Workload of a collision avoidance system for remotely piloted aircraft

Chapter 17 - An introduction to air traffic control and the application of human factors

Facing flight centred air traffic control (ATC) and more monitoring tasks at future controller working positions (CWP), it becomes even more important that air traffic controllers (ATCo) always focus their attention at the relevant spots on their human machine interface (HMI). This paper outlines relevant literature about attention and attention guidance (AG) in different domains, explains the concept for an AG prototype for sectorless air traffic management (ATM) and the plan for its validation in the course of Single European Sky ATM Research (PJ.16-04-03, SESAR2020). The AG prototype considers three aspects. First, the desired area of attention: An assistance system calculates where the ATCo should look at depending on input data like radar and flight plan data. Second, an external system relying on eye tracking and user inputs determines where the current ATCo focus is. Third, if the desired and the actual area of attention are not the same, mechanisms to guide the ATCo’s attention will be triggered taking a strategy of escalating visual cues into account. The latter comprises an intelligent display of action indicators with respect to time, position and appearance as well as pre-tactical inattention indicators. The AG prototype aims to increase controller productivity, improve situation awareness as well as reduce workload and stress level in a future flight centred ATC environment.

<div class="htmlview paragraph">Many problems exist in meeting the future surveillance and communication needs of air traffic control. Many functions and services are now being developed for eventual implementation beginning after 1977. The operation, role, and impact of the Discrete Address Beacon System in meeting these needs and functions are discussed in this paper.</div>

With the advent of digital avionic techniques, it has become possible to plan the integration of computer systems for performing on-line optimization tasks during flight operation. These computers can be used for computing attitude and control strategies by minimizing different cost functions. Digital systems will play an even bigger part on tomorrow's flight deck because of the improved control capabilities. This paper presents the results for a simulation study in which a minicomputer was used for computing four-dimensional flight trajectories in an air traffic control environment. Special interest was given to helical approach for a transport aircraft, in this case a DC-10/30.

Both ground-based ATC (Air Traffic Control) and airborne CAS (Collision Avoidance Systems) are needed now and in the future to cope with the problem of collision aloft. They should be considered mutually complementary. The limited form of the CAS known as a PWI (Proximity Warning Indicator) is believed not to be sufficient for safety. The two essential elements of a CAS are 1) an indication of the effective maneuver to secure adequate miss distance, and 2) effective means for discovering and assessing the original risk. Miss distance produced by a maneuver never exceeds maneuver displacement. The ratio of the two may be low unless escape time is of the order of 30 seconds or more. In nearly all cases increasing escape time is more effective to insure adequate miss distance than is increasing maneuver severity. The preferred form of CAS would be self-sufficient, but this form appears not to be feasible for basic physical reasons. Cooperative CAS presents many problems, but is believed to have sufficient promise of success to justify careful study and substantial development effort.

Operations in the Next Generation Air Transportation System (NextGen) are planned to have a reduced dependency on primary surveillance radar and use Automatic Dependent Surveillance - Broadcast (ADS-B) to provide aircraft state information to Air Traffic Control (ATC) and onboard collision detection and avoidance systems. With the ongoing integration of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS), ADS-B is expected to become the main surveillance input to UAS collision avoidance. Traffic Alert and Collision Avoidance System (TCAS) is unable to meet requirements in terms of adaptability to future operations with reduced separation margins, addition of new user groups (e.g., UAS), and support of additional surveillance inputs. Airborne Collision Avoidance System (ACAS X) is being designed to meet these requirements and to increase surveillance, alerting, and resolution performance. The RTCA has released Minimum Operational Performance Standards (MOPS) to provide system and operational performance characteristics that ADS-B must provide. This paper analyzes recorded ADS-B data from test flights that were performed in the Continental U.S. (CONUS) and verifies measured performance with specified operational characteristics in terms of coverage, accuracy, and integrity.

