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1
Ding, Xu Chu. "Real-time optimal control of autonomous switched systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31725.
Повний текст джерелаАнотація:
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.Committee Chair: Egerstedt, Magnus; Committee Co-Chair: Wardi, Yorai; Committee Member: Riley, George; Committee Member: Taylor, David; Committee Member: Tovey, Craig; Committee Member: Yezzi, Anthony. Part of the SMARTech Electronic Thesis and Dissertation Collection.
2
Hornung, Thomas. "Optimal control with ultrashort laser pulses." Diss., lmu, 2002. http://nbn-resolving.de/urn:nbn:de:bvb:19-2963.
Повний текст джерела
3
Hunt, K. J. "Stochastic optimal control theory with application in self-tuning control." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382399.
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4
Tsai, Mi-Ching. "Super-optimal control system design for multivariable plants." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238170.
Повний текст джерела
5
Barth, Eric J. "Approximating infinite horizon discrete-time optimal control using CMAC networks." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/19464.
Повний текст джерела
6
Liu, Ying. "An integrated optimal control system for emergency evacuation." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7018.
Повний текст джерелаАнотація:
Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Civil Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
7
Hemasilpin, Nat. "Toward Optimal Adaptive Control of Hemodialysis." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378112378.
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8
Wang, Kon-King. "Complete synthesis of optimal control (single input linear systems)." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1057165454.
Повний текст джерела
9
de, Azevedo Ricardo. "Fully Decentralized Multi-Agent System for Optimal Microgrid Control." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2461.
Повний текст джерелаАнотація:
In preparation for the influx of renewable energy sources that will be added to the electrical system, flexible and adaptable control schemes are necessary to accommodate the changing infrastructure. Microgrids have been gaining much attention as the main solution to the challenges of distributed and intermittent generation, but due to their low inertia, they need fast-acting control systems in order to maintain stability. Multi-Agent Systems have been proposed as dynamic control and communication frameworks. Decentralized arrangements of agents can provide resiliency and the much-desired “plug and play” behavior. This thesis describes a control system that implements droop control and the diffusion communication scheme without the need of a centralized controller to coordinate the Microgrid agents to maintain the frequency and stable operating conditions of the system. Moreover, the inter-agent communication is unaffected by changing network configurations and can achieve optimal economic dispatch through distributed optimization.
10
Manzano, Ramos Edgar André. "Optimal control algorithm design for a prototype of active noise control system." Master's thesis, Pontificia Universidad Católica del Perú, 2017. http://tesis.pucp.edu.pe/repositorio/handle/123456789/8499.
Повний текст джерелаАнотація:
High-level noise can represent a serious risk for the health, industrial operations often
represent continuous exposure to noise, thus an important trouble to handle.
An alternative of solution can be the use of passive mechanisms of noise reductions,
nonetheless its application cannot diminish low-frequency noise.
Active Noise Control (ANC) is the solution used for low-frequency noise, ANC systems
work according to the superposition principle generating a secondary anti-noise
signal to reduce both.
Nevertheless, the generation of an anti-noise signal with same oppose characteristics
of the original noise signal presupposes the utilization of special techniques such
as adaptive algorithms. These algorithms involve computational costs.
The present research present the optimization of a specific ANC algorithm in the
step-size criteria. Delayed Filtered-x LMS (FxLMS) algorithm using an optimal
step-size is evaluated in a prototype of ANC system.Tesis
11
Veatch, Michael H., and Lawrence M. Wein. "Optimal Control of Two-Station Tandem Production/Inventory System." Massachusetts Institute of Technology, Operations Research Center, 1992. http://hdl.handle.net/1721.1/5214.
Повний текст джерелаАнотація:
A manufacturing facility consisting of two stations in tandem operates in a maketo-stock mode: after production, items are placed in a finished goods inventory that services an exogenous demand. Demand that cannot be met from inventory is backordered. Each station is modelled as a queue with controllable production rate, and the problem is to control these rates to minimize inventory holding and backordering costs. Optimal controls are computed using dynamic programming and compared with kanban and buffer control mechanisms, popular in manufacturing, and with the base stock mechanism popular in inventory/distribution systems. Conditions are found under which certain simple controls are optimal using stochastic coupling arguments. Insights are gained into when to hold work-in-process and finished goods inventory, comparable to previous studies of production lines in make-to-order and unlimited demand ("push") environments.
12
Mensah, Edoe F. Kwatny Harry G. "Logic-based optimal control for shipboard power system management /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2765.
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13
Spindler, Henry C. (Henry Carlton) 1970. "System identification and optimal control for mixed-mode cooling." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30334.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004."September 2004."
Includes bibliographical references (p. 285-294).
The majority of commercial buildings today are designed to be mechanically cooled. To make the task of air conditioning buildings simpler, and in some cases more energy efficient, windows are sealed shut, eliminating occupants' direct access to fresh air. Implementation of an alternative cooling strategy-mixed-mode cooling-is demonstrated in this thesis to yield substantial savings in cooling energy consumption in many U.S. locations. A mixed-mode cooling strategy is one that relies on several different means of delivering cooling to the occupied space. These different means, or modes, of cooling could include: different forms of natural ventilation through operable windows, ventilation assisted by low-power fans, and mechanical air conditioning. Three significant contributions are presented in this thesis. A flexible system identification framework was developed that is well-suited to accommodate the unique features of mixed-mode buildings. Further, the effectiveness of this framework was demonstrated on an actual multi- zone, mixed-mode building, with model prediction accuracy shown to exceed that published for other naturally ventilated or mixed-mode buildings, none of which exhibited the complexity of this building. Finally, an efficient algorithm was constructed to optimize control strategies over extended planning horizons using a model-based approach. The algorithm minimizes energy consumption subject to the constraint that indoor temperatures satisfy comfort requirements. The system identification framework was applied to another mixed-mode building, where it was found that the aspects integral to the modeling framework led to prediction improvements relative to a simple model.
(cont.) Lack of data regarding building apertures precluded the use of the model for control purposes. An additional contribution was the development of a procedure for extracting building time constants from experimental data in such a way that they are constrained to be physically meaningful.
by Henry C. Spindler.
Ph.D.
14
Williams, R. A. "Comparison of classical and optimal active suspension control systems." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/25139.
