DEVELOPMENT OF COAXIAL ROTOR MICRO UNMANNED AERIAL VEHICLE

Micro Unmanned Helicopter with ability of takeoff, landing and hovering offeres excellent support tool for missions in indoor environment. In this paper, a review of preliminary studies towards the development of autonomous coaxial helicopter MAV is presented. The paper starts with the statement of coaxial helicoper MAV development. Then, it is continued by the introduction of development of dynamic model for a typical coaxial rotor platform. In the third issues, initial steps in development of sensory system and control system will be dealt with. In brief, an analytical mathematical model has successful derived. This model together with the developed sensor system will act important role towards the full development of the dynamics model as the system identification is carried out

Multivariable Super Twisting Based Robust Trajectory Tracking Control for Small Unmanned Helicopter

This paper presents a highly robust trajectory tracking controller for small unmanned helicopter with model uncertainties and external disturbances. First, a simplified dynamic model is developed, where the model uncertainties and external disturbances are treated as compounded disturbances. Then the system is divided into three interconnected subsystems: altitude subsystem, yaw subsystem, and horizontal subsystem. Second, a disturbance observer based controller (DOBC) is designed based upon backstepping and multivariable super twisting control algorithm to obtain robust trajectory tracking property. A sliding mode observer works as an estimator of the compounded disturbances. In order to lessen calculative burden, a first-order exact differentiator is employed to estimate the time derivative of the virtual control. Moreover, proof of the stability of the closed-loop system based on Lyapunov method is given. Finally, simulation results are presented to illustrate the effectiveness and robustness of the proposed flight control scheme

Controlling a Quadrotor with a Robotic Arm using Nonlinear Model Predictive Control

This thesis designs a method to control a quadrotor equipped with a robotic arm. The arm has been developed in Institut de Rob otica i Inform atica Industrial (CSIC-UPC), namely here IRI. During the project, an algorithm has been made as a rst approximation to control a quadrotor that is working with the robotic arm. In order to compensate the perturbations of the arm's dynamic, a NMPC algorithm has been chosen while others have been discarded as it is discussed in the state of the art (PID, Linear Model Predictive Control or LQR). PID and model predictive control have been discarded because is not possible to handle the nonlinearities of the system studied and reach the desired control objectives. Also there are no possibilites to restrict the system using physical constraints. Finally, three scenarios have been simulated and tested to verify the performances and robustness of the designed method. A takeo maneuver, where the quadrotor reaches a speci c altitude. A hover mode where the system should compensate the dynamics of the arm while it is static or it is in movement. Finally, the quadorotor has to move to a speci c point in the space while the arm it is static or in movement. The goal of the controller is to reject the perturbation due the movement of the arm and stabilize the system. This thesis presents the results obtained after simulating the designed controller with the scenarios considered

Research on the accuracy of algorithms for autonomous aircraft navigation

Disertacijoje nagrinėjamos nedidelių autonominių orlaivių navigacijos algoritmų įtakos skrydžio tikslumui bei orlaivio deviacijos nuo užduotos skrydžio trajektorijos vertinimo problemos. Pagrindinis tyrimų objektas yra autonominės navigacijos algoritmai. Autonominio skrydžio tikslumas yra tiesiogiai susijęs su skrydžio sauga. Dėl šios priežasties pagrindinis disertacijos tikslas yra ištirti naudojamus ar siūlomus naudoti navigacijos algoritmus bei pateikti autonominio skrydžio saugos gerinimo metodus per navigacijos prizmę. Darbe sprendžiami trys pagrindiniai uždaviniai: autonominio orlaivio navigacijos matematinio modelio parinkimas bei matematinis aprašymas, navigacijos algoritmų įtakos skrydžio tikslumui vertinimas, mažesnę įtaką skrydžio nuokrypiams turinčio algoritmo sukūrimas, kurio paskirtis – saugiai apskristi ir išvengti antžeminių kliūčių. Pirmasis uždavinys skirtas įvertinti didelės imties navigacijos duomenų statistinę aibę. Antrasis bei trečiasis skirti pačių algoritmų analizei. Disertaciją sudaro įvadas, trys skyriai, bendrosios išvados, literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir šeši priedai. Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė reikšmė, ginamieji teiginiai. Įvade pateiktos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra. Pirmasis skyrius skirtas literatūros analizei. Jame pateikta autonominių orlaivių klasifikacija. Pateikta autonominių orlaivių navigacijos, kontrolės bei valdymo algoritmų analizė. Skyriaus pabaigoje formuluojamos išvados ir tikslinami disertacijos uždaviniai. Antrajame skyriuje pateiktas tyrimuose taikomas matematinis autonominio orlaivio navigacijos modelis. Pateikta šiuo modeliu gautų navigacijos duomenų analizė bei vertinimas. Trečiajame skyriuje teoriniai rezultatai lyginami su gautais praktinių skrydžių metu bei naudojant SITL (angl. Software In The Loop) skrydžio imitaciją. Pasiūlyta metodika bei autonominių orlaivių navigacijos algoritmas automatizuotam antžeminių kliūčių apskridimui. Disertacijos tema paskelbti 6 straipsniai: du – straipsniai žurnaluose, įtrauktuose į Thomson ISI duomenų bazę, du – recenzuojamuose žurnaluose kitose duomenų bazėse, bei du – kitų tarptautinių bei respublikinių konferencijų medžiagoje. Disertacijos tema perskaityti 6 pranešimai Lietuvos bei kitų šalių konferencijose

