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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
441

AUTOMATISERADE FLYGPLAN: EN EMPIRISK STUDIE OM FLYGPASSAGERARES INSTÄLLNING

Efstathiou, Teresia January 2019 (has links)
Automatiska flygningssystem och kontrollpresentationsenheter utvecklas hela tiden inom flygteknik. Avionik företag skapar datoriserade system som ska kunna automatisera ytterligare aspekter av de operationer som sker i cockpit. Att flyga ska inte bedömas vara något riskfyllt och för att säkerställa säkerhetssynen är det betydelsefullt att ta reda på om människor uppfattar teknikens framgång som positiv. Syftet är att ta reda på människans uppfattning och inställning till automatiserade flygplan. Frågeställningen besvaras genom en empirisk studie där först en noggrann bakgrundsundersökning gjorts för att få fram information om var automatiserade flygplan befinner sig gällande dess utveckling och framgång. Med hjälp av en gedigen bakgrund har en kvantitativ enkät undersökning genomförts som på bästa sätt ger svar på frågeställningen om automatiserade flygplan anses vara ett säkert transportmedel. Majoriteten av respondenterna, 86,9%, anser det vara viktigt eller väldigt viktigt att det finns en pilot som styr flygplanet. Automatiserade fraktflygplan är det som ligger närmast i framtiden jämfört med civila flygplan. Det har framförts att ökad förståelse om teknik ger en ökad tillit till AI och ju mer tillit till AI desto större chans till att skapa en bättre trygghetskänsla till automatiserade flygplan. Det kan även konkluderas att pilotlösa flygplan som styrs från kontrollrum på marken inte bör agera som en övergång till helt automatiserade flygplan. Istället föredras en stegvis automatisering i form av en digital andrepilot som hjälpmedel. Det måste dessutom skapas en större medvetenhet i hur flygplanen opererar för att få passagerare mottagbara till vidare utveckling. Slutligen måste inte automatiserade flygplan vara helt perfekta och eftersträva en omöjlig standard. / Automatic flight systems and control presentation units are constantly being developed in aviation technology. Avionic companies create computerized systems that will be able to automate additional aspects of the operations that take place in the cockpit. Flying should not be judged to be somewhat risky and to ensure safety, it is important to find out whether people perceive the technology's success as positive. The purpose is to find out about the people’s perception and attitude towards automated aircraft. The question is answered through an empirical study in which a thorough background study was first made to obtain information about where automated aircraft are located in relation to its development and success. With the help of a solid background, a quantitative questionnaire survey has been conducted that best answers the question of whether automated aircraft are considered a safe means of transport. The majority of respondents, 86.9%, consider it important or very important that there is a pilot who controls the aircraft. Automated cargo aircraft are the closest in the future compared to civil aircraft. It has been argued that increased understanding of technology gives increased confidence in AI and the more confidence in AI the greater the chance of creating a better sense of security for automated aircraft. It can also be concluded that pilotless aircraft controlled from control rooms on the ground should not act as a transition to fully automated aircraft. Instead, a step-by-step automation in the form of a digital second pilot is preferred. In addition, a greater awareness must be created in how the aircraft operate to get passengers susceptible to further development. Finally, automated aircraft need not be perfectly perfect and strive for an impossible standard.
442

Svenska stridspiloters årliga fysiska tester / The every year physical test for Swedish fighter pilots