Повний текст джерелаАнотація:
British Rail has been designing active suspensions for some 16 years, starting with tilt systems for the Advanced Passenger train. These have been designed using classical control techniques requiring a combination of experience, intuition and frequency response stability techniques, such as Nichols' plots. In order to see if a more systematic approach to control system design could produce improvements in performance and implementation the current investigation was instigated in which controllers designed using classical techniques are compared with controllers designed using linear optimal control theory. The active suspension used for the investigation was an Electro Magnetic active vertical suspension fitted to a service MkIII coach. Design of the actuators is described in the thesis along with the design of analogue and digital control systems. Two classical control systems were designed. a simple "Sky Hook" damper control system and a more sophisticated position control system developed from British Rail's experience with Maglev suspensions. A regulator designed using linear optimal control theory was found to give very good results in theory. However to implement the regulator it was necessary to design a system observer. In order to achieve a practically realisable observer considerable rationalisation of the vehicle model was required, which drew heavily on experience gained designing classical control systems. The classical control systems proved to be much easier to commission than the optimal controllers as they were designed with implementation in mind. During track testing problems of interaction between vehicles were encountered, as a result the biggest improvements in ride were obtained with the simple Sky Hook damper, as it was less specific to the vehicle than the other configurations. With further development one of the optimal control systems considered will probably turn out to be the most effective as it draws on the attributes of both classical and optimal design techniques.
15
Nezhadali, Vaheed. "Modeling and Optimal Control of Heavy-Duty Powertrains." Doctoral thesis, Linköpings universitet, Fordonssystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-128002.
Повний текст джерелаАнотація:
Heavy duty powertrains are complex systems with components from various domains, different response times during transient operations and different efficient operating ranges. To ensure efficient transient operation of a powertrain, e.g. with low fuel consumption or short transient duration, it is important to come up with proper control strategies. In this dissertation, optimal control theory is used to calculate and analyze efficient heavy duty powertrain controls during transient operations in different applications. This is enabled by first developing control ready models, usable for multi-phase optimal control problem formulations, and then using numerical optimal control methods to calculate the optimal transients. Optimal control analysis of a wheel loader operating in a repetitive loading cycle is the first studied application. Increasing fuel efficiency or reducing the operation time in such repetitive loading cycles sums up to large savings over longer periods of time. Load lifting and vehicle traction consume almost all of the power produced by a diesel engine during wheel loader operation. Physical models are developed for these subsystems where the dynamics are described by differential equations. The model parameters are tuned and fuel consumption estimation is validated against measured values from real wheel loader operation. The sensitivity of wheel loader trajectory with respect to constrains such as the angle at which the wheel loader reaches the unloading position is also analyzed. A time and fuel optimal trajectory map is calculated for various unloading positions. Moreover, the importance of simultaneous optimization of wheel loader trajectory and the component transients is shown via a side to side comparison between measured fuel consumption and trajectories versus optimal control results. In another application, optimal control is used to calculate efficient gear shift controls for a heavy duty Automatic Transmission system. A modeling and optimal control framework is developed for a nine speed automatic transmission. Solving optimal control problems using the developed model, time and jerk efficient transient for simultaneous disengagement of off-going and engagement of in-coming shift actuators are obtained and the results are analyzed. Optimal controls of a diesel-electric powertrain during a gear shift in an Automated Manual Transmission system are calculated and analyzed in another application of optimal control. The powertrain model is extended by including driveline backlash angle as an extra state in the system. This is enabled by implementation of smoothing techniques in order to describe backlash dynamics as a single continuous function during all gear shift phases. Optimal controls are also calculated for a diesel-electric powertrain corresponding to a hybrid bus during a tip-in maneuver. It is shown that for optimal control analysis of complex powertrain systems, minimizing only one property such as time pushes the system transients into extreme operating conditions far from what is achievable in real applications. Multi-objective optimal control problem formulations are suggested in order to obtain a compromise between various objectives when analyzing such complex powertrain systems.
16
Oremland, Matthew Scott. "Optimization and Optimal Control of Agent-Based Models." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/78119.
Повний текст джерелаАнотація:
Agent-based models are computer models made up of agents that can exist in a finite number of states. The state of the system at any given time is determined by rules governing agents' interaction. The rules may be deterministic or stochastic. Optimization is the process of finding a solution that optimizes some value that is determined by simulating the model. Optimal control of an agent-based model is the process of determining a sequence of control inputs to the model that steer the system to a desired state in the most efficient way. In large and complex models, the number of possible control inputs is too large to be enumerated by computers; hence methods must be developed for use with these models in order to find solutions without searching the entire solution space. Heuristic algorithms have been applied to such models with some success. Such algorithms are discussed; case studies of examples from biology are presented. The lack of a standard format for agent-based models is a major issue facing the study of agent-based models; presentation as polynomial dynamical systems is presented as a viable option. Algorithms are adapted and presented for use in this framework.Master of Science
17
Rabi, Maben, Karl Henrik Johansson, and Mikael Johansson. "Optimal stopping for event-triggered sensing and actuation." KTH, Reglerteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-80709.
Повний текст джерелаАнотація:
Novel event-triggered sensing and actuation strategies are presented for networked control systems with limited communication resources. Two architectures are considered: one with the controller co-located with the sensor and one with the control co-located with the actuator. A stochastic control problem with an optimal stopping rule is shown to capture two interesting instances of these architectures. The solution of the problem leads to a parametrization of the control alphabet as piecewise constant commands. The execution of the control commands is triggered by stopping rules for the sensor. In simple situations, it is possible to analytically derive the optimal controller. Examples illustrate how the new event-based control and sensing strategies outperform conventional time-triggered schemes.© 2008 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Qc 20120220
18
Chen, Yufeng. "Optimal supervisory control of flexible manufacturing systems." Thesis, Paris, CNAM, 2015. http://www.theses.fr/2015CNAM0990/document.
