Nonlinear Control Of Fixed Wing Uavs With Time Varying And Unstructured Uncertainties

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Nonlinear Control of Fixed-Wing UAVs with Time-Varying and Unstructured Uncertainties

Author : Michail G. Michailidis
Publisher : Springer Nature
ISBN 13 : 3030407160
Total Pages : 119 pages
Book Rating : 4.0/5 (34 download)

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Book Synopsis Nonlinear Control of Fixed-Wing UAVs with Time-Varying and Unstructured Uncertainties by : Michail G. Michailidis

Download or read book Nonlinear Control of Fixed-Wing UAVs with Time-Varying and Unstructured Uncertainties written by Michail G. Michailidis and published by Springer Nature. This book was released on 2020-02-21 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces a comprehensive and mathematically rigorous controller design for families of nonlinear systems with time-varying parameters and unstructured uncertainties. Although the presented methodology is general, the specific family of systems considered is the latest, NextGen, unconventional fixed-wing unmanned aircraft with circulation control or morphing wings, or a combination of both. The approach considers various sources of model and parameter uncertainty, while the controller design depends not on a nominal plant model, but instead on a family of admissible plants. In contrast to existing controller designs that consider multiple models and multiple controllers, the proposed approach is based on the ‘one controller fits all models’ within the unstructured uncertainty interval. The book presents a modeling-based analysis and synthesis approach with additive uncertainty weighting functions for accurate realization of the candidate systems. This differs significantly from existing designs in that it is capable of handling time-varying characteristics. This research monograph is suitable for scientists, engineers, researchers and graduate students with a background in control system theory who are interested in complex engineering nonlinear systems.

Cyber-Physical Systems: Design and Application for Industry 4.0

Author : Alla G. Kravets
Publisher : Springer Nature
ISBN 13 : 3030660818
Total Pages : 440 pages
Book Rating : 4.0/5 (36 download)

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Book Synopsis Cyber-Physical Systems: Design and Application for Industry 4.0 by : Alla G. Kravets

Download or read book Cyber-Physical Systems: Design and Application for Industry 4.0 written by Alla G. Kravets and published by Springer Nature. This book was released on 2021-03-25 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of chapters dedicated to the questions of cyber-physical system design and its usage for the chemical industry and new material design. Also, the contribution of the book covers scientific research and their results for cyber-physical systems design and application in the energy domain and solutions regarding engineering education for cyber-physical systems design. The book offers unique content for researchers and practitioners who are looking for new knowledge and skills in the framework of Industry 4.0 solutions. The book also benefits researchers and practitioners in chemistry and new material design and manufacturing to understand how cyber-physical systems can be applied to increase efficiency and performance. The target audience of the book are practitioners, enterprises representatives, scientists, Ph.D. and master students who perform scientific research or applications of cyber-physical systems in the concept of Industry 4.0.

Advanced Robust Nonlinear Control Approaches for Quadrotor Unmanned Aerial Vehicle

Author : Moussa Labbadi
Publisher : Springer
ISBN 13 : 9783030810139
Total Pages : 249 pages
Book Rating : 4.8/5 (11 download)

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Book Synopsis Advanced Robust Nonlinear Control Approaches for Quadrotor Unmanned Aerial Vehicle by : Moussa Labbadi

