6 research outputs found
Close Formation Flight Missions Using Vision-Based Position Detection System
In this thesis, a formation flight architecture is described along with the implementation and evaluation of a state-of-the-art vision-based algorithm for solving the problem of estimating and tracking a leader vehicle within a close-formation configuration. A vision-based algorithm that uses Darknet architecture and a formation flight control law to track and follow a leader with desired clearance in forward, lateral directions are developed and implemented. The architecture is run on a flight computer that handles the process in real-time while integrating navigation sensors and a stereo camera. Numerical simulations along with indoor and outdoor actual flight tests demonstrate the capabilities of detection and tracking by providing a low cost, compact size and low weight solution for the problem of estimating the location of other cooperative or non-cooperative flying vehicles within a formation architecture
Autonomous landing of fixed-wing aircraft on mobile platforms
E
n esta tesis se propone un nuevo sistema que permite la operación de aeronaves
autónomas sin tren de aterrizaje. El trabajo está motivado por el interés industrial
en aeronaves con la capacidad de volar a gran altitud, con más capacidad de carga útil y
capaces de aterrizar con viento cruzado.
El enfoque seguido en este trabajo consiste en eliminar el sistema de aterrizaje de una
aeronave de ala fija empleando una plataforma móvil de aterrizaje en tierra. La aeronave y
la plataforma deben sincronizar su movimiento antes del aterrizaje, lo que se logra mediante
la estimación del estado relativo entre ambas y el control cooperativo del movimiento.
El objetivo principal de esta Tesis es el desarrollo de una solución práctica para el
aterrizaje autónomo de una aeronave de ala fija en una plataforma móvil. En la tesis se
combinan nuevos métodos con experimentos prácticos para los cuales se ha desarrollado
un sistema de pruebas específico.
Se desarrollan dos variantes diferentes del sistema de aterrizaje. El primero presta atención especial a la seguridad, es robusto ante retrasos en la comunicación entre vehículos y
cumple procedimientos habituales de aterrizaje, al tiempo que reduce la complejidad del
sistema. En el segundo se utilizan trayectorias optimizadas del vehículo y sincronización
bilateral de posición para maximizar el rendimiento del aterrizaje en términos de requerimientos de longitud necesaria de pista, pero la estabilidad es dependiente del retraso de
tiempo, con lo cual es necesario desarrollar un controlador estabilizador ampliado, basado
en pasividad, que permite resolver este problema.
Ambas estrategias imponen requisitos funcionales a los controladores de cada uno de
los vehículos, lo que implica la capacidad de controlar el movimiento longitudinal sin
afectar el control lateral o vertical, y viceversa. El control de vuelo basado en energía se
utiliza para proporcionar dicha funcionalidad a la aeronave.
Los sistemas de aterrizaje desarrollados se han analizado en simulación estableciéndose los límites de rendimiento mediante múltiples repeticiones aleatorias. Se llegó a
la conclusión de que el controlador basado en seguridad proporciona un rendimiento de
aterrizaje satisfactorio al tiempo que suministra una mayor seguridad operativa y un menor
esfuerzo de implementación y certificación. El controlador basado en el rendimiento es
prometedor para aplicaciones con una longitud de pista limitada. Se descubrió que los beneficios del controlador basado en el rendimiento son menos pronunciados para una
dinámica de vehículos terrestres más lenta.
