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Protocolbased conflict resolution for air traffic control
 AIR TRAFFIC CONTROL QUARTERLY 15(1)
, 2002
"... This paper proposes a method for multipleaircraft conflict avoidance. We assume that aircraft cruise at constant altitude with varying velocities and that conflicts are resolved in the horizontal plane using heading change, velocity change, or a combination thereof. We assume that each aircraft’s ..."
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Cited by 26 (2 self)
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This paper proposes a method for multipleaircraft conflict avoidance. We assume that aircraft cruise at constant altitude with varying velocities and that conflicts are resolved in the horizontal plane using heading change, velocity change, or a combination thereof. We assume that each aircraft’s position, heading, and velocity are available to all aircraft involved in the conflict, we constrain the maneuver to be two straight paths of equal length, and we assume that all aircraft initiate conflict resolution maneuvers at the same time and that once an aircraft has initiated a maneuver, its velocity along the maneuver remains constant. Our multipleaircraft conflict resolution methodology is presented in two steps; first, we consider an unrealistic but geometrically simple exact conflict, in which the original trajectories of all aircraft collide at a point, in order to derive a closedform analytic solution for the required heading change, and then we consider a realistic inexact conflict, in which conflict points of multiple aircraft do not coincide. Heading change is a main control input for conflict resolution, yet velocity change is also used for an inexact conflict. We then construct a finite partition of the airspace around the conflict, and using our analytic solution, we derive a protocol for resolving the worstcase conflict within each partition. The result is a multipleaircraft conflict resolution protocol, or a simple rule which is easily understandable and
Flightmodebased aircraft conflict detection using a residualmean interacting multiple model algorithm
 in: Proceedings of the AIAA Guidance, Navigation, and Control Conference
, 2003
"... Based on the trajectory prediction error model proposed by Paielli and Erzberger, we propose nominal and probabilistic conflict detection algorithms using flight mode estimates as well as the aircraft current state estimates. This is different from previous conflict detection algorithms which use cu ..."
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Cited by 13 (2 self)
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Based on the trajectory prediction error model proposed by Paielli and Erzberger, we propose nominal and probabilistic conflict detection algorithms using flight mode estimates as well as the aircraft current state estimates. This is different from previous conflict detection algorithms which use current state estimates only. Our algorithms are therefore based on hybrid models of aircraft, which allow for both continuous dynamics and discrete mode switching. To obtain accurate state and mode estimates, we propose a modified version of the Interacting Multiple Model (IMM) algorithm designed by BarShalom et al. called the ResidualMean Interacting Multiple Model (RMIMM) method. RMIMM is a multiplemodelbased estimation algorithm based on a new likelihood function which uses the mean of the residual produced by each mode matched filter (usually Kalman filter), producing better mode estimates, and therefore better state estimates, than in the IMM case. We demonstrate our algorithm on multiple aircraft scenarios, and in the latter part of the paper, the probabilistic conflict detection algorithm is combined with the protocolbased conflict resolution algorithm, designed by the authors in earlier work.
S.: Aircraft conflict prediction in the presence of a spatially correlated wind field
 IEEE Trans. on Intelligent Transportation Systems
, 2005
"... Abstract—In this paper, the problem of automated aircraft conflict prediction is studied for twoaircraft midair encounters. A model is introduced to predict the aircraft positions along some lookahead time horizon, during which each aircraft is trying to follow a prescribed flight plan despite the ..."
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Cited by 11 (1 self)
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Abstract—In this paper, the problem of automated aircraft conflict prediction is studied for twoaircraft midair encounters. A model is introduced to predict the aircraft positions along some lookahead time horizon, during which each aircraft is trying to follow a prescribed flight plan despite the presence of additive wind perturbations to its velocity. A spatial correlation structure is assumed for the wind perturbations such that the closer the two aircraft, the stronger the correlation between the perturbations to their velocities. Using this model, a method is introduced to evaluate the criticality of the encounter situation by estimating the probability of conflict, namely, the probability that the two aircraft come closer than a minimum allowed distance at some time instant during the lookahead time horizon. The proposed method is based on the introduction of a Markov chain approximation of the stochastic processes modeling the aircraft motions. Several generalizations of the proposed approach are also discussed. Index Terms—Air traffic control, conflict prediction, stochastic approximation, stochastic fields, stochastic modeling, wind correlation. I.
EFFICIENT IMPLEMENTATION OF AIR TRAFFIC CONTROL USING THE CLEARSPEED CSX600 SYSTEM
"... Past approaches for air traffic control (ATC) problems use MIMD solutions and have severe problems meeting the requirements of ATC. We propose a new and efficient solution to the ATC problem using SIMD architecture ClearSpeed CSX620. This solution uses synchronous processing of jobs and proposes a ..."
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Cited by 7 (2 self)
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Past approaches for air traffic control (ATC) problems use MIMD solutions and have severe problems meeting the requirements of ATC. We propose a new and efficient solution to the ATC problem using SIMD architecture ClearSpeed CSX620. This solution uses synchronous processing of jobs and proposes a new tracking algorithm that can estimate states accurately and a new conflict detection and resolution(CD&R) algorithm that can guarantee the qualities of safety and efficiency. A preliminary prototype of the proposed method has been developed on the ClearSpeed CSX620 and results are presented.
efficient associative processor solution to an air traffic control problem
 in Large Scale Parallel Processing IEEE Workshop at the International Parallel and Distributed Processing Symposium (IPDPS2010
, 2010
"... Abstract—This paper proposes a SIMD solution to air traffic control (ATC) using an enhanced SIMD machine model called an Associative Processor (AP). This differs from previous ATC systems that are designed for MIMD computers and have a great deal of difficulty meeting the predictability requirements ..."