An Agent-Based Approach to Aircraft Conflict Resolution with Constraints

Fuel conservative procedures, including profile descents and decelerating approaches, can reduce fuel consumption significantly when executed as planned, but their effectiveness is strongly influenced by the Air Traffic Control (ATC) environment. Real-time pilot-and-controller-in-the-loop simulations have been used to establish the fuel savings potential as well as the operational problems of these procedures in the current ATC system. Simulation results have shown that fuel savings are realized under moderately heavy traffic conditions. In heavy traffic, high controller workload together with reduced fuel savings indicate that time-controlled (4D) guidance in the aircraft and computer-assisted scheduling may be necessary to realize the full potential of fuel conservative procedures. A computer-assisted technique, termed Constrained Position Shifting (CPS), is proposed to integrate these procedures into the future ATC system. CPS also increases capacity and reduces delay by accounting for the differences in aircraft sizes, capabilities and routes.

Mankind has been using ships for more than 5,000 years and has developed a range of related technologies. However, despite such a long history, compared to aircraft with a history of approximately one century, the pace of progress has been markedly slow. Even though technological progress of ships or the installation of various navigation equipment have been achieved, seaborne collisions have occurred quite frequently. This study analyzed the TCAS( Traffic Collision Avoidance System) that has contributed to the prevention of collisions with other transport methods including aircraft to suggest a collision avoidance system that can be deployed for ships. To apply the technologies applied to aircraft that move in 3D to ships that move in 2D, the difference in the operational environment between the two modes was analyzed to identify elements that need to be applied to ships. The suggested display of data on the collision prevention system is one that manipulates the augmented reality display device used in automobiles that over the past few years has undergone rapid development. Based on the presentation of technological elements that need to be considered when adopting the SCAS or the Seaborne Collision Avoidance System as suggested in this study, the authors hope to contribute to the prevention of collisions.

Objective: The objectives of current study are to explore whether serious fatigue of Air Traffic Controller (ATC) exist in their duty, and to explore a sensitive fatigue index. Method: Number recognition task was used to explore ATC fatigue. Following results were found, firstly, significant fatigue effect was found in all 55 ATC. Besides, significant fatigue effects were only found in ATC in tower control area and terminal control area, but not in regional control area. Thirdly, only reaction time before and after ATC duty were found significant difference but not in accuracy. Conclusion: Fatigue effect really exist in ATC after their duty, and ATC in different work location suffer different work load. Finally, reaction time of number recognition task can be a very sensitive and reliable fatigue index.

Current study is aiming to find a more suitable behavioral fatigue index for Air Traffic Controllers(ATC) using PVT test and fatigue self-assessment questionnaires as tools, and gives these tests before and after ATC duty. Through PVT test and self-assessment questionnaire, this finding indicates hit rate and hit response time (the first 20% trials) of PVT can be potential fatigue index since we found first 2min hit response time of air traffic controller(ATC) after duty is significantly longer than before duty, together with the hit rate after duty is lower than before duty. 8 items in Stanford Sleepiness Scale(SSS) and Visual Analogy Scale(VAS) also show significant difference in self assessment on fatigue. ATCs think themselves are much more fatigue after duty than before duty.Besides, ATCs in regional control area show significant fatigue effect than those in terminal control area, indicating different work load in two different working areas. Those ATC work at night especially in midnight show much more significant fatigue than those work in the daytime showed by longer first 20% hit response time. In sum, hit rate and first 20% (first 2min) hit response time can be effective fatigue indexes of ATC.

