73 research outputs found

    Planification et commande d'une plate-forme aéroportée stationnaire autonome dédiée à la surveillance des ouvrages d'art

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    Today, the inspection of structures is carried out through visual assessments effectedby qualified inspectors. This procedure is very expensive and can put the personal indangerous situations. Consequently, the development of an unmanned aerial vehicleequipped with on-board vision systems is privileged nowadays in order to facilitate theaccess to unreachable zones.In this context, the main focus in the thesis is developing original methods to deal withplanning, reference trajectories generation and tracking issues by a hovering airborneplatform. These methods should allow an automation of the flight in the presence of airdisturbances and obstacles. Within this framework, we are interested in two kinds ofaerial vehicles with hovering capacity: airship and quad-rotors.Aujourd'hui, l'inspection des ouvrages d'art est réalisée de façon visuelle par des contrôleurs sur l'ensemble de la structure. Cette procédure est coûteuse et peut être particulièrement dangereuse pour les intervenants. Pour cela, le développement du système de vision embarquée sur des drones est privilégié ces jours-ci afin de faciliter l'accès aux zones dangereuses.Dans ce contexte, le travail de cette thèse porte sur l'obtention des méthodes originales permettant la planification, la génération des trajectoires de référence, et le suivi de ces trajectoires par une plate-forme aéroportée stationnaire autonome. Ces méthodes devront habiliter une automatisation du vol en présence de perturbations aérologiques ainsi que des obstacles. Dans ce cadre, nous nous sommes intéressés à deux types de véhicules aériens capable de vol stationnaire : le dirigeable et le quadri-rotors.Premièrement, la représentation mathématique du véhicule volant en présence du vent a été réalisée en se basant sur la deuxième loi de Newton. Deuxièmement, la problématique de génération de trajectoire en présence de vent a été étudiée : le problème de temps minimal est formulé, analysé analytiquement et résolu numériquement. Ensuite, une stratégie de planification de trajectoire basée sur les approches de recherche opérationnelle a été développée.Troisièmement, le problème de suivi de trajectoire a été abordé. Une loi de commande non-linéaire robuste basée sur l'analyse de Lyapunov a été proposée. En outre, un pilote automatique basée sur les fonctions de saturations pour un quadri-rotors a été développée.Les méthodes et algorithmes proposés dans cette thèse ont été validés par des simulations

    Fixed point control of high altitude airship based on state estimations and the characteristic model

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    针对风场干扰下高空飞艇的定点驻留控制问题,阐述如何利用系统状态估计值和特征模型对飞艇进行控制器设计。首先,在平流层飞艇受力分析的基础上,建立了数学模型;然后设计了扩展卡尔曼滤波器,利用测量得到的飞艇位置信息估算飞艇当前的位置、艇速和风速3个状态变量;随后建立系统特征模型,并将估计所得的状态变量和基于特征模型的黄金分割控制器相结合,对飞艇进行定点控制;最后通过数学仿真验证本文所设计的控制器的有效性,并且和传统PD控制器的控制结果对比,表明了该控制器的优越性。To solve the problem of the fixed point control of high altitude airship disturbed by the wind field, the design of a controller based on the system state estimation and the characteristic model is presented. First, the mathematical model is established based on the force analysis of the stratospheric airship, and then designed the extended Kalman filter, using the measured location information of the airship to estimate the airship current position, airship speed and wind speed. Then the system characteristic model is established, and the estimated state variables are combined with the golden section controller based on the characteristic model. Finally, the effectiveness of the proposed controller is verified by mathematical simulation, and compared with the control results of the traditional PD controller, the superiority of the proposed controller is demonstrated.基金项目:国家自然科学基金面上项目(61273199

    Aerial Vehicles

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    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

