing maneuvers by guiding action toward optimal behavior in complex and stressful situations, the question of the optimal information to be displayed to feed the pilots’ natural information-movement coupling remains to be investigated. Novice participants were instructed to land a simplified helicopter on a ship in a virtual reality simulator while minimizing energy at impact and landing duration. The wave amplitude and related ship heave were manipulated. We compared the benefits of two types of visual augmentation whose design was based on either solving cockpit-induced visual occlusion problems or strengthening the online regulation of the deceleration by keeping the current τ ˙ variable around an ideal value of -0.5 to conduct smooth and efficient landing. Our results showed that the second augmentation, ecologically grounded, offers benefits at several levels of analysis. It decreases the landing duration, improves the control of the helicopter displacement, and sharpens the sensitivity to changes in τ ˙ . This underlines the importance for designers of augmented reality systems to collaborate with psychologists to identify the relevant perceptual-motor strategy that must be encouraged before designing an augmentation that will enhance it.
... A third application of the HUD is the presentation of an integrated graphic flight path representation, often termed "Highway in the Sky' (HITS, Thomas and Wickens 2004). The primary objective of the HITS is to facilitate the pilot's ability to successfully aviate and navigate (Alexander et al. 2003), with previous research demonstrating that the use of HITS can facilitate the descent and landing phases of rotary-wing operations ( Stanton et al. 2019). ...
Degraded visual conditions present a great challenge to rotary-wing aircraft. These conditions can obscure cues used to interpret speed, location and approach. With such cues obscured, pilots must rely on in-cockpit instrumentation, increasing workload, whilst reducing situation awareness. When operating within degraded visual conditions, pilots require easy access to flight critical information, presented in a way that minimises additional workload and maximises situation awareness. One technology that can be beneficial within such conditions is a head-up display (HUD). This study explores the impact of an iteratively designed HUD on pilots’ workload and situation awareness during the safety-critical descent and landing flight phases, during both clear and degraded visual conditions across a series of simulated trials. Results suggest that access to the HUD facilitated pilot awareness, whilst maintaining workload in all conditions. Results support the view that HUDS are beneficial to rotary-wing pilots, particularly in degraded visual environments.
... A further potential application of the HUD is the presentation of an integrated graphic flight path representation, often termed 'a highway in the sky' (HITS, Thomas & Wickens 2004). The primary objective of the HITS is to facilitate the tasks of flying and navigating (Alexander et al. 2003). HITSs have been shown to facilitate increased maintenance of lateral and vertical flight path awareness (Williams et al. 2001) and the inclusion of synthetic terrain has been shown to significantly increase the situation awareness improvement potential of HITSs (Snow and Reising 1999). ...
The safety of rotary-wing operations is significantly affected by the local weather conditions, especially during key phases of flight including hover and landing. Despite the operational flexibility of rotary-wing craft, such craft accounts for a significantly greater proportion of accidents than their fixed-wing counterparts. A key period of risk when operating rotary-wing aircraft is during operations that occur in degraded visual environments, for example as a result of thick fog. During such conditions, pilots’ workload significantly increases and their situation awareness can be greatly impeded. The current study examines the extent to which providing information to pilots via the use of a head-up display (HUD) influenced perceived workload and situation awareness, when operating in both clear and degraded visual environments. Results suggest that whilst the HUD did not benefit pilots during clear conditions, workload was reduced when operating in degraded visual conditions. Overall results demonstrate that access to the HUD reduces the difficulties associated with flying in degraded visual environments.
... Generally, the content of the HUD includes primary flight information normally found on the primary flight display, additional flight path symbology (e.g. 'Highway in the sky') and conformal, graphical, representations of the outside environment (Alexander et al., 2003;Thomas and Wickens, 2004;Harris, 2011). A HUD allows the pilot to fly 'eyes out' rather than switching attention to head-down displays (HDD) inside the cockpit. ...
... However, enhancements can be made to the HUD to increase its utility even further. For example, many studies demonstrate the effectiveness of 'Highway in the Sky' (HITS) symbology (Williams et al., 2001;Alexander et al., 2003;Thomas and Wickens, 2004). This is usually in the form of a graphical flight path representation. ...
