nxControl: Konzept zur Vorgaberegelung für die Längsbeschleunigung des Flugzeugs

Der zukünftige Luftverkehr erfordert präzisere Einhaltung von komplexeren Trajektorien. Automatische Flugführung mittels Autopilot und Autothrottle erlauben bereits heute die Einhaltung komplexer Flugtrajektorien. Jedoch muss stets gewährleistet sein, dass die Piloten die erhöhten Anforderungen an die Bahnführung auch im manuellen Flug erfüllen können. Moderne Verkehrsflugzeuge sind mit elektronischen Flugregelungscomputern ausgestattet, die die manuelle Flugsteuerung unterstützen. Die sogenannten Vorgaberegler nutzen ausschließlich die aerodynamischen Stellelemente und verwenden diese bisher nur für die Lageregelung. Die für die Bahnführung zusätzlich notwendigen und in Längsrichtung wirkenden Stellelemente für Schub und Widerstand müssen hingegen konventionell angesteuert werden, was im Bezug zu den zukünftigen Anforderungen zu erhöhter Arbeitsbelastung führen kann. Im Projekt nxControl wird ergänzend zu den bereits bestehenden Flugsteuerungssystemen ein Regler zur Vorgabe der Längsbeschleunigung entwickelt, der alle in Längsrichtung wirkenden Stellelemente verwendet. Daran angepasst wird eine Mensch-Maschine-Schnittstelle entwickelt, die das Situationsbewusstsein und die Führungsgenauigkeit verbessert, ohne die Arbeitsbelastung zu erhöhen. In diesem Beitrag wird das Konzept des Vorgabereglers und der Mensch-Maschine-Schnittstelle erläutert

Implementing energy status in head-down cockpit displays: impact of augmented energy information on pilot’s performance

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.It is safety critical for pilots to be aware of the aircraft’s energy state in terms of proper altitude and airspeed. A loss of energy awareness is an important human factors issue in modern civil aircraft. In order to maintain the energy awareness and support the manual flying skills, several cockpit display concepts suggest to augment the current energy status of the aircraft on primary flight displays in terms of the total energy angle. An experiment was carried out to determine which effect this additional energy information has on pilots’ flight path control, instrument scanning, and situation awareness. Outcomes of the study show a significant shift of the scanning pattern from airspeed, altitude scale, and engine parameter towards the center of the primary flight display with unchanged situation awareness. In addition, pilots are better able to maintain given speed targets

Granule cell raphes in the developing mouse cerebellum

The cerebellar cortex of many vertebrates shows a striking parasagittal compartmentation that is thought to play a role in the establishment and maintenance of functional cerebellar connectivity. Here, I demonstrate the existence of multiple parasagittal raphes of cells in the molecular layer of the developing cerebellar cortex of postnatal mouse. The histological appearance and immunostaining profile of the raphe cells suggest that they are migrating granule cells. I therefore conclude that the granule cell raphes previously described in birds also exist in a mammalian species. The raphes in mouse are visible on nuclear stains from around birth to postnatal day 6 and are frequently found at the boundaries of Purkinje cell segments that differentially express cadherins (“early-onset” parasagittal banding pattern). A similar relation between the raphe pattern and various markers for the early-onset banding pattern has been found in the chicken cerebellum. One of the cadherins mapped in the present study (OL-protocadherin) continues to be expressed in specific Purkinje cell segments until at least postnatal day 14. At this stage of development, the borders of the OL-protocadherin-positive Purkinje cell segments coincide with the borders of Purkinje cell segments that express zebrin II, a marker for the “late-onset” parasagittal banding pattern which persists in the adult cerebellum. These findings demonstrate that the early-onset banding pattern, as reflected in the complementary arrangement of raphes/Purkinje cell segments, and the late-onset pattern of zebrin II expression share at least some positional cues during development

Manual flying and energy awareness : Beneficial effects of energy displays combined with a new approach of augmented thrust control

In order to enable pilots to better maintain energy awareness and energy management in manual flight, a new concept has been proposed, which transfers the demand control principle of fly-by-wire control laws also to the control of thrust. It includes a total-energy-related augmented thrust controller combined with a modified cockpit instrumentation enriched by specific energy displays. In order to empirically evaluate the human performance consequences of this new approach, an experimental study was conducted in a flight simulator investigating its effects on pilots’ performance, workload, and situation awareness. A total of 24 commercial aircraft pilots performed a landing and approach on a complex flight trajectory with and without the new system elements. The results confirm the expected beneficial effects of the new system on flight precision and lowered effort involved in thrust control as compared with conventional raw data flying. No negative side effects, for example, impaired situation awareness, were found