Повний текст джерелаАнотація:
Notre thèse est consacrée à l’étude de la supervision des réseaux de Petri en vue de la conception de systèmes manufacturiers flexibles. L’objectif est la définition de stratégies de pilotage en ligne pour l’évitement de conflits et d’interblocages, dans le cadre de la théorie de la supervision. Le point de départ de notre travail est d’exploiterle graphe de marquage du réseau de Petri, ce qui permet en particulier d’obtenir des stratégies de commande maximalement permissive pour des problèmes d’évitement de conflits et d’interblocages. Nous avons ainsi introduit des techniques originales, manipulations d’inégalités ou réductions d’ensembles de marquages, destinées à diminuerla complexité algorithmique d’une telle méthode. Dans premier temps, nous avons focalisé sur la synthèse de superviseurs dits purs, ce qui correspond au cas particulier où l’ensemble de marquage légaux, est convexe.Cette optimisation est ensuite considérée du point de vue de la facilité de mise en oeuvre. Nous traitons ainsi de la minimisation de la structure du superviseur et de son coût d’implémentation en préservant une structure de supervision qui offre à la fois la permissivité maximale et une complexité de calcul raisonnable en vue d’utilisationsur des installations réelles. Aussi, nous avons cherché à réduire le nombre de places de contrôle nécessaires pour réaliser un superviseur maximalement permissif, pour cela nous avons formule le calcul du nombre minimal de places de contrôle en termes d’un problème de programmation linéaire. Afin d’affaiblir la complexité de ce calcul de superviseur, deux versions de l’algorithme sont proposées. Ce problème de minimisation de la taille dusuperviseur, quoique fondamental, n’est pas abordé aussi directement dans la littérature. Il s’agit là d’une première contribution.Dans u second temps, nous nous sommes intéressés aux réseaux de Petri à boucles (self-loops). Les boucles étant représentées par une variable qui s’ajoute dans la contrainte inégalité définissant l’ensemble de marquages légaux. Après avoir proposé une méthode de réduction du nombre d’inégalités ainsi que du superviseur optimalen se basant sur les approches et résultats précédents, nous avons établi une condition suffisante d’obtention d’un superviseur maximalement permissif permettant de traiter des ensembles de marquages légaux non convexes.Enfin nous proposons une méthode de synthèse de contrôleur pour une nouvelle classe de réseaux de Petri, avec des arcs inhibiteurs correspondant à des contraintes définies par des intervalles. La taille du contrôleur ainsi obtenu et défini en termes d’arcs inhibiteurs à intervalles s’en trouve réduite ainsi que par conséquent sont coût d’implémentationReachability graph analysis is an important technique for deadlockcontrol, which always suffers from a state explosion problem since it requires togenerate all or a part of reachable markings.Based on this technique, an optimal or suboptimal supervisor with high behavioralpermissiveness can always be achieved. This thesis focuses on designing liveness enforcing Petri net supervisors for FMSs by considering their behavioralpermissiveness, supervisory structure, and computationnal complexity.The following research contributions are made in this thesis.1. The design of a maximally permissive liveness-enforcing supervisor for an FMSis proposed by solving integer linear programming problems (ILPPs).2. Structural complexity is also an important issue for a maximally permissivePetri net supervisor. A deadlock prevention policy for FMSs is proposed, which canobtain a maximally permissive liveness-enforcing Petri net supervisor while thenumber of control places is compressed.3. In order to overcome the computational complexity problem in MCPP and ensurethat the controlled system is maximally permissive with a simple structure, wedevelop an iterative deadlock prevention policy and a modified version.4. We consider the hardware and software costs in the stage of controlimplementation of a deadlock prevention policy, aiming to obtain a maximallypermissive Petri net supervisor with the lowest implementation cost. A supervisorconsists of a set of control places and the arcs connecting control places totransitions. We assign an implementation cost for each control place and controland observation costs for each transition. Based on reachability graph analysis,maximal permissiveness can be achieved by designing place invariants that prohibitall FBMs but no legal markings.5. Self-loops are used to design maximally permissive supervisors. A self-loop ina Petri net cannot be mathematically represented by its incidence matrix. Wepresent a mathematical method to design a maximally permissive Petri netsupervisor that is expressed by a set of control places with self-loops. A controlplace with a self-loop can be represented by a constraint and a selfloopassociated with a transition whose firing may lead to an illegal marking
19
Schöllig, Angela. "Optimal Control of Hybrid Systems with Regional Dynamics." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19874.
Повний текст джерелаАнотація:
In this work, hybrid systems with regional dynamics are considered. These are systems where transitions between different dynamical regimes occur as the continuous state of the system reaches given switching surfaces. In particular, the attention is focused on the optimal control problem associated with such systems. More precisely, given a specific cost function, the goal is to determine the optimal path of going from a given starting point to a fixed final state during an a priori specified time horizon.
The key characteristic of the approach presented in this thesis is a hierarchical decomposition of the hybrid optimal control problem, yielding to a framework which allows a solution on different levels of control. On the highest level of abstraction, the regional structure of the state space is taken into account and a discrete representation of the connections between the different regions provides global accessibility relations between regions. These are used on a lower level of control to formulate the main theorem of this work, namely, the Hybrid Bellman Equation for multimodal systems, which, in fact, provides a characterization of global optimality, given an upper bound on the number of transitions along a hybrid trajectory. Not surprisingly, the optimal solution is hybrid in nature, in that it depends on not only the continuous control signals, but also on discrete decisions as to what domains the system's continuous state should go through in the first place.
The main benefit with the proposed approach lies in the fact that a hierarchical Dynamic Programming algorithm can be used to representing both a theoretical characterization of the hybrid solution's structural composition and, from a more application-driven point of view, a numerically implementable calculation rule yielding to globally optimal solutions in a regional dynamics framework. The operation of the recursive algorithm is highlighted by the consideration of numerous examples, among them, a heterogeneous multi-agent problem.
20
Gugat, Martin. "Time-optimal control algorithms based upon moment equations and parametric programming /." [S.l. : s.n.], 1998. http://deposit.ddb.de/cgi-bin/dokserv?idn=961031328.
Повний текст джерела
21
Roddy, D. J. "Application of optimal control to bank-to-turn CLOS guidance." Thesis, Queen's University Belfast, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373543.
Повний текст джерела
22
Merkoulova, Daniel. "Optimal Input Design by Model Predictive Control for System Identification." Thesis, KTH, Reglerteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215712.
Повний текст джерелаАнотація:
Mathematical models are an essential part of analysis of autonomous systemsas they ease the formulation of control laws and allow experiments tobe performed in a simulation environment. For complex systems, parts of themodel may be missing which increases uncertainties and limits practical applications.Using input-output measurements makes it possible to estimate themodel, but requires the measurements to be informative. The idea in so-calledinput design is to find an input sequence for the system such that the measurementsreveal the properties and dynamics of the true system as much aspossible. This is commonly formulated as an optimization problem.This thesis focuses on formulating an optimization algorithm for inputdesign, which is implemented as an open-loop receding horizon optimizationproblem. The problem consists of classical A-, D-, E-optimality criteria andfinite combinatorial constraints on the input signal. The resulting optimizationproblem is non-convex. Two approaches are explored to solve the problem;a combinatorial and a convex relaxation. The method is finally evaluated ina simulation environment on a second-order system and first-order linearizedwater tank system.Matematiska modeller är essentiella när det kommer till autonoma systemeftersom det förenklar formuleringar av styrlagar och tillåter tester i simuleringsmiljöer.För komplexa system kan delar av modellen saknas vilket ökarosäkerheten hos modellen och begränsar praktiska tillämpningar. Genom attanvända in-ut data är det möjligt att estimera modellen men det kräver attmätningarna är av relativ kvalitet. Idén är således att finna en sekvens av indataså att dynamiken hos systemet avslöjas vilket kan formuleras som ettoptimeringsproblem.Det här arbetet fokuserar på att formulera ett optimeringsproblem somska implementeras i modell prediktiv reglering. Problemet består utav klassiskA,D, E-optimalitet med begränsade diskreta bivillkor på insignalen. Metodenevalueras i simulering på ett godtyckligt andra ordningens system och på ettlineariserat första ordningens vattentankssystem.
