9,128 research outputs found
Intelligent Autonomous Decision-Making and Cooperative Control Technology of High-Speed Vehicle Swarms
This book is a reprint of the Special Issue “Intelligent Autonomous Decision-Making and Cooperative Control Technology of High-Speed Vehicle Swarms”,which was published in Applied Sciences
Distributed Bio-inspired Humanoid Posture Control
This paper presents an innovative distributed bio-inspired posture control
strategy for a humanoid, employing a balance control system DEC (Disturbance
Estimation and Compensation). Its inherently modular structure could
potentially lead to conflicts among modules, as already shown in literature. A
distributed control strategy is presented here, whose underlying idea is to let
only one module at a time perform balancing, whilst the other joints are
controlled to be at a fixed position. Modules agree, in a distributed fashion,
on which module to enable, by iterating a max-consensus protocol. Simulations
performed with a triple inverted pendulum model show that this approach limits
the conflicts among modules while achieving the desired posture and allows for
saving energy while performing the task. This comes at the cost of a higher
rise time.Comment: 2019 41st Annual International Conference of the IEEE Engineering in
Medicine & Biology Society (EMBC
The predictive functional control and the management of constraints in GUANAY II autonomous underwater vehicle actuators
Autonomous underwater vehicle control has been a topic of research in the last decades. The challenges addressed vary depending on each research group's interests. In this paper, we focus on the predictive functional control (PFC), which is a control strategy that is easy to understand, install, tune, and optimize. PFC is being developed and applied in industrial applications, such as distillation, reactors, and furnaces. This paper presents the rst application of the PFC in autonomous underwater vehicles, as well as the simulation results of PFC, fuzzy, and gain scheduling controllers. Through simulations and navigation tests at sea, which successfully validate the performance of PFC strategy in motion control of autonomous underwater vehicles, PFC performance is compared with other control techniques such as fuzzy and gain scheduling control. The experimental tests presented here offer effective results concerning control objectives in high and intermediate levels of control. In high-level point, stabilization and path following scenarios are proven. In the intermediate levels, the results show that position and speed behaviors are improved using the PFC controller, which offers the smoothest behavior. The simulation depicting predictive functional control was the most effective regarding constraints management and control rate change in the Guanay II underwater vehicle actuator. The industry has not embraced the development of control theories for industrial systems because of the high investment in experts required to implement each technique successfully. However, this paper on the functional predictive control strategy evidences its easy implementation in several applications, making it a viable option for the industry given the short time needed to learn, implement, and operate, decreasing impact on the business and increasing immediacy.Peer ReviewedPostprint (author's final draft
Efficient Automated Driving Strategies Leveraging Anticipation and Optimal Control
Automated vehicles and advanced driver assistance systems bring computation, sensing, and communication technologies that exceed human abilities in some ways. For example, automated vehicles may sense a panorama all at once, do not suffer from human impairments and distractions, and could wirelessly communicate precise data with neighboring vehicles. Prototype and commercial deployments have demonstrated the capability to relieve human operators of some driving tasks up to and including fully autonomous taxi rides in some areas. The ultimate impact of this technology’s large-scale market penetration on energy efficiency remains unclear, with potential negative factors like road use by empty vehicles competing with positive ones like automatic eco-driving. Fundamentally enabled by historic and look-ahead data, this dissertation addresses the use of automated driving and driver assistance to optimize vehicle motion for energy efficiency.
