Vu Duong

Conflict Resolution Advisory Service in autonomous aircraft operations

Recent advances in air traffic Communication Navigation and Surveillance (CNS) have encouraged investigations into the concept following which Air Traffic Control functions can be delegated to the flight deck, allowing more freedom of movement to airspace users. In late 1995, an initiative, known under the project name FREER, for Free-Route Experimental Encounter Resolution, was introduced at EUROCONTROL to investigate the feasibility of this concept. In this paper, we present the initial results obtained from the Autonomous Aircraft Operations study (FREER-I) that targets full delegation of ATC to aircraft operating in low-density airspace. Specific issues of Autonomous Aircraft Operations (AAO) supporting free-route, free flight and user-preferred routing are discussed. A description of the current prototype illustrating the Airborne Interactive Conflict Resolution Advisory service is included.

Airspace sectorization with constraints

We consider the Airspace Sectorization Problem (ASP) in which airspace has to be partitioned into a given number of sectors, each of which being assigned to a team of air traffic controllers. The objective is to minimize the coordination workload between adjacent sectors while balancing the total workload of controllers. Many specific constraints, including both geometrical and aircraft related constraints are taken into account. The problem is solved in a constraint programming framework. Experimental results show that our approach can be used on real life problems.

Non-negative Sparse Principal Component Analysis for Multidimensional Constrained Optimization

One classic problem in air traffic management (ATM) has been the problem of detection and resolution of conflicts between aircraft. Traditionally, a conflict between two aircraft is detected whenever the two protective cylinders surrounding the aircraft intersect. In Trajectory-based Air Traffic Management, a baseline for the next generation of air traffic management system, we suggest that these protective cylinders be deformable volumes induced by variations in weather information such as wind speed and directions subjected to uncertainties of future states of trajectory controls. Using contact constraints on deforming parametric surfaces of these protective volumes, a constrained minimization algorithm is proposed to compute collision between two deformable bodies, and a differential optimization scheme is proposed to resolve detected conflicts. Given the covariance matrix representing the state of aircraft trajectory and its control and objective functions, we consider the problem of maximizing the variance explained by a particular linear combination of the input variables where the coefficients in this combination are required to be non-negative, and the number of non-zero coefficients is constrained (e.g. state of trajectory and estimated time of arrival over one change point). Using convex relaxation and re-weighted l 1 technique, we reduce the problem to solving some semi-definite programming ones, and reinforce the non-negative principal components that satisfy the sparsity constraints. Numerical results show that the method presented in this paper is efficient and reliable in practice. Since the proposed method can be applied to a wide range of dynamic modeling problems such as collision avoidance in dynamic autonomous robots environments, dynamic interactions with 4D computer animation scenes, financial asset trading, or autonomous intelligent vehicles, we also attempt to keep all descriptions as general as possible.

An algorithm for computing a generalized problem of controllability radii

Given a linear control system, the controllability radii for a linear control system is the norm of the smallest perturbation that makes the given system uncontrollable. In this paper, we propose a generalized problem for controllability radii when both or only one of system matrices is perturbed. Then, based on recent methods of Gu, Burke-Lewis-Overton and Gu-Mengi-Overton-Xia-Zhu, we present an algorithm to computing the generalized controllability radius problem. This algorithm achieves the complexity of O(k4) on average, where k is the order of the system. Numerical experiments indicate that the new method is reliable in practice.

Preliminary Results of Investigations into The Concept of Delegation of ATC From The Ground to The Air

Abstract The EUROCONTROL FREER project investigates the feasibility of the concept following which ATC tasks could be delegated to the flight deck. Two operational scenarios are considered: (1) Ground-Air Cooperative Control Operations in ECAC highdensity airspace, representing partial delegation of ATC tasks within limited time and specific circumstances, and (2) Autonomous Aircraft Operations in low-density airspace representing the full delegation of ATC from the ground to the air. In this paper, initial results of the investigations are presented, including those relating to the trends of benefits of the concepts; autonomous operation with Airborne Separation Assurance System, and analysis of applicability of free-flight mode in European airspace.