23
Alaya, Oussama, and Maik Fiedler. "Optimal pressure control using switching solenoid valves." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200545.
Повний текст джерелаАнотація:
This paper presents the mathematical modeling and the design of an optimal pressure tracking controller for an often used setup in pneumatic applications. Two pneumatic chambers are connected with a pneumatic tube. The pressure in the second chamber is to be controlled using two switching valves connected to the first chamber and based on the pressure measurement in the first chamber. The optimal control problem is formulated and solved using the MPC framework. The designed controller shows good tracking quality, while fulfilling hard constraints, like maintaining the pressure below a given upper bound.
24
Wamalwa, Fhazhil. "Optimal control of a conventional hydropower system with hydrokinetic/wind powered pumpback operation." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/61549.
Повний текст джерелаАнотація:
The need to ease pressure from the depleting fossil fuel reserves coupled with the rising global energy demand has seen a drastic increase in research and uptake of renewable energy sources in recent decades. Of the commonly exploited renewable energy resources, hydropower is currently the most popular resource accounting for 17% of the world's total energy generation, a portion which translates to 85% of the renewable energy share. However, despite the huge potential, hydropower is dependent on the availability of water resource, which is affected by climate change. During wet seasons, hydropower system operators are faced with a deluge of floods which results in excess power generation and spillage. The situation reverses in dry seasons where system operators are compelled to curtail power generation because of low water levels in the hydro reservoirs. The later situation is more pronounced in drought prone regions such as Southern Africa where some hydropower plants are completely shut down in dry seasons due to water shortage.
This dissertation focuses on the application of optimal control to hydropower plants with pumpback retrofits powered by on-site hydrokinetic and wind power systems. The first section of this work develops an optimal operation strategy for a high head hydropower plant retrofitted with hydrokinetic-powered cascaded pumpback system in dry season. The objective of pumpback operation is to recycle a part of the downstream discharged water back to the main dam to maintain a high water level required for optimal power generation. The problem is formulated as a discrete optimisation problem to simultaneously minimise the grid pumping energy demand, minimise the wear and tear associated with the switching frequency of the two pumps in cascade, maximise restoration of the reservoir volume through pumpback operation and maximise the use of on-site generated hydrokinetic power for pumping operation. Simulation results based on a practical case study show the pumping energy saving advantages of the cascaded pumping system as compared to a classical pumped storage (PS) system.
The second section of this work develops an optimal control system for assessing the effects of ecological flow constraints to the operation of a hydropower plant with a hydrokinetic-wind powered pumpback retrofit. The aim of the control law in this case is to use the allocated water to optimally meet the contractual obligations of the power plant. The problem is formulated as a discrete optimisation problem to maximise the energy output of the reservoir subject to some defined technical and hydrological constraints. In this system, pumping power is met primarily by the wind power generator output supplemented by the on-site generated hydrokinetic power. The excess hydrokinetic power is exported to the grid to meet the committed demand. Three different optimisation scenarios are developed: The first scenario is the baseline operation of the hydropower plant without any intervention. The second scenario incorporates the hydrokinetic-wind-powered pumpback operation in the optimal control policy. The third scenario includes the downstream flow constraint to the optimal control policy of the second optimisation scenario. Simulation results based on a practical case study show that ecological flow constraints have negative effects to the economic performance of a hydropower plant.Dissertation (MEng)--University of Pretoria, 2017.
MasterCard Foundation Scholars Program
Centre of New Energy Systems
University of Pretoria
Electrical, Electronic and Computer Engineering
MEng
Unrestricted
25
Ikeda, Takuya. "Sparse Optimal Control for Continuous-Time Dynamical Systems." Kyoto University, 2019. http://hdl.handle.net/2433/242441.
Повний текст джерела
26
Burger, Michael [Verfasser]. "Optimal Control of Dynamical Systems: Calculating Input Data for Multibody System Simulation / Michael Burger." München : Verlag Dr. Hut, 2011. http://d-nb.info/1018982701/34.
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27
Timmerman, Marc A. A. "Sub-optimal momentum managed control of 1-Dof nonlinear systems." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/17332.
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28
Viljoen, Johannes Henning. "Modelling and optimal control of the market of a telecommunications operator." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-09152004-100823.
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29
Hicks, Dawn L. "Optimal design of digital model-following systems." Thesis, University of Salford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284423.
Повний текст джерела
30
Aragón, Ayala Danielo Eduardo. "Optimal control for a prototype of an active magnetic bearing system." Master's thesis, Pontificia Universidad Católica del Perú, 2017. http://tesis.pucp.edu.pe/repositorio/handle/123456789/8675.
Повний текст джерелаАнотація:
First applications of the electromagnetic suspension principle have been in experimental
physics, and suggestions to use this principle for suspending transportation
vehicles for high-speed trains go back to 1937. There are various ways of designing
magnetic suspensions for a contact free support, the magnetic bearing is just one of
them [BCK+09].
Most bearings are used in applications involving rotation. Nowadays, the use of
contact bearings solves problems in the consumer products, industrial machinery, or
transportation equipment (cars, trucks, bicycles, etc). Bearings allow the transmition
of power from a motor to moving parts of a rotating machine [M+92].
For a variety of rotating machines, it would be advantageous to replace the mechanical
bearings for magnetic bearings, which rely on magnetic elds to perform
the same functions of levitation, centering, and thrust control of the rotating parts
as those performed by a mechanical bearing. An advantage of the magnetic bearings
(controlled or not) against purely mechanical is that magnetic bearings are contactless
[BHP12]. As a consequence these properties allow novel constructions, high
speeds with the possibility of active vibration control, operation with no mechanical
wear, less maintenance and therefore lower costs. On the other hand, the complexity
of the active (controlled) and passive (not controlled) magnetic bearings requires
more knowledge from mechanics, electronics and control [LJKA06].
The passive magnetic bearing (PMB) presents low power loss because of the
absence of current, lack of active control ability and low damping sti ness [FM01,
SH08]. On the other hand, active magnetic bearing (AMB) has better control ability
and high sti ness, whereas it su ers from high power loss due to the biased current
[JJYX09].
Scientists of the 1930s began investigating active systems using electromagnets for high-speed ultracentrifuges. However, not controlled magnetic bearings are physically
unstable and controlled systems only provide proper sti ness and damping
through sophisticated controllers and algorithms. This is precisely why, until the
last decade, magnetic bearings did not become a practical alternative to rolling element
bearings. Today, magnetic bearing technology has become viable because of
advances in microprocessing controllers that allow for con dent and robust active
control [CJM04].
