Dissertations / Theses: 'Backstepping methods in control design'

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Shekar, Sadahalli Arjun. "ADAPTIVE CONTROL DESIGN FOR QUADROTORS." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1472.

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Unmanned Aerial Vehicles (UAV) control has become a very important point of scientific study. The control design challenges of a UAV make it one of the most researched areas in modern control applications. This thesis specifically chooses the Quadrotor as the UAV platform. Considering the quadrotor has 4 rotors and 6 degrees of freedom, it is an underactuated system and is dynamically unstable that has to be stabilized by a suitable control algorithm in order to operate autonomously. This thesis focuses on the quaternion representation of the quadrotor system dynamics and develops an adaptive control for its trajectory tracking problem. The control design uses the certainty equivalence principle where adaptive tracking controls are designed separately for each of the translational and rotational subsystems. With this approach, the success of the outer loop translational control relies on the fast convergence of the inner loop rotational control in order to guarantee the system’s stability while achieving the tracking objective. For the translational subsystem in the outer loop, a modified geometric control technique is considered with an adaptive component for the estimation of the uncertain mass of the quadrotor. For the rotational subsystem in the inner loop a backstepping based control design is adopted due to its systematic design and intuitive approach. An adaptive component is further integrated with it to estimate the integrated components of the uncertain Moment of Inertia matrix and other constant parameters in the system dynamics to guarantee the stability of the inner loop system while achieving the tracking objective. Furthermore, a complete backstepping control design methodology is presented which overcomes the issues of certainty equivalence principle where the inner loop needs to execute significantly faster than the outer loop to stabilize the system.

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Dahlgren, Johan. "Robust nonlinear control design for a missile using backstepping." Thesis, Linköping University, Department of Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1574.

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This thesis has been performed at SAAB Bofors Dynamics. The purpose was to derive a robust control design for a nonlinear missile using backstepping. A particularly interesting matter was to see how different design choices affect the robustness. Backstepping is a relatively new design method for nonlinear systems which leads to globally stabilizing control laws. By making wise decisions in the design the resulting closed loop can receive significant robustness. The method also makes it possible to benefit from naturally stabilizing aerodynamic forces and momentums. It is based on Lyapunov theory and the control laws and a Lyapunov function are derived simultaneously. This Lyapunov function is used to guarantee stability. In this thesis the control laws for the missile are first derived by using backstepping. The missile dynamics are described with aerodynamic coeffcients with corresponding uncertainties. The robustness of the design w.r.t. the aerodynamic uncertainties is then studied further in detail. One way to analyze how the stability is affected by the errors in the coeffcients is presented. To improve the robustness and remove static errors, dynamics are introduced in the control laws by adding an integrator. One conclusion that has been reached is that it is hard to immediately determine how a certain design choice affects the robustness. Instead it is at the point when algebraic expressions for the closed loop system have been obtained, that it is possible to analyze the affects of a certain design choice. The designed control laws are evaluated by simulations which shows satisfactory results.

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Henriquez, Acacio Alejandro Morales. "Flight control design for a flexible conceptual aircraft using backstepping technique." Instituto Tecnológico de Aeronáutica, 2011. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=2170.

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A nonlinear flight control system is proposed for a conceptual flexible aircraft using Backstepping technique to achieve global stability in the rigid and flexible dynamics. It is introduced a controller to lead the model to a rigid-body model approximation, minimizing structural dynamics effects using static Backstepping approach, that system can be called as flexible modes suppressor. Afterward, it is applied a controller with an internal loop involving the angular rates of the aircraft and an external loop which includes pitch angle, sideslip angle and bank angle without the two-timescale assumption to separate slow and fast dynamics and without consider aerodynamics forces and moments increments caused by structural dynamics. In addition, external looping are built using Backstepping for first order systems in order to control aircraft course and altitude, the results are reference inputs to be introduced in the previous loop developed for rigid body control. Also, it is implemented a separate controller to track velocity using Backstepping approach, as a result, aircraft autopilot system is completed. Nonlinear six degree of freedom simulation results for a conceptual model of a medium size jet, like Embraer 190/195 and Boeing 737-200/300, are presented to demonstrate the effectiveness of the proposed control law in several conditions. It is assumed that the aerodynamics coefficients are fixed and the model presents augmented flexible features.

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Mahmoud, Nawrous Ibrahim. "A Backstepping Design of a Control System for a Magnetic Levitation System." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1960.

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The subject of this thesis is the design of a control law for a magnetic levitation system, which in this case is the system 33-210. The method used is backstepping technique and specifically adaptive observer backstepping due to parameter uncertainties and lack of access to all the states of the system. The second state of the system, the speed of the steel ball, was estimated by a reduced order observer. The model used gave us the opportunity to estimate a parameter which in the literature is denoted virtual control coefficient. Backstepping method gives us a rather straight forward way to design the controlling unit for a system with these properties. Stabilization of the closed-loop system is achieved by incorporating a Lypapunov function, which were chose a quadratic one in this thesis. If thederivative of this function is rendered negative definite by the control law, then we achieve stability. The results of the design were evaluated in simulations and real-time measurements by testing the tracking performance of the system. The simulation results were very promising and the validations in real-time were satisfying. Note that this has been done in previous studies; the new aspect here is the limitation of the voltage input. The real-time results showed that the parameter estimation converges only locally.

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Kroeger, Kenneth Edward. "Design and Evaluation of a Fixed-Pitch Multirotor UAV with a Nonlinear Control Strategy." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23109.

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The use and practical applications of small UAV systems has continually grown in the past several years in both the public and private sectors. These UAV systems are used for not only defensive purposes, but for commercial applications such as exterior bridge and home inspections, wildlife/wildfire management and observation, conservation exercises, law-enforcement, radio-repeating operations, and a wide variety of other uses that may not warrant the use, expense, space constraints, or risk of a manned aircraft. This thesis focuses on the design of a fixed pitch multirotor UAV system for use in furthering research projects and facilitating payload data collection from a flying platform without the expense or risk of testing with available larger UAV systems.

