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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

A novel approach to the control of quad-rotor helicopters using fuzzy-neural networks

Poyi, Gwangtim Timothy January 2014 (has links)
Quad-rotor helicopters are agile aircraft which are lifted and propelled by four rotors. Unlike traditional helicopters, they do not require a tail-rotor to control yaw, but can use four smaller fixed-pitch rotors. However, without an intelligent control system it is very difficult for a human to successfully fly and manoeuvre such a vehicle. Thus, most of recent research has focused on small unmanned aerial vehicles, such that advanced embedded control systems could be developed to control these aircrafts. Vehicles of this nature are very useful when it comes to situations that require unmanned operations, for instance performing tasks in dangerous and/or inaccessible environments that could put human lives at risk. This research demonstrates a consistent way of developing a robust adaptive controller for quad-rotor helicopters, using fuzzy-neural networks; creating an intelligent system that is able to monitor and control the non-linear multi-variable flying states of the quad-rotor, enabling it to adapt to the changing environmental situations and learn from past missions. Firstly, an analytical dynamic model of the quad-rotor helicopter was developed and simulated using Matlab/Simulink software, where the behaviour of the quad-rotor helicopter was assessed due to voltage excitation. Secondly, a 3-D model with the same parameter values as that of the analytical dynamic model was developed using Solidworks software. Computational Fluid Dynamics (CFD) was then used to simulate and analyse the effects of the external disturbance on the control and performance of the quad-rotor helicopter. Verification and validation of the two models were carried out by comparing the simulation results with real flight experiment results. The need for more reliable and accurate simulation data led to the development of a neural network error compensation system, which was embedded in the simulation system to correct the minor discrepancies found between the simulation and experiment results. Data obtained from the simulations were then used to train a fuzzy-neural system, made up of a hierarchy of controllers to control the attitude and position of the quad-rotor helicopter. The success of the project was measured against the quad-rotor’s ability to adapt to wind speeds of different magnitudes and directions by re-arranging the speeds of the rotors to compensate for any disturbance. From the simulation results, the fuzzy-neural controller is sufficient to achieve attitude and position control of the quad-rotor helicopter in different weather conditions, paving way for future real time applications.
102

Χαρακτηριστικά και ρυθμίσεις Α.Π.Ε. σύμφωνα με τις απαιτήσεις σύνδεσης στο δίκτυο

Θεοτόκης, Εμμανουήλ 16 May 2014 (has links)
Στο πρώτο κεφάλαιο, γίνεται μία αναφορά στις ανανεώσιμες πηγές ενέργειας και αναλύεται περισσότερο η αιολική. Αναφέρεται η πορεία αξιοποίησής της, και παραθέτονται πληροφορίες για την τωρινή χρήση της στην παραγωγή ηλεκτρικής ενέργειας αλλά και μελλοντικές βλέψεις. Στο δεύτερο κεφάλαιο παρουσιάζονται τα χαρακτηριστικά του ανέμου και οι εξισώσεις της ανεμογεννήτριας που μας επιτρέπουν να απομαστεύουμε ενέργεια από τον άνεμο μέσω των ανεμογεννητριών. Στο τρίτο κεφάλαιο παρουσιάζονται τα δομικά στοιχεία και ο τρόπος με τον οποίο γίνεται η κατηγοριοποίηση των ανεμογεννητριών, οι έλεγχοι που χρησιμοποιούνται και τα είδη των ανεμογεννητριών που χρησιμοποιούνται σήμερα στη βιομηχανία. Στο τέταρτο κεφάλαιο παρουσιάζονται οι τεχνικές απαιτήσεις για τους αιολικούς σταθμούς στο ελληνικό Σ.Η.Ε. Στο πέμπτο κεφάλαιο, γίνεται η προσομοίωση μέσω του προγράμματος Matlab - Simulink ενός μη γραμμικού ελέγχου ισχύος ανεμογεννητριών DFIG για ενσωμάτωση σε εικονικούς σταθμού ισχύος (V.P.P). / In the first chapter, there is a general description about renewable energy resources and more specific, about the wind energy. We present the current worldwide electrical power production and the future requirements for electrical power production in Europe and Greece. In the second chapter, we study the features of the wind performance and the equations that allows us to drain energy from the wind ,using a wind turbine. The third chapter presents the components, the kinds of control and the categories of wind turbines that are in use in industry nowadays. The fourth chapter presents the technical requirements for the wind farms in the Greek System of Electrical Energy. In the fifth chapter we use the program Matlab - Simulink in order to simulate a non-linear direct power control of DFIG wind turbines for Virtual Power Plant (V.P.P.) integration.
103

