8 research outputs found

    Controle em Ambientes Interiores de Veículos Aéreos Não Tripulados

    Get PDF
    Esta Tese de Doutorado propõe controladores não lineares para serem aplicados a veículos aéreos não tripulados (VANTs) em missões de posicionamento, rastreamento de caminhos e seguimento de trajetória no espaço aéreo 3D. Adicionalmente, mostra-se um protótipo de uma plataforma para utilização dos VANTs em ambientes interiores, com diversas ferramentas computacionais que possibilitam utilizar robôs aéreos nessas missões clássicas de navegação. Para contextualizar as ferramentas desenvolvidas, destacam-se o desenvolvimento de algoritmos de detecção e localização de objetos no ambiente e um modelo de fusão sensorial descentralizado que é utilizado para melhorar os dados de postura (posição e orientação) do VANT medidos, além de detectar obstáculos. Posteriormente, o mesmo filtro de fusão é utilizado para combinar sinais de controle PVTOL (do inglês Planar Vertical Takeoff and Landing), relaxando as restrições de movimento da aeronave, antes limitadas ao deslocamento no eixo Z e nos planos verticais XZ e YZ. De forma complementar, a implementação de sistemas de navegação e controle é baseada em dois modelos dinâmicos diferentes, um deles simples e o outro detalhado. Os sistemas de controle são projetados utilizando-se técnicas clássicas de inversão de modelo, que se demonstra uma metodologia eficiente para o projeto de controladores para as aplicações desenvolvidas, a saber posicionamento, seguimento de trajetória e seguimento de caminhos. Adicionalmente, são projetados um controlador de desvio de obstáculo, para evitar colisão, um controlador adaptativo e um controlador com saturação das velocidades máximas. A estabilidade dos controladores é comprovada pela convergência assintótica das variáveis de controle e pelo cumprimento do objetivo de controle durante as simulações e experimentos realizados, em conformidade com a análise teórica. Palavras-chave: Veículos aéreos não tripulados (VANTs), controle não linear, fusão sensorial, navegação autônoma, robótica aérea

    Aerial Vehicles

    Get PDF
    This book contains 35 chapters written by experts in developing techniques for making aerial vehicles more intelligent, more reliable, more flexible in use, and safer in operation.It will also serve as an inspiration for further improvement of the design and application of aeral vehicles. The advanced techniques and research described here may also be applicable to other high-tech areas such as robotics, avionics, vetronics, and space

    Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

    Get PDF
    The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones

    Exploiting Heterogeneity in Networks of Aerial and Ground Robotic Agents

    Get PDF
    By taking advantage of complementary communication technologies, distinct sensing functionalities and varied motion dynamics present in a heterogeneous multi-robotic network, it is possible to accomplish a main mission objective by assigning specialized sub-tasks to specific members of a robotic team. An adequate selection of the team members and an effective coordination are some of the challenges to fully exploit the unique capabilities that these types of systems can offer. Motivated by real world applications, we focus on a multi-robotic network consisting off aerial and ground agents which has the potential to provide critical support to humans in complex settings. For instance, aerial robotic relays are capable of transporting small ground mobile sensors to expand the communication range and the situational awareness of first responders in hazardous environments. In the first part of this dissertation, we extend work on manipulation of cable-suspended loads using aerial robots by solving the problem of lifting the cable-suspended load from the ground before proceeding to transport it. Since the suspended load-quadrotor system experiences switching conditions during this critical maneuver, we define a hybrid system and show that it is differentially-flat. This property facilitates the design of a nonlinear controller which tracks a waypoint-based trajectory associated with the discrete states of the hybrid system. In addition, we address the case of unknown payload mass by combining a least-squares estimation method with the designed controller. Second, we focus on the coordination of a heterogeneous team formed by a group of ground mobile sensors and a flying communication router which is deployed to sense areas of interest in a cluttered environment. Using potential field methods, we propose a controller for the coordinated mobility of the team to guarantee inter-robot and obstacle collision avoidance as well as connectivity maintenance among the ground agents while the main goal of sensing is carried out. For the case of the aerial communications relays, we combine antenna diversity with reinforcement learning to dynamically re-locate these relays so that the received signal strength is maintained above a desired threshold. Motivated by the recent interest of combining radio frequency and optical wireless communications, we envision the implementation of an optical link between micro-scale aerial and ground robots. This type of link requires maintaining a sufficient relative transmitter-receiver position for reliable communications. In the third part of this thesis, we tackle this problem. Based on the link model, we define a connectivity cone where a minimum transmission rate is guaranteed. For example, the aerial robot has to track the ground vehicle to stay inside this cone. The control must be robust to noisy measurements. Thus, we use particle filters to obtain a better estimation of the receiver position and we design a control algorithm for the flying robot to enhance the transmission rate. Also, we consider the problem of pairing a ground sensor with an aerial vehicle, both equipped with a hybrid radio-frequency/optical wireless communication system. A challenge is positioning the flying robot within optical range when the sensor location is unknown. Thus, we take advantage of the hybrid communication scheme by developing a control strategy that uses the radio signal to guide the aerial platform to the ground sensor. Once the optical-based signal strength has achieved a certain threshold, the robot hovers within optical range. Finally, we investigate the problem of building an alliance of agents with different skills in order to satisfy the requirements imposed by a given task. We find this alliance, known also as a coalition, by using a bipartite graph in which edges represent the relation between agent capabilities and required resources for task execution. Using this graph, we build a coalition whose total capability resources can satisfy the task resource requirements. Also, we study the heterogeneity of the formed coalition to analyze how it is affected for instance by the amount of capability resources present in the agents