Enhancing manual flight precision and reducing pilot workload using a new manual control augmentation system for energy angle

With rising demands on flight precision and more complex flight trajectories, pilots' workload during manual flight is increasing. This is especially the case for thrust and spoiler control during approach and landing. The presented nxControl system enables pilots to manually control the longitudinal load factor nx instead of engine parameters and spoiler deflections. This load factor is equivalent to total energy angle and is directly influenced by engine thrust and aerodynamic drag. The nxController complements existing control augmentation systems such as the fly-by-wire control laws of today's commercial airliners. It aims at higher precision with lower workload during manual flight. The controller input can be set and monitored by an adapted human-machine interface consisting of a thrust-lever-like inceptor and additional display elements to enhance energy awareness. This paper presents the nxControl system with focus on the command control system and an evaluation study with 24 airline pilots in a research flight simulator. The task was a demanding and steep approach with required navigation performance RNP 0.1 in a mountainous area. The results show higher precision and lower workload with the nxControl system despite minimal amount of training

Verbesserung von Flugpräzision und Arbeitsbeanspruchung bei manuellen RNP-Anflügen durch Vorgaberegler und Anzeigen für den Energiewinkel (nxControl)

Mit steigenden Präzisionsanforderungen bei immer komplexeren Flugtrajektorien erhöht sich die Arbeitsbeanspruchung der Piloten im manuellen Flug besonders bei der Ansteuerung von Triebwerken und Bremsklappen. Die konventionelle Steuerung über Hilfsparameter wie Triebwerksdrehzahl bzw. Hebelstellung erlaubt keine exakte Vorhersage der Zustandsänderung. Stattdessen muss abgewartet und die Eingaben gegebenenfalls angepasst werden. Ergänzend zu bestehenden Vorgaberegelungen im Cockpit (z. B. am Sidestick bzw. Steuerhorn) wurde deshalb im DFG-Vorhaben nxControl für die Steuerung von Triebwerken und Bremsklappen ein Vorgaberegler entwickelt, der das Lastvielfache in Flugbahnrichtung nx als Kommandowert verwendet (nxController). Das x-Lastvielfache ist synonym zum Gesamtenergiewinkel und wird direkt durch Schub- und Widerstandskraft aber auch durch Wind beeinflusst. Dieser Parameter gibt Auskunft über die Stärke der Zustands- bzw. der Gesamtenergieänderung, weshalb ein direkter Zusammenhang zwischen erwarteter Reaktion und Eingabe hergestellt wird. Der nxController soll somit ermöglichen, im manuellen Flug hohe Präzisionsanforderungen mit geringer Arbeitsbeanspruchung zu erfüllen. Eine Mensch-Maschine-Schnittstelle, bestehend aus Eingabehebel und Anzeigeelementen in den primären und sekundären Anzeigen des Cockpits, zur Ansteuerung und Überwachung soll zudem das Energiebewusstsein erhöhen. Das Gesamtsystem wurde in einen Forschungssimulator integriert und in verschiedenen Studien evaluiert. Dieser Beitrag stellt das nxControl-System mit Fokus auf dem Vorgaberegler und die Evaluationsergebnisse bei Standard-ILS-Landeanflügen ohne Störungen sowie anspruchsvoller und steiler RNP-Landeanflüge vor. Die Ergebnisse der Studien zeigen, dass die Versuchspersonen nach kurzem Training mit dem System die gestellten Aufgaben mit der geforderten Präzision erfüllen können. Beim RNP-Landeanflug sind zudem Verbesserungen in der Flugpräzision bei verringerter Arbeitsbeanspruchung durch das nxControl-System zu beobachten. Das System verspricht somit, manuelles Fliegen unter hohen Präzisionsansprüchen bei akzeptabler Beanspruchung zu ermöglichen

nxControl instead of pitch-and-power: a concept for enhanced manual flight control