Karlsson, Erik January 2010 (has links)
<p>Piloter i försvarsmakten har en väldigt unik arbetsmiljö med särskilda påfrestningar från bland annat höga G-krafter och snabba tryckförändringar. I dagsläget utför svenska stridspiloter i princip samma slags fysiska tester som all Försvarsmaktspersonal. De årliga fysiska testerna för svenska stridspiloter är uppdelade i två olika tester; ett konditionstest och ett multitest i styrka. Validiteten för dessa tester kan dock ifrågasättas. De ger endast en grov bild över en persons allmänna fysiska status och har, enligt min åsikt, egentligen inte direkt någonting att göra med huruvida piloten skall kunna klara av att utföra sin tjänst. Man kan dock fråga sig i om en god allmän hälsa indirekt är en förutsättning för att piloten skall kunna utföra sin tjänst på bästa sätt. Ökad styrka och anaerob förmåga, framförallt ökad styrka i benmusklerna, bål och även armar har förts fram som faktorer som ökar G-toleransen. Flera studier visar på sådana resultat med koppling till ökad G-toleransoch tiden innan en person blir utmattad av AGSM. Det finns dock några studier vars resultat kontradikterar mot detta och som istället menar att muskelutmattning vid utförandet av AGSM sannolikt inte påverkar G-toleransen. Samtidigt som ingen studie har lyckats visa att aerob förmåga ökar G-toleransen. Det är väldigt svårt att mäta G-toleransen och framförallt att mäta den på rätt sätt. Många har försökt men tyvärr finns det vissa tveksamheter och många möjliga felkällor i alla studier jag undersökt. Det återstår således att utföra mer forskning på området för att säkerställa dessa resultat. Då det idag inte råder några tvivel om att aerob förmåga inte ökar G-toleransen och eftersom anaerob förmåga, främst styrkan i ben och bål men också i armar och övriga kroppen, i flertalet studier antytts kunna öka G-toleransenanser jag att man borde fokuseras på att testa styrkan i de muskler som används vid AGSM i de årliga fysiska testerna och att styrketräning överlag borde premieras för stridspiloter. Jag har inte kommit fram till särskilt många förslag på nya tester men det var heller inte mitt syfte med uppsatsen. Däremot vill jag bestämt föreslå att de årliga fysiska testerna för svenska stridspiloter snarast borde ges en grundlig översyn, framför allt bentestet. Cykeltestet borde omarbetas för att bli likvärdigt med löptesterna. Ett nacktest vore också högst önskvärt i dessa framtida tester. Men först måste det noggrant utredas vad det egentliga syftet med testerna skall vara.</p> / <p>Fighter pilots have a very unique working environment in Swedens Armed Foces, stress from high G-forces and fast pressures changes to name a few. Up to days date Swedish fighter pilots conduct almost exactly the same physical tests each year as the rest of Swedens Armed Forces. Each years physical testing is divided into two seperate tests; one fitness test and one multi test of strength. But the validity of both these test can be questioned. These test only gives a rough estimation of a persons overall physical standard and has little to do with whether the pilot manage to cope with his serving or not. However, you could argue that a fighter pilot indirect requires a good general physical state to stay on acitve duty. Anaerobic fitness and most of all increased strength in muscles groups such as legs, abdominal and arms has been brought up as evidence to support the conclusion that strength training increases G-tolerance. Multiple studies all share these same results. The results connected to G-tolerance and the time before a person losses consiousness because of the repeated execution of the AGSM. There are however a few studies made that contradict the very conclusion of the studies above. They found out that musclefatigue as a result of repeated execution of tha AGSM is unlikely to affect G-tolerance. At the same time, no present studie that I have been able to find has found any evidence that support that fact that aerobic fitness would have any effect on G-tolerance. To meassure G-tolerance and most of all to get it right is difficult work. Many have tried and few or perhaps none has completly succeeded. There are some doubts and alot of possible sources of errors in all studies I have found. Hence alot of work are still to be done in this particular region of science before we can know for sure that these facts are correct. I suggest that since there are no doubts about the fact that aerobic fitness does not contribute to G-tolerance and since anaerobic fitness and strenght in first of all legs and abdominal mucles but also arms and the upper body has been found to somehow affect G-tolerance positivly focus should be on meassuring the strength in first of all the muscles that are involved in the AGSM in the every year physical tests and that fighter pilots should be encouraged to exercise strength training. I have not come up with many suggestions regarding new tests but that was not the aim of this paper. But I strongly suggest that someone is to overlook these tests soon, especially the leg test. I also think that the bicycle test should be made more equivalent to the running tests. A neck test would also be most appropriate to include in these future tests to come. But first of all it needs to be determined what the main purpose of these tests should be.</p>
443