The design of a multirotor UAV system with a flight control scheme, communication architecture and hardware, electrical architecture and hardware, and mechanical design is presented. An Extended Kalman Filter (EKF) strategy is implemented aboard a developed Inertial Measurement Unit (IMU) to estimate vehicle state. Experiments then validated the estimates from the EKF through a comparative approach between the developed unit and a commercial unit. A nonlinear flight control system is implemented based on an Integral-Backstepping control strategy. The flight control strategy was then fully simulated and exhaustively tested under a variety of external disturbances and initial conditions from a fully dynamic modeled environment. Parameters about the vehicle were experimentally determined to increase the accuracy of the model which would increase the chances of successful flight operations.

Flight demonstrations were conducted to evaluate the abilities and performance of the control system, along with testing the interface abilities and reliability between a universal ground control station (UGCS) and the aircraft. Lastly, the model was revisited with the input data from the flight control experiment and the output captured was evaluated against the output of the model system to evaluate effectiveness, reliability, and accuracy of the model. The results of the comparison showed that the computer simulation was accurate in predicting attitude and altitude of the vehicle to that of the realized system.
Master of Science

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Isaksen, Trond Willi. "Discrete-Time Backstepping Design Applied to Position Tracking Control of an Electro-Pneumatic Clutch Actuator." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8743.

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This thesis investigates different methods of backstepping controller design for an electro-pneumatic clutch actuator used in heavy duty trucks. The first part of the thesis is a literature study, where the subject is control of nonlinear-sampled data systems in general. Sampled-data systems contain a continuous-time plant and a digitally implemented controller, which in general make them harder to analyze and control than systems that operate purely in the continuous-time or discrete-time domain. The available theory of nonlinear sampled-data control systems is scarce, but three different methods are described in this thesis; emulation design, direct discrete-time design, and sampled-data design. The electro-pneumatic clutch actuator is controlled using a continuous-time backstepping controller implemented digitally. This is essentially the procedure of emulation design and is the common, if not only, method used in practical engineering tasks so far. However, redesign of the continuous-time controller using the direct discrete-time method shows great potential of improving performance and robustness of sampled-data systems. Direct discrete-time design is based on an approximate discrete-time model of the plant, giving the controller a structure that accounts for the sampling of the hybrid system. Potentially, one can utilize slower sampling in the system by implementing a discrete-time controller into the digial computer instead of a continuous-time one. Examples and case studies that prove the improvement one can achieve by chosing the direct discrete-time design is included in the first part of the thesis. Both a third- and fifth-order model of the electro-pneumatic clutch actuator are presented, and used as a basis for continuous- and discrete-time state-feedback backstepping controllers. These controllers are simulated with different sampling intervals to show their performance under different circumstances. The continuous-time controllers prove good reference trajectory tracking of the pure continuous-time system, while the performance of the sampled-data systems descends as higher sampling intervals are used. And, as opposed to the mentioned examples and case studies, the controller designed when taking the sampling into account shows no sign to outperform the controller that was designed without considering the sampling, at least not for the relative fast sampling the clutch actuator operates with.

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Riccardo, Zanella Riccardo. "Decoupled Controllers for Mobile Manipulation with Aerial Robots : Design, Implementation and Test." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187649.

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This work considers an aerial robot system composed of an Unmanned Aerial Vehicle (UAV) and a rigid manipulator, to be employed in mobile manipulation tasks. The strategy adopted for accomplishing the aerial manipulation is a decomposition of the previous system in two decoupled subsystems: one concerning the center of mass of the aerial robot; and another concerning the manipulator's orientation. Two Lyapunov-based controllers are developed, using a back stepping procedure, for solving the trajectory tracking problems related to the two subsystems. In the controller design, three inputs are assumed available: a translational acceleration along a body direction of the UAV; an angular velocity vector of this body rotation; and, finally, a torque at the spherical, or revolute, joint connecting the UAV and the manipulator. The first two inputs are generated by the same controller in order to drive the center of mass on a desired trajectory; while a second controller drives, through the third input, the manipulator's orientation to track a desired orientation. Formal stability proofs are provided that guarantee asymptotic trajectory tracking. Finally, the proposed control strategy is experimentally tested and validated.

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Akyürek, Emre. "Remote-controlled ambidextrous robot hand actuated by pneumatic muscles : from feasibility study to design and control algorithms." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/11671.

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This thesis relates to the development of the Ambidextrous Robot Hand engineered in Brunel University. Assigned to a robotic hand, the ambidextrous feature means that two different behaviours are accessible from a single robot hand, because of its fingers architecture which permits them to bend in both ways. On one hand, the robotic device can therefore behave as a right hand whereas, on another hand, it can behave as a left hand. The main contribution of this project is its ambidextrous feature, totally unique in robotics area. Moreover, the Ambidextrous Robot Hand is actuated by pneumatic artificial muscles (PAMs), which are not commonly used to drive robot hands. The type of the actuators consequently adds more originality to the project. The primary challenge is to reach an ambidextrous behaviour using PAMs designed to actuate non-ambidextrous robot hands. Thus, a feasibility study is carried out for this purpose. Investigating a number of mechanical possibilities, an ambidextrous design is reached with features almost identical for its right and left sides. A testbench is thereafter designed to investigate this possibility even further to design ambidextrous fingers using 3D printing and an asymmetrical tendons routing engineered to reduce the number of actuators. The Ambidextrous Robot Hand is connected to a remote control interface accessible from its website, which provides video streaming as feedback, to be eventually used as an online rehabilitation device. The secondary main challenge is to implement control algorithms on a robot hand with a range twice larger than others, with an asymmetrical tendons routing and actuated by nonlinear actuators. A number of control algorithms are therefore investigated to interact with the angular displacement of the fingers and the grasping abilities of the hand. Several solutions are found out, notably the implementations of a phasing plane switch control and a sliding-mode control, both specific to the architecture of the Ambidextrous Robot Hand. The implementation of these two algorithms on a robotic hand actuated by PAMs is almost as innovative as the ambidextrous design of the mechanical structure itself.