    A Survey of path following control strategies for UAVs focused on quadrotors

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    The trajectory control problem, defined as making a vehicle follow a pre-established path in space, can be solved by means of trajectory tracking or path following. In the trajectory tracking problem a timed reference position is tracked. The path following approach removes any time dependence of the problem, resulting in many advantages on the control performance and design. An exhaustive review of path following algorithms applied to quadrotor vehicles has been carried out, the most relevant are studied in this paper. Then, four of these algorithms have been implemented and compared in a quadrotor simulation platform: Backstepping and Feedback Linearisation control-oriented algorithms and NLGL and Carrot-Chasing geometric algorithms.Peer ReviewedPostprint (author's final draft

    Aeronautical engineering: A continuing bibliography with indexes (supplement 202)

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    This bibliography lists 447 reports, articles and other documents introduced into the NASA scientific and technical information system in June 1986

    Gust Load Alleviation for an Aeroelastic System Using Nonlinear Control

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    The author develops a nonlinear longitudinal model of an aircraft modeled by rigid fuselage, tail, and wing, where the wing is attached to the fuselage with a torsional spring. The main focus of this research is to retain the full nonlinearities associated with the system and to perform gust load alleviation for the model by comparing the impact of a proportional-integral- lter nonzero setpoint linear controller with control rate weighting and a nonlinear Lyapunov-based controller. The four degree of freedom longitudinal system under consideration includes the traditional longitudinal three degree of freedom aircraft model and one additional degree of freedom due to the torsion from the wing attachment. Computational simulations are performed to show the aeroelastic response of the aircraft due to a gust load disturbance with and without control. Results presented in this thesis show that the linear model fails to capture the true nonlinear response of the system and the linear controller based on the linear model does not stabilize the nonlinear system. The results from the Lyapunov-based control demonstrate the ability to stabilize the nonlinear response, including the presence of an LCO, and emphasize the importance of examining the fully nonlinear system with a nonlinear controller

    Aeronautical Engineering: A special bibliography with indexes, supplement 56

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    This bibliography lists 439 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1975

    DYNAMICS AND CONTROL OF MINI AERIAL VEHICLE USING MODEL PREDICTIVE CONTROL

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    Nowadays Mini Aerial Vehicles (MAVs) are popular in many areas such as aerial photography, inspection, surveillance and search and rescue missions in complex and dangerous environments due to their low cost, small size, superior mobility, and hover capability. Multifarious applications of MAVs inspire researchers to concentrate on different types of controllers like linear, nonlinear or learning-based. The attention of this work is to design a robust controller and to develop an accurate mathematical model of Quadrotor, a type of MAV as it behaves roughly in uncertain environments. Quadrotor is an under-actuated and highly nonlinear system with six degrees of freedom (DOF). The mathematical model of quadrotor is derived based on Newton-Euler method that includes aerodynamic drag and moment that are sometimes overlooked in literatures. For higher precision modelling, model uncertainties are also included in the system. In addition, the kinematic model is derived utilizing Euler angles and Quaternion methods. Quaternion approach has the advantage of singularity free orientation while Euler angles are easy to visualize. This work investigates the performance of three different controllers which includes Proportional-Integral-Derivative (PID), Linear Quadratic Regulator (LQR) and Model Predictive Control (MPC) based on several performance evaluation factors. PID offers fast response to the system comparing to other controllers although choosing proper gain is challenging for PID. However, it cannot handle directly under-actuated system and due to the fact, some states are required to be decoupled. LQR ensures fast response and can deal with Multiple Input Multiple Output (MIMO) system at the same time. The main drawback of the LQR controller is its incapability of dealing with steady-state error. Conversely, MPC has the functionalities of dealing with MIMO system with constraints and uncertainties while other controllers fail. The performance of the controllers are presented based on tracking accuracy using Root Mean Square Error (RMSE) method and control stability using control input norm method. MATLAB and Simulink environment is considered to carry out the simulations. Based on simulated experiments, it is found that MPC could track the trajectories more accurately with stable control effort comparing to PID controllers and LQR

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

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    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

    A cumulative index to Aeronautical Engineering: A continuing bibliography

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    This bibliography is a cumulated index to the abstracts contained in NASA SP-7037(132) through NASA SP-7037(143) of Aeronautical Engineering: A continuing bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes
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