Svenska stridspiloters årliga fysiska tester / The every year physical test for Swedish fighter pilots

Karlsson, Erik January 2010 (has links)
Piloter i försvarsmakten har en väldigt unik arbetsmiljö med särskilda påfrestningar från bland annat höga G-krafter och snabba tryckförändringar. I dagsläget utför svenska stridspiloter i princip samma slags fysiska tester som all Försvarsmaktspersonal. De årliga fysiska testerna för svenska stridspiloter är uppdelade i två olika tester; ett konditionstest och ett multitest i styrka. Validiteten för dessa tester kan dock ifrågasättas. De ger endast en grov bild över en persons allmänna fysiska status och har, enligt min åsikt, egentligen inte direkt någonting att göra med huruvida piloten skall kunna klara av att utföra sin tjänst. Man kan dock fråga sig i om en god allmän hälsa indirekt är en förutsättning för att piloten skall kunna utföra sin tjänst på bästa sätt. Ökad styrka och anaerob förmåga, framförallt ökad styrka i benmusklerna, bål och även armar har förts fram som faktorer som ökar G-toleransen. Flera studier visar på sådana resultat med koppling till ökad G-toleransoch tiden innan en person blir utmattad av AGSM. Det finns dock några studier vars resultat kontradikterar mot detta och som istället menar att muskelutmattning vid utförandet av AGSM sannolikt inte påverkar G-toleransen. Samtidigt som ingen studie har lyckats visa att aerob förmåga ökar G-toleransen. Det är väldigt svårt att mäta G-toleransen och framförallt att mäta den på rätt sätt. Många har försökt men tyvärr finns det vissa tveksamheter och många möjliga felkällor i alla studier jag undersökt. Det återstår således att utföra mer forskning på området för att säkerställa dessa resultat. Då det idag inte råder några tvivel om att aerob förmåga inte ökar G-toleransen och eftersom anaerob förmåga, främst styrkan i ben och bål men också i armar och övriga kroppen, i flertalet studier antytts kunna öka G-toleransenanser jag att man borde fokuseras på att testa styrkan i de muskler som används vid AGSM i de årliga fysiska testerna och att styrketräning överlag borde premieras för stridspiloter. Jag har inte kommit fram till särskilt många förslag på nya tester men det var heller inte mitt syfte med uppsatsen. Däremot vill jag bestämt föreslå att de årliga fysiska testerna för svenska stridspiloter snarast borde ges en grundlig översyn, framför allt bentestet. Cykeltestet borde omarbetas för att bli likvärdigt med löptesterna. Ett nacktest vore också högst önskvärt i dessa framtida tester. Men först måste det noggrant utredas vad det egentliga syftet med testerna skall vara. / Fighter pilots have a very unique working environment in Swedens Armed Foces, stress from high G-forces and fast pressures changes to name a few. Up to days date Swedish fighter pilots conduct almost exactly the same physical tests each year as the rest of Swedens Armed Forces. Each years physical testing is divided into two seperate tests; one fitness test and one multi test of strength. But the validity of both these test can be questioned. These test only gives a rough estimation of a persons overall physical standard and has little to do with whether the pilot manage to cope with his serving or not. However, you could argue that a fighter pilot indirect requires a good general physical state to stay on acitve duty. Anaerobic fitness and most of all increased strength in muscles groups such as legs, abdominal and arms has been brought up as evidence to support the conclusion that strength training increases G-tolerance. Multiple studies all share these same results. The results connected to G-tolerance and the time before a person losses consiousness because of the repeated execution of the AGSM. There are however a few studies made that contradict the very conclusion of the studies above. They found out that musclefatigue as a result of repeated execution of tha AGSM is unlikely to affect G-tolerance. At the same time, no present studie that I have been able to find has found any evidence that support that fact that aerobic fitness would have any effect on G-tolerance. To meassure G-tolerance and most of all to get it right is difficult work. Many have tried and few or perhaps none has completly succeeded. There are some doubts and alot of possible sources of errors in all studies I have found. Hence alot of work are still to be done in this particular region of science before we can know for sure that these facts are correct. I suggest that since there are no doubts about the fact that aerobic fitness does not contribute to G-tolerance and since anaerobic fitness and strenght in first of all legs and abdominal mucles but also arms and the upper body has been found to somehow affect G-tolerance positivly focus should be on meassuring the strength in first of all the muscles that are involved in the AGSM in the every year physical tests and that fighter pilots should be encouraged to exercise strength training. I have not come up with many suggestions regarding new tests but that was not the aim of this paper. But I strongly suggest that someone is to overlook these tests soon, especially the leg test. I also think that the bicycle test should be made more equivalent to the running tests. A neck test would also be most appropriate to include in these future tests to come. But first of all it needs to be determined what the main purpose of these tests should be.
444

