The main topic of this thesis is to exhibit how robust control techniques can be applied to real time systems. Presently, the control techniques used in the industry are very simple even when applied to complex systems; these techniques are intuitive and not necessarily systematic. Moreover, the notion of optimality of robustness is absent. Control design procedures are mostly based on SISO techniques, thus, overlooking the intrinsic multivariable aspect of the design that a MIMO system requires. In this thesis a modern control technique is presented to manipulate a 3DOF birotor helicopter in real time. The objective of this research is to demonstrate the performance of more efficient control algorithms to control these kinds of systems. The robust method proposed in this thesis is an H infinity controller which exhibits robustness to plant model uncertainties, and good disturbance and noise rejection.

This thesis describes the development of the Texas A&M University Autonomous Helicopter System and the integration of obstacle avoidance capabilities into that system. The helicopter system, composed of a Bergen Observer helicopter and a Rotomotion Autonomous Flight Control System (AFCS), was developed as a platform to support the development of the obstacle avoidance system through integration of sensors and onboard processing capabilities. The system has proven in various flight tests that it has the capability to autonomously hover and fly to user defined GPS waypoints. The obstacle avoidance algorithm has been proven in simulations involving an interface with the Rotomotion AFCS and the flight simulation software they created to facilitate the development of that system. The helicopter has also demonstrated appropriate responses to sensor input commensurate with the obstacle avoidance algorithm. Full avoidance tests were unable to be performed due to hardware malfunctions inherent in the obstacle avoidance sensors.

Thesis (M.S.)--California Polytechnic State University, 2010. / Mode of access: Internet. Title from PDF title page; viewed on March 15, 2010. Major professor: Dr. Eric A. Mehiel. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Aerospace Engineering." "February 2010." Includes bibliographical references (p. 80-83).

The use of artificial potential fields is beneficial in most two dimensional environments but they are bound by limitations. Introduction of the third dimension eradicates some of the limitations and brings about a set of new problems. If the emergent problems are solved then the new approach can give way to smarter helicopters and consequently a new game-play experience or possibly safer flight. This thesis aims to solve the emergent problems and proposes a new solution for guidance of autonomous helicopter agents in 3D games based on artificial potential fields. This new approach is compared to the most used alternative the A* pathfinding algorithm. Our experiments reveal that potential fields is a formidable alternative for navigation of helicopters. It can perform many times faster than the A* alternative and has lower rate of collision. / Neoaxis PFA

No description available.

Human Systems Integration Capstone. / Unlimited distribution. / Expeditionary Helicopter Sea Combat Squadrons (HSC) operate on Navy amphibious assault ships to provide search and rescue (SAR), logistics and combat support. When embarked, the detachments are the primary SAR asset and have requirements levied upon them by NAVAIR 00-80T-106 to maintain aircraft SAR readiness postures in support of ship and embarked Marine Corps aircraft operations. The goal of this study was to identify what impacts would occur to flight support personnel effectiveness if OPNAV 3710.7U sleep requirements were deviated from in order to meet minimum personnel requirements. The conclusion reached was that safety concerns are present when OPNAV 3710.7U sleep requirements for flight support personnel are violated to maintain NAVAIR 00-80T-106 operational requirements. The study found that worker effectiveness varies systematically with the duration of sleep interruption encountered. Minimum predicted effectiveness comes at three hours with the predicted values at two, three and four hours being essentially equal. When sleep interruptions exceed 1.55 hours, effectiveness levels drop below 70%, equivalent to experiencing a .08 BAC. A model for subsequent interruptions over the preceding days found that worker effectiveness varies systematically with the number of days between interruptions. The effect of sleep interruptions of multiple nights was greatest two days between interruptions. A minimum of four to five days between sleep interruptions is required for interruption effects to not be cumulative.

Autorotation maneuvers are required to perform a safe landing of a helicopter in cases of engine loss in a single engine vehicle and transmission or tail rotor malfunction. The rise of autonomous helicopter technology, and the pilot skill required to manually perform an autorotation, motivate the need for new autonomous autorotation control laws. Previous approaches to automatic control for this maneuver have relied on control law optimization based on a high-fidelity model of the helicopter, or have attempted to match recorded trajectories flown by an expert human pilot. In this paper, a new expert control system is proposed. The term “expert control system” is used because the system is intended to mimic the actions that a human pilot might take, does not require any iterative learning, model prediction, or optimization at runtime, and is based on an inference system that involves fuzzy logic, PID, and other conventional control techniques. The multi-stage control law drives the helicopter to a near-optimal steady-state descent and uses an estimate of the time to impact to safely flare and land the helicopter in the vast majority of flight conditions. The control law is validated using a full 6-degree-of-freedom simulation of both a full-size attack helicopter and a small hobby-class helicopter. The pro- posed control design is highly flexible and may be used to perform fully autonomous autorotation or to provide guidance to pilots during manual autorotation maneuvers.

