The Discrete Address Beacon System in the Air Traffic Control Environment

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

Active air traffic controllers and remotely piloted aircraft pilots were studied in a real time simulation providing results on actual and desired behaviour of the studied concept of a mid-air collision avoidance system in an air traffic control environment. The workload for the studied system seems to be acceptable at this state, and no major concerns regarding workload were found during the simulations. However, areas where the studied concept may be improved were identified concerning for instance suggested manoeuvre. A general conclusion from the simulations was that it is important that the D&A-system is correctly designed in regard to sensitivity.

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.

<div class="section abstract"><div class="htmlview paragraph">While hybrid electric powertrains are the standard for passenger cars, the application to motorcycles is almost nil. The reason is the increase in weight, cost and overall dimensions, which can compromise the layout and dynamics of the motorcycle. A viable path is to replace the standard internal combustion engine with a much smaller and lighter unit, which leaves room for the installation of the electric components. The 2-Stroke (2S) cycle technology, thanks to double cycle frequency and inherent simplicity, can be the key to reduce engine dimensions, weight and cost, while keeping high power outputs.</div><div class="htmlview paragraph">The HybridTec project, discussed in this paper, aims to develop a compact and lightweight V-90° two-cylinder 2S engine, coupled to an electric motor installed downstream of the gearbox (P3 configuration). The total installed power should be about 110 kW.</div><div class="htmlview paragraph">The engine features loop-scavenging, actuated by a crankshaft-driven supercharger, while an exhaust rotary valve and electronic fuel injection minimize fuel short-circuit over a broad operating range. Moreover, the control of air and residuals trapped within the cylinder is made by a bypass valve downstream of the supercharger. A 4-Stroke-like forced lubrication system is also adopted.</div><div class="htmlview paragraph">Another advantage of this engine design is the possibility to dilute the fresh charge with exhaust gas, at any operating condition: a proper percentage of residuals helps to cut NO<sub>x</sub> emissions without the need for complex and expensive after-treatment systems.</div><div class="htmlview paragraph">A single-cylinder prototype of the engine was preliminarily built and tested, the initial design being carried out with the support of a 1D model, which was then calibrated based on a preliminary configuration of the engine.</div><div class="htmlview paragraph">According to the 1D simulation results, the engine is able to meet the performance targets and shows good potential at part-load operation, but engine injection system and control strategy need further optimization, which will be supported by future detailed 3D-CFD analysis.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Today turbo-diesel powertrains offering low fuel consumption and good low-end torque comprise a significant fraction of the light-duty vehicle market in Europe. Global CO₂ regulation and customer fuel prices are expected to continue providing pressure for powertrain fuel efficiency. However, regulated emissions for NO</div><div class="htmlview paragraph"> and particulate matter have the potential to further expand the incremental cost of diesel powertrain applications. Vehicle segments with the most cost sensitivity like compacts under 1400 kg weight look for alternatives to meet the CO₂ challenge but maintain an attractive customer offering. In this paper the concepts of downsizing and downspeeding gasoline engines are explored while meeting performance needs through increased BMEP to maintain good driveability and vehicle launch dynamics. A critical enabler for the solution is adoption of gasoline direct injection (GDi) fuel systems. GDi provides the ability to utilize increased scavenging without sacrificing hydrocarbon emissions because fueling and air controls can be separated. In-cylinder injection with GDi also provides charge cooling benefit yielding the knock reduction necessary for turbocharged applications. Several options within GDi are explored including multi-hole and single pintle spray generators, as well as side-mount versus central-mount applications. Both 3-cylinder and 4-cylinder base engine configurations are explored for turbocharged engines downsized to 1.2 L. Improvements in hydrocarbon emissions, heat losses and scavenging favor fewer cylinders. This is re-enforced by packaging and cost considerations. The next system aspect considered is emissions aftertreatment. Stoichiometric turbocharged GDi provides the lowest cost using the established 3-way catalyst. Stratified GDi is expected to require a lean NO</div><div class="htmlview paragraph"> trap (LNT) and diesel Euro 6 systems require addition of a diesel particulate filter (DPF) and possibly NO</div><div class="htmlview paragraph"> aftertreatment. Although the aftertreatment system to meet Euro 6 NO</div><div class="htmlview paragraph"> requirement is not known today, addition of a DPF, DPF with LNT, or DPF with urea selective catalytic reduction (SCR) represent significant cost and packaging challenges. The analysis concludes by comparing the 3-cylinder turbocharged GDi to other offerings in the context of value tradeoff of CO₂ reduction to system on-cost. Stratified 3-cylinder turbocharged GDi systems offer up to 22% CO₂ reduction compared to a baseline port-fuel-injected 4-cylinder engine. CO₂ reduction of 18% is possible for a stoichiometric GDi mechanization that employs variable valve actuation (VVA) and a conventional 3-way catalytic converter. At Euro 6 emission levels, stoichiometric 3-cylinder turbocharged GDi powertrains offer excellent value. The 3-cylinder turbo-diesel offers similar value if it is capable of meeting the NO</div><div class="htmlview paragraph"> emissions standard without lean aftertreatment. Powertrains with higher engine-out NO</div><div class="htmlview paragraph"> levels that require lean aftertreatment are significantly disadvantaged. Based on the price sensitivity of the compact car segment, the value analysis predicts the 3-cylinder turbocharged GDi engine as the powertrain of choice.</div></div>

