Flight Management System Research Articles

Horizontal flight trajectories optimisation for commercial aircraft through a flight management system

AbstractTo reduce aircraft emissions to the atmosphere, the fuel burn from aircraft has to be reduced. For long flights, the cruise is the phase where the most significant reduction can be obtained. A new horizontal profile optimisation methodology to achieve lower emissions is described in this article. The impact of wind during a flight can reduce the flight time, either by taking advantage of tailwinds or by avoiding headwinds. A set of alternative trajectories are evaluated to determine the quickest flight time, and therefore, the lowest fuel burn. To determine the expected amount of fuel reduction, the performance databases used on actual FMS devices, were used. These databases represent the flight performance of commercial aircraft.

Development of a tool to study aircraft trajectory optimisation in the presence of icing conditions

With the increasing demand of air travel, the impact on the environment due to aviation has shown a significant increase in recent times. As a result, there is a growing demand for new technologies and flight procedures that will enable aircraft operators to burn less fuel and reduce the adverse effect of aviation on the environment. Conventional approaches to trajectory optimisation do not take the effect of aircraft systems into account. Neglecting these effects may be inadequate, especially when one considers real aircraft operations in real weather scenarios. This research has developed a tool capable of simulating aircraft ice protection performance for trajectory optimisation, which enables the development of a decision making process dependent on weather within the flight management system, thus transforming the conventional ice protection system to a more intelligent system. Presently, thermal ice protection methods are the leading ice protection technology on most of the medium and large transport aircraft. An enhanced aircraft anti-icing model was developed based on Messinger mass and energy balance method for thermal anti-icing. The tool developed in this work can calculate the total water catch and evaluate power requirement due to icing under a wide range of meteorological conditions. The model was successfully integrated with a trajectory optimisation framework for independent assessment of fuel penalty due to icing and investigation of pollutant emissions reduction through aircraft trajectory optimisation. A case of typical departure from London Airport Heathrow was optimised for fuel burn and time. The preliminary results show that when operating in known icing condition, including icing parameters in the optimisation loop could give as much as 2.1% fuel savings.

Joined-wing test bed UAV

The future green aircraft will be required to meet demanding constraints, including weight reduction, high energy and aerodynamic efficiencies and high performance, to be compliant with pollutant emissions and noise generation regulations. The joined-wing concept is considered a trade-off variant for a green aircraft design with a lower cruise drag and lower structural weight. In addition, the requirements for low pollution and noise could be met using an all-electric aircraft. Hence, the aim of the present study is to design and produce a joined-wing unmanned aircraft test bed or flight laboratory. The basic design incorporates tip-joined front and rear wings with wing-tip vertical joints. The airframe is mainly composed of carbon and glass fibre composite materials. The power plant consists of an electric ducted fan, speed controller and Li-Po batteries. The aircraft integrates the Piccolo II Flight Management System, which offers a state-of-the-art navigation and flight data acquisition. Prior to production and flight testing of the prototype, aircraft aerodynamics and flight dynamics were analysed. Potential models with wind tunnel tests have been used to determine aircraft aerodynamics. One of the major problems found during simulation and flight experiments is the Dutch roll effect. This is thoroughly discussed in the paper. Some problems that concern autopilot tuning are also described.

Flight Management System for Unmanned Reusable Space Vehicle Atmospheric and Re-Entry Trajectory Optimisation

The design and trajectory computation algorithms of an innovative Flight Management System (FMS) for Unmanned Reusable Space Vehicle (URSV) are presented. The proposed FMS features a number of common functionalities with modern aircraft FMS that enable flight planning in non-segregated airspace, as well as specific features for optimal trajectory generation and space segment monitoring of the flight mission. The general avionics architecture of URSV is presented and the specific FMS algorithms are developed to cope with the flight vehicle optimal trajectory planning and monitoring. Simulation case studies are performed in a realistic operational scenario resulting in the rapid generation of feasible trajectories, ensuring no violation of the defined mission and vehicle dynamics constraints. Additionally, error budget analysis is performed on longitudinal profile trajectories to evaluate the URSV performance.