Download or read book Advanced Robust Nonlinear Control Approaches for Quadrotor Unmanned Aerial Vehicle written by Moussa Labbadi and published by Springer. This book was released on 2021-10-21 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies selected advanced flight control schemes for an uncertain quadrotor unmanned aerial vehicle (UAV) systems in the presence of constant external disturbances, parametric uncertainties, measurement noise, time-varying external disturbances, and random external disturbances. Furthermore, in all the control techniques proposed in this book, it includes the simulation results with comparison to other nonlinear control schemes recently developed for the tracking control of a quadrotor UAV. The main contributions of the present book for quadrotor UAV systems are as follows: (i) the proposed control methods are based on the high-order sliding mode controller (SMC) and hybrid control algorithm with an optimization method. (ii) the finite-time control schemes are developed by using fast terminal SMC (FTSMC), nonsingular FTSMC (NFTSMC), global time-varying SMC, and adaptive laws. (iii) the fractional-order flight control schemes are developed by using the fractional-order calculus theory, super twisting algorithm, NFTSMC, and the SMC. This book covers the research history and importance of quadrotor system subject to system uncertainties, external wind disturbances, and noise measurements, as well as the research status of advanced flight control methods, adaptive flight control methods, and flight control based on fractional-order theory. The book would be interesting to most academic undergraduate, postgraduates, researchers on flight control for drones and applications of advanced controllers in engineering field. This book presents a must-survey for advanced finite-time control for quadrotor system. Some parts of this book have the potential of becoming the courses for the modelling and control of autonomous flying machines. Readers (academic researcher, undergraduate student, postgraduate student, MBA/executive, and education practitioner) interested in nonlinear control methods find this book an investigation. This book can be used as a good reference for the academic research on the control theory, drones, terminal sliding mode control, and related to this or used in Ph.D. study of control theory and their application in field engineering.

Neural Network Based Adaptive Control for Autonomous Flight of Fixed Wing Unmanned Aerial Vehicles

Author : Vishwas Ramadas Puttige
Publisher :
ISBN 13 :
Total Pages : 185 pages
Book Rating : 4.:/5 (54 download)

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Book Synopsis Neural Network Based Adaptive Control for Autonomous Flight of Fixed Wing Unmanned Aerial Vehicles by : Vishwas Ramadas Puttige

Download or read book Neural Network Based Adaptive Control for Autonomous Flight of Fixed Wing Unmanned Aerial Vehicles written by Vishwas Ramadas Puttige and published by . This book was released on 2009 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the development of small, inexpensive unmanned aerial vehicles (UAVs) to achieve autonomous fight. Fixed wing hobby model planes are modified and instrumented to form experimental platforms. Different sensors employed to collect the flight data are discussed along with their calibrations. The time constant and delay for the servo-actuators for the platform are estimated. Two different data collection and processing units based on micro-controller and PC104 architectures are developed and discussed. These units are also used to program the identification and control algorithms. Flight control of fixed wing UAVs is a challenging task due to the coupled, time-varying, nonlinear dynamic behaviour. One of the possible alternatives for the flight control system is to use the intelligent adaptive control techniques that provide online learning capability to cope with varying dynamics and disturbances. Neural network based indirect adaptive control strategy is applied for the current work. The two main components of the adaptive control technique are the identification block and the control block. Identification provides a mathematical model for the controller to adapt to varying dynamics. Neural network based identification provides a black-box identification technique wherein a suitable network provides prediction capability based upon the past inputs and outputs. Auto-regressive neural networks are employed for this to ensure good retention capabilities for the model that uses the past outputs and inputs along with the present inputs. Online and offline identification of UAV platforms are discussed based upon the flight data. Suitable modifications to the Levenberg-Marquardt training algorithm for online training are proposed. The effect of varying the different network parameters on the performance of the network are numerically tested out. A new performance index is proposed that is shown to improve the accuracy of prediction and also reduces the training time for these networks. The identification algorithms are validated both numerically and flight tested. A hardware-in-loop simulation system has been developed to test the identification and control algorithms before flight testing to identify the problems in real time implementation on the UAVs. This is developed to keep the validation process simple and a graphical user interface is provided to visualise the UAV flight during simulations. A dual neural network controller is proposed as the adaptive controller based upon the identification models. This has two neural networks collated together. One of the neural networks is trained online to adapt to changes in the dynamics. Two feedback loops are provided as part of the overall structure that is seen to improve the accuracy. Proofs for stability analysis in the form of convergence of the identifier and controller networks based on Lyapunov's technique are presented. In this analysis suitable bounds on the rate of learning for the networks are imposed. Numerical results are presented to validate the adaptive controller for single-input single-output as well as multi-input multi-output subsystems of the UAV. Real time validation results and various flight test results confirm the feasibility of the proposed adaptive technique as a reliable tool to achieve autonomous flight. The comparison of the proposed technique with a baseline gain scheduled controller both in numerical simulations as well as test flights bring out the salient adaptive feature of the proposed technique to the time-varying, nonlinear dynamics of the UAV platforms under different flying conditions.