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.

<div class="section abstract"><div class="htmlview paragraph">The VUSIL program has developed a concept for the integration of unmanned aircraft systems (UAS) into non-segregated airspace, which is also used by manned civil aviation. For the integration of UAS it is necessary for the Unmanned Aircraft (UA) pilot to be aware of the surrounding traffic in order to recognise and resolve possible conflicts. Therefore the surrounding traffic was displayed in the pilot ground control station (GCS) based on Radar data provided by DFS Deutsche Flugsicherung GmbH (DFS). The pilot was supported in detecting potential conflicts by means of a “Sense and Avoid” tool provided by ESG GmbH. This tool shows conflicts and possible avoidance manoeuvres on a separate display. To validate the concept, two flight campaigns with two different UAS (LUNA by EMT GmbH and NEO by Swiss UAV) and several intruders were conducted. In the first flight campaign, the intruders for the real flying UAS were simulated. In the second flight campaign the intruder was a manned helicopter supplied and flown by the German Federal Police. The proof of concept has been validated by the results of both flight campaigns.</div><div class="htmlview paragraph">Additionally, a safety analysis was conducted, aiming at demonstration of safe integration of UAS. Especially the equivalent level of safety (ELOS) of “See and Avoid” in manned aviation and “Sense and Avoid” as developed in the VUSIL program was addressed. Based on the results of the flight trials, workshops with aviation experts and relevant literature, under some conditions and assumptions, ELOS of VUSIL's integration concept has been shown.</div><div class="htmlview paragraph">Collecting the ability requirements of unmanned aircraft pilots was also part of the program. To this end, the UA pilots filled in a job analysis questionnaire to gather first information about the required abilities. The results were compared with the results from air traffic controllers and pilots.</div></div>

Objective job difficulty, behavioural response, and sector characteristics in air route traffic control centres.

An Agent-Based Approach to Aircraft Conflict Resolution with Constraints

<div class="section abstract"><div class="htmlview paragraph">The air pollution is increasing at an alarming rate now a day mainly due to emissions coming out of automotive vehicles. The exhaust emissions gases are hazardous to human health. The increased number of vehicles on road will make the scenario even worse. In order to control the pollution level, the regulatory bodies are now implementing stringent emission norms. In India, the regulatory authorities has framed the transition of BS IV to BS VI emission norms in 2020 by skipping the BS V emission norms which makes the automotive industries to work on more advanced fuel management technologies. It is more tedious to control the tail pipe emissions beyond BS IV emission norms with the conventional carburetor system since it is operating on open loop system. It is evident that in order to meet the stringent emission norms we need to have a closed loop system which controls the Air Fuel Ratio (AFR) close to stoichiometric to increase the conversion efficiency of the catalytic converter. The vehicle with fuel injection system can able to work on closed loop system, but the fuel injection system is not cost effective.</div><div class="htmlview paragraph">This paper illustrates the development of a cost effective smart engine management system for two wheeler application to meet the upcoming emission norms with some modification from the conventional carburetor system. Instead of controlling the fuel flow to keep the AFR close to the stoichiometric as in fuel injection system, the smart engine management system has a sophisticated air control mechanism to make the AFR close to stoichiometric. The carburetor was modified to incorporate an air control solenoid which is operated on the pulse width modulation to vary the air flow according to our requirement. The lambda sensor measures the AFR from the exhaust pipe and provides information to the ECU.</div><div class="htmlview paragraph">Based on the feedback from the lambda sensor, TPS, CPS, etc., the ECU maintains the AFR stoichiometric by controlling the flow through the air control solenoid with varying duty cycles. The vehicle performance test was carried out with vehicle having smart engine management system (Electronic carburetor) and also with fuel injection equipped vehicle on the chassis dynamometer. The test results show that the air fuel ratio of the electronic carburetor vehicle was maintained close to stoichiometric as in fuel injection vehicle which in turn reduce the emission to a considerable extent. Hence the smart engine management system caters a new way for an efficient low cost fuel management system.</div></div>