Developing a training program for the traffic alert and collision avoidance system in context

Fleming, Elizabeth Scott 26 March 2013 (has links)
The Traffic alert and Collision Avoidance System (TCAS) is an aircraft collision avoidance system designed to prevent mid-air collisions. During an advisory, danger is imminent, and TCAS is assumed to have better, more up-to-date information than the ground operated air traffic control (ATC) facility. Following a TCAS RA is generally the safe course of action during an advisory. However, pilot compliance with RAs is surprisingly low. Results from a TCAS monitoring study show pilots are not complying with many TCAS advisories. As revealed by pilot-submitted Aviation Safety Reporting System (ASRS) reports, this noncompliance could be attributed, in part, to pilot confusion to TCAS operation as well as misunderstandings of the appropriate response to a TCAS issued advisory. This thesis details the development and evaluation of a TCAS training program intended to improve pilots' understanding of TCAS use for collision avoidance in a range of traffic situations. The training program integrated Demonstration Based and Event Based Training techniques. Its efficacy was analyzed in an integrated ATC-cockpit simulator study in which eighteen commercial airline pilots were asked to complete the TCAS training program and afterwards experienced twelve experimental traffic events. The trained pilots' performance was compared to the performance of 16 baseline pilots who did not receive the modified training. Overall, the training program did have a significant impact on the pilots' behavior and response to TCAS advisories. The measure Time Pilots First Achieved Compliance decreased with the trained pilots, as did the measure Autopilot Disconnect Time After RA Initiation. Trained pilots exhibited less aggressive performance in response to a TCAS RA (including a decrease in the measures Altitude Deviation Over Duration Of RA, Average Vertical Rate Difference, Maximum Vertical Rate Difference, and Maximum Vertical Rate). The measure Percent Compliance did not significantly vary between trained and baseline pilots, although trained pilots had a more consistent response in the traffic event with conflicting ATC guidance. Finally, on the post-experiment questionnaires, pilots commented on their increase in understanding of TCAS as well as an increase in their trust in the advisory system. Results of this research inform TCAS training objectives provided by the FAA as well as the design of TCAS training. Additionally, conclusions extend more broadly to improved training techniques for other similar complex, time-critical situations.
445

Rotorcraft trim by a neural model-predictive auto-pilot

Riviello, Luca 14 April 2005 (has links)
In this work we investigate the use of state-of-the-art tools for the regulation of complex, non-linear systems to improve the methodologies currently applied to trim comprehensive virtual prototypes of rotors and rotorcrafts. Among the several methods that have been proposed in the literature, the auto-pilot approach has the potential to solve trim problems efficiently even for the large and complex vehicle models of modern comprehensive finite element-based analysis codes. In this approach, the trim condition is obtained by adjusting the controls so as to virtually ``fly' the system to the final steady (periodic) flight condition. Published proportional auto-pilots show to work well in many practical instances. However, they cannot guarantee good performance and stability in all flight conditions of interest. Limit-cycle oscillations in control time histories are often observed in practice because of the non-linear nature of the problem and the difficulties in enforcing the constant-in-time condition for the controls. To address all the above areas of concern, in this research we propose a new auto-pilot, based on non-linear model-predictive control (NMPC). The formulation uses a non-linear reference model of the system augmented with an adaptive neural element, which identifies and corrects the mismatch between reduced model and controlled system. The methodology is tested on the wind-tunnel trim of a rotor multibody model and compared to an existing implementation of a classic auto-pilot. The proposed controller shows good performance without the need of a potentially very expensive tuning phase, which is required in classical auto-pilots. Moreover, model-predictive control provides a framework for guaranteeing stability of the non-linear closed-loop system, so it seems to be a viable approach for trimming complete rotorcraft comprehensive models in free-flight.
446