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Beren, Eric B. "Methods for optimization based fixed-order control design /." Online version, 1997. http://bibpurl.oclc.org/web/29659.

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Grace, A. C. W. "Computer-aided control system design using optimization methods." Thesis, Bangor University, 1989. https://research.bangor.ac.uk/portal/en/theses/computeraided-control-system-design-using-optimization-methods(077b2955-3ca3-4c71-99d8-003098f9c378).html.

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Control System Design methods are presented in terms of optimization techniques that incorporate Multi-Objective design criteria. Computer-Aided Control System Design (CACSD) environments make the approach easy-to-use and accessible to the practising control engineer. Two CACSD environments have been developed using different versions of the MATLAB package, one interfacing the ADS optimization package to an upgraded FORTRAN version of MATLAB, the other using Non-linear Programming algorithms coded in the PRO-MATLAB command language. In both environments, optimization problems are entered interactively and in a flexible manner using simple interpreted commands and programs. A Control System Design method has been implemented using optimal control theory and integral quadratic measures of control. The theory has been developed to incorporate a large number of design options, control structures and disturbance types. An evolutionary design process is used so that the control order and number of design criteria are systematically increased to incorporate more complex control structures and a wide set of performance objectives. In the later stages of this evolutionary design process, a Multi-Objective design strategy, known as the Goal Attainment method, is used to address multiple performance objectives.

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Benouarets, Mourad. "Some design methods for linear and nonlinear controllers." Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333454.

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BACCOLI, ANTONELLO. "Boundary control and observation of coupled parabolic PDEs." Doctoral thesis, Università degli Studi di Cagliari, 2016. http://hdl.handle.net/11584/266880.

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Reaction-diffusion equations are parabolic Partial Differential Equations (PDEs) which often occur in practice, e.g., to model the concentration of one or more substances, distributed in space, under the in uence of different phenomena such as local chemical reactions, in which the substances are transformed into each other, and diffusion, which causes the substances to spread out over a surface in space. Certainly, reaction-diffusion PDEs are not confined to chemical applications but they also describe dynamical processes of non-chemical nature, with examples being found in thermodynamics, biology, geology, physics, ecology, etc. Problems such as parabolic Partial Differential Equations (PDEs) and many others require the user to have a considerable background in PDEs and functional analysis before one can study the control design methods for these systems, particularly boundary control design. Control and observation of coupled parabolic PDEs comes in roughly two settingsdepending on where the actuators and sensors are located \in domain" control, where the actuation penetrates inside the domain of the PDE system or is evenly distributed everywhere in the domain and \boundary" control, where the actuation and sensing are applied only through the boundary conditions. Boundary control is generally considered to be physically more realistic because actuation and sensing are nonintrusive but is also generally considered to be the harder problem, because the \input operator" and the "output operator" are unbounded operators. The method that this thesis develops for control of PDEs is the so-called backstepping control method. Backstepping is a particular approach to stabilization of dynamic systems and is particularly successful in the area of nonlinear control. The backstepping method achieves Lyapunov stabilization, which is often achieved by collectively shifting all the eigenvalues in a favorable direction in the complex plane, rather than by assigning individual eigenvalues. As the reader will soon learn, this task can be achieved in a rather elegant way, where the control gains are easy to compute symbolically, numerically, and in some cases even explicitly. In addition to presenting the methods for boundary control design, we present the dual methods for observer design using boundary sensing. Virtually every one of our control designs for full state stabilization has an observer counterpart. The observer gains are easy to compute symbolically or even explicitly in some cases. They are designed in such a way that the observer error system is exponentially stabilized. As in the case of finite-dimensional observer-based control, a separation principle holds in the sense that a closed-loop system remains stable after a full state stabilizing feedback is replaced by a feedback that employs the observer state instead of the plant state.

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Tanasa, Valentin. "Development of theoretical and computational tools for the design of control strategies for nonlinear sampled-data systems." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00763971.

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This thesis is concerned with the sampled-data control of non-linear continuous-time systems. Sampled-data systems are present in all computer controlled, hybrid or embedded systems. The design and computation of suitable digital controllers represent unavoidable tasks since both continuous and discrete-time components interact. The basic framework of this work takes part of a wide research activity performed by S. Monaco and D. Normand-Cyrot regarding non-linear sampled-data systems. The underlying idea is to design digital controllers that recover certain continuous-time properties that are usually degraded through sampling as it is the case when continuous-time controllers are implemented by means of zero-order holder devices (emulated control). This thesis brings contributions into three different directions. The first one regards theoretical developments: a new digital backstepping-like strategy design for strict-feedback systems is proposed. This method is compared with other strategies proposed in the literature. The second contribution is the development of a control designer and of a simulation toolbox (in Matlab) for non-linear sampled-data systems. This toolbox includes different digital design strategies such as: multi-rate control, input-output/Lyapunov matching, digital backstepping design, etc. The third contribution concerns several case studies conducted to highlight the performances of the sampled-data controller designs, computed by the means of the software toolbox. Experimental and simulation results are described for various real examples especially in the area of electrical and mechanical processes.

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Swift, Stuart John. "Applicability of hybrid methods in engine control system design." Thesis, University of Cambridge, 2009. https://www.repository.cam.ac.uk/handle/1810/265493.

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The new control techniques of off-line model predictive control and level set methods have been applied to the challenges of engine management for diesel exhaust aftertreatment. Theoretical work has been supported by experiments carried out in a diesel engine test cell. A control relevant air-path model was developed using experimental work carried out on a diesel engine and dynamometer, with the aim of improving the engine control during the transients required by aftertreatment devices. This was considered as a two input and two output system, using an intake throttle and a valve associated with the exhaust gas recirculation system to control the in-cylinder quantities of fresh air and exhaust gas. Model predictive control techniques were used to design a hybrid controller, which was compared to a traditional proportional and integral controller and a 1-{00 controller in simulation. Level set methods were used to analyse supervisory hybrid control of a lean NOx trap model. In this system periodic mode changes are required to purge the NOx trapped on the filter and convert it to less harmful products. A novel diesel particulate filter model suitable for control was developed to represent the thermal wave behaviour observed in worst-case regenerations, where the soot in the filter burns to create local high temperature regions. A DPF was instrumented and fitted to the diesel engine and tested in the development of this model, particularly focusing upon these worst-case conditions. This new theoretical model was analysed using level set methods in a comparison with a simple control oriented DPF model. A supervisory hybrid control strategy to determine when to take emergency action to avoid thermal damage to the filter was designed using the simple DPF model. This strategy used safe conditions verified from the experimental work undertaken.