Robust Formation Control for Multiple Unmanned Aerial Vehicles

Author : Hao Liu
Publisher : CRC Press
ISBN 13 : 1000788539
Total Pages : 180 pages
Book Rating : 4.0/5 (7 download)

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Book Synopsis Robust Formation Control for Multiple Unmanned Aerial Vehicles by : Hao Liu

Download or read book Robust Formation Control for Multiple Unmanned Aerial Vehicles written by Hao Liu and published by CRC Press. This book was released on 2022-12-01 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the authors’ recent research results on formation control problems, including time-varying formation, communication delays, fault-tolerant formation for multiple UAV systems with highly nonlinear and coupled, parameter uncertainties, and external disturbances. Differentiating from existing works, this book presents a robust optimal formation approach to designing distributed cooperative control laws for a group of UAVs, based on the linear quadratic regulator control method and the robust compensation theory. The proposed control method is composed of two parts: the nominal part to achieve desired tracking performance and the robust compensation part to restrain the influence of highly nonlinear and strongly coupled parameter uncertainties, and external disturbances on the global closed-loop control system. Furthermore, this book gives proof of their robust properties. The influence of communication delays and actuator fault tolerance can be restrained by the proposed robust formation control protocol, and the formation tracking errors can converge into a neighborhood of the origin bounded by a given constant in a finite time. Moreover, the book provides details about the practical application of the proposed method to design formation control systems for multiple quadrotors and tail-sitters. Additional features include a robust control method that is proposed to address the formation control problem for UAVs and theoretical and experimental research for the cooperative flight of the quadrotor UAV group and the tail-sitter UAV group. Robust Formation Control for Multiple Unmanned Aerial Vehicles is suitable for graduate students, researchers, and engineers in the system and control community, especially those engaged in the areas of robust control, UAV swarming, and multi-agent systems.

Applying the PPO Algorithm to Fixed-Wing UAV Attitude Control

Author : Po-Hsun Wu
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis Applying the PPO Algorithm to Fixed-Wing UAV Attitude Control by : Po-Hsun Wu

Download or read book Applying the PPO Algorithm to Fixed-Wing UAV Attitude Control written by Po-Hsun Wu and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis applies the reinforcement learning (RL) to design the attitude controller for fixed-wing unmanned aerial vehicle. In contrast to traditional linear control theory, which are limited to linearization, or complex nonlinear control theory solving processes, reinforcement learning utilizes an artificial neural network as the control law and applies RL algorithm to train the network by adjusting its parameters. The results demonstrate that the controller designed using the RL framework exhibits advantages over traditional control laws. Within the RL architecture, there are four main elements: policy, algorithm, reward function, and environment. In this thesis, a combination of a quadratic performance index and a time varying coefficient is used as the reward function. The categorize policy is employed as the controller, and the linearized UAV dynamic model and the fourth order Runge-Kutta method are utilized as the training environment. The Proximal Policy Optimization algorithm (PPO algorithm) is used to train the policy. Upon completing the training, a neural network controller is obtained. The results demonstrate that the trained controller successfully achieves the goal of controlling the UAV's attitude.

Mathematical Reviews

Author :
Publisher :
ISBN 13 :
Total Pages : 844 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Mathematical Reviews by :

Download or read book Mathematical Reviews written by and published by . This book was released on 2004 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Robust Discrete-Time Flight Control of UAV with External Disturbances

Author : Shuyi Shao
Publisher : Springer
ISBN 13 : 9783030579593
Total Pages : 207 pages
Book Rating : 4.5/5 (795 download)

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Book Synopsis Robust Discrete-Time Flight Control of UAV with External Disturbances by : Shuyi Shao

Download or read book Robust Discrete-Time Flight Control of UAV with External Disturbances written by Shuyi Shao and published by Springer. This book was released on 2021-09-28 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies selected discrete-time flight control schemes for fixed-wing unmanned aerial vehicle (UAV) systems in the presence of system uncertainties, external disturbances and input saturation. The main contributions of this book for UAV systems are as follows: (i) the proposed integer-order discrete-time control schemes are based on the designed discrete-time disturbance observers (DTDOs) and the neural network (NN); and (ii) the fractional-order discrete-time control schemes are developed by using the fractional-order calculus theory, the NN and the DTDOs. The book offers readers a good understanding of how to establish discrete-time tracking control schemes for fixed-wing UAV systems subject to system uncertainties, external wind disturbances and input saturation. It represents a valuable reference guide for academic research on uncertain UAV systems, and can also support advanced / Ph.D. studies on control theory and engineering.