Contrôle non linéaire par backstepping d'un hélicoptère de type quadrotor pour des applications autonomes

Le quadrotor est un aéronef faisant partie de la famille des hélicoptères, plus particulièrement de la famille des multirotors. Le quadrotor possède plusieurs caractéristiques (simplicité mécanique, décollage/atterrissage vertical, vol stationnaire, agilité) qui lui procurent plusieurs avantages opérationnels par rapport à d’autres types d’appareils. Cependant, ces caractéristiques proviennent de la dynamique hautement non linéaire, couplée et sousactionnée du quadrotor, ce qui le rend impossible à commander sans l’action d’un contrôleur. Ce mémoire propose donc de concevoir un contrôleur permettant d’asservir précisément la position du quadrotor dans l’espace. Ce contrôleur pourra ensuite être utilisé pour effectuer des missions autonomes à l’aide d’un quadrotor. L’application qui nous intéresse dans ce mémoire provient de la problématique de recherche du projet « Launch and Forget : Aerial Relay Node » de l’École de technologie supérieure (ÉTS) en collaboration avec la compagnie Ultra-Electronics. Celle-ci cherche à concevoir et implémenter une loi d’autonavigation innovatrice permettant d’utiliser un drone comme un relais de télécommunication. L’objectif général du projet de recherche présenté dans ce mémoire est de concevoir un contrôleur non linéaire de type backstepping pour permettre la navigation du quadrotor selon des points de contrôle prédéfinis et d’offrir les fonctionnalités nécessaires pour implémenter la loi d’autonavigation développée dans le cadre du projet «Launch and Forget ». Pour ce faire, une modélisation mathématique du quadrotor a été effectuée. Par la suite, la conception du contrôleur backstepping a été effectuée à partir du modèle. Sa stabilité a ensuite été validée à l’aide de la théorie de stabilité de Lyapunov et à l’aide de la théorie de la stabilité entrées à états (Input to State Stability - ISS). Un estimateur exact de dérivée basé sur un algorithme de mode glissant d’ordre 2 est utilisé lors de la conception du contrôleur qui permet d’évaluer les variations des commandes virtuelles d’ordre élevé. L’approche de commande choisie est validée en simulation à l’aide du modèle théorique et en pratique à l’aide d’un quadrotor de type Pelican fabriqué par la compagnie Ascending Technologies

Nonlinear robust H∞ control.

A new theory is proposed for the full-information finite and infinite horizontime robust H∞ control that is equivalently effective for the regulation and/or tracking problems of the general class of time-varying nonlinear systems under the presence of exogenous disturbance inputs. The theory employs the sequence of linear-quadratic and time-varying approximations, that were recently introduced in the optimal control framework, to transform the nonlinear H∞ control problem into a sequence of linearquadratic robust H∞ control problems by using well-known results from the existing Riccati-based theory of the maturing classical linear robust control. The proposed method, as in the optimal control case, requires solving an approximating sequence of Riccati equations (ASRE), to find linear time-varying feedback controllers for such disturbed nonlinear systems while employing classical methods. Under very mild conditions of local Lipschitz continuity, these iterative sequences of solutions are known to converge to the unique viscosity solution of the Hamilton-lacobi-Bellman partial differential equation of the original nonlinear optimal control problem in the weak form (Cimen, 2003); and should hold for the robust control problems herein. The theory is analytically illustrated by directly applying it to some sophisticated nonlinear dynamical models of practical real-world applications. Under a r -iteration sense, such a theory gives the control engineer and designer more transparent control requirements to be incorporated a priori to fine-tune between robustness and optimality needs. It is believed, however, that the automatic state-regulation robust ASRE feedback control systems and techniques provided in this thesis yield very effective control actions in theory, in view of its computational simplicity and its validation by means of classical numerical techniques, and can straightforwardly be implemented in practice as the feedback controller is constrained to be linear with respect to its inputs