Facets of this problem include car following, co-optimized acceleration and lane change planning, and collaborative multi-agent guidance. Optimal control, especially model predictive control, is used extensively to improve energy efficiency while maintaining safe and timely driving via constraints. Techniques including chance constraints and mixed integer programming help overcome uncertainty and non-convexity challenges. Extensions of these techniques to tractor trailers on sloping roads are provided by making use of linear parameter-varying models. To approach the wheel-input energy eco-driving problem over generally shaped sloping roads with the computational potential for closed-loop implementation, a linear programming formulation is constructed. Distributed and collaborative techniques that enable connected and automated vehicles to accommodate their neighbors in traffic are also explored and compared to centralized control. Using simulations and vehicle-in-the-loop car following experiments, the proposed algorithms are benchmarked against others that do not make use of look-ahead information
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
A Review of Shared Control for Automated Vehicles: Theory and Applications
The last decade has shown an increasing interest on advanced driver assistance systems (ADAS) based on shared control, where automation is continuously supporting the driver at the control level with an adaptive authority. A first look at the literature offers two main research directions: 1) an ongoing effort to advance the theoretical comprehension of shared control, and 2) a diversity of automotive system applications with an increasing number of works in recent years. Yet, a global synthesis on these efforts is not available. To this end, this article covers the complete field of shared control in automated vehicles with an emphasis on these aspects: 1) concept, 2) categories, 3) algorithms, and 4) status of technology. Articles from the literature are classified in theory- and application-oriented contributions. From these, a clear distinction is found between coupled and uncoupled shared control. Also, model-based and model-free algorithms from these two categories are evaluated separately with a focus on systems using the steering wheel as the control interface. Model-based controllers tested by at least one real driver are tabulated to evaluate the performance of such systems. Results show that the inclusion of a driver model helps to reduce the conflicts at the steering. Also, variables such as driver state, driver effort, and safety indicators have a high impact on the calculation of the authority. Concerning the evaluation, driver-in-the-loop simulators are the most common platforms, with few works performed in real vehicles. Implementation in experimental vehicles is expected in the upcoming years.This work was supported in part by the ECSEL Joint Undertaking, which funded the PRYSTINE project under Grant 783190, and in part by the AUTOLIB project (ELKARTEK 2019 ref. KK-2019/00035; Gobierno Vasco Dpto. Desarrollo económico e infraestructuras)
A Review of Shared Control for Automated Vehicles: Theory and Applications
The last decade has shown an increasing interest on advanced driver assistance systems (ADAS) based on shared control, where automation is continuously supporting the driver at the control level with an adaptive authority. A first look at the literature offers two main research directions: 1) an ongoing effort to advance the theoretical comprehension of shared control, and 2) a diversity of automotive system applications with an increasing number of works in recent years. Yet, a global synthesis on these efforts is not available. To this end, this article covers the complete field of shared control in automated vehicles with an emphasis on these aspects: 1) concept, 2) categories, 3) algorithms, and 4) status of technology. Articles from the literature are classified in theory- and application-oriented contributions. From these, a clear distinction is found between coupled and uncoupled shared control. Also, model-based and model-free algorithms from these two categories are evaluated separately with a focus on systems using the steering wheel as the control interface. Model-based controllers tested by at least one real driver are tabulated to evaluate the performance of such systems. Results show that the inclusion of a driver model helps to reduce the conflicts at the steering. Also, variables such as driver state, driver effort, and safety indicators have a high impact on the calculation of the authority. Concerning the evaluation, driver-in-the-loop simulators are the most common platforms, with few works performed in real vehicles. Implementation in experimental vehicles is expected in the upcoming years
Space shuttle avionics system
The Space Shuttle avionics system, which was conceived in the early 1970's and became operational in the 1980's represents a significant advancement of avionics system technology in the areas of systems and redundacy management, digital data base technology, flight software, flight control integration, digital fly-by-wire technology, crew display interface, and operational concepts. The origins and the evolution of the system are traced; the requirements, the constraints, and other factors which led to the final configuration are outlined; and the functional operation of the system is described. An overall system block diagram is included
Quadrotor team modeling and control for DLO transportation
94 p.Esta Tesis realiza una propuesta de un modelado dinámico para el transporte de sólidos lineales deformables (SLD) mediante un equipo de cuadricópteros. En este modelo intervienen tres factores: - Modelado dinámico del sólido lineal a transportar. - Modelo dinámico del cuadricóptero para que tenga en cuenta la dinámica pasiva y los efectos del SLD. - Estrategia de control para un transporte e ciente y robusto. Diferenciamos dos tareas principales: (a) lograr una con guración cuasiestacionaria de una distribución de carga equivalente a transportar entre todos los robots. (b) Ejecutar el transporte en un plano horizontal de todo el sistema. El transporte se realiza mediante una con guración de seguir al líder en columna, pero los cuadricópteros individualmente tienen que ser su cientemente robustos para afrontar todas las no-linealidades provocadas por la dinámica del SLD y perturbaciones externas, como el viento. Los controladores del cuadricóptero se han diseñado para asegurar la estabilidad del sistema y una rápida convergencia del sistema. Se han comparado y testeado estrategias de control en tiempo real y no-real para comprobar la bondad y capacidad de ajuste a las condiciones dinámicas cambiantes del sistema. También se ha estudiado la escalabilidad del sistema
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