Nonlinear Estimation and Control Methods for Mechanical and Aerospace Systems Under Actuator Uncertainty

Author : Krishna Bhavithavya Kidambi
Publisher :
ISBN 13 :
Total Pages : 270 pages
Book Rating : 4.:/5 (112 download)

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Book Synopsis Nonlinear Estimation and Control Methods for Mechanical and Aerospace Systems Under Actuator Uncertainty by : Krishna Bhavithavya Kidambi

Download or read book Nonlinear Estimation and Control Methods for Mechanical and Aerospace Systems Under Actuator Uncertainty written by Krishna Bhavithavya Kidambi and published by . This book was released on 2019 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Air flow velocity field control is of crucial importance in aerospace applications to prevent the potentially destabilizing effects of phenomena such as cavity ow oscillations, flow separation, flow-induced limit cycle oscillations (LCO) (flutter), vorticity, and acoustic instabilities. Flow control is also important in aircraft applications to reduce drag in aircraft wings for improved flight performance. Although passive flow control approaches are often utilized due to their simplicity, active flow control (AFC) methods can achieve improved flight performance over a wider range of time-varying operating conditions by automatically adjusting their level of control actuation in response to real-time sensor measurements. Although several methods for AFC have been presented in recent literature, there remain numerous challenges to be overcome in closed-loop nonlinear AFC design. Additional challenges arise in control design for practical systems with limited onboard sensor measurements and uncertain actuator dynamics. In this thesis, robust nonlinear control methods are developed, which are rigorously proven to achieve reliable control of fluid flow systems under uncertain, time-varying operating conditions and actuator model uncertainty. Further, to address the practical control design challenges resulting from sensor limitations, this thesis research will investigate and develop new methods of sliding mode estimation, which are shown to achieve finite-time state estimation for systems with limited onboard sensing capabilities. The specific contributions presented in this thesis include: 1) the application of proper orthogonal decomposition (POD)-based model order reduction techniques to develop simplified, control-oriented mathematical models of actuated fluid flow dynamic systems; 2) the rigorous development of nonlinear closed-loop active flow control techniques to achieve asymptotic regulation of fluid flow velocity fields; 3) the design of novel sliding mode estimation and control methods to regulate fluid flow velocity fields in the presence of actuator uncertainty; 4) the design of a nonlinear control method that achieves simultaneous fluid flow velocity control and LCO suppression in a flexible airfoil; and 5) the analysis of a discontinuous hierarchical sliding mode estimation method using a differential inclusions-based technique."--Abstract.

Robust Formation Control for Multiple Unmanned Aerial Vehicles

Author : Hao Liu (Of Beijing hang kong hang tian da xue)
Publisher :
ISBN 13 : 9781032150246
Total Pages : 0 pages
Book Rating : 4.1/5 (52 download)

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Book Synopsis Robust Formation Control for Multiple Unmanned Aerial Vehicles by : Hao Liu (Of Beijing hang kong hang tian da xue)

Download or read book Robust Formation Control for Multiple Unmanned Aerial Vehicles written by Hao Liu (Of Beijing hang kong hang tian da xue) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is based on the authors' recent research results on formation control problems, including time-varying formation, communication delays, fault-tolerant formation for multiple UAV systems with highly nonlinear and coupled, parameter uncertainties, and external disturbances. Differentiating from existing works, this book presents a robust optimal formation approach to designing distributed cooperative control laws for a group of UAVs, based on the linear quadratic regulator control method and the robust compensation theory. The proposed control method is composed of two parts: the nominal part to achieve desired tracking performance and the robust compensation part to restrain the influence of highly nonlinear and strongly coupled, parameter uncertainties, and external disturbances on the global closed-loop control system. Furthermore, this book gives proof of their robust properties. The influence of communication delays and actuator fault tolerance can be restrained by the proposed robust formation control protocol, and the formation tracking errors can converge into a neighborhood of the origin bounded by a given constant in a finite time. Moreover, the book provides details about the practical application of the proposed method to design formation control systems for multiple quadrotors and tail-sitters. Additional features include a robust control method that is proposed to address the formation control problem for UAVs and theoretical and experimental research for the cooperative flight of the quadrotor UAV group and the tail-sitter UAV group. Robust Formation Control for Multiple Unmanned Aerial Vehicles is suitable for graduate students, researchers, and engineers in the system and control community, especially those engaged in the areas of robust control, UAV swarming, and multi-agent systems."--