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Nanka-Bruce, Oona. "Some computer aided design methods for nonlinear control systems." Thesis, University of Sussex, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252934.

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Zeng, Sheng. "Robust Adaptive Control Design for Classes of SISO and MIMO Linear Systems Under Noisy Output Measurements." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1172767648.

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Ritchie, Paul Andrew 1960. "A systematic, experimental methodology for design optimization." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276698.

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Much attention has been directed at off-line quality control techniques in recent literature. This study is a refinement of and an enhancement to one technique, the Taguchi Method, for determining the optimum setting of design parameters in a product or process. In place of the signal-to-noise ratio, the mean square error (MSE) for each quality characteristic of interest is used. Polynomial models describing mean response and variance are fit to the observed data using statistical methods. The settings for the design parameters are determined by minimizing a statistical model. The model uses a multicriterion objective consisting of the MSE for each quality characteristic of interest. Minimum bias central composite designs are used during the data collection step to determine the settings of the parameters where observations are to be taken. Included is the development of minimum bias designs for various cases. A detailed example is given.

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McCaskey, Suzanne D. "Robust design of dynamic systems." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/24223.

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Bolognani, Saverio. "Methods and applications in networked control and Feedback control design for quantum systems." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3422000.

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Two quite different topics are covered in the thesis. Methods and Applications in Networked Control The first topic is networked control, identification, and optimization, with particular interest in the design of individual control laws for multi-agent networked systems. These systems consist in a large, sometimes unknown and time-varying, number of agents. These agents can communicate, they interact with an underlying physical system by sensing and actuating it, and none of them has a complete knowledge of the system state and parameters. The main challenges in designing control, identification, and optimization algorithms for these systems are the need for scalability, the constraints in the communication capabilities of the agents, the need for robustness in case of agent failure, and the adaptivity to changes in the system (node appearance and disappearance, communication failures, change in the agents' placement, etc.). Some mathematical tools and methods from the literature are reviewed, and their application to the problem of networked control are explored. A series of original mathematical methods and algorithms have then be derived: - analysis results on the stability and scalability of consensus algorithms for unstable dynamics; - distributed parametric identification via least-square estimation; - distributed quasi-Newton methods for convex optimization; - randomized iterative methods for quadratic, linearly constrained optimization. These methods are presented via their application to some motivating examples of networked control systems. All of them are also of great interest per se, and can be considered challenging open problems in the field of networked control. They are the following: - leaderless, distributed, clock synchronization in networks of agents with extremely limited computational, communication, and energy resources; - distributed, online estimation of the wireless channel parameters for localization of mobile nodes via triangulation; - management architectures and distributed networked control laws for reactive power compensation (and other ancillary services) in the so called smart grids, with a particular focus on microgrids at the power distribution level. These open problems will be explored both as a motivating testbed for the proposed methods and as an outlook for future directions of investigation. Feedback Control Design for Quantum Systems The second topic is the problem of control of quantum dynamical systems, via the design of stabilizing feedback control law when quantum measurements are available. Discrete time models for quantum dynamics are reviewed, with a particular attention to those control problems that are typical key tasks in quantum information processing: - preparation of states of maximal information; - engineering of protected realization of quantum information, i.e. the realization of information encodings that preserve the fragile quantum states from the action of noise. These tasks can be casted into the more general problem of engineering stable quantum dynamical subspaces. In this part of the thesis the asymptotic behavior of discrete-time, Markovian quantum systems with respect to a subspace of interest, is analyzed. The results of this analysis, based on a Ljapunov approach, provide necessary and sufficient conditions on the dynamical model that ensure global asymptotic stability of a certain quantum subspace. It is then introduced a control scheme that allows modifying the underlying dynamics by indirectly measuring it and by applying unitary control actions conditioned on the outcome of the measurement. For this discrete-time feedback control scheme, an original design algorithm capable of stabilizing a target subspace is introduced. It is guaranteed that if the control problem is feasible, then the algorithm returns an effective control choice. In order to prove this result, a new technical tool is derived, namely a canonical QR matrix decomposition, which is also used to establish the control scheme potential for the simulation of open-system dynamics.
Nella tesi vengono trattati due argomenti distinti. Metodi e applicazioni nel controllo distribuito Il primo argomento trattato riguarda il controllo, l'identificazione e l'ottimizzazione distribuiti (networked), con particolare interesse per la progettazione di leggi di controllo per sistemi multiagenti distribuiti. Questi sistemi consistono di un numero di agenti elevato, talvolta sconosciuto e variabile nel tempo. Questi agenti sono in grado di comunicare, di interagire con il sistema fisico nel quale si trovano tramite operazioni di misura e attuazione, e nessuno di essi ha una conoscenza completa dello stato e dei parametri del sistema. Le sfide maggiori per la progettazione di algoritmi di controllo, identificazione e ottimizzazione per questi sistemi sono i requisiti di scalabilità, vincoli nelle comunicazioni tra gli agenti, i requisiti di robustezza nei confronti di guasti degli agenti, e la capacità di adattarsi a modifiche del sistema (apparizione e scomparsa di nodi, errori di comunicazione, spostamento e riconfigurazione degli agenti, ecc.). Sono stati riportati alcuni strumenti e metodi matematici disponibili in letteratura, illustrando la loro applicazione al problema del controllo distribuito. E` stata poi ricavata un serie di metodi e algoritmi originali: - risultati sull'analisi di stabilità e di scalabilità degli algoritmi di consenso per sistemi dinamici instabili; - identificazione parametrica distribuita tramite stima ai minimi quadrati; - metodi quasi-Newton distribuiti per problemi di ottimizzazione convessa; - metodi iterativi randomizzati per l'ottimizzazione quadratica con vincoli lineari. Questi metodi vengono presentati illustrandone l'applicazione ad alcuni esempi di sistemi di controllo distribuiti. Questi esempi di applicazione sono interessanti di per sè, in quando possono essere considerati problemi tuttora aperti nel campo del controllo distribuito. Essi sono: - sincronizzazione temporale completamente decentralizzata in reti di agenti dotati di limitate capacit\`a di calcolo, comunicazione e autonomia; - stima online distribuita dei parametri del canale di comunicazione wireless per la localizzazione di nodi mobili tramite triangolazione; - architetture e leggi di controllo distribuite per la compensazione della potenza reattiva nelle smart grids, ed in particolare nelle micro-reti di distribuzione. Queste applicazioni vengono illustrati sia come banchi di prova per i metodi proposti, sia come possibili futuri sviluppi della ricerca in questo campo. Controllo a retroazione per sistemi quantistici Il secondo argomento riguarda il problema del controllo di sistemi dinamici quantistici tramite la progettazione di leggi di retroazione stabilizzanti, in presenza di misure quantistiche. Innanzitutto vengono richiamati modelli a tempo discreto per sistemi quantistici, con particolare interesse per i problemi del controllo quantistico che sono di maggiore rilevanza per la teoria dell'informazione quantistica: - preparazione di stati di massima informazione; - protezione dell'informazione quantistica, ovvero realizzazione di codifiche dell'informazione che preservino gli stati quantistici dall'azione del rumore. Questi compiti possono essere interpretati all'interno del problema più ampio di stabilizzazione di sottospazi nei sistemi quantistici. In questa parte della tesi viene analizzato il comportamento asintotico di sistemi quantistici Markoviani a tempo discreto rispetto ad un sottospazio di interesse. Il risultato di questa analisi, basato su un approccio alla Ljapunov, fornisce condizioni necessarie e sufficienti sul modello dinamico per garantire la stabilità asintotica di un certo sottospazio. Viene poi introdotto uno schema di controllo che permette di modificare la dinamica del sistema tramite misure indirette e tramite l'applicazione di azioni di controllo coerenti, condizionate dal risultato della misura. Viene proposto un algoritmo originale per la progettazione della legge di controllo capace di stabilizzare un dato sottospazio. E` garantito che, se il problema di controllo ha soluzione, allora l'algoritmo fornisce una legge di controllo stabilizzante. Per dimostrare questi risultati è stato necessario definire un nuovo strumento: una decomposizione QR canonica, che viene anche utilizzata per studiare le potenzialità dello schema di controllo per la simulazione di dinamiche diverse da quelle del sistema.