A command system for manual control of the longitudinal load factor in flight path direction of an aircraft is designed that completes existing flight control command systems (e.g. with sidesticks that command normal load factor). The system is called nxControl. It aims to assist pilots during manual flight by reducing the workload for monitoring flight parameters as well as for controlling thrust and airbrakes. Important for the nxControl concept is the direct flight mechanical relation between longitudinal load factor and changes of the total aircraft energy. This paper presents the system concept and a prototype realization. The nxControl system consists of the control law that combines the actuation commands for engines and airbrakes, a new input device for the longitudinal load factor command and augmented display elements informing pilots about aircraft energy states to assure situation awareness. In order to investigate the feasibility of the concept as well as to evaluate consequences on human performance, a flight simulator study with airline pilots was conducted. The nxControl prototype was used by the pilots as expected. Changes in instrument scanning behaviour and thrust lever usage confirmed this. After just a short familiarization and practice, the pilots were able to perform standard flight tasks with nxControl without exceeding given tolerance limits. So, the results provide first evidence for the feasibility of the concept

nxControl instead of pitch-and-power : concept and first results of a control system for manual flight

A command system for manual control of the longitudinal load factor (nx) of an aircraft is designed that completes existing flight control command systems (e.g. sidesticks normal load factor nz). nxControl's aim is to assist pilots during manual flight by reducing the workload for monitoring flight parameters and the controlling of thrust and airbrakes. Important for nxControl concept is the direct relation between load factor and changes of the total aircraft energy. In the current paper a system concept and a prototype realisation are presented. The nxControl system consists of the control law that combines the actuation commands for engines and airbrakes in flight, a new input device for the longitudinal load factor command and new display elements that informs pilots about energy states to assure situation awareness. In order to investigate the feasibility of the concept as well as human performance consequences and cognitive demands, a flight simulator study with airline pilots was conducted.The results provide first evidence for the feasibility of the concept. As expected a change of scanning behaviour became apparent. For test scenarios with standard flight tasks, no impact in situation awareness and performance was observable. However, for more demanding tasks benefits are expected. Additionally, the assumed effect of a lower input device activity with the use of nxControl can be confirmed

Applying eigenstructure assignment to inner-loop flight control laws for a multibody aircraft

Unmanned aircraft used as high-altitude platform system has been studied in research and industry as alternative technologies to satellites. Regarding actual operation and flight performance of such systems, multibody aircraft seems to be a promising aircraft configuration. In terms of flight dynamics, this aircraft strongly differs from classical rigid-body and flexible aircraft, because a strong interference between flight mechanic and formation modes occurs. For unmanned operation in the stratosphere, flight control laws are required. While control theory generally provides a number of approaches, the specific flight physics characteristics can be only partially considered. This paper addresses a flight control law approach based on a physically exact target model of the multibody aircraft dynamics rather than conventionally considering the system dynamics only. In the target model, hypothetical spring and damping elements at the joints are included into the equations of motion to transfer the configuration of a highly flexible multibody aircraft into one similar to a classical rigid-body aircraft. The differences between both types of aircraft are reflected in the eigenvalues and eigenvectors. Using the eigenstructure assignment, the desired damping and stiffness are established by the inner-loop flight control law. In contrast to other methods, this procedure allows a straightforward control law design for a multibody aircraft based on a physical reference model.TU Berlin, Open-Access-Mittel – 202

Untersuchung der mentalen Repräsentation von Energiemanagement bei der Flugzeugführung zur Entwicklung eines Pilotenassistenzsystems

Um die mentale Repräsentation des Energiemanagements bei der manuellen Flugzeugführung zu untersuchen, wurde eine Simulatorkampagne mit n = 12 lizenzierten Verkehrspiloten durchgeführt. Ihre Aufgabe war es, künstlich generierte Höhen- und Geschwindigkeitsablagen auf dem Gleitpfad des Instrumentenlandesystems (ILS) im Endanflug zu korrigieren. Dabei wurde untersucht, ob und inwiefern sie von dem Prinzip des Energieaustauschs Gebrauch machen. Die Ergebnisse zeigen eine wenig einheitlich ausgeprägte Repräsentation des Wissens bezüglich des Energiemanagements. Des Weiteren war zu erkennen, dass nicht die vollen Möglichkeiten des Energieaustausches genutzt wurden. Vielmehr wurden damit lediglich kleine Korrekturen durchgeführt