Intelligent Adaptive Control for Nonlinear Applications

Author : Shaaban Ali Salman Ali
Publisher :
ISBN 13 :
Total Pages : 168 pages
Book Rating : 4.:/5 (3 download)

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Book Synopsis Intelligent Adaptive Control for Nonlinear Applications by : Shaaban Ali Salman Ali

Download or read book Intelligent Adaptive Control for Nonlinear Applications written by Shaaban Ali Salman Ali and published by . This book was released on 2008 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis deals with the design and implementation of an Adaptive Flight Control technique for Unmanned Aerial Vehicles (UAVs). The application of UAVs has been increasing exponentially in the last decade both in Military and Civilian fronts. These UAVs fly at very low speeds and Reynolds numbers, have nonlinear coupling, and tend to exhibit time varying characteristics. In addition, due to the variety of missions, they fly in uncertain environments exposing themselves to unpredictable external disturbances. The successful completion of the UAV missions is largely dependent on the accuracy of the control provided by the flight controllers. Thus there is a necessity for accurate and robust flight controllers. These controllers should be able to adapt to the changes in the dynamics due to internal and external changes. From the available literature, it is known that, one of the better suited adaptive controllers is the model based controller. The design and implementation of model based adaptive controller is discussed in the thesis. A critical issue in the design and application of model based control is the online identification of the UAV dynamics from the available sensors using the onboard processing capability. For this, proper instrumentation in terms of sensors and avionics for two platforms developed at UNSW@ADFA is discussed. Using the flight data from the remotely flown platforms, state space identification and fuzzy identification are developed to mimic the UAV dynamics. Real time validations using Hardware in Loop (HIL) simulations show that both the methods are feasible for control. A finer comparison showed that the accuracy of identification using fuzzy systems is better than the state space technique. The flight tests with real time online identification confirmed the feasibility of fuzzy identification for intelligent control. Hence two adaptive controllers based on the fuzzy identification are developed. The first adaptive controller is a hybrid indirect adaptive controller that utilises the model sensitivity in addition to output error for adaptation. The feedback of the model sensitivity function to adapt the parameters of the controller is shown to have beneficial effects, both in terms of convergence and accuracy. HIL simulations applied to the control of roll stabilised pitch autopilot for a typical UAV demonstrate the improvements compared to the direct adaptive controller. Next a novel fuzzy model based inversion controller is presented. The analytical approximate inversion proposed in this thesis does not increase the computational effort. The comparisons of this controller with other controller for a benchmark problem are presented using numerical simulations. The results bring out the superiority of this technique over other techniques. The extension of the analytical inversion based controller for multiple input multiple output problem is presented for the design of roll stabilised pitch autopilot for a UAV. The results of the HIL simulations are discussed for a typical UAV. Finally, flight test results for angle of attack control of one of the UAV platforms at UNSW@ADFA are presented. The flight test results show that the adaptive controller is capable of controlling the UAV suitably in a real environment, demonstrating its robustness characteristics.