Next Generation Flight Management System for Real-Time Trajectory Based Operations

This paper presents the concept of operations, architecture and trajectory optimisation algorithms of a Next Generation Flight Management System (NG-FMS). The NG-FMS is developed for Four Dimensional (4D) Intent Based Operations (IBO) in the next generation Communications, Navigation, Surveillance and Air Traffic Management system (CNS+A) context. The NG-FMS, primarily responsible for the aircraft navigation and guidance task, acts as a key enabler for achieving higher level of operational efficiency and mitigating environmental impacts both in manned and unmanned aircraft applications. The NG-FMS is interoperable with the future ground based 4DT Planning, Negotiation and Validation (4-PNV) systems, enabling automated Trajectory/Intent Based Operations (TBO/IBO). After the NG-FMS architecture is presented, the key mathematical models describing the trajectory generation and optimisation modes are introduced. A detailed error analysis is performed and the uncertainties affecting the nominal trajectories are studied to obtain the total NG-FMS error budgets. These are compared with the Required Navigation Performance (RNP) values for the various operational flight tasks considered.

Real-Time Trajectory Optimisation Models for Next Generation Air Traffic Management Systems

This paper presents models and algorithms for real-time 4-Dimensional Flight Trajectory (4DT) operations in the next generation Communications, Navigation, Surveillance/Air Traffic Management (CNS/ATM) systems. In particular, the models are employed for multi-objective optimisation of 4DT intents in ground-based 4DT Planning, Negotiation and Validation (4-PNV) systems and in airborne Next Generation Flight Management Systems (NG-FMS). The assumed timeframe convention for offline and online air traffic operations is introduced and discussed. The adopted formulation of the multi-objective 4DT optimisation problem includes a number of environmental objectives and operational constraints. In particular, the paper describes a real-time multi-objective optimisation algorithm and the generalised expression of cost function adopted for penalties associated with specific airspace volumes, accounting for weather models, condensation trails models and noise models.

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

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

SOA-Cloud Computing Based Fast and Scalable Simulation Architecture for Advanced Flight Management System

This paper presents a SOA and cloud computing based architecture for the distributed simulation of advanced flight management system (FMS). The architecture is designed to facilitate the fast simulation, validation and evaluation of different FMS system designs and functionalities with customized system configurations and widely varying aircraft equipage levels under various operation conditions. It is also intended to accommodate the potential evolutionary extensions of new avionics concepts and functionalities such as the future CNS/ATM and 4-D trajectory based technologies. To address the requirements of flexibility, scalability and reusability, the design of the simulation architecture takes advantage of the cloud computing and service oriented architecture (SOA) and the key enabling technologies are developed: simulation unit service encapsulation, simulation agent technology and simulation orchestration. Based on the proposed architecture associated technologies, the simulation components are encapsulated as services or accessed through agents, and the configuration of different FMS system frameworks and simulation tasks can be achieved through simulation orchestration. A prototype avionic simulation system that implements the SOA/cloud computing architecture is developed and illustrated with application cases. The applications demonstrate that the proposed architecture enables fast and scalable simulation of both existing and new FMS design and technologies.

Are you ready to get on a pilotless plane?

Along with improved safety, pilotless passenger planes could offer dramatic cost savings for airlines and passengers alike. At the heart of this revolution lies a simple fact: computers now do so much on planes that airline pilots rarely have cause to take the controls. Autoflight computers can take over when the plane is just 30 meters off the ground, maintaining whatever speed, heading and height the crew tap into the flight management system. And the computer has long been able to home in on a runway radio beacon and land the aircraft automatically. Here, Marks examines why automation introduces fresh challenges for pilots.