Behavioral Performance and Evolution of Feeding Modes in Odontocetes

Kane, Emily A. 2009 May 1900 (has links)
Vertebrate evolution has resulted in a diversity of feeding mechanisms. Cetaceans are secondarily derived tetrapods that have returned to a marine habitat. As a result, they display feeding modes that have converged with more basal aquatic vertebrates, but display a diversity of new solutions and adaptations. To begin to explore the diversity of feeding adaptations among odontocetes, kinematics of feeding modes and feeding adaptations for belugas (Delphinapterus leucas), Pacific white-sided dolphins (Lagenorhynchus obliquidens), and long-finned pilot whales (Globicephala melas) were characterized. In addition, direct measurements of intraoral pressure were collected to determine maximum suction performance. Characters from these analyses were combined with data for other odontocetes, and were mapped onto a phylogeny of Odontoceti to begin to explore where changes in feeding modes took place. Feeding modes were diverse in belugas, Pacific white-sided dolphins, and pilot whales and included suction, ram, and a combination of both. In general, four phases were observed: (I) preparatory, (II) jaw opening, (III) gular depression, and (IV) jaw closing. Suction was a large component of the prey capture method in belugas and subambient pressures in excess of 100 kPa were generated. Belugas were also capable of lateral lip gape occlusion and anterior lip pursing to form a small anterior aperture. Pacific whitesided dolphins relied on ram to capture prey. However, some degree of pursing and resultant subambient pressure was observed that was likely used to compensate for high ram speeds or for prey manipulation and transport to the esophagus. Pilot whales were more similar to belugas in kinematics, but maintained high approach velocities and did not generate significant suction pressures; suction and ram were used in combination. Belugas and pilot whales appeared to employ hyolingual depression as a primary suction generation mechanism, whereas Pacific white-sided dolphins relied on fast jaw opening. Ancestral state reconstructions indicated that suction feeding capability evolved independently at least six times within Odontoceti. These results indicate the diversity of feeding behaviors in odontocetes and provide directives for future studies on the diversity of feeding in secondarily aquatic mammals.
447

High Angle Of Attack Maneuvering And Stabilization Control Of Aircraft

Atesoglu, Ozgur Mustafa 01 July 2007 (has links) (PDF)
In this study, the implementation of modern control techniques, that can be used both for the stable recovery of the aircraft from the undesired high angle of attack flight state (stall) and the agile maneuvering of the aircraft in various air combat or defense missions, are performed. In order to accomplish this task, the thrust vectoring control (TVC) actuation is blended with the conventional aerodynamic controls. The controller design is based on the nonlinear dynamic inversion (NDI) control methodologies and the stability and robustness analyses are done by using robust performance (RP) analysis techniques. The control architecture is designed to serve both for the recovery from the undesired stall condition (the stabilization controller) and to perform desired agile maneuvering (the attitude controller). The detailed modeling of the aircraft dynamics, aerodynamics, engines and thrust vectoring paddles, as well as the flight environment of the aircraft and the on-board sensors is performed. Within the control loop the human pilot model is included and the design of a fly-by-wire controller is also investigated. The performance of the designed stabilization and attitude controllers are simulated using the custom built 6 DoF aircraft flight simulation tool. As for the stabilization controller, a forced deep-stall flight condition is generated and the aircraft is recovered to stable and pilot controllable flight regimes from that undesired flight state. The performance of the attitude controller is investigated under various high angle of attack agile maneuvering conditions. Finally, the performances of the proposed controller schemes are discussed and the conclusions are made.
448