    PVTOL maneuvers guided by a high-level nonlinear controller applied to a rotorcraft machine

    No full text
    This work proposes a nonlinear controller, based on the Theory of Lyapunov, to stabilize a quadrotor when accomplishing positioning and trajectory tracking tasks restricted to a vertical plane. The maneuvers addressed here are commonly accomplished by PVTOL (Planar Vertical Take-off and Landing) vehicles due to the flight constraints: movement restricted to the Z-axis or to the XZ/YZ planes. The contributions of the paper are the nonlinear controller itself, the proof of stability of the equilibrium of the closed-loop system, and the proposal of an analytical solution to saturate the control signals to prevent the saturation of the physical actuators. Experimental results are also presented, which validate the proposed controller.Fil: Brandãoa, Alexandre Santos. Universidade Federal de Viicosa. Vicosa; BrasilFil: Gandolfo, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; ArgentinaFil: Sarcinelli Filho, Mário. Universidade Federal do Espírito Santo; BrasilFil: Carelli Albarracin, Ricardo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Automática. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Automática; Argentin

    Commande référencée vision pour drones à décollages et atterrissages verticaux

    Get PDF
    La miniaturisation des calculateurs a permis le développement des drones, engins volants capable de se déplacer de façon autonome et de rendre des services, comme se rendre clans des lieux peu accessibles ou remplacer l'homme dans des missions pénibles. Un enjeu essentiel dans ce cadre est celui de l'information qu'ils doivent utiliser pour se déplacer, et donc des capteurs à exploiter pour obtenir cette information. Or nombre de ces capteurs présentent des inconvénients (risques de brouillage ou de masquage en particulier). L'utilisation d'une caméra vidéo dans ce contexte offre une perspective intéressante. L'objet de cette thèse était l'étude de l'utilisation d'une telle caméra dans un contexte capteur minimaliste: essentiellement l'utilisation des données visuelles et inertielles. Elle a porté sur le développement de lois de commande offrant au système ainsi bouclé des propriétés de stabilité et de robustesse. En particulier, une des difficultés majeures abordées vient de la connaissance très limitée de l'environnement dans lequel le drone évolue. La thèse a tout d'abord étudié le problème de stabilisation du drone sous l'hypothèse de petits déplacements (hypothèse de linéarité). Dans un second temps, on a montré comment relâcher l'hypothèse de petits déplacements via la synthèse de commandes non linéaires. Le cas du suivi de trajectoire a ensuite été considéré, en s'appuyant sur la définition d'un cadre générique de mesure d'erreur de position par rapport à un point de référence inconnu. Enfin, la validation expérimentale de ces résultats a été entamée pendant la thèse, et a permis de valider bon nombre d'étapes et de défis associés à leur mise en œuvre en conditions réelles. La thèse se conclut par des perspectives pour poursuivre les travaux.The computers miniaturization has paved the way for the conception of Unmanned Aerial vehicles - "UAVs"- that is: flying vehicles embedding computers to make them partially or fully automated for such missions as e.g. cluttered environments exploration or replacement of humanly piloted vehicles for hazardous or painful missions. A key challenge for the design of such vehicles is that of the information they need to find in order to move, and, thus, the sensors to be used in order to get such information. A number of such sensors have flaws (e.g. the risk of being jammed). In this context, the use of a videocamera offers interesting prospectives. The goal of this PhD work was to study the use of such a videocamera in a minimal sensors setting: essentially the use of visual and inertial data. The work has been focused on the development of control laws offering the closed loop system stability and robustness properties. In particular, one of the major difficulties we faced came from the limited knowledge of the UAV environment. First we have studied this question under a small displacements assumption (linearity assumption). A control law has been defined, which took performance criteria into account. Second, we have showed how the small displacements assumption could be given up through nonlinear control design. The case of a trajectory following has then been considered, with the use of a generic error vector modelling with respect to an unknown reference point. Finally, an experimental validation of this work has been started and helped validate a number of steps and challenges associated to real conditions experiments. The work was concluded with prospectives for future work.TOULOUSE-ISAE (315552318) / SudocSudocFranceF
    corecore