Enhancing NextGen RNAV Capabilities: Human Performance Evaluation of NRS Waypoint Nomenclatures

As part of the Next Generation Air Transportation System (NextGen) initiative, a redevelopment of the high-altitude airspace is underway to realize the benefits of area navigation (RNAV) capabilities. Three nomenclatures were evaluated as possible alternatives to the current waypoint nomenclature used in the Navigation Reference System (NRS). A part-task study was conducted to assess if speed of NRS waypoint location on an en route chart, speed of flight management system (FMS) entry, number of FMS entry errors, and NRS waypoint reroute use were different among the nomenclatures tested. Overall preference was also assessed.

A New Approach to an Automated Air Traffic Control

This paper identifies areas of improvements of the air traffic control system and proposes modification of the concept of automation by using available technologies. With the proposed modification, the current Europe wide en route network structure can be modified in order to make routes more optimal. For this new route network structure, a new concept of automation will be used to manage with the air traffic. The first identified area of improvement is implementation of automation process that will enable decentralization of the air traffic control functionality to each individual aircraft and this will be achieved through automated routing of the aircrafts and CD&R (conflict detection and resolution). The FMS (flight management system) at the aircraft will make decisions for the optimal flight route based on the sensor inputs, information on selection of the routes, next hope points and flight levels, all received by ADS-B (automatic dependant surveillance-broadcast). The second area is processing the information about the deviation from the optimal route as in flight plan due to a traffic management (vectoring, level change) and taking it into consideration when further actions are undertaken. For each action, a cost factor will be calculated from the fuel burned for that action. This factor will be used to select conflict resolution protocol. The proposed concept shall increase the capacity of the network, and enable the air traffic more efficient and more environmentally friendly while maintaining safe separation. Language: en

Research on Collision Avoidance in Terminal Area Based on RNP and 3D Paths

We describes an operational concept in this paper, it enables increased airspace and airport capacity by using the Flight Management System (FMS), Required Navigation Performance capabilities (RNP) and air traffic management automation tools. This concept can be applied to en route and terminal operation. It realizes ground to air communication by using of voice and data chain. This paper analyzes several key performance parameters which affect arrival management process. This concept models the arrivals by using the performance modeling approach. The results of the modeling proves several factors that influence the delivery accuracy and delay in the arrival process ,these factors include the path and speed discretization, wind, trajectory prediction and navigation performance.

A novel approach for trajectory tracking of UAVs

Purpose The purpose of this paper is to present a novel approach for trajectory tracking of UAVS. Research on unmanned aircraft is constantly improving the autonomous flight capabilities of these vehicles to provide performance needed to use them in even more complex tasks. The UAV path planner (PP) plans the best path to perform the mission. This is a waypoint sequence that is uploaded on the flight management system providing reference to the aircraft guidance, navigation and control system (GNCS). The UAV GNCS converts the waypoint sequence in guidance references for the flight control system (FCS) that, in turn, generates the command sequence needed to track the optimum path.

Space-Indexed Control for Aircraft Vertical Guidance with Time Constraint

With the growth of civil aviation traffic capacity, safety and environmental considerations urge today for the development of guidance systems with improved accuracy for spatial and temporal trajectory tracking. This should induce increased practical capacity by allowing timely operations at minimum separation standards while at takeoff and landing and trajectory dispersion should be reduced, resulting in better controlled noise impacts on airport surrounding communities. Current civil aviation guidance systems operate with real-time corrective actions to maintain the aircraft trajectory as close as possible to a space-indexed planned trajectory while the flight management system copes indirectly with overfly time constraints. In this paper, the design of new longitudinal guidance laws is considered so that accurate vertical tracking is achieved while overfly time constraints are satisfied. Here, distance to land is adopted as the independent variable for the aircraft flight dynamics since it is today available onboard aircraft with acceptable accuracy. A representation of aircraft longitudinal guidance dynamics is developed according to this spatial variable, and a space-indexed nonlinear inverse control law is established to make the aircraft follow accurately a vertical profile and a desired airspeed. The desired airspeed is defined by an outer space-indexed control loop to make the aircraft overfly different waypoints according to a planned timetable. Numerical simulation experiments with different wind conditions for a transportation aircraft performing a descent approach for landing under this new guidance law are described. The resulting guidance performances are compared with those obtained from a classical time-based guidance control law.