Forecasting congestion in transmission line and voltage stability with wind integration

Kang, Han 30 September 2011 (has links)
Due to growth of wind power, system operators are being challenged by the integration of large wind farms into their electrical power systems. Large scale wind farm integration has adverse effects on the power system due to its variable characteristic. These effects include two main aspects: voltage stability and active line flow. In this thesis, a novel techniques to forecast active line flow and select pilot bus are introduced with wind power integration. First, this thesis introduces a methodology to forecast congestion in the transmission line with high wind penetration. Since most wind resources tend to be located far away form the load center, the active line flow is one of the most significant aspects when wind farm is connected to electrical grid. By providing the information about the line flow which can contribute to transmission line congestion, the system operators would be able to respond such as by requesting wind power or load reduction. The second objective of this thesis is to select the weakest bus, called pilot bus, among all load buses. System reliability, especially voltage stability, can be adversely affected by wind variability. In order to ensure reliable operation of power systems with wind power integration, the index to select the pilot bus is developed, and further prediction of voltage profile at the pilot bus is fulfilled. The objective function to select the pilot bus takes account of the N-1 contingency analysis, loading margin, and reactive power sensitivity. Through on the objective function, the pilot bus is representative of all load buses as well as controllable by reactive power regulation. Predicting the voltage profile at the pilot bus is also useful for system operators to determine wind power output. / text
449

Design, implementation, and characterisation of a novel lidar ceilometer

Vande Hey, Joshua D. January 2013 (has links)
A novel lidar ceilometer prototype based on divided lens optics has been designed, built, characterised, and tested. The primary applications for this manufacturable ground-based sensor are the determination of cloud base height and the measurement of vertical visibility. First, the design, which was developed in order to achieve superior performance at a low cost, is described in detail, along with the process used to develop it. The primary design considerations of optical signal to noise ratio, range-dependent overlap of the transmitter and receiver channels, and manufacturability, were balanced to develop an instrument with good signal to noise ratio, fast turn-on of overlap for detection of close range returns, and a minimised number of optical components and simplicity of assembly for cost control purposes. Second, a novel imaging method for characterisation of transmitter-receiver overlap as a function of range is described and applied to the instrument. The method is validated by an alternative experimental method and a geometric calculation that is specific to the unique geometry of the instrument. These techniques allow the calibration of close range detection sensitivity in order to acquire information prior to full overlap. Finally, signal processing methods used to automate the detection process are described. A novel two-part cloud base detection algorithm has been developed which combines extinction-derived visibility thresholds in the inverted cloud return signal with feature detection on the raw signal. In addition, standard approaches for determination of visibility based on an iterative far boundary inversion method, and calibration of attenuated backscatter profile using returns from a fully-attenuating water cloud, have been applied to the prototype. The prototype design, characterisation, and signal processing have been shown to be appropriate for implementation into a commercial instrument. The work that has been carried out provides a platform upon which a wide range of further work can be built.
450

Evaluation of the Commercial Groundfish Integration Pilot Program in British Columbia

Mawani, Tameezan 16 September 2010 (has links)
In 2006, the Minister of Fisheries and Oceans Canada (DFO) accepted an industry proposal called the Commercial Groundfish Integration Pilot Program (CGIPP), which integrated each of the seven commercial groundfish fisheries in British Columbia. The industry proposal, developed by the Commercial Industry Caucus (CIC), was the result of guiding principles developed by DFO that focused on the conservation of certain rockfish species on the Pacific Coast. If industry had not developed a plan, DFO would have developed an alternative fishing plan (AFP). This thesis evaluates whether DFO's conservation objectives were met under the CGIPP and if there were any social and economic impacts. These same impacts are compared to what may have occurred under the AFP. The results of this thesis indicate that the CGIPP is a sustainable template for multi-species commercial fisheries--a first step in achieving an ecosystem-based approach to fisheries management.

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