Thesis (M.S. in Program Management)--Naval Postgraduate School, December 2002. / Thesis advisor(s): Michael W. Boudreau, Richard G. Rhoades. Includes bibliographical references (p. 63-65). Also available online.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Roberto Szechtman. Includes bibliographical references (p. 67-70). Also available online.

Made available in DSpace on 2014-06-11T19:28:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-29Bitstream added on 2014-06-13T20:37:36Z : No. of bitstreams: 1 braga_gw_me_guara.pdf: 3089752 bytes, checksum: 837118811a801f0f57c8d0d5994cdd4c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No desempenho de suas atividades aéreas, os pilotos de helicópteros são submetidos a posturas que impõem tensões contínuas em determinados grupos musculares, ao mesmo tempo em que deixam outras musculaturas em desuso. Diante disso, observam-se inúmeros casos de lombalgia que acometem pilotos de helicópteros Esquilo, principalmente nas Forças Armadas, sendo prováveis causas a ergonomia do assento e a vibração que o corpo sofre. Diante de tal fato, este estudo teve os seguintes objetivos: (1) mensurar os níveis de aceleração (vibração), na direção longitudinal (eixo z) da coluna lombar a que os pilotos de helicópteros As-350 L1 Esquilo estão expostos durante o voo; (2) verificar a atividade muscular dos eretores da espinha dos pilotos de helicópteros As-350 L1 Esquilo, com um aparelho de eletromiografia, durante a exposição à vibração em voo; (3) analisar os dados dos pilotos, da aceleração, os sinais de eletromiografia dos músculos eretores da espinha e a sua correlação. A fim de atingir esses objetivos, foram distribuídos 60 questionários para os pilotos de Esquilo do Complexo de Aviação do Exército em Taubaté-SP. Posteriormente, foram selecionados dois pilotos do sexo masculino, de estatura média e acima da média, na faixa etária de 30 a 35 anos de idade, com mais de 300 horas de voo e com classificações morfológicas corporais diferentes, de acordo com a tabela IMC. Após a coleta dos dados, os resultados foram analisados através da norma ISO 2631: 1997 e tratados estatisticamente. No estudo, observou-se que esses pilotos estão expostos a uma vibração de corpo inteiro que requer cautela em relação ao risco à saúde, pois os valores de aceleração encontrados no estudo encontraram-se compreendidos na... / The helicopter pilot’s posture while operating an aircraft can cause continuing strain on certain muscle groups while leaving others unused. Many Esquilo helicopter pilots, especially in the military, are reported to suffer from low back pain, the probable causes being seat ergonomics and the effect of aircraft vibration on the body. With this in mind, this study proposed the following objectives: (1) measure the levels of acceleration (vibration) in the longitudinal direction (z axis) to which the L1-350 Esquilo pilot lumbar spine is exposed during flight, (2) check the L1-350 Esquilo pilot spinal erector muscle activity while exposed to vibration during flight, using electromyography and (3) analyze the data pertaining to the pilot and acceleration, the spinal erector muscle electromyography signals and the correlation between them. In order to achieve these goals, 60 questionnaires were distributed to Esquilo pilots from the Army Aviation Compound of Taubaté (Complexo de Aviação do Exército de Taubaté) in São Paulo. Then, two male pilots were selected, between the ages of 30 and 35, each with more than 300 flight hours, with different body morphological classifications according to the BMI table, one of average height and the other above average height. The collected data was analyzed according to ISO 2631:1997 and statistically studied. It was observed that the pilots’ whole-body vibration levels are such that caution is required to avoid health problems, especially considering those pilots who are members of the military whose exposure is higher due to the number of operational flights. The electromyogram also showed that pilot muscle activity was insignificant due to the small variation in the activity potential of the analyzed muscle. It was... (Complete abstract click electronic access below)