Magnetic bearings operate contactlessly and are therefore free of lubricant and
wear. They are largely immune to heat, cold and aggressive substances and are operational
in vacuum. Because of their low energy losses they are suited for applications
with high rotation speeds. The forces act through an air gap, which allows magnetic
suspension through hermetic encapsulations [Bet00].Tesis
31
Ponce, Cuspinera Luis Alejandro. "Optimal control of a flywheel-based automotive kinetic energy recovery system." Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/45260/.
Повний текст джерелаАнотація:
This thesis addresses the control issues surrounding flywheel-based Kinetic Energy Recovery Systems (KERS) for use in automotive vehicle applications. Particular emphasis is placed on optimal control of a KERS using a Continuously Variable Transmission (CVT) for volume car production, and a wholly simulation-based approach is adopted. Following consideration of the general control issues surrounding KERS operation, a simplified system model is adopted, and the scope for use of optimal control theory is explored. Both Pontryagin's Maximum Principle, and Dynamic Programming methods are examined, and the need for numerical implementation established. With Dynamic Programming seen as the most likely route to practical implementation for realistic nonlinear models, the thesis explores several new strategies for numerical implementation of Dynamic Programming, capable of being applied to KERS control of varying degrees of complexity. The best form of numerical implementation identified (in terms of accuracy and efficiency) is then used to establish via simulation, the benefits of optimal KERS control in comparison with a more conventional non-optimal strategy, showing clear benefits of using optimal control.
32
Hou, Yunkui. "Stochastic optimal control of G/M/1 queueing system with breakdowns /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487694702782079.
Повний текст джерела
33
Park, Sang Gyun. "Optimal control based method for design and analysis of continuous descent arrivals." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53005.
Повний текст джерелаАнотація:
Continuous Descent Arrival (CDA) is a procedure where aircraft descend, at or near idle thrust, from their cruise altitude to their Final Approach Fix without leveling off. By eliminating inefficient leveling off at low altitude, CDA provides benefits such as fuel savings, flight time savings, and the significant noise reduction near airports, but the usage of CDAs has been limited in low traffic condition due to difficulty in the separation management. For the successful CDA without degradation of the runway throughput, air traffic controllers should know the performance bound of the CDA trajectory and control the time of arrival for each aircraft, which is interpreted as Required Time of Arrival (RTA) from the aircraft standpoint.
This thesis proposes a novel trajectory optimization methodology to meet RTA constraint. The CDA trajectory optimization problem in the flight management system is modeled as a path constrained optimal control problem of switched dynamical system. A sequential method that performs mode sequence estimation and parameter optimization, sequentially, is proposed to solve this problem. By analyzing the relaxed optimal solution with simplified dynamics, a computationally efficient algorithm to find the optimal switching structure is proposed and applied for the mode sequence estimation. This thesis also proposes a performance-bound analysis methodology using optimal control techniques to help controllers make a feasible schedule for CDA operations at a meter fix. The feasible time range analysis for a wide variety of aircraft is performed by using the proposed methodology. Based on the analysis result, a single flight time strategy is proposed for the application of CDA in high traffic conditions. The simulation with real traffic data has been shown that the single flight time strategy, combined with the proposed fixed RTA trajectory optimization, guarantees the conflict free CDA operation.
34
Said, Munzir. "Computational optimal control modeling and smoothing for biomechanical systems." University of Western Australia. Dept. of Mathematics and Statistics, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0082.
Повний текст джерелаАнотація:
[Truncated abstract] The study of biomechanical system dynamics consists of research to obtain an accurate model of biomechanical systems and to find appropriate torques or forces that reproduce motions of a biomechanical subject. In the first part of this study, specific computational models are developed to maintain relative angle constraints for 2-dimensional segmented bodies. This is motivated by the fact that there is a possibility of models of segmented bodies, moving under gravitational acceleration and joint torques, for its segments to move past the natural relative angle limits. Three models to maintain angle constraints between segments are proposed and compared. These models are: all-time angle constraints, a restoring torque in the state equations and an exponential penalty model. The models are applied to a 2-D three segment body to test the behaviour of each model when optimizing torques to minimize an objective. The optimization is run to find torques so that the end effector of the body follows the trajectory of a half circle. The result shows the behavior of each model in maintaining the angle constraints. The all-time constraints case exhibits a behaviour of not allowing torques (at a solution) which make segments move past the constraints, while the other two show a flexibility in handling the angle constraints more similar to a real biomechanical system. With three computational methods to represent the angle contraint, a workable set of initial torques for the motion of a segmented body can be obtained without causing integration failure in the ordinary differential equation (ODE) solver and without the need to use the “blind man method” that restarts the optimal control many times. ... With one layer of penalty weight balancing between trajectory compliance penalty and other optimal control objectives (minimizing torque/smoothing torque) already difficult to obtain (as explained by the L-curve phenomena), adding the second layer penalty weight for the closeness of fit for each of the body segments will further complicate the weight balancing and too much trial and error computation may be needed to get a reasonably good set of weighting values. Second order regularization is also added to the optimal control objective and the optimization has managed to obtain smoother torques for all body joints. To make the current approach more competitive with the inverse dynamic, an algorithm to speed up the computation of the optimal control is required as a potential future work.
35
Sheldon, Sarah (Sarah Elizabeth). "Optimal control in an open quantum system : selecting DNP pathways in an electron-nuclear system." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82867.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-107).
There is much interest in improving quantum control techniques for the purposes of quantum information processing. High fidelity control is necessary for the future of quantum computing. Optimal control theory has been used successfully to numerically optimize control sequences for spin-based systems. Previous control pulse finding efforts have primarily optimized pulses to a desired unitary control. Non-unitary dynamics are unavoidable in quantum systems, and, to improve current control techniques, interactions with the environment and stochastic noise processes must be incorporated into pulse design. We present here a method of pulse optimization that includes decoherence. This thesis discusses a particular example of engineering control for an open quantum system: selecting transfer pathways in dynamic nuclear polarization. Dynamic nuclear polarization (DNP) is a method of increasing the nuclear spin magnetization in a nuclear magnetic resonance experiment. DNP works by transferring polarization from a coupled electron spin. In solid state systems, however, there are multiple pathways through which polarization can be transferred. Excitation of more than one pathway can prevent the nuclear spin from achieving the maximum possible polarization. It is demonstrated in this thesis that optimal control theory (OCT) can be used to design pulses which will select one pathway and suppress the others. The pulses were found considering the open quantum system dynamics. This work includes an algorithm for generating noise realizations from a spectral density function. Future efforts to engineer high-fidelity control could use this method to incorporate stochastic noise in the pulse finding process.
by Sarah Sheldon.
Ph.D.
