Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 192

This bibliography lists 247 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1979

Human-centered automation of air traffic control operations in the terminal area

Cover titleNovember 2, 1994Series statement handwritten on coverProposal for the Interdepartmental Doctoral Program in Human Factors and AutomationIncludes bibliographical references (p. 70-73)Introduction: Air Traffic Control operations are described extensively in the ATC manuals such as the Airman's Information Manual [1] and the ATC Controller's Handbook [2]. Mathematical analysis has also been conducted for the ATC operations as evident in the many theses that have been published in ATC research [3, 4, 5]. A brief description is due here however in order to provide a background for the following document. There are six major ATC functions in the terminal area and a summary of their description in Sadoune's thesis [5] follows: Flow Management: The flow management purpose is to provide efficient transition between the en-route corridors and the terminal area through the metering fixes. The en-route corridors are the airways connecting the airports, the terminal area is the designated space around the airport, and the metering fixes are the points at which aircraft enter the terminal area under the flow control process called metering. The flow management system is capable of delivering the aircraft to the metering fix at predetermined time, altitude, and speed, minimizing fuel consumption and flight time. Beyond the metering fix however the concern in no longer fuel and cost, it is the separation between the aircraft and the landing schedule. Ground-based flight path generation is needed at that point. Runway Scheduling: The runway capacity is the limiting factor of the flow of traffic at congested airports. There are many reasons why runways are not used efficiently in the current tactical practice. These include the independent scheduling of landings and takeoffs, the ad hoc fashion in which takeoffs are inserted between landings, and the common use of the first-come-first-serve approach which is fair but not optimal. Runway scheduling is a queuing process and can be optimized for maximum throughput, long term service, and minimum delays of aircraft, taking into account fuel consumption, duration of flight, and other factors. The difficulty is in the dynamic nature of the schedule where modifications are needed as new entrants arrive or as environmental conditions change. The determination of the runway capacity and its improvement through the use of advanced technologies are discussed in Flow Control: Through traffic redistribution the flow control process helps smooth the demand fluctuations leading to a controlled number of aircraft simultaneously present in the terminal area. Two processes accomplish flow control: metering and holding. Metering divides the approach to the airport into successive stages between metering fixes. The flow management system delivers the aircraft to the metering fixes at the predetermined time, altitude, and speed. Holding points are assigned where holding aircraft are stacked and isolated from traffic. Holding aircraft circle in holding patterns awaiting landing clearance. Therefore, while metering moves the delays resulting from the runway capacity upstream, holding extends the flight path in time to accommodate arrival delays. These practices however can result in idle runway time in favor of more flow control leading to less efficient use of the runway. Flight Path Generation: There are standard routes both from the terminal area entry points to the runway for approach and from the runway to the en-route corridors for departure. These predefined routes can be used at low traffic flow rates, and add to the precision since automatic flight control systems are capable of flying along them automatically. However they are not optimal in using the space, or in exploiting the aircraft capabilities, or in maximizing the runway capacity. Automated flight path generation allows the incorporation of the space organization, the ATC separation criteria, the landing and takeoff schedule, the aircraft dynamics and performance limitations, and the maneuvering characteristics of the pilot in generating more optimal and flexible paths. This subject will be emphasized further in this document. Path Conformance Monitoring: In order to supervise the execution of the flight path plan, the radar surveillance system provides vague and non-precise measurement of the position of the aircraft. The controllers base their estimates of the conformance on 2-dimensional radar displays, and have to wait few intervals to estimate the direction of the aircraft. To adjust for the path conformance error the controllers issue heading, altitude, and speed clearances (vectors) to the pilots. Communication between controllers and pilots is done via radio transmission. Errors result from misunderstanding between the pilot and the controller, pilot response, as well as wind and unexpected atmospheric disturbances. Again new technologies and more automation are expected to improve the path conformance capabilities. These include better surveillance using satellites, digital data links for communication between the controller and the pilot, and display of the path to the pilot on board the aircraft. Questions of resolution and threshold of the conformance error become critical to the automation of the monitoring function. Hazard Monitoring: This includes detecting possible collisions between aircraft and with the ground. There is a trade off between false alarms and missed alarms in setting the threshold for the hazard alarm. Namely the more conservative the alarm threshold is set, the less is the risk of collision due to a missed alarm. But the disturbance to the traffic flow caused by the large number of false alarms is higher

Existing and Required Modeling Capabilities for Evaluating ATM Systems and Concepts