Autonomous and Semi-autonomous Control of Agile Fixed-wing Unmanned Aerial Vehicles

Author : Juan Carlos Hernandez Ramirez
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

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Book Synopsis Autonomous and Semi-autonomous Control of Agile Fixed-wing Unmanned Aerial Vehicles by : Juan Carlos Hernandez Ramirez

Download or read book Autonomous and Semi-autonomous Control of Agile Fixed-wing Unmanned Aerial Vehicles written by Juan Carlos Hernandez Ramirez and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Unmanned aerial vehicles (UAVs) have been increasingly employed for a wide range of civilian applications, including scientific and commercial endeavours. Striving for versatility, novel UAV designs have been proposed which incorporate features from different aircraft categories. The agile fixed-wing UAV is one such platform, which combines the fast andefficient flight of conventional fixed-wing aircraft with the highly maneuverable hovering capabilities of rotorcraft. These aircraft have enormous potential but are challenging to operate, demonstrating the need for control systems capable of harnessing their maneuvering capabilities. The objective of this thesis is to develop a comprehensive control strategy for the agile fixed-wing UAV, considering both autonomous, and pilot-assist, semi-autonomous operation. The thesis begins by introducing the fixed-wing UAV model, including previously developed aerodynamic and slipstream models needed for controller design and verification. Controllerdesign begins in the next chapter, where the core attitude control system is developed. We propose several geometric control strategies which are then evaluated through simulations and experiments. The next chapter presents a nonlinear control strategy to enable UAV velocity and position control. This is a unified control architecture, where a single controller is valid for steady and hover flight regimes. Rigorous stability analysis, together with simulations and experimental flights demonstrate the capabilities of the proposed system. The following chapter, we propose an additional control loop to enable path-following functionality, allowing us to prioritize the task of reaching and following spatial paths. As part of this system, a novel moving path frame is developed, specifically tailored for the task of motion control in three-dimensional space. Finally, a reference generator capable of translating limited pilot inputs into time-parametrized trajectories or spatial paths is developed. This system is then integrated with the control systems to achieve a semi-autonomous control solution. As demonstrated through experimental flights, the proposed system enables a human pilot to safely operate the aircraft inany regime without sacrificing its maneuverability"--

Robust Post-stall Perching with a Fixed-wing UAV

Author : Joseph Lawrence Moore
Publisher :
ISBN 13 :
Total Pages : 137 pages
Book Rating : 4.:/5 (91 download)

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Book Synopsis Robust Post-stall Perching with a Fixed-wing UAV by : Joseph Lawrence Moore

Download or read book Robust Post-stall Perching with a Fixed-wing UAV written by Joseph Lawrence Moore and published by . This book was released on 2014 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consider a bird perching on a branch. In the presence of environmental disturbances and complicated fluid flow, the animal exploits post-stall pressure drag to rapidly decelerate and land on a perch with a precision far beyond the capabilities of our best aircraft control systems. In this thesis, I present a controller synthesis technique for achieving robust, post-stall perching with a fixed-wing Unmanned Aerial Vehicle (UAV). Using sum-of-squares (SOS) programming and building on a novel control synthesis approach known as LQR-Trees, I demonstrate the ability to improve the robustness of the post-stall perching manuever to variable initial conditions, modeling error, and external disturbances. I achieve this by developing methods for carrying out rigorous robust verification of the nonlinear aircraft model along a time-varying nominal perching trajectory in the presence of both dynamic and parametric uncertainty. I also present methods for carrying out stochastic verification in the presence of Gaussian acceleration uncertainty and adaptive control techniques for improving controller performance in the presence of parametric uncertainty. Using the robust verification techniques for dynamic uncertainty, I proceed to generate a robust LQR-Tree controller and test that controller on real hardware using a small 24 inch wing span glider and a Vicon motion capture studio. The experiments show successful perching for 94 percent of the 147 flights launched between 6 and 8 m/s. I further demonstrate robustness to initial pitch variations by launching the glider by hand and showing repeatable successful perching results. Following these experiments, I then build a magnetic field sensing system capable of estimating the position of the perching UAV using the magnetic field generated by a powerline. I demonstrate on hardware that the aircraft is still capable of successfully executing a closed-loop perching maneuver indoors using the lower fidelity state estimates. I then move the entire experiment outdoors and begin testing the UAV's perching performance in the presence of wind gusts. Very quickly, it becomes apparent that the glider can not reliably perch in wind. To address this, I describe a control approach for mitigating the effects of wind on aircraft performance and propose an experiment for testing this approach.