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Stefanidis, Peter. "Pole-placement design of multivariable control systems using algebraic methods /." Title page, abstract and contents only, 1989. http://web4.library.adelaide.edu.au/theses/09ENS/09enss816.pdf.

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MacKenzie, Ian (Ross Ian). "Design and control methods for high-accuracy variable reluctance actuators." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100138.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 421-427).
This thesis presents the design and control techniques of a variable reluctance actuator for driving a reticle motion stage in photolithography scanners. The primary thesis contributions include the design and experimental demonstration of a magnetic flux controller that uses a sense coil measurement, the design and experimental demonstration of a novel method to estimate actuator hysteresis in real-time, and the development of an actuator model that incorporates the effects of eddy currents. The reticle stage in a scanning lithography machine requires high accelerations combined with sub-nanometer position accuracy. Reluctance actuators are capable of providing high force densities (force per moving mass) and lower power values relative to the present state-of-the-art Lorentz actuators that are used to drive the reticle stage. However, reluctance actuators are highly nonlinear with both current and air gap. They also display other nonlinear behavior from hysteresis and eddy currents. Linearizing the reluctance actuator is required for the high force accuracy required in the scanning stage. In this thesis, we present a way to linearize the reluctance actuator with flux control using a sense coil as the feedback measurement. Because the sense coil is AC-coupled, we design a low-frequency estimate of the magnetic flux based upon the actuator current and air gap measurements. We combine the low-frequency estimate with the sense coil measurement using a complementary filter pair that provides an estimate of the flux from DC to frequencies of several kHz. For the low-frequency estimate, we develop a novel method for estimating the actuator hysteresis in realtime. For this flux estimator, we use an observer to model the actuator flux which treats the changing air gap as a disturbance to the plant model. The use of an observer allows the identification of a single-variable hysteresis model of actuator current rather than a two-variable hysteresis model of current and air gap. We also introduce a novel way for expressing the actuator hysteresis, whereby we incorporate the linearizing effect of the air gap directly into a Preisach hysteresis model via a change of variables. We demonstrate experimentally that this method is numerically stable in the presence of a dynamically changing gap, in contrast to some alternative methods. We designed and built a reluctance actuator prototype and 1-DoF motion testbed to demonstrate the accuracy of the actuator models and control techniques. We experimentally demonstrated that we can achieve a flux control bandwidth of 4 kHz that is capable of reducing the stiffness of the reluctance actuator to less than 0.012 N/[mu]m for frequencies up to 100 Hz. This results in a force error of less than 0.03% of the full-scale force for a 10 [mu]m air gap disturbance at this frequency. We also demonstrate that the actuator hysteresis model is capable of estimating the actuator flux accurately in the presence of dynamic gap disturbances of at least 35 1m peak-to-peak and with a static offset from the nominal air gap of at least 50 [mu]m.
by Ian MacKenzie.
Ph. D.