Two studies were conducted to examine the use of grounded embodied pedagogy, construction of Imaginary Worlds (Study 1), and context of instructional materials (Study 2) for developing learners' Computational Thinking (CT) Skills and Concept knowledge during the construction of digital artifacts using Scratch, a block-based programming language. Utilizing a conceptual framework for grounded embodied pedagogy called Instructional Embodiment, learners physically enacted (Direct Embodiment) and mentally simulated (Imagined Embodiment) the actions and events as presented within pre-defined Scripts. Instructional Embodiment utilizes action, perception, and environment to create a dynamic, interactive teaching & learning scenario that builds upon previous research in embodied teaching and learning. The two studies described herein examined the effects of Instructional Embodiment, Imaginary World Construction, and Context on the development of specific Computational Thinking Concepts and Skills. In particular, certain CT Concepts, such as Conditionals, Variables, Thread Synchronization, Collision Detection, & Events, and CT Skills, such as abstraction and pattern recognition, were identified and measured within the learners' individual digital artifacts. Presence and/or frequency of these Concepts and Skills were used to determine the extent of Computational Thinking development. In Study 1, fifty-six sixth- and seventh-grade students participated in a fifteen-session curricular program during the academic school day. This study examined the type of instruction and continuity of Imaginary World Construction on the development of certain CT Skills and Concepts used in a visual novel created in Scratch. Main effects were found for learners who physically embodied the pre-defined instructional materials: embodying the pre-defined Scripts led to the learners using significantly more ‘speech’ Blocks in their projects and more Absolute Positioning Blocks for ‘motion’ than those who did not physically embody the same Scripts. Significant main effects were also found for continuity of Imaginary World Construction: learners who were instructed to continue the premise of the first digital artifact (Instructional Artifact) implemented significantly more computational structures in their second digital artifact (Unique Artifact) than those who were instructed to create a Unique Artifact with a premise of their own design. In Study 2, seventy-eight sixth- and seventh-grade students participated in a seventeen-session curricular program during the academic school day. This study examined the type of instruction and context of instructional materials on the development of CT Skills and Concepts during the construction of a video game using Scratch. Similar to Study 1, findings suggest that physically embodying the actions presented within the pre-defined instructional materials leads to greater implementation of many of these same structures during individual artifact construction. The study also showed that as the pre-defined Scripts become more complex (e.g. single-threaded to multi-threaded), the effect of physical embodiment on the development of CT Skills and complex CT Concept structures becomes less pronounced. Findings from this study also suggest that Context has a significant effect on identifying & implementing the CT Skill pattern recognition: learning CT Concepts from an Unfamiliar Context had a significant positive effect on the implementation of both Broadcast/Receive couplings and Conditional Logic & Operator patterns. In sum, the findings suggest that the type of instruction, the continuity of the Imaginary World being constructed, and the context of the instructional materials all play a significant role in the learners' ability to develop certain Computational Thinking Skills and Concept knowledge. The findings also suggest that a physically embodied approach to teaching abstract concepts that is grounded in an unfamiliar context is the most effective way to integrate a grounded embodied approach to pedagogy within a formal instructional setting.

Air traffic controllers (ATCos) monitor flight operations and resolve predicted aircraft conflicts to ensure safe flights, making them one of the essential human operators in air traffic control systems. Researchers have been studying ATCos with human subjective approaches to understand their tasks and air traffic managing processes. As a result, models were developed to predict ATCo actions. However, there is a gap between our knowledge and the real-world. The developed models have never been validated against the real-world, which creates uncertainties in our understanding of how ATCos detect and resolve predicted aircraft conflicts. Moreover, we do not know how information from air traffic control systems affects their actions. This Ph.D. dissertation work introduces methods to evaluate existing ATCo action prediction models. It develops a prediction model based on flight contextual information (information describing flight operations) to explain the relationship between ATCo actions and information. Unlike conventional approaches, this work takes data-driven approaches that collect large-scale flight tracking data. From the collected real-world data, ATCo actions and corresponding predicted aircraft conflicts were identified by developed algorithms. Comparison methods were developed to measure both qualitative and quantitative differences between solutions from the existing prediction models and ATCo actions on the same aircraft conflicts. The collected data is further utilized to develop an ATCo action prediction model. A hierarchical structure found from analyzing the collected ATCo actions was applied to build a structure for the model. The flight contextual information generated from the collected data was used to predict the actions. Results from this work found that the collected ATCo actions do not show any preferences on the methods to resolve aircraft conflicts. Results found that the evaluated existing prediction model does not reflect the real-world. Also, a large portion of the real conflicts was to be solved by the model both physically and operationally. Lastly, the developed prediction model showed a clear relationship between ATCo actions and applied flight contextual information. These results suggest the following takeaways. First, human actions can be identified from closed-loop data. It could be an alternative approach to collect human subjective data. Second, the importance of evaluating models before implications. Third, potentials to utilize the flight contextual information to conduct high-end prediction models.

Adapting a Human – Automation Trust Scale to an Air Traffic Management Environment

<div class="htmlview paragraph">This paper provides a summary of the data and findings from a ten-month evaluation of the Traffic Alert and Collision Avoidance System (TCAS) II Industry Prototype installed on a Piedmont Airlines' Boeing 727 aircraft. The data presented represents quantitative and qualitative information on the performance of TCAS II in the National airspace System (KAS) and identifies the impacts of TCAS on Air Traffic Control and the flight crew. The information provided concentrates on the characteristics of the TCAS encounters and the operational use of the system.</div>