Adaptive and Optimal Motion Control of Multi-UAV Systems

Author : Nasrettin Köksal
Publisher :
ISBN 13 :
Total Pages : 137 pages
Book Rating : 4.:/5 (112 download)

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Book Synopsis Adaptive and Optimal Motion Control of Multi-UAV Systems by : Nasrettin Köksal

Download or read book Adaptive and Optimal Motion Control of Multi-UAV Systems written by Nasrettin Köksal and published by . This book was released on 2019 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies trajectory tracking and coordination control problems for single and multi unmanned aerial vehicle (UAV) systems. These control problems are addressed for both quadrotor and fixed-wing UAV cases. Despite the fact that the literature has some approaches for both problems, most of the previous studies have implementation challenges on real-time systems. In this thesis, we use a hierarchical modular approach where the high-level coordination and formation control tasks are separated from low-level individual UAV motion control tasks. This separation helps efficient and systematic optimal control synthesis robust to effects of nonlinearities, uncertainties and external disturbances at both levels, independently. The modular two-level control structure is convenient in extending single-UAV motion control design to coordination control of multi-UAV systems. Therefore, we examine single quadrotor UAV trajectory tracking problems to develop advanced controllers compensating effects of nonlinearities and uncertainties, and improving robustness and optimality for tracking performance. At first, a novel adaptive linear quadratic tracking (ALQT) scheme is developed for stabilization and optimal attitude control of the quadrotor UAV system. In the implementation, the proposed scheme is integrated with Kalman based reliable attitude estimators, which compensate measurement noises. Next, in order to guarantee prescribed transient and steady-state tracking performances, we have designed a novel backstepping based adaptive controller that is robust to effects of underactuated dynamics, nonlinearities and model uncertainties, e.g., inertial and rotational drag uncertainties. The tracking performance is guaranteed to utilize a prescribed performance bound (PPB) based error transformation. In the coordination control of multi-UAV systems, following the two-level control structure, at high-level, we design a distributed hierarchical (leader-follower) 3D formation control scheme. Then, the low-level control design is based on the optimal and adaptive control designs performed for each quadrotor UAV separately. As particular approaches, we design an adaptive mixing controller (AMC) to improve robustness to varying parametric uncertainties and an adaptive linear quadratic controller (ALQC). Lastly, for planar motion, especially for constant altitude flight of fixed-wing UAVs, in 2D, a distributed hierarchical (leader-follower) formation control scheme at the high-level and a linear quadratic tracking (LQT) scheme at the low-level are developed for tracking and formation control problems of the fixed-wing UAV systems to examine the non-holonomic motion case. The proposed control methods are tested via simulations and experiments on a multi-quadrotor UAV system testbed.

Nonlinear Control Systems

Author : Alberto Isidori
Publisher : Springer Science & Business Media
ISBN 13 : 1846286158
Total Pages : 557 pages
Book Rating : 4.8/5 (462 download)

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Book Synopsis Nonlinear Control Systems by : Alberto Isidori

Download or read book Nonlinear Control Systems written by Alberto Isidori and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to present a self-contained description of the fun damentals of the theory of nonlinear control systems, with special emphasis on the differential geometric approach. The book is intended as a graduate text as weil as a reference to scientists and engineers involved in the analysis and design of feedback systems. The first version of this book was written in 1983, while I was teach ing at the Department of Systems Science and Mathematics at Washington University in St. Louis. This new edition integrates my subsequent teaching experience gained at the University of Illinois in Urbana-Champaign in 1987, at the Carl-Cranz Gesellschaft in Oberpfaffenhofen in 1987, at the University of California in Berkeley in 1988. In addition to a major rearrangement of the last two Chapters of the first version, this new edition incorporates two additional Chapters at a more elementary level and an exposition of some relevant research findings which have occurred since 1985.

Adaptive Estimation and Control with Application to Vision-based Autonomous Formation Flight

Author : Ramachandra Jayant Sattigeri
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (173 download)

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Book Synopsis Adaptive Estimation and Control with Application to Vision-based Autonomous Formation Flight by : Ramachandra Jayant Sattigeri