Teniendo en cuenta la dinámica lenta de la configuración del demostrador, se eligió el
enfoque basado en la seguridad para los primeros experimentos de aterrizaje. El sistema
de aterrizaje se validó en diversas pruebas de aterrizaje exitosas, que, a juicio del autor,
son las primeras en el mundo realizadas con aeronaves reales. En última instancia, el
concepto propuesto ofrece importantes beneficios y constituye una estrategia prometedora
para futuras soluciones de aterrizaje de aeronaves.In this thesis a new landing system is proposed, which allows for the operation of
autonomous aircraft without landing gear. The work was motivated by the industrial
need for more capable high altitude aircraft systems, which typically suffer from low
payload capacity and high crosswind landing sensitivity. The approach followed in this
work consists in removing the landing gear system from the aircraft and introducing a
mobile ground-based landing platform. The vehicles must synchronize their motion prior
to landing, which is achieved through relative state estimation and cooperative motion
control. The development of a practical solution for the autonomous landing of an aircraft
on a moving platform thus constitutes the main goal of this thesis. Therefore, theoretical
investigations are combined with real experiments for which a special setup is developed
and implemented.
Two different landing system variants are developed — the safety-based landing system is
robust to inter-vehicle communication delays and adheres to established landing procedures,
while reducing system complexity. The performance-based landing system uses optimized
vehicle trajectories and bilateral position synchronization to maximize landing performance
in terms of used runway, but suffers from time delay-dependent stability. An extended
passivity-based stabilizing controller was implemented to cope with this issue. Both
strategies impose functional requirements on the individual vehicle controllers, which
imply independent controllability of the translational degrees of freedom. Energy-based
flight control is utilized to provide such functionality for the aircraft.
The developed landing systems are analyzed in simulation and performance bounds are
determined by means of repeated random sampling. The safety-based controller was found
to provide satisfactory landing performance while providing higher operational safety,
and lower implementation and certification effort. The performance-based controller
is promising for applications with limited runway length. The performance benefits
were found to be less pronounced for slower ground vehicle dynamics. Given the slow
dynamics of the demonstrator setup, the safety-based approach was chosen for first landing
experiments. The landing system was validated in a number of successful landing trials,
which to the author’s best knowledge was the first time such technology was demonstrated on the given scale, worldwide. Ultimately, the proposed concept offers decisive benefits
and constitutes a promising strategy for future aircraft landing solutions
Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) 2019 Annual Report
Prepared for: Dr. Brian Bingham, CRUSER DirectorThe Naval Postgraduate School (NPS) Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) provides a collaborative environment and community of interest for the advancement of unmanned systems (UxS) education and research endeavors across the Navy (USN), Marine Corps (USMC) and Department of Defense (DoD). CRUSER is a Secretary of the Navy (SECNAV) initiative to build an inclusive community of interest on the application of unmanned systems (UxS) in military and naval operations. This 2019 annual report summarizes CRUSER activities in its eighth year of operations and highlights future plans.Deputy Undersecretary of the Navy PPOIOffice of Naval Research (ONR)Approved for public release; distribution is unlimited
Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) 2019 Annual Report
Prepared for: Dr. Brian Bingham, CRUSER DirectorThe Naval Postgraduate School (NPS) Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) provides a collaborative environment and community of interest for the advancement of unmanned systems (UxS) education and research endeavors across the Navy (USN), Marine Corps (USMC) and Department of Defense (DoD). CRUSER is a Secretary of the Navy (SECNAV) initiative to build an inclusive community of interest on the application of unmanned systems (UxS) in military and naval operations. This 2019 annual report summarizes CRUSER activities in its eighth year of operations and highlights future plans.Deputy Undersecretary of the Navy PPOIOffice of Naval Research (ONR)Approved for public release; distribution is unlimited
Kinematics and Robot Design I, KaRD2018
This volume collects the papers published on the Special Issue “Kinematics and Robot Design I, KaRD2018” (https://www.mdpi.com/journal/robotics/special_issues/KARD), which is the first issue of the KaRD Special Issue series, hosted by the open access journal “MDPI Robotics”. The KaRD series aims at creating an open environment where researchers can present their works and discuss all the topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”. KaRD2018 received 22 papers and, after the peer-review process, accepted only 14 papers. The accepted papers cover some theoretical and many design/applicative aspects
Aeronautical Engineering: A continuing bibliography with indexes
This bibliography lists 529 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in May 1980