36
Kreikebaum, Frank Karl. "Control of transmission system power flows." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50392.
Повний текст джерелаАнотація:
Power flow (PF) control can increase the utilization of the transmission system and connect lower cost generation with load. While PF controllers have demonstrated the ability to realize dynamic PF control for more than 25 years, PF control has been sparsely implemented.
This research re-examines PF control in light of the recent development of fractionally-rated PF controllers and the incremental power flow (IPF) control concept. IPF control is the transfer of an incremental quantity of power from a specified source bus to specified destination bus along a specified path without influencing power flows on circuits outside of the path.
The objectives of the research are to develop power system operation and planning methods compatible with IPF control, test the technical viability of IPF control, develop transmission planning frameworks leveraging PF and IPF control, develop power system operation and planning tools compatible with PF control, and quantify the impacts of PF and IPF control on multi-decade transmission planning.
The results suggest that planning and operation of the power system are feasible with PF controllers and may lead to cost savings. The proposed planning frameworks may incent transmission investment and be compatible with the existing transmission planning process. If the results of the planning tool demonstration scale to the national level, the annual savings in electricity expenditures would be $13 billion per year (2010$). The proposed incremental packetized energy concept may facilitate a reduction in the environmental impact of energy consumption and lead to additional cost savings.
37
Loxton, Ryan Christopher. "Optimal control problems involving constrained, switched, and delay systems." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1479.
Повний текст джерелаАнотація:
In this thesis, we develop numerical methods for solving five nonstandard optimal control problems. The main idea of each method is to reformulate the optimal control problem as, or approximate it by, a nonlinear programming problem. The decision variables in this nonlinear programming problem influence its cost function (and constraints, if it has any) implicitly through the dynamic system. Hence, deriving the gradient of the cost and the constraint functions is a difficult task. A major focus of this thesis is on developing methods for computing these gradients. These methods can then be used in conjunction with a gradient-based optimization technique to solve the optimal control problem efficiently.The first optimal control problem that we consider has nonlinear inequality constraints that depend on the state at two or more discrete time points. These time points are decision variables that, together with a control function, should be chosen in an optimal manner. To tackle this problem, we first approximate the control by a piecewise constant function whose values and switching times (the times at which it changes value) are decision variables. We then apply a novel time-scaling transformation that maps the switching times to fixed points in a new time horizon. This yields an approximate dynamic optimization problem with a finite number of decision variables. We develop a new algorithm, which involves integrating an auxiliary dynamic system forward in time, for computing the gradient of the cost and constraints in this approximate problem.The second optimal control problem that we consider has nonlinear continuous inequality constraints. These constraints restrict both the state and the control at every point in the time horizon. As with the first problem, we approximate the control by a piecewise constant function and then transform the time variable. This yields an approximate semi-infinite programming problem, which can be solved using a penalty function algorithm. A solution of this problem immediately furnishes a suboptimal control for the original optimal control problem. By repeatedly increasing the number of parameters used in the approximation, we can generate a sequence of suboptimal controls. Our main result shows that the cost of these suboptimal controls converges to the minimum cost.The third optimal control problem that we consider is an applied problem from electrical engineering. Its aim is to determine an optimal operating scheme for a switchedcapacitor DC-DC power converter—an electronic device that transforms one DC voltage into another by periodically switching between several circuit topologies. Specifically, the optimal control problem is to choose the times at which the topology switches occur so that the output voltage ripple is minimized and the load regulation is maximized. This problem is governed by a switched system with linear subsystems (each subsystem models one of the power converter’s topologies). Moreover, its cost function is non-smooth. By introducing an auxiliary dynamic system and transforming the time variable (so that the topology switching times become fixed), we derive an equivalent semi-infinite programming problem. This semi-infinite programming problem, like the one that approximates the continuously-constrained optimal control problem, can be solved using a penalty function algorithm.The fourth optimal control problem that we consider involves a general switched system, which includes the model of a switched-capacitor DC-DC power converter as a special case. This switched system evolves by switching between several subsystems of nonlinear ordinary differential equations. Furthermore, each subsystem switch is accompanied by an instantaneous change in the state. These instantaneous changes—so-called state jumps—are influenced by control variables that, together with the subsystem switching times, should be selected in an optimal manner. As with the previous optimal control problems, we tackle this problem by transforming the time variable to obtain an equivalent problem in which the switching times are fixed. However, the functions governing the state jumps in this new problem are discontinuous. To overcome this difficulty, we introduce an approximate problem whose state jumps are governed by smooth functions. This approximate problem can be solved using a nonlinear programming algorithm. We prove an important convergence result that links the approximate problem’s solution with the original problem’s solution.The final optimal control problem that we consider is a parameter identification problem. The aim of this problem is to use given experimental data to identify unknown state-delays in a nonlinear delay-differential system. More precisely, the optimal control problem involves choosing the state-delays to minimize a cost function measuring the discrepancy between predicted and observed system output. We show that the gradient of this cost function can be computed by solving an auxiliary delay-differential system. On the basis of this result, the optimal control problem can be formulated—and hence solved—as a standard nonlinear programming problem.
38
Young, Derek W. G. "Design, simulation and practical implementation of optimal excitation controllers for synchronous generators." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010652.
Повний текст джерелаАнотація:
This thesis describes the design of multivariable excitation controllers for synchronous generators, and their practical implementation on a laboratory machine system. The main objectives of the investigation were aimed at extending the steady-state stability limit of the generator and improving its general controllability. The present work is principally concerned with the implementation and test of the designs. Instrumentation has been developed to measure and combine feedback signals; this instrumentation and the laboratory generator system are described in detail. The performances of the controllers are predicted by computer simulation and evaluated by practical testing; attention is focussed on comparison of predicted and experimental performances. The theoretical basis of the design strategy is described, in which an optimal control algorithm applies the system states as feedback signals to the open-loop system, thereby shifting certain of the system eigenvalues to more desirable, predetermined locations. The state variables are selected as physically measurable quantities which obviates the need for implementing state estimation techniques.
39
Cunningham, Janet L. "Spin stabilization of the ORION satellite using a thruster attitude control system with optimal control considerations." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27282.
Повний текст джерелаАнотація:
The controlled system is the ORION satellite spinning about its single axis of symmetry. Hydrazine thrusters are used as the control and are modeled by ideal, constant magnitude step functions. The system is normalized and driven from non-zero initial angular velocities of the two axes other than the spin axis to the final condition zero. The control profiles required to do this are determined based on a desired controller duty cycle. Adaption of the duty cycle changes the ratio of the time the thrusters are on (fuel use) and total time to completion of the evolution. A comparison between a single axis and a dual axis controller is presented. Simulation programs for the normalized system using a single axis controller simulation program, with each controller having a duty cycle of no more than 50%, are developed. Operation of the system is optimized using a system cost function. An equation relating the controller duty cycle of the dual system to the fuel/time trade-off parameter of the system cost function is required. A nonlinear feedback control algorithm (function of attitude angle rates) is developed from iterations of the simulation, and a priori knowledge of the form of the control from optimal control theory. This numerical solution will allow system designers to incorporate a closed form state feedback control for minimum fuel/time strategies using the ORION satellite's onboard software
40
Godoy, Rodrigo Juliani Corrêa de. "Plantwide control: a review and proposal of an augmented hierarchical plantwide control design technique." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3139/tde-07112017-140120/.
