Solution Space-Based Complexity Analysis of ATC Aircraft Merging Tasks

Air traffic controller workload is considered to be a limiting factor in the growth of air traffic. In this paper a new method of assessing controller task demand load will be developed and tested. Based on the hypothesis that workload is primarily caused by the complexity of the task to be conducted, the concept of the “solution space” is described. For any particular air traffic control problem, the solution space describes the constraints in the environment that limit (and therefore, guide) air traffic controller decisions and actions. The complexity of that particular control problem can then be analyzed by considering the properties of the solution space. The task of merging an aircraft into a stream of other aircraft that fly along a fixed route is considered. An experiment has been conducted in which subjects were instructed to solve merging problem scenarios of varying complexity. After completing each scenario, subjects were asked to rate the task complexity. High correlations are found between several solution space properties and reported complexity

Ecological Synthetic Vision Display to Support Pilot Terrain Awareness

A Synthetic Vision Display is generally believed to support pilot terrain awareness. Many studies have shown, however, that perspective views are biased, which can cause pilots to make judgment errors regarding the relative location, height, and ultimately the avoidance of terrain obstacles. Therefore, this system is usually backed by terrain avoidance systems that provide explicit resolutions to circumvent conflicts. They are, however, far from optimal regarding terrain awareness as they fail to present the rationale of the automation. This paper presents an extension to a Synthetic Vision Display that promotes pilot terrain awareness by means of overlays that reveal the functional meaning of the terrain. It is designed to effectively deal with terrain conflict situations while preserving the freedom of maneuvering as much as possible. An experiment showed that the overlays improved pilot situation awareness and decision-making (in unanticipated events) as compared to a command-based interface counterpart

Supporting Pilots in Recovering Trajectories with Tunnel-In-The-Sky Displays

Tunnel-in-the-sky displays have shown great potential for reducing pilot workload and navigation error. Although it is a well-evaluated concept, only little research has been conducted on situations in which the pilot has (deliberately or not) flown outside of the tunnel. This paper describes the experimental evaluation of various alternatives to support pilots in recapturing their nominal trajectory. The concepts studied include the use of guiding arrows, path deviation indicators, a symbol representing the tunnel and a “return tunnel”. Results from a pilot-in-the-loop experiment indicate that a “return tunnel” performed best on situation awareness and workload aspects and that most pilots participating in the experiment had a general preference for this support concept

The Effect of Measuring Situation Awareness on Pilot Behavior

When developing new human-machine interfaces for aircraft cockpits, the contribution of the interface to the pilot’s situation awareness is of interest because this might inf uence human decisionmaking. Besides subjective measures, a frequently used objective method of measuring SA is the freezing of the task, removing information from the displays and querying the pilot about the situation. Research has indicated that by doing so, the pilot’s notion of what is important during this task may change, thereby potentially inf uencing decision-making. This paper describes an experiment in which pilots are given a terrain avoidance task, either with or without an interruption and SA query. The results showed a reorientation of the pilot’s gaze without having a signif cant effect on the decision-making

Pilot Support for Distance-Based In-Trail Following Tasks

Transferring the spacing task from the air traffic controller to the pilot can benefit efficiency and capacity. To separate a chain of aircraft, time-based rather than distance-based principles are preferred as they result in better performance in case of gradual reducing speeds in arrival streams. The present-day air traffic management systems, however, operate mainly on a spatial rather than a temporal basis, and air traffic controllers monitor the distance between trailing aircraft to determine if separation requirements are satisfied. If the disadvantages of distance-based spacing can be dealt with, the implications of introducing distance-based procedures for the current controller and pilot working environment would be much smaller than compared to time-based procedures. This paper presents the spacing reduction concept as a solution for the principal disadvantage of distance-based in-trail following, the slowdown effect. Displays and procedures were tested in a pilot-in-the-loop experiment. It is shown that distance-based spacing procedures can produce a stable chain of up to five aircraft, with very low pilot workload