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Cited by 6 (1 self)
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Abstract—This paper proposes a SIMD solution to air traffic control (ATC) using an enhanced SIMD machine model called an Associative Processor (AP). This differs from previous ATC systems that are designed for MIMD computers and have a great deal of difficulty meeting the predictability requirements for ATC, which are critical for meeting the strict certification standards required for safety critical software components. The proposed SIMD solution will support accurate and meaningful predictions of worst case execution times and will guarantee all deadlines are met. Also, the software will be much simpler and smaller in size than the current corresponding ATC software. An important consequence of these features is that the V&V (Validation and Verification) process will be considerably simpler than for current ATC software. Additionally, the associative processor is enhanced SIMD hardware and is considerably cheaper and simpler than the MIMD hardware currently used to support ATC. The ClearSpeed CSX600 accelerator is used to emulate the AP model. A preliminary implementation of the proposed method has been developed and experimental results comparing MIMD and CSX600 approaches are presented. The performance of CSX600 has better scalability, efficiency, and predictability than that of MIMD.
Separation Assurance and Collision Avoidance Concepts for the Next Generation Air Transportation
 System,” Human Interface, Part II, HCII 2009, LNCS 5618
, 2009
"... Abstract. A review was conducted of separation assurance and collision avoidance operational concepts for the next generation air transportation system. The concepts can be distributed along two axes: the degree to which responsibility for separation assurance and collision avoidance is assigned to ..."
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Cited by 4 (0 self)
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Abstract. A review was conducted of separation assurance and collision avoidance operational concepts for the next generation air transportation system. The concepts can be distributed along two axes: the degree to which responsibility for separation assurance and collision avoidance is assigned to the controller verses the pilot(s), and the degree to which automation augments or replaces controller and pilot functions. Based on an analysis of the implications of these concepts from a human factors standpoint, as well as the technological readiness of the concepts, it appears that some form of supervisory control of separation by controllers is the most viable concept.
Air Traffic Control Command Monitoring System Based on Information Integration
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Automated verification of continuous and hybrid dynamical systems
, 2014
"... The standard method used for verifying the behaviour of a dynamical system is simulation. But simulation can check only a finite number of operating conditions and system parameters, leading to a potentially incomplete verification result. This dissertation presents several automated theorem proving ..."
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The standard method used for verifying the behaviour of a dynamical system is simulation. But simulation can check only a finite number of operating conditions and system parameters, leading to a potentially incomplete verification result. This dissertation presents several automated theorem proving based methods that can, in contrast to simulation, completely guarantee the safety of a dynamical system model. To completely verify a purely continuous dynamical system requires proving a universally quantified first order conjecture, which represents all possible trajectories of the system. Such a closed form solution may contain transcendental functions, rendering the problem undecidable in the general case. The automated theorem prover MetiTarski can be used to solve such a problem by reducing it to one over the real closed fields. The main issue is the doubly exponential complexity of the backend decision procedures that it depends on. This dissertation proposes several techniques that make the required conjectures eas
DEVELOPING AND VALIDATING HUMAN FACTORS CERTIFICATION CRITERIA FOR COCKPIT DISPLAYS OF TRAFFIC INFORMATION AVIONICS
, 2004
"... This report examines issues associated with traffic awareness and conflict detection and resolution applications, particularly the predictive and planning support offered by the Cockpit Display of Traffic Information (CDTI). However, inferences about future trajectories of ownship and traffic made ..."
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This report examines issues associated with traffic awareness and conflict detection and resolution applications, particularly the predictive and planning support offered by the Cockpit Display of Traffic Information (CDTI). However, inferences about future trajectories of ownship and traffic made by the CDTI logic will, by nature, be imperfect, leading to an apparent loss of reliability of the prediction/planning tools. This loss of reliability and its impact on pilots’ behavior and cognition is the focus of this report. Three specific aspects of the CDTI are distinguished: Alerts, visual symbology, and planning tools. The report draws from general human factors literature. The tradeoff between false alarms (FAs) and misses (or late alerts), how these tradeoffs affect trust and reliance in the alerting system, and how low baserate events necessarily create a high false alarm rate (FAR), if highcost misses are to be minimized, are examined. The report concludes with general recommendations emerging from the literature on solutions to mitigate the problems of FAs, with an emphasis on multilevel alerts. Also literature that has addressed the FA–late alert tradeoff and evaluated the CDTI alerts with pilotintheloop (PIL) data was reviewed. Lessons
A Stochastic Games Framework for Verification and Control of Discrete Time Stochastic Hybrid Systems
"... We describe a framework for analyzing probabilistic reachability and safety problems for discrete time stochastic hybrid systems within a dynamic games setting. In particular, we consider finite horizon zerosum stochastic games in which a control has the objective of reaching a target set while avo ..."
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We describe a framework for analyzing probabilistic reachability and safety problems for discrete time stochastic hybrid systems within a dynamic games setting. In particular, we consider finite horizon zerosum stochastic games in which a control has the objective of reaching a target set while avoiding an unsafe set in the hybrid state space, and a rational adversary has the opposing objective. We derive an algorithm for computing the maximal probability of achieving the control objective, subject to the worstcase adversary behavior. From this algorithm, sufficient conditions of optimality are also derived for the synthesis of optimal control policies and worstcase disturbance strategies. These results are then specialized to the safety problem, in which the control objective is to remain within a safe set. We illustrate our modeling framework and computational approach using both a tutorial example with jump Markov dynamics and a practical application in the domain of air traffic management.