Повний текст джерелаАнотація:
The problem of designing control systems for entire plants is studied. A review of previous works, available techniques and current research challenges is presented, followed by the description of some theoretical tools to improve plantwide control, including the proposal of an augmented lexicographic multi-objective optimization procedure. With these, an augmented hierarchical plantwide control design technique and an optimal multi-objective technique for integrated control structure selection and controller tuning are proposed. The main contributions of these proposed techniques are the inclusion of system identification and optimal control tuning as part of the plantwide design procedure for improved results, support to multi-objective control specifications and support to any type of plant and controllers. Finally, the proposed techniques are applied to industrial benchmarks to demonstrate and validate its applicability.O problema de projetar sistemas de controle para plantas inteiras é estudado. Uma revisão de trabalhos anteriores, técnicas disponíveis e atuais desafios de pesquisa é apresentada, seguida da descrição de algumas ferramentas teóricas para melhorar o controle plantwide, incluindo a proposta de um procedimento de otimização multi-objetivo lexicográfico aumentado. Com tais elementos, são propostas uma nova técnica hierárquica aumentada de projeto de sistemas de controle plantwide e uma técnica multi-objetivo para seleção de estrutura de controlador integrada à sintonia ótima do controlador. As principais contribuições das técnicas propostas são a inclusão de identificação de sistemas e sintonia ótima de controladores como parte do procedimento de projeto de controle plantwide para melhores resultados, suporte a especificações multi-objetivo e suporte a quaisquer tipos de plantas e controladores. Finalmente, as técnicas propostas são aplicadas a benchmarks industriais para demonstrar e validar sua aplicabilidade.
41
Gianto, Rudy. "Coordination of power system controllers for optimal damping of electromechanical oscillations." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0056.
Повний текст джерелаАнотація:
This thesis is devoted to the development of new approaches for control coordination of PSSs (power system stabilisers) and FACTS (flexible alternating current transmission system) devices for achieving and enhancing small-disturbance stability in multi-machine power systems. The key objectives of the research reported in the thesis are, through optimal control coordination of PSSs and/or FACTS devices, those of maintaining satisfactory power oscillation damping and secure system operation when the power system is subject to persisting disturbances in the form of load demand fluctuations and switching control. Although occurring less frequently, fault disturbances are also considered in the assessment of the control coordination performance. Based on the constrained optimisation method in which the eigenvalue-based objective function is minimised to identify the optimal parameters of power system damping controllers, the thesis first develops a procedure for designing the control coordination of PSSs and FACTS devices controllers. The eigenvalue-eigenvector equations associated with the selected electromechanical modes form a set of equality constraints in the optimisation. The key advance of the procedure is that there is no need for any special software system for eigenvalue calculations, and the use of sparse Jacobian matrix for forming the eigenvalue-eigenvector equations leads to the sparsity formulation which is essential for large power systems. Inequality constraints include those for imposing bounds on the controller parameters. Constraints which guarantee that the modes are distinct ones are derived and incorporated in the control coordination formulation, using the property that eigenvectors associated with distinct modes are linearly independent. The robustness of the controllers is achieved very directly through extending the sets of equality constraints and inequality constraints in relation to selected eigenvalues and eigenvectors associated with the state matrices of power systems with loading conditions and/or network configurations different from that of the base case. On recognising that the fixed-parameter controllers, even when designed with optimal control coordination, have an inherent limitation which precludes optimal system damping for each and every possible system operating condition, the second part of ii the research has a focus on adaptive control techniques and their applications to power system controllers. In this context, the thesis reports the development of a new design procedure for online control coordination which leads to adaptive PSSs and/or supplementary damping controllers (SDCs) of FACTS devices for enhancing the stability of the electromechanical modes in a multi-machine power system. The controller parameters are adaptive to the changes in system operating condition and/or configuration. Central to the design is the use of a neural network synthesised to give in its output layer the optimal controller parameters adaptive to system operating condition and configuration. A novel feature of the neural adaptive controller is that of representing the system configuration by a reduced nodal impedance matrix which is input to the neural network.
42
Kang, Bei. "STATISTICAL CONTROL USING NEURAL NETWORK METHODS WITH HIERARCHICAL HYBRID SYSTEMS." Diss., Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/122303.
Повний текст джерелаАнотація:
Electrical EngineeringPh.D.
The goal of an optimal control algorithm is to improve the performance of a system. For a stochastic system, a typical optimal control method minimizes the mean (first cumulant) of the cost function. However, there are other statistical properties of the cost function, such as variance (second cumulant) and skewness (third cumulant), which will affect the system performance. In this dissertation, the work on the statistical optimal control are presented, which extends the traditional optimal control method using cost cumulants to shape the system performance. Statistical optimal control will allow more design freedom to achieve better performance. The solutions of statistical control involve solving partial differential equations known as Hamilton-Jacobi-Bellman equation. A numerical method based on neural networks is employed to find the solutions of the Hamilton-Jacobi-Bellman partial differential equation. Furthermore, a complex problem such as multiple satellite control, has both continuous and discrete dynamics. Thus, a hierarchical hybrid architecture is developed in this dissertation where the discrete event system is applied to discrete dynamics, and the statistical control is applied to continuous dynamics. Then, the application of a multiple satellite navigation system is analyzed using the hierarchical hybrid architecture. Through this dissertation, it is shown that statistical control theory is a flexible optimal control method which improves the performance; and hierarchical hybrid architecture allows control and navigation of a complex system which contains continuous and discrete dynamics.
Temple University--Theses
43
Gao, Lingchong, Boyang Shi, Michael Kleeberger, and Johannes Fottner. "Optimal control of the hydraulic actuated boom system based on port-hamiltonian formulation." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71119.