A 4D ATM Trajectory Concept Integrating GNSS and FMS?

NextGen and SESAR have now been under development for several years, but have increasingly complex engineering and operational specifications. A variant Air Traffic Management (ATM) concept is sketched for generating fuel-efficient, very accurate and air-ground synchronized 4D-trajectories by using flight segment groundspeed profiles and linking Global Navigation Satellite Systems (GNSS) data to the aircraft Flight Management Systems (FMS) with feedback control. Is this a flawed concept or a feasible and operationally practical proposition?

Practice Summary: Flight Trajectory Optimization

We developed and implemented a novel algorithm to control the trajectory of an aircraft flight to reduce the costs it incurs. Our algorithm computes the values for the parameters to be entered into the aircraft’s flight management system to minimize the fuel and schedule-adherence costs incurred on the flight. We implemented it in a prototype software system that is currently in use at GE Aviation Services.

Demonstration of Improved Trajectory Prediction Using Future Air Navigation Systems

This paper aims to demonstrate how current technology can assist to improve ground-based trajectory prediction. The lack of accurate ground-based trajectory prediction is often associated with the inefficiencies resulting from current Air Traffic Control (ATC) practices. To this purpose, results from different ground-based Trajectory Predictors (TPs) – both standard and enhanced with Future Air Navigation Systems (FANS) data-link – are compared using operations into Los Angeles (LAX). At first sight, direct use of trajectory information down-linked through FANS from the aircraft’s Flight Management System (FMS) seems logical, but numerous arguments exist against that approach. Instead, this research inferred parameters as speed schedule and aircraft mass from the FMS down-linked trajectory. Contrary to the trajectory data itself, these parameters can be used as input to many legacy TPs and are often unknown such that nominal values must be assumed. This paper indicates that with use of this inferred information significant improvements in ground-based trajectory prediction can be achieved. The 95% spread in the estimate time of arrival and top of descent error were reduced by a maximum 79% and 86%, respectively. The predicted trajectories from some enhanced TPs were found to be even more accurate than the original downlink predictions on which the inferred information was based, providing arguments for a combined air-ground solution to trajectory prediction rather than reliance on solely airborne trajectory data.FANS is standard equipment on most wide-body aircraft, and fitting options exist on the major single-aisle aircraft fleet. With the infrastructure to obtain the required data already in place, the approach proposed in this paper is feasible today with minimum investment and aircraft system changes for airlines transitioning towards more advanced concepts and developing technologies.

Algorithm for the aircraft trajectories considering No Fly Zones for a Flight Management System

In this paper, optimal four dimensions trajectories (three space dimensions and one time dimension) are designed using new conceived algorithms, to connect all waypoints specified in the flight plan of an aircraft. The designs of these trajectories also include the management of No-FlyZones, which are zones over which flying is forbidden or temporarily refused. These zones can be either a meteorological obstacle to by-pass or zones in which air conflicts would be already too dense to allow the flying of a new aircraft.

Algorithm for the aircraft trajectories considering No Fly Zones for a Flight Management System

Algorithm for the aircraft trajectories considering No Fly Zones for a Flight Management System

Advance human–machine interface automatic evaluation

The need for accessibility evaluation tools is motivated by several endogenous and exogenous reasons coming from the end user (the designer and the developer) and companies releasing information systems. Existing evaluation tools mainly concentrate on examining the code of Web pages: Web pages more and more frequently contain non-HTML parts that entirely escape from being treated by existing techniques. This is the case of the advanced human---machine interface (AHMI), a piece of software programmed in C/C++, used for controlling the advanced flight management system in the aircraft cockpit. Studying this new user interface (UI) requires a structured approach to evaluate and validate AHMI designs. The goal in this work is to develop an evaluation tool to automate the process of evaluating the AHMI. The method addresses: support of multiple bases of guidelines (accessibility or usability or both) on-demand (partial or total evaluation), with different levels of details (a presentation for developers and for those responsible for certifying accessibility). The method goes a step toward the automatic evaluation of UI containing non-HTML parts.