Dynamic modelling and swing control of a quadrotor with a cable-suspended payload

A quadrotor is a highly nonlinear system due to the presence of aerodynamic factors such as Coriolis and gyroscopic effects when in flight. In meeting todays’ demands, the applications of quadrotors have been extended to include transportation and therefore, the study of Quadrotor Suspended Load (QSL) systems has become equally as important. However, the presence of the suspended load further complicates the quadrotor system as there is strong coupling with the load and excessive load swinging. This is a problem which forms the basis for this work. This project begins by providing a mathematical description of the QSL system using Euler-Lagrange equations as they are much simplified, yet encompass the many factors present during quadrotor operation and subsequently control excessive payload swinging. The main strength of this work is that unlike other previous work, it covers 8 degrees of freedom (8 DOF) in representing the system dynamics. This presents a much more comprehensive and definitive way of describing the quadrotor and payload positions. Input shaping is used as the swing controller as it is more practical and has been used for swing control of other systems. Validation of the swing controller performance is done using MATLAB SIMULINK. Unlike other controllers that require sophisticated algorithms for their implementation, input shaping will be used as a swing controller as it is much simplified in handling excessive load swinging

Swarms of Unmanned Aerial Vehicles – A Survey

The purpose of this study is to focus on the analysis of the core characteristics of swarms of drones or Unmanned Aerial Vehicles and to present them in a way that facilitates analysis of public awareness on such swarms. Furthermore, the functionality, problems, and importance of drones are highlighted. Lastly, the experimental survey from a bunch of academic population demonstrates that the swarms of drones are fundamental future agendas and will be adapted by the time.</p

Commande non linéaire hiérarchique d'un drone de type quadrotor sans mesure de la vitesse linéaire

Le quadrotor est parmi les drones multi-rotors les plus connus dans la recherche, en raison de la simplicité de sa structure, son faible coût, et sa capacité d’effectuer des vols stationnaires, et d’atterrir et décoller verticalement. Malgré une complexité moindre de cet engin, la commande d’un tel système nécessite une attention particulière, puisque ce système est fortement non linéaire, multi-variable, couplé et sous actionné. Ce mémoire propose alors un contrôleur non linéaire pour être en mesure de stabiliser le quadrotor en vol. Un des scénarios qui doit être effectué par le quadrotor est la navigation autonome. En effet, la mise en oeuvre d’une telle mission nécessite la mesure des états du véhicule. Cependant certains de ces états peuvent être non accessibles, en plus les mesures des capteurs sont souvent affectées par les bruits extérieurs. Dans ce mémoire on s’intéresse au cas où la mesure de la vitesse linéaire n’est pas disponible pour la réalisation d’une loi de commande. Pour ce faire, une modélisation a été réalisée selon la formulation de Newton-Euler, par la suite la synthèse du contrôleur hiérarchique a été effectuée sur ce modèle, tel que le contrôleur de position implique un filtre non linéaire pour l’estimation de vitesse linéaire, et le contrôleur d’attitude est de type backstepping conçu avec des fonctions barrières de Lyapunov. Le choix des paramètres de ce régulateur a été basé sur l’analyse de la stabilité lorsque celle-ci est possible. La validation du contrôleur proposé a été effectuée en simulation sur plusieurs manoeuvres, puis une analyse a été faite à la fois sur le contrôleur hiérarchique simple et avec intégrale pour tester sa robustesse vis à vis des perturbations externes

Nonlinear and Geometric Controllers for Rigid Body Vehicles

In this thesis we investigate the motion control problem for a class of vehicles C V , which includes satellites, quadrotors, underwater vehicles, and tailsitters. Given a globally represented model of C V , and a curve, the motion control problem entails following the curve using control inputs. In this thesis the motion control problem is viewed under two settings, 1) as a local path following problem, 2) as a geometric trajectory tracking problem. We provide solutions to both problems by designing controllers based on the concept of feedback linearization. In the local path following problem, the C V class of vehicles is represented by a local chart. The problem is solved in a monolithic control setting, and the path that needs to be followed is treated as a set to be stabilized. The nonlinear model under study is first dynamically extended and then converted into a fully linear form through a coordinate transformation and smooth feed- back. This approach achieves path invariance. We also design a fault tolerant local controller that ensure path following and path invariance in the presence of a one rotor failure for a quadrotor. The second major problem addressed is the geometric trajectory tracking problem, which is treated in an inner-outer loop setting. Specifically, we design a controller class for the attitude dy- namics of the C V class of vehicles. The novel notion of Lie algebra valued functions are defined on the Special Orthogonal group SO(3), which constitutes a family of functions. This family of functions induces a novel geometric controller class, which consists of almost globally stable and locally stable controllers. This class is designed using the idea of feedback linearization, and is proven to be asymptotically stable through a Lyapunov-like argument. This allows the system to perform multiple flips. We also design geometric controllers for the position loop, which are demonstrated to work with the attitude controller class through simulations with noisy sensor data