Повний текст джерелаАнотація:
The boom systems of mobile cranes and aerial platform vehicles are driven by hydraulic systems, to be specified, valve-controlled hydraulic cylinders. This hydraulic actuated boom system can accomplish the tasks such as lifting heavy loads or carrying personal to high position, by the design of a long boom structure. In practice, the boom structure is designed as light and slender as possible to control the structure self-weight. However, such structure is quite flexible and can be easily stimulated by the loads, including the driving force or torque from the hydraulic system. Our research focuses on trajectory planning for hydraulic actuated boom where both hydraulic driven system and boom structure deformation are considered. In this paper, the hydraulic actuated boom system is formulated as a port-Hamiltonian system which is a proper modelling method for multi-domain system. The problems of trajectory optimization and vibration control are formulated as optimal control problem based on port-Hamiltonian model and this procedure is tested on a model of hydraulic cylinder. A reasonable result is solved with the selected cost function and inputs.
44
Snell, Jared James. "Improved modeling and optimal control of an electric arc furnace." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/741.
Повний текст джерелаАнотація:
This thesis centers around an electric arc furnace (EAF) at a steel mini-mill in Wilton, IA. First, the thesis replicates previous optimization attempts. Next, the modeling is greatly altered to produce a much improved steel-melting model. Then, a new optimal control system is created and used to reduce energy and fuel costs over the melting process. Finally, results are presented. This thesis shows that when the new optimal control is simulated, the system shows significant energy and fuel savings.
45
Kramer, Boris Martin Josef. "Model and Data Reduction for Control, Identification and Compressed Sensing." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/75179.
Повний текст джерелаАнотація:
This dissertation focuses on problems in design, optimization and control of complex, large-scale dynamical systems from different viewpoints. The goal is to develop new algorithms and methods, that solve real problems more efficiently, together with providing mathematical insight into the success of those methods. There are three main contributions in this dissertation.
In Chapter 3, we provide a new method to solve large-scale algebraic Riccati equations, which arise in optimal control, filtering and model reduction. We present a projection based algorithm utilizing proper orthogonal decomposition, which is demonstrated to produce highly accurate solutions at low rank. The method is parallelizable, easy to implement for practitioners, and is a first step towards a matrix free approach to solve AREs. Numerical examples for n >= 100,000 unknowns are presented.
In Chapter 4, we develop a system identification method which is motivated by tangential interpolation. This addresses the challenge of fitting linear time invariant systems to input-output responses of complex dynamics, where the number of inputs and outputs is relatively large. The method reduces the computational burden imposed by a full singular value decomposition, by carefully choosing directions on which to project the impulse response prior to assembly of the Hankel matrix. The identification and model reduction step follows from the eigensystem realization algorithm. We present three numerical examples, a mass spring damper system, a heat transfer problem, and a fluid dynamics system. We obtain error bounds and stability results for this method.
Chapter 5 deals with control and observation design for parameter dependent dynamical systems. We address this by using local parametric reduced order models, which can be used online. Data available from simulations of the system at various configurations (parameters, boundary conditions) is used to extract a sparse basis to represent the dynamics (via dynamic mode decomposition). Subsequently, a new compressed sensing based classification algorithm is developed which incorporates the extracted dynamic information into the sensing basis. We show that this augmented classification basis makes the method more robust to noise, and results in superior identification of the correct parameter. Numerical examples consist of a Navier-Stokes, as well as a Boussinesq flow application.Ph. D.
46
Petersson, Daniel. "A Nonlinear Optimization Approach to H2-Optimal Modeling and Control." Doctoral thesis, Linköpings universitet, Reglerteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93324.
Повний текст джерелаАнотація:
Mathematical models of physical systems are pervasive in engineering. These models can be used to analyze properties of the system, to simulate the system, or synthesize controllers. However, many of these models are too complex or too large for standard analysis and synthesis methods to be applicable. Hence, there is a need to reduce the complexity of models. In this thesis, techniques for reducing complexity of large linear time-invariant (lti) state-space models and linear parameter-varying (lpv) models are presented. Additionally, a method for synthesizing controllers is also presented. The methods in this thesis all revolve around a system theoretical measure called the H2-norm, and the minimization of this norm using nonlinear optimization. Since the optimization problems rapidly grow large, significant effort is spent on understanding and exploiting the inherent structures available in the problems to reduce the computational complexity when performing the optimization. The first part of the thesis addresses the classical model-reduction problem of lti state-space models. Various H2 problems are formulated and solved using the proposed structure-exploiting nonlinear optimization technique. The standard problem formulation is extended to incorporate also frequency-weighted problems and norms defined on finite frequency intervals, both for continuous and discrete-time models. Additionally, a regularization-based method to account for uncertainty in data is explored. Several examples reveal that the method is highly competitive with alternative approaches. Techniques for finding lpv models from data, and reducing the complexity of lpv models are presented. The basic ideas introduced in the first part of the thesis are extended to the lpv case, once again covering a range of different setups. lpv models are commonly used for analysis and synthesis of controllers, but the efficiency of these methods depends highly on a particular algebraic structure in the lpv models. A method to account for and derive models suitable for controller synthesis is proposed. Many of the methods are thoroughly tested on a realistic modeling problem arising in the design and flight clearance of an Airbus aircraft model. Finally, output-feedback H2 controller synthesis for lpv models is addressed by generalizing the ideas and methods used for modeling. One of the ideas here is to skip the lpv modeling phase before creating the controller, and instead synthesize the controller directly from the data, which classically would have been used to generate a model to be used in the controller synthesis problem. The method specializes to standard output-feedback H2 controller synthesis in the lti case, and favorable comparisons with alternative state-of-the-art implementations are presented.
47
Williams, Timothy Alphonzo. "Optimal parachute guidance, navigation, and control for the Affordable Guided Airdrop System (AGAS)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA380301.
Повний текст джерелаАнотація:
Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, June 2000.Thesis advisor(s): Kaminer, Isaac I.; Yakimenko, Oleg A. "June 2000." Includes bibliographical references (p. 81-82). Also available in print.
48
巫志鴻. "L1 Optimal Control of Seeking System of Optical Drives." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/88093983550173443631.
Повний текст джерела
49
Sahay, Pankaj. "Optimal Control Of A Stochastic Hybrid System." Thesis, 1997. http://etd.iisc.ernet.in/handle/2005/1811.
Повний текст джерела
50
WENG, TING-CHING, and 翁頂清. "Optimal Control System Design for Fuel Processing System." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/04152012946279247192.
Повний текст джерелаАнотація:
碩士大葉大學
電機工程學系
96
This paper presents that an optimal control system which consists of both feedforward and state-feedback controllers is designed using a well-developed linear quadratic Gaussian and loop transfer recovery (LQG/LTR) method for a fuel processing system (FPS).This FPS uses natural gas as fuel and reacts with atmospheric air through a catalytic partial oxidation (CPO)，after pure supply to proton exchange membrane fuel cell (PEMFC) stack . The objectives of this paper are to use the Matlab/Simulink software tool to model such an optimal control system and to analyze the system performance. The proposed method achieves better performance and robustness properties in both time-domain and frequency-domain responses.