Effects of Haptic Feedback in the Tele-Operation of an Unmanned Aerial Vehicle

This paper will describe an experiment that investigates the influence of force feedback on collision avoidance, control behavior and workload in the tele-operation of an unmanned aerial vehicle (UAV). Artificial force fields are used to provide force information. Subjects are asked to control a stability-augmented UAV helicopter through an obstacle-loaded environment. Visual information is provided by a display containing the simulated forward looking camera view and a navigation display, providing a top-down view. The force feedback algorithm is only implemented for the horizontal plane. Problems related to the general principle of an artificial force field that occur with autonomous robots, such as difficult passage through closely-spaced obstacles or oscillatory motions of the vehicle might also occur here, and are represented by the stick motions. Various subtasks during the experiment are conducted to investigate whether these possible problems actually occur and how they affect the operator performance and workload. The experiment results indicate that haptic feedback is very useful to assist the human tele-operator to avoid collisions, especially in cases where the visual information becomes insufficient. The minimum distance between the vehicle and an obstacle increases and the time spent within a critical distance towards an obstacle decreases, all leading to a higher level of safety

EID of a Pilot Support System for Airborne Separation Assurance

In a flexible airspace environment the pilot disposes of an increased amount of travel opportunities. At the same time the airspace traffic situation becomes more complex and the aircraft separation assurance task is shifted towards the cockpit. The design paradigm of Ecological Interface Design is applied to support the pilot with the airborne planning of efficient trajectory paths that maintain spatial separation from other traffic. The desired pilot behavior is achieved by visualizing travel-relevant airspace affordances in terms of realistic aircraft locomotion. As a result, a novel interface the ”state vector envelope” presents safe and efficient travel opportunities in a state vector field. The concept has been evaluated through on-line simulations of a number of basic conflict situations

Example of Work Domain Analysis Applied to Total Energy Control System

Automation is often accused of adding to the complexity of a system and unnecessarily increasing operator’s workload, and the potential for human error. An approach is needed that guides designers to make the right design choices. Cognitive Systems Engineering (CSE) is a promising approach. However, this field is still young and tangible examples of automation design with an explicit CSE approach do not exist. This paper describes how the design of Total Energy Control System (TECS) that was founded in the late 1970’s can be regarded as an example avant la letter. TECS is an automated flight control system designed to solve many of the issues that classical autopilot and auto-throttle systems have. Since TECS has been designed, implemented, and evaluated it could teach valuable lessons on how Work Domain Analysis (WDA) can guide the design of automated systems as the first phase of CSE approach. The application of WDA to TECS is exemplified using the abstraction hierarchy and the abstraction decomposition space

Towards a Meaningful Presentation of FMS Trajectory Information for Tactical Self-Separation

In the context of future airspace management concepts, the flight crew will need tactical navigation support for airborne self-separation. Applying ecological interface design principles, a state-based navigation tool was designed that uses functional information overlays that show how traffic and aircraft performance constrain the horizontal maneuvering. The state-based system has been enhanced with a visualization of intent information from the flight plan trajectory (Van Dam, Paassen, & Mulder, 2007). This paper discusses in detail the exchange of intent information using ADS-B. It presents some promising ideas to show intent in a more meaningful and pilot-intuitive way, particularly focusing on the impact of mode transition from trajectory control mode (Flight Management System) to target state control mode

Towards Integrating Traffic and Terrain Constraints into a Vertical Situation Display

Future airspace operations will allow flight crews to plan and fly their own preferred route and time of arrival without much intervention from air traffic control. Thereby, pilots will become more responsible for planning their own route while maintaining safe separations from traffic and/or terrain. This demands for strategic and tactical planning tools that supports pilots in these tasks. The work in this paper focuses on supporting the airborne separation assurance task in the vertical plane by means of portraying traffic and terrain conflict zones onto an enhanced Vertical Situation Display. In a simulator evaluation the experimental display was compared to a baseline display that only showed a terrain profile and intruder aircraft location relative to ownship. The experiment results revealed that although the overlays decreased pilot workload, and resulted in slightly less traffic conflicts, decision-making and conflict awareness did not significantly improve