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Colton, Shane W. (Shane William). "Design and prototyping methods for brushless motors and motor control." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61599.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.
"June 2010." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 109).
In this report, simple, low-cost design and prototyping methods for custom brushless permanent magnet synchronous motors are explored. Three case-study motors are used to develop, illustrate and validate the methods. Two 500W hub motors are implemented in a direct-drive electric scooter. The third case study, a 10kW axial flux motor, is used to demonstrate the flexibility of the design methods. A variety of ways to predict the motor constant, which relates torque to current and speed to voltage, are presented. The predictions range from first-order DC estimates to full dynamic simulations, yielding increasingly accurate results. Ways to predict winding resistance, as well as other sources of loss in motors, are discussed in the context of the motor's overall power rating. Rapid prototyping methods for brushless motors prove to be useful in the fabrication of the case study motors. Simple no-load evaluation techniques confirm the predicted motor constants without large, expensive test equipment. Methods for brushless motor controller design and prototyping are also presented. The case study, a two channel, 1kW per channel brushless motor controller, is fully developed and used to illustrate these methods. The electrical requirements of the controller (voltage, current, frequency) influence the selection of components, such as power transistors and bus capacitors. Mechanical requirements, such as overall dimensions, heat transfer, and vibration tolerance, also play a large role in the design. With full-system prototyping in mind, the controller integrates wireless data acquisition for debugging. Field-oriented AC control is implemented on low-cost hardware using a novel modification of the standard synchronous current regulator. The controller performance is evaluated under load on two case study systems: On the direct-drive electric scooter, it simultaneously and independently controls the two motors. On a high-performance remote-control car, a more extreme operating point is tested with one motor.
by Shane W. Colton.
S.M.

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Malekpoor, Somayeh. "Optimization methods for deadbeat control design : a state space approach." Thesis, City University London, 2016. http://openaccess.city.ac.uk/14396/.

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This thesis addresses the synthesis problem of state deadbeat regulator using state space techniques. Deadbeat control is a linear control strategy in discrete time systems and consists of driving the system from any arbitrary initial state to a desired final state infinite number of time steps. Having described the framework for development of the thesis which is in the form of a lower linear-fractional transformation (LFT), the conditions for internal stability based on the notion of coprime factorization over the set of proper and stable transfer matrices, namely RH, is discussed. This leads to the derivation of the class of all stabilizing linear controllers, which are parameterized affinely in terms of a stable but otherwise free parameter Q, usually known as the Q-parameterization. In this work, the classical Q- parameterization is generalized to deliver a parameterization for the family of deadbeat regulators. Time response characteristics of the deadbeat system are investigated. In particular, the deadbeat regulator design problem in which the system must satisfy time domain specifications and minimize a quadratic (LQG-type) performance criterion is examined. It is shown that the attained parameterization for deadbeat controllers leads to the formulation of the synthesis problem in a quadratic programming framework with Q regarded as the design variable. The equivalent formulation of this objective as a quadratic integral in the frequency domain provides the means for shaping the frequency response characteristics of the system. Using the LMI characterization of the standard H problem, a new scheme for shaping the system frequency response characteristics by minimizing the infinity norm of an appropriate closed-loop transfer function is introduced. As shown, the derived parameterization of deadbeat compensators simplifies considerably the formulation and solution of this problem. The last part of the work described in this thesis is devoted to addressing the synthesis problem of deadbeat regulators in a robust way, when the plant is subject to structured norm-bounded parametric uncertainties. A novel approach which is expressed as an LMI feasibility condition has been proposed and analysed.

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Shafiei, Ziaedin. "Design and analysis of robust control systems by frequency response methods." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317391.

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Savarese, Paul Tenzing. "New design comparison criteria in Taguchi's robust parameter design." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-171200/.

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McNamara, O. P. "Computer-aided design of nonlinear control systems using describing function based methods." Thesis, University of Sussex, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375843.

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Hartley, Gerald A. "F-18 robust control design using H2 and H-infinity methods." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA242562.

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Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990.
Thesis Advisor(s): Collins, Daniel J. Second Reader: Schmidt, Louis V. "September 1990." Description based on title screen as viewed on December 29, 2009. DTIC Identifier(s): Flight control systems, control theory, computer files, theses, input output processing, F-18 aircraft. Author(s) subject terms: Modern control theory, H infinity control theory, H2 control theory, multivariable robustness, F-18 control design or synthesis, super augmented aircraft. Includes bibliographical references (p. 110). Also available in print.

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Anthony, David Keith. "Robust optimal design using passive and active methods of vibration control." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312863.

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Zhao, Qingrong. "Reduced-Order Robust Adaptive Controller Design and Convergence Analysis for Uncertain SISO Linear Systems with Noisy Output Measurements." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1194564628.

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Davidson, Timothy Norman. "Low-order stabilization : advances in indirect, fixed-order and fixed-structure methods." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240555.

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Bae, Suk Joo. "Analysis of dynamic robust design experiment and modeling approach for degradation testing." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04052004-180010/unrestricted/bae%5Fsuk%5Fj%5F2003%5Fphd.pdf.

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Wang, Zhongli. "New methods for the direct digital control of discrete-time systems." Thesis, Lancaster University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383582.

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Olsson, Markus. "Simulation Comparison of Auto-Tuning Methods for PID Control." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11106.

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Auto-tuning has become an important function in distributed control systems (DCS) and is especially appreciated in large industries that can have hundreds of controllers. In the DCS 800xA manufactured by ABB, there is an auto-tuning method implemented based on a relay experiment to determine the ultimate gain and the ultimate period, with which the PID parameters are obtained using the modified Ziegler-Nichols tuning rules. The tuning procedure can then proceed with a step identification experiment to get additional parameters for kappa-tau tuning. In the previous DCS, called Advant, there was another auto-tuning approach implemented. This method was based on dominant pole design, which included an identification of the process. The purpose of this thesis is to compare these auto-tuning methods, to investigate if the dominant pole placement method should be migrated to the 800xA system.

Automatisk trimning har blivit en viktig funktion i distribuerade styrsystem (DCS och är speciellt av intresse för stora industrier som kan ha ﬂera hundra regulatorer. Den automatiska trimningen som idag är implementerad i ABB:s DCS 800xA är baserad på ett reläexperiment för att bestämma den ultimata förstärkningen och den ultimata periodtiden. Modiﬁerade Ziegler-Nichols trimningsregler används sedan för att bestämma PID parametrarna. Vidare kan trimningen fortsätta med ett stegsvars-experiment för att erhålla ytterliggare parametrar och trimma med kappa-tau metoden. Den automatiska trimningsmetoden som var implementerad i tidigare DCS, Advant, var baserad på dominant polplacering med identiﬁering av processen. Syftet med detta examensarbete är att jämföra dessa automatiska trimningsmetoder för att undersöka om den tidigare trimningsmetoden baserad på dominant polplacering ska implementeras i 800xA systemet.