Helicopters have the potential to be an integral part of the future transport system. They offer a means of rapid transit in an overly populated transport environment. However, one of the biggest limitations on rotary wing flight is their inability to fly in degraded visual conditions in the critical phases of approach and landing. This paper presents a study that developed and evaluated a Head up Display (HUD) to assist rotary wing pilots by extending landing to degraded visual conditions. The HUD was developed with the assistance of the Cognitive Work Analysis method as an approach for analysing the cognitive work of landing the helicopter. The HUD was tested in a fixed based flight simulator with qualified helicopter pilots. A qualitative analysis to assess situation awareness and workload found that the HUD enabled safe landing in degraded conditions whilst simultaneously enhancing situation awareness and reducing workload. Continued development in this area has the potential to extend the operational capability of helicopters in the future.
Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.
... The naturalistic look of an SVD may be more ecologically plausible than coplanar displays 3 and it has been shown to increase flight technical performance, spatial orientation awareness, and situation recognition. 4 However, the level of 'terrain awareness' obtained from the synthetic view to avoid an impending terrain collision can be debated. ...
... 3,5 To mitigate these issues, the SVS community has explored solutions such as terrain coloring to indicate high-elevated areas, using high-resolution textures to increase speed perception and judgment of distances, 6 and optimal field-of-view settings to reduce spatial biases. 4,6 Another, more important, issue is that an SVD does not present information to help pilots relate the aircraft status to the terrain. They need to interpret the raw status data into a meaningful functional description to understand how and when to act. ...
A synthetic vision display is generally believed to support pilot terrain awareness. Many studies have shown, however, that the bias in perspective views can cause pilots to make judgment errors regarding the relative location, height, and ultimately the avoid- ance of terrain obstacles. Therefore, alerting systems are required to keep pilots at safe distances from the terrain. These systems provide explicit guidance commands to cir- cumvent terrain conflicts, which is far from optimal regarding pilot terrain awareness as it fails to present the rationale of the terrain separation problem. Consequently, this can affect the trust in and the reliance on these systems and pose a potential safety risk, especially in events or situations unfamiliar to the alerting system. This paper presents the design and evaluation of an extension to a synthetic vision display that aims to make the constraints of the alerting automation more transparent in order to help pilots better understand why, how, and when they should act. A pilot-in-the-loop experi- ment, using sixteen glass-cockpit pilots in a fixed-based flight simulator, showed that the constraint-based overlays indeed improved the overall pilot terrain awareness compared to a command-based display. The decision-making only improved in the unanticipated events introduced in the experiment. The utility of the energy angle was found to be im- portant for recognizing the off-normal events and to prevent terrain crashes. However, the pilot response time, flight safety in terms of low altitude flying, and pilot workload are better when using the command display. This indicates that a last-resort alerting and advisory system would still be required in operations at the periphery of safe system performance.
... One problem with the highlighting strategy according to St. John, Smallman, Manes, Feher, and Morrison (2005, p. 509) is "that because it is such an effective form of cuing, it can impede the detection of important objects that are mistakenly left un-highlighted (and hence un-cued) when the automation is imperfect or the situation is uncertain". This statement is supported by Alexander, Wickens, and Hardy (2003). Since Smallman et al. advocate the decluttering strategy their implicit message seems to be that this problem will diminish for this alternative. ...
... Consistent with the urgency hypothesis, Abbott and Moen (1981) found that pilots maintained a more accurate spacing interval behind a lead aircraft when a cockpit display of traffic information was increased in size. In contrast, Alexander, Wickens, and Hardy (2003) found an influence of scale, as rendered by field of view in Figure 1b, on flight control performance, suggesting that larger scale produced greater error, thus disagreeing with predictions of the urgency hypothesis. Prinzel et al. (2004), however, reported no effect for display size. ...
Experiments were conducted to assess the impact of display size on flight control, airspace surveillance, and goal-directed target search.
Research of 3-D displays has shown that display scale compression influences the perception of flight path deviation, though less is known about the causes that drive this effect. In addition, research on attention-based tasks has shown that information displaced to significant eccentricities can amplify effort, but it is unclear whether the effect generates a performance difference in complex displays.
In Experiment 1, 16 pilots completed a low-fidelity flight control task under single- and dual-axis control. In Experiment 2, the control task from Experiment 1 was scaled up to a more realistic flight environment, and pilots performed hazard surveillance and target search tasks.
For flight control, pilots exhibited less path error and greater stick activity with a large display, which was attributed both to greater enhanced resolution and to the fact that larger depictions of error lead to greater urgency in correcting deviations. Size did not affect hazard surveillance or search, as pilots were adaptive in altering scanning patterns in response to the enlargement of the displays.