ATM systems throughout the world are entering a period of major transition and change. The combination of important technological developments and of the globalization of the air transportation industry has necessitated a reexamination of some of the fundamental premises of existing Air Traffic Management (ATM) concepts. New ATM concepts have to be examined, concepts that may place more emphasis on: strategic traffic management; planning and control; partial decentralization of decision-making; and added reliance on the aircraft to carry out strategic ATM plans, with ground controllers confined primarily to a monitoring and supervisory role. 'Free Flight' is a case in point. In order to study, evaluate and validate such new concepts, the ATM community will have to rely heavily on models and computer-based tools/utilities, covering a wide range of issues and metrics related to safety, capacity and efficiency. The state of the art in such modeling support is adequate in some respects, but clearly deficient in others. It is the objective of this study to assist in: (1) assessing the strengths and weaknesses of existing fast-time models and tools for the study of ATM systems and concepts and (2) identifying and prioritizing the requirements for the development of additional modeling capabilities in the near future. A three-stage process has been followed to this purpose: 1. Through the analysis of two case studies involving future ATM system scenarios, as well as through expert assessment, modeling capabilities and supporting tools needed for testing and validating future ATM systems and concepts were identified and described. 2. Existing fast-time ATM models and support tools were reviewed and assessed with regard to the degree to which they offer the capabilities identified under Step 1. 3 . The findings of 1 and 2 were combined to draw conclusions about (1) the best capabilities currently existing, (2) the types of concept testing and validation that can be carried out reliably with such existing capabilities and (3) the currently unavailable modeling capabilities that should receive high priority for near-term research and development. It should be emphasized that the study is concerned only with the class of 'fast time' analytical and simulation models. 'Real time' models, that typically involve humans-in-the-loop, comprise another extensive class which is not addressed in this report. However, the relationship between some of the fast-time models reviewed and a few well-known real-time models is identified in several parts of this report and the potential benefits from the combined use of these two classes of models-a very important subject-are discussed in chapters 4 and 7

Modeling and Evaluating Pilot Performance in NextGen: Review of and Recommendations Regarding Pilot Modeling Efforts, Architectures, and Validation Studies

NextGen operations are associated with a variety of changes to the national airspace system (NAS) including changes to the allocation of roles and responsibilities among operators and automation, the use of new technologies and automation, additional information presented on the flight deck, and the entire concept of operations (ConOps). In the transition to NextGen airspace, aviation and air operations designers need to consider the implications of design or system changes on human performance and the potential for error. To ensure continued safety of the NAS, it will be necessary for researchers to evaluate design concepts and potential NextGen scenarios well before implementation. One approach for such evaluations is through human performance modeling. Human performance models (HPMs) provide effective tools for predicting and evaluating operator performance in systems. HPMs offer significant advantages over empirical, human-in-the-loop testing in that (1) they allow detailed analyses of systems that have not yet been built, (2) they offer great flexibility for extensive data collection, (3) they do not require experimental participants, and thus can offer cost and time savings. HPMs differ in their ability to predict performance and safety with NextGen procedures, equipment and ConOps. Models also vary in terms of how they approach human performance (e.g., some focus on cognitive processing, others focus on discrete tasks performed by a human, while others consider perceptual processes), and in terms of their associated validation efforts. The objectives of this research effort were to support the Federal Aviation Administration (FAA) in identifying HPMs that are appropriate for predicting pilot performance in NextGen operations, to provide guidance on how to evaluate the quality of different models, and to identify gaps in pilot performance modeling research, that could guide future research opportunities. This research effort is intended to help the FAA evaluate pilot modeling efforts and select the appropriate tools for future modeling efforts to predict pilot performance in NextGen operations

An overview of decision table literature 1982-1995.

This report gives an overview of the literature on decision tables over the past 15 years. As much as possible, for each reference, an author supplied abstract, a number of keywords and a classification are provided. In some cases own comments are added. The purpose of these comments is to show where, how and why decision tables are used. The literature is classified according to application area, theoretical versus practical character, year of publication, country or origin (not necessarily country of publication) and the language of the document. After a description of the scope of the interview, classification results and the classification by topic are presented. The main body of the paper is the ordered list of publications with abstract, classification and comments.

Terrain Representation And Reasoning In Computer Generated Forces : A Survey Of Computer Generated Forces Systems And How They Represent And Reason About Terrain

Report on a survey of computer systems used to produce realistic or intelligent behavior by autonomous entities in simulation systems. In particular, it is concerned with the data structures used by computer generated forces systems to represent terrain and the algorithmic approaches used by those systems to reason about terrain

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 292)

This bibliography lists 192 reports, articles and other documents introduced into the NASA scientific and technical information system in December, 1986

State-of-the-art Assessment For Simulated Forces

Summary of the review of the state of the art in simulated forces conducted to support the research objectives of Research and Development for Intelligent Simulated Forces

Intelligent Simulation Modeling of a Flexible Manufacturing System with Automated Guided Vehicles

Although simulation is a very flexible and cost effective problem solving technique, it has been traditionally limited to building models which are merely descriptive of the system under study. Relatively new approaches combine improvement heuristics and artificial intelligence with simulation to provide prescriptive power in simulation modeling. This study demonstrates the synergy obtained by bringing together the "learning automata theory" and simulation analysis. Intelligent objects are embedded in the simulation model of a Flexible Manufacturing System (FMS), in which Automated Guided Vehicles (AGVs) serve as the material handling system between four unique workcenters. The objective of the study is to find satisfactory AGV routing patterns along available paths to minimize the mean time spent by different kinds of parts in the system. System parameters such as different part routing and processing time requirements, arrivals distribution, number of palettes, available paths between workcenters, number and speed of AGVs can be defined by the user. The network of learning automata acts as the decision maker driving the simulation, and the FMS model acts as the training environment for the automata network; providing realistic, yet cost-effective and risk-free feedback. Object oriented design and implementation of the simulation model with a process oriented world view, graphical animation and visually interactive simulation (using GUI objects such as windows, menus, dialog boxes; mouse sensitive dynamic automaton trace charts and dynamic graphical statistical monitoring) are other issues dealt with in the study