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Xie, Changwen. "Methods, tools and components paradigms for the design and buidling of distributed machine control systems." Thesis, De Montfort University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391700.

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Cheraghi, Seyed Hossein 1957. "MULTIPLE CHOICE MODULAR DESIGN PROBLEM EXPERIMENTAL RESULTS AND SENSITIVITY ANALYSIS." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276429.

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Favuzzi, Pedro Antonio. "Ab-initio design methods for selective and efficient optomechanical control of nanophotonic structures." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/185207.

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Hasan, Basri Mundzir. "Two new methods for optimal design of subsurface barrier to control seawater intrusion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ62638.pdf.

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Kimera, Sharadhuli I. "Methods for the design and evaluation of East Coast fever (ECF) control strategies." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242338.

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Mu, Junxia. "Design and application of advanced control methods to gas turbines and networked systems." Thesis, University of South Wales, 2005. https://pure.southwales.ac.uk/en/studentthesis/design-and-application-of-advanced-control-methods-to-gas-turbines-and-networked-systems(c6311aed-db75-415a-8b2a-f1594479f685).html.

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This thesis deals with the design and application of modern control techniques to a Rolls Royce aircraft gas turbine engine and networked systems. It is motivated by the need to fully exploit recent advances in control engineering and investigate the suitability of various control methods to gas turbine engines and networked systems. The main contributions of the first part of the thesis relate to the gas turbine engine control. Due to the nonlinearities of the gas turbine engines, the rate limiter and saturation constraints on the fuel feed, the aim is to illustrate the potential of a global nonlinear controller to cover the engine operating range. Several nonlinear control methods, gain-scheduling PID controller, approximate model predictive control (AMPC) and nonlinear model predictive control (NMPC), are presented along with the corresponding control algorithms. Since the parameters in a gain-scheduling PID controller change with the operating range, the need is apparent for a global nonlinear controller to cover its operating range. AMPC and NMPC are then demonstrated to be capable of providing a global nonlinear controller for the engine and can be used in the place of the gain scheduling PID controller. It is shown that AMPC is more preferable than NMPC if computational time is at a premium. The main theme of the second part of the thesis is the design and application of the networked predictive control (NPC) to compensate for the network delay and data packet dropout in both forward and backward channels for networked systems. NPC using both modified model predictive control and generic polynomial method is presented along with the corresponding control algorithms. For both approaches, the system stability for a fixed network delay is presented and an analytical stability criterion is obtained. This provides some guidelines on how to choose the NPC parameters in the case of random network delay. The performance of NPC can be further improved by using a robust NPC (RNPC). To validate the performance using the proposed control methods, a servo motor system is then used for both Intranet and Internet based simulations and practical experiments. A networked control test rig along with the network delay measurement method is used for real-time implementation. It is shown that both NPC and RNPC can efficiently compensate for the network delay and data packet dropout in both channels. This thesis provides basis for the real-time implementation of advanced control methods in gas turbine engines. While this work was applied to a gas turbine engine, these techniques can be applied to a range of nonlinear control systems. The work on the networked predictive control presented in this thesis can provide basis for further research relating to this area.

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Tachmazidou, Ioanna. "Bayesian statistical methods for genetic association studies with case-control and cohort design." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4398.

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Large-scale genetic association studies are carried out with the hope of discovering single nucleotide polymorphisms involved in the etiology of complex diseases. We propose a coalescent-based model for association mapping which potentially increases the power to detect disease-susceptibility variants in genetic association studies with case-control and cohort design. The approach uses Bayesian partition modelling to cluster haplotypes with similar disease risks by exploiting evolutionary information. We focus on candidate gene regions and we split the chromosomal region of interest into sub-regions or windows of high linkage disequilibrium (LD) therein assuming a perfect phylogeny. The haplotype space is then partitioned into disjoint clusters within which the phenotype-haplotype association is assumed to be the same. The novelty of our approach consists in the fact that the distance used for clustering haplotypes has an evolutionary interpretation, as haplotypes are clustered according to the time to their most recent common mutation. Our approach is fully Bayesian and we develop Markov Chain Monte Carlo algorithms to sample efficiently over the space of possible partitions. We have also developed a Bayesian survival regression model for high-dimension and small sample size settings. We provide a Bayesian variable selection procedure and shrinkage tool by imposing shrinkage priors on the regression coefficients. We have developed a computationally efficient optimization algorithm to explore the posterior surface and find the maximum a posteriori estimates of the regression coefficients. We compare the performance of the proposed methods in simulation studies and using real datasets to both single-marker analyses and recently proposed multi-marker methods and show that our methods perform similarly in localizing the causal allele while yielding lower false positive rates. Moreover, our methods offer computational advantages over other multi-marker approaches.

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Wells, Scott R. "Application of sliding mode methods to the design of reconfigurable flight control systems /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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Rauh, Andreas [Verfasser]. "Sensitivity Methods for Analysis and Design of Dynamic Systems with Applications in Control Engineering : Feedforward Control – Feedback Control – Robust Control – State Estimation / Andreas Rauh." Aachen : Shaker, 2017. http://d-nb.info/1149278722/34.

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Cuevas, Salcido Alvaro. "Using the Taguchi design and central composite design to increase the robustness of a process from its raw material variability." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

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Grayson, James M. (James Morris). "Economic Statistical Design of Inverse Gaussian Distribution Control Charts." Thesis, University of North Texas, 1990. https://digital.library.unt.edu/ark:/67531/metadc332397/.