This work presents a risk assessment methodology, preliminary proposed in [1], which is the fusion of the absolute and the relative risk assessment methods adopted by the International Civil Aviation Organization. The proposed methodology uses the Fluid Stochastic Petri Net (FSPN) as modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed and the legacy system models. It was applied to assess the safety properties of a new air traffic surveillance concept, named automatic dependent surveillance - broadcasting (ADS-B). As conclusions, the proposed methodology assured to assess the safety properties of systems based on the current safety critical system paradigm - especially concerning the air transportation system. Besides, the FSPN formalism provided important modeling capabilities and discrete event simulation allowing estimating the desired safety metrics. Finally, the ADS-B (proposed system) has significantly reduced the risks of separation losses between aircrafts if compared to the usual surveillance radar systems (legacy system) in air traffic control (ATC) environment.

<div class="htmlview paragraph">The basic process of air traffic control is a complex control feedback system, with human servomechanisms at its input (traffic controller) and output (airplane pilot) ends. Controller and pilot interact via communication links, receiving and transmitting information displayed almost exclusively to the visual and auditory senses. Human abilities and limitations for handling the required data are discussed with respect to present and proposed display techniques. The effects of quantity, rate, reliability (ambiguity) and storage of data are related to air traffic control system effectiveness. The means by which this may be determined are considered from a human factors viewpoint with regard to safety, convenience, and economy.</div>

<div class="section abstract"><div class="htmlview paragraph">Systems such as satellites, airplanes, cars and air traffic controls are becoming more complex and/or highly integrated. These systems integrate several technologies inside themselves, and must be able to work in very demanding environments, sometimes with few or none maintenance services due to their severe conditions of work. To survive such severe work conditions, the systems must present high levels of reliability, which are achieved through different approaches, processes, etc. These unfold in many: levels of aggregation (systems, subsystems, equipments, components, etc.), phases of their lifecycles (conception, design, manufacturing, assembly, integration, tests, operation, etc.), environments (land, sea, air, space, etc.), types of components/applications/experiences/technological communities (nuclear, aerospace, military, automotive, medical, commercial, etc.), leaded by the widespread use of semiconductors. So, the aim of this work is to analyze some semiconductors by the Handbook MILHDBK-217 FN2 to improve the reliability of aerospace and automotive electronic equipments. To do that, this work: 1) summarizes the applicable methods, tools, components, etc., of the Handbook MIL-HDBK-217 NF2; 2) selects some semiconductors such as diodes of low frequency for power rectifiers and voltage regulators; 3) analyze their fault rates; and 4) discusses its factors, to improve the reliability of aerospace and automotive electronic equipments.</div></div>

<div class="section abstract"><div class="htmlview paragraph">Systems such as satellites, airplanes, cars and air traffic controls are becoming more and more complex and/or highly integrated. These systems integrate several technologies inside themselves, and must be able to work in very demanding environments, sometimes with few, or none, maintenance services, because of their severe conditions of work. To survive to such severe work conditions, the systems must present high levels of reliability, which are achieved through different approaches and processes. Therefore, it is necessary that the processes of decision analysis and making are progressively improved, taking into account experiences collected before by several technological communities, and then propose efficient modifications in the local processes. These experiences influence the proposition and improvement of several Reliability Standards Series taken by four different approaches and several technological communities. The first and second approaches were already discussed in a previous paper. So, in this work we discuss the fault correction and the fault prediction approaches for improving the reliability of aerospace and automotive systems. To do that, we review the basic concepts and literature, the items and necessary analyses on a reliability analysis document by those approaches, allowing the assessment of the reliability of the same subsystem for different mission times, and examples to illustrate them. The results obtained so far suggest that they can contribute to improving the reliability of aerospace and automotive systems.</div></div>

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