Although pilots were adaptive to display changes in search and surveillance, display size reduction diminished estimates of flight path deviation and control performance because of lowered resolution and control urgency.
Care should be taken when manipulating display size, as size reduction can diminish control performance.
... Synthetic Vision Systems provide pilots with a realistic 3D image of the terrain in front of the aircraft, with a primary objective of increasing terrain awareness, and reducing the likelihood of CFIT accidents (Prinzel Comstock, Glaab, Kramer, Arthur, & Barry, 2004;Schnell, Kwon, Merchant, & Etherington, 2004). As shown in Figure 1 (upper left panel), within the 3D ego-referenced SVS pictorial display, it is reasonable to consider designs that might also host three additional forms of information: (1) 3D information regarding the forward flightpath, in the form of a pathway, tunnel, or "highway-in-the-sky" (Alexander, Wickens, & Hardy, 2003;Beringer, 2000;Fadden, Ververs & Wickens, 2001;Williams, 2002), (2) information about traffic near the forward flightpath (Merwin, 1998), and (3) other aspects of the primary flight display, represented as a head-up display (HUD) -like overlay (Fadden et al., 2001, Merwin, 1998. ...
... The assessment of which display configuration is optimal is complicated by the fact that such a system is intended to support a variety of tasks, and performance on these may trade off Tunnel Datalink Overlay Separate with each other across different designs. For example, routine flightpath tracking is well supported by the tunnel (e.g., Alexander et al., 2003;Fadden et al., 2001;Iani & Wickens, 2004;Prinzel et al., 2004;Schnell et al., 2004), but flightpath tracking may sometimes be inhibited by the added clutter of overlay on the display (Fadden et al., 2001). Traffic detection may be supported by the reduced scanning of overlay (Fadden et al., 2001), but could be inhibited in this condition by the clutter caused by this overlay, particularly if traffic is neither expected nor salient (Wickens, Ververs, & Fadden, 2004;Yeh, Merlo, Wickens, & Brandenburg, 2003). ...
... Merwin examined traffic, but not a tunnel, whereas Schnell et al., and Prinzel et al., and Beringer and Ball (2001) examined a tunnel, but no traffic, and Fadden et al., evaluated a tunnel and traffic, but not with an SVS terrain background. Alexander Wickens and Hardy (2003) did compare traffic detection on an SVS system that hosted a tunnel, with one that hosted only a "follow me airplane" for guidance (less clutter), and observed no difference in traffic detection performance between them, so long as the tunnel was presented at a low level of intensity. ...
Fourteen pilots flew a synthetic vision system (SVS) display through a terrain and traffic-rich environment in a high fidelity flight simulator. Traffic information was hosted on the SVS display. In a 2x2 factorial design, the SVS display hosted a highway-in-the-sky in half the conditions, while instrument panel information and a flight path velocity vector was the sole means for guidance in the other conditions. In half the trials the instrument panel overlaid the SVS display, and in the other half it was separate, allowing us to examine the effects of the resulting clutter. Tunnel guidance, and clutter effects were examined as they influenced routine flight performance, SVS traffic detection and change awareness, and the pilots' response to off-normal events, as these were mediated by visual scanning measures of attention allocation. The tunnel greatly improved flight path tracking and detection of traffic on the SVS display, and did not hurt the detection of traffic changes present on a CDTI. However the tunnel disrupted the detection of the two off-normal events: unexpected outside world traffic, and of a runway offset. The instrument panel overlay provided no benefits to tracking and a clutter-related time cost to SVS traffic detection. Scanning analysis on 8 of the pilots revealed that visual attention was focused on the SVS display over half the time, and rarely on the outside world, even in visual meteorological conditions (VMC). This scanning pattern indicated a source of possible cognitive tunneling. However in general, scanning was not tightly linked to performance. The final section of this report describes our efforts to apply a computational model to predict the visual scanning data.
... Comstock et al. (2003) found a similar result, showing that an enlargement in the physical size of an attitude directional indicator resulted in superior flight control. In contrast, Alexander, Wickens, and Hardy (2003) found an influence of scale (see field of view in Figure 1b) on tracking performance that was opposite to the urgency hypothesis, showing that larger scale produced greater error. Prinzel et al. (2004), as well as Comstock et al. (2001), however, reported no effect of display size. ...