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Statistical quality control (SQC) is one technique companies are using in the development of a Total Quality Management (TQM) culture. Shewhart control charts, a widely used SQC tool, rely on an underlying normal distribution of the data. Often data are skewed. The inverse Gaussian distribution is a probability distribution that is wellsuited to handling skewed data. This analysis develops models and a set of tools usable by practitioners for the constrained economic statistical design of control charts for inverse Gaussian distribution process centrality and process dispersion. The use of this methodology is illustrated by the design of an x-bar chart and a V chart for an inverse Gaussian distributed process.

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Johansson, M. Annette. "Immunosensor methods for drug residue control of food : assay design and sample matrix effects /." Uppsala : Dept. of Microbiology, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a457.pdf.

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Unnikrishnan, Suraj. "Adaptive Envelope Protection Methods for Aircraft." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11478.

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Carefree handling refers to the ability of a pilot to operate an aircraft without the need to continuously monitor aircraft operating limits. At the heart of all carefree handling or maneuvering systems, also referred to as envelope protection systems, are algorithms and methods for predicting future limit violations. Recently, envelope protection methods that have gained more acceptance, translate limit proximity information to its equivalent in the control channel. Envelope protection algorithms either use very small prediction horizon or are static methods with no capability to adapt to changes in system configurations. Adaptive approaches maximizing prediction horizon such as dynamic trim, are only applicable to steady-state-response critical limit parameters. In this thesis, a new adaptive envelope protection method is developed that is applicable to steady-state and transient response critical limit parameters. The approach is based upon devising the most aggressive optimal control profile to the limit boundary and using it to compute control limits. Pilot-in-the-loop evaluations of the proposed approach are conducted at the Georgia Tech Carefree Maneuver lab for transient longitudinal hub moment limit protection. Carefree maneuvering is the dual of carefree handling in the realm of autonomous Uninhabited Aerial Vehicles (UAVs). Designing a flight control system to fully and effectively utilize the operational flight envelope is very difficult. With the increasing role and demands for extreme maneuverability there is a need for developing envelope protection methods for autonomous UAVs. In this thesis, a full-authority automatic envelope protection method is proposed for limit protection in UAVs. The approach uses adaptive estimate of limit parameter dynamics and finite-time horizon predictions to detect impending limit boundary violations. Limit violations are prevented by treating the limit boundary as an obstacle and by correcting nominal control/command inputs to track a limit parameter safe-response profile near the limit boundary. The method is evaluated using software-in-the-loop and flight evaluations on the Georgia Tech unmanned rotorcraft platform- GTMax. The thesis also develops and evaluates an extension for calculating control margins based on restricting limit parameter response aggressiveness near the limit boundary.

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Frazier, William Garth. "Search-based methods for computer-aided controller design improvement." Ohio : Ohio University, 1993. http://www.ohiolink.edu/etd/view.cgi?ohiou1173760387.

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Taylor, Jonathan. "Robust Bode Methods for Feedback Controller Design of Uncertain Systems." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/447.

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In this work, we introduce several novel approaches to feedback controller design, known collectively as the “Robust Bode” methods, which adapt classical control principles to a modern robust control (H∞) framework. These methods, based on specially modified Bode diagrams extend familiar frequency-domain controller design techniques to linear and nonlinear, single–input/single– output (SISO) and multi–input/multi–output (MIMO) systems with parametric and/or unstructured uncertainties. In particular, we introduce the Contoured Robust Controller Bode (CRCBode) plots which show contours (level-sets) of a robust metric on the Bode magnitude and phase plots of the controller. An iterative loop shaping design procedure is then employed in an attempt to eliminate all intersections of the controller frequency response with certain forbidden regions indicating that a robust stability and performance criteria is satisfied. For SISO systems a robust stability and performance criterion is derived using Nyquist arguments leading to the robust metric used in the construction of the CRCBode plots. For open-loop unstable systems and for non-minimum phase systems the Youla parametrization of all internally stabilizing controllers is used to develop an alternative Robust Bode method (QBode). The Youla parametrization requires the introduction of state-space methods for coprime factorization, and these methods lead naturally to an elegant connection between linear-quadratic Gaussian (LQG) optimal control theory and Robust Bode loop-shaping controller design. Finally, the Robust Bode approach is extended to MIMO systems. Utilizing a matrix norm based robustness metric on the MIMO CRCBode plots allows cross-coupling between all input/output channels to be immediately assessed and accounted for during the design process, making sequential MIMO loop-shaping controller design feasible.

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Lin, Yao. "Robust design goal formulations and metamodeling techniques." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15908.

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Gallo, Andrea <1993&gt. "Advanced decision-support methods for the design, control, and optimization of perishable products life cycle." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9595/1/gallo_andrea_tesi.pdf.

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In the last decades, global food supply chains had to deal with the increasing awareness of the stakeholders and consumers about safety, quality, and sustainability. In order to address these new challenges for food supply chain systems, an integrated approach to design, control, and optimize product life cycle is required. Therefore, it is essential to introduce new models, methods, and decision-support platforms tailored to perishable products. This thesis aims to provide novel practice-ready decision-support models and methods to optimize the logistics of food items with an integrated and interdisciplinary approach. It proposes a comprehensive review of the main peculiarities of perishable products and the environmental stresses accelerating their quality decay. Then, it focuses on top-down strategies to optimize the supply chain system from the strategical to the operational decision level. Based on the criticality of the environmental conditions, the dissertation evaluates the main long-term logistics investment strategies to preserve products quality. Several models and methods are proposed to optimize the logistics decisions to enhance the sustainability of the supply chain system while guaranteeing adequate food preservation. The models and methods proposed in this dissertation promote a climate-driven approach integrating climate conditions and their consequences on the quality decay of products in innovative models supporting the logistics decisions. Given the uncertain nature of the environmental stresses affecting the product life cycle, an original stochastic model and solving method are proposed to support practitioners in controlling and optimizing the supply chain systems when facing uncertain scenarios. The application of the proposed decision-support methods to real case studies proved their effectiveness in increasing the sustainability of the perishable product life cycle. The dissertation also presents an industry application of a global food supply chain system, further demonstrating how the proposed models and tools can be integrated to provide significant savings and sustainability improvements.

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Dissertations / Theses on the topic 'Backstepping methods in control design'

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