Download or read book Adaptive Estimation and Control with Application to Vision-based Autonomous Formation Flight written by Ramachandra Jayant Sattigeri and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of vision as an additional sensing mechanism has received a lot of attention in recent years in the context of autonomous flight applications. Modern Unmanned Aerial Vehicles (UAVs) are equipped with vision sensors because of their light-weight, low-cost characteristics and also their ability to provide a rich variety of information of the environment in which the UAVs are navigating in. The problem of vision based autonomous flight is very difficult and challenging since it requires bringing together concepts from image processing and computer vision, target tracking and state estimation, and flight guidance and control. This thesis focuses on the adaptive state estimation, guidance and control problems involved in vision-based formation flight. Specifically, the thesis presents a composite adaptation approach to the partial state estimation of a class of nonlinear systems with unmodeled dynamics. In this approach, a linear time-varying Kalman filter is the nominal state estimator which is augmented by the output of an adaptive neural network (NN) that is trained with two error signals. The benefit of the proposed approach is in its faster and more accurate adaptation to the modeling errors over a conventional approach. The thesis also presents two approaches to the design of adaptive guidance and control (G & C) laws for line-of-sight formation flight. In the first approach, the guidance and autopilot systems are designed separately and then combined together by assuming time-scale separation. The second approach is based on integrating the guidance and autopilot design process. The developed G & C laws using both approaches are adaptive to unmodeled leader aircraft acceleration and to own aircraft aerodynamic uncertainties. The thesis also presents theoretical justification based on Lyapunov-like stability analysis for integrating the adaptive state estimation and adaptive G & C designs. All the developed designs are validated in nonlinear, 6DOF fixed-wing aircraft simulations. Finally, the thesis presents a decentralized coordination strategy for vision-based multiple-aircraft formation control. In this approach, each aircraft in formation regulates range from up to two nearest neighboring aircraft while simultaneously tracking nominal desired trajectories common to all aircraft and avoiding static obstacles.

Neural Network Based Identification and Control of an Unmanned Helicopter

Author : Mahendra Kumar Samal
Publisher :
ISBN 13 :
Total Pages : 227 pages
Book Rating : 4.:/5 (54 download)

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Book Synopsis Neural Network Based Identification and Control of an Unmanned Helicopter by : Mahendra Kumar Samal

Download or read book Neural Network Based Identification and Control of an Unmanned Helicopter written by Mahendra Kumar Samal and published by . This book was released on 2009 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work provides the development of an Adaptive Flight Control System (AFCS) for autonomous hover of a Rotary-wing Unmanned Aerial Vehicle (RUAV). Due to the complex, nonlinear and time-varying dynamics of the RUAV, indirect adaptive control using the Model Predictive Control (MPC) is utilised. The performance of the MPC mainly depends on the model of the RUAV used for predicting the future behaviour. Due to the complexities associated with the RUAV dynamics, a neural network based black box identification technique is used for modelling the behaviour of the RUAV. Auto-regressive neural network architecture is developed for offline and online modelling purposes. A hybrid modelling technique that exploits the advantages of both the offline and the online models is proposed. In the hybrid modelling technique, the predictions from the offline trained model are corrected by using the error predictions from the online model at every sample time. To reduce the computational time for training the neural networks, a principal component analysis based algorithm that reduces the dimension of the input training data is also proposed. This approach is shown to reduce the computational time significantly. These identification techniques are validated in numerical simulations before flight testing in the Eagle and RMAX helicopter platforms. Using the successfully validated models of the RUAVs, Neural Network based Model Predictive Controller (NN-MPC) is developed taking into account the non-linearity of the RUAVs and constraints into consideration. The parameters of the MPC are chosen to satisfy the performance requirements imposed on the flight controller. The optimisation problem is solved numerically using nonlinear optimisation techniques. The performance of the controller is extensively validated using numerical simulation models before flight testing. The effects of actuator and sensor delays and noises along with the wind gusts are taken into account during these numerical simulations. In addition, the robustness of the controller is validated numerically for possible parameter variations. The numerical simulation results are compared with a base-line PID controller. Finally, the NN-MPCs are flight tested for height control and autonomous hover. For these, SISO as well as multiple SISO controllers are used. The flight tests are conducted in varying weather conditions to validate the utility of the control technique. The NN-MPC in conjunction with the proposed hybrid modelling technique is shown to handle additional disturbances successfully. Extensive flight test results provide justification for the use of the NN-MPC technique as a reliable technique for control of non-linear complex dynamic systems such as RUAVs.