Development And Control Of Urban Water Network Models

Rai, Pawan Kumar 12 1900 (has links) (PDF)
Water distribution systems convey drinking water from treatment plant and make available to consumers’ taps. It consists of essential components like pipes, valves, pumps, tanks and reservoirs etc. The main concern in the working of a water distribution system is to assure customer demands under a choice of quantity and quality throughout the complete life span for the probable loading situations. However, in some cases, the existing infrastructure may not be adequate to meet the customer’s requirements. In such cases, system modeling plays an important role in proper management of water supply systems. In present scenario, modeling plays a significant task in appropriate execution of water distribution system. From the angle of taking management decisions valve throttling control and pumps speed control are very important. These operational problems can be addressed by manual control or by automatic control. The problem is the use of manual controls that slow down the effectiveness of the system. It reduces the efficiency of operation of valve or pump. To improve the efficiency of such water distribution systems, an automatic control based technology has been developed that links the operation of the variable speed pump control or valve throttling control. By employing an automatic control, the pump can adjust its speed at all times to meet the actual flow requirements of each load served. In case of real system design Simulink is the most widely used tool. Commercial software package Matlab/Simulink used for creation of WDS model. The goal was to produce a model that could numerically analyze the dynamic performance of a water distribution system. A Comparison of single platform methodology (Simulink based control) and double platform methodology (Matlab and EPANET based control) has been done. Nonlinear Dynamic Inversion (DI) Control system model is developed for WDS model in Matlab/Simulink environment. Controller gain parameters are the very important value in control prospective. If the controller gain parameters are chosen incorrectly, the controlled process input can be unstable, i.e. its output diverges, with or without oscillation Tuning is the adjustment of control parameters (gains) to the optimum values for the desired control response. There are several methods for tuning controller like manual tuning (Trial and error procedure), Ziegler-Nichols method, Output Constraint Tuning (OCT) etc. Establishment of a pump operational policy by which all the reservoirs can be fed simultaneously to meet their requirements without creating undue transients. Tune the gain of DI controllers by different tuning methods and evaluate the best tuning method on the basis of controller performance. Development of meaningful additional objective is search of lower bound pump speed on the basis of control time or settling time. To bring the pump speeds in feasible range, application of constraint in pumps speed is introduced. The magnitude of constraints can be found using Monte Carlo methods. Monte Carlo methods are frequently used in simulating physical and mathematical systems. This method may be the most commonly applied statistical method in engineering and science disciplines. Another benefit is providing increased confidence that a model is robust using Monte Carlo testing. Model development for generalized control system for water distribution network provides the simplification needed for the simulation of large systems. Model development is based on the study of symmetric and non symmetric small, irregular networks, as well as large, regular and open bifurcating water distribution system. The problem considered in this section is that of flow dynamics in simple to complex, regular network which bifurcates in the form of a branching tree. In addition the control application of the flow network is investigated using valves as the manipulated variables to control branch flow rates. Communication between the network hydraulics coming from EPANET and control algorithm develop on Matlab (Programming Language) can be generalized with the help of development of general purpose control algorithm model.
104

Návrh řídícího algoritmu ABS pro nákladní vozidlo / Development of ABS Control Algorithm for Heavy Commercial Vehicle

Slepánek, David January 2018 (has links)
This thesis is concerned with ABS algorithm project for commercial vehicles. In the first part the reader is introduced to the history and first usage of the anti-blocking system, its principles and main functions. There are also driving algorithms and functionality system control. The second part is dedicated to the dynamic model, programs and ADAMS Car and MATLAB Simulink interfaces. It also contains the description of the algorithm, its parameters and basic functionality assay. Simulation, program interlink, testing and tuning are also described. The concluding part deals with results and their assessment.
105

Algoritmy pro systémy s technikou adaptivního frekvenčního skákání / Algorithms for adaptive frequency hopping spread spectrum systems

Zunt, Tomáš January 2009 (has links)
This master's thesis deal the system, which use the Frequency Hopping (FH). Is explained principle those techniques and her benefits and disadvantages. Follows description techniques Adaptive Frequency Hopping (AFH) that used the Bluetooth. Follows description other method for setup hopset such as Dynamic Frequency Hopping (DFH), which used standards 802.22. 22. Is an emerging standard for Wireless Regional Area Networks (WRAN) operating on a license-exempt and non-interference basis in the spectrum allocated to TV broadcast services (between 47–910 MHz). Other method introduces the Adaptive Frequency Rolling (AFR), a particular instance of frequency hopping (FH) that enables the collocated WPANs to cooperate and avoid the self-interference. The AFR uses as input solely the observed packet error rate (PER) and it does not require any exchange of information among the collocated WPANs. The effect of the FR over a longer time interval is that the WPANs use the complete set of disposable channels in an implicit time-division and cooperative manner. Last method described in this Thesis is Dynamic Adaptive Frequency Hopping (DAFH). The basic strategy applied in DAFH is a binary search for a hopset that offers smaller PER. The set of admissible hopsets depends on the total number of available channels and the maximal level of binary divisions. Practical part of the master's thesis describes proposal model AFH, with usage of Matlab Simulink programme. In thesis are described function each blocks a their setting. Simulation parameters can change in simple graphic interface. The model is able to simulate influence of static and dynamic interference in transmission band of two communicating devices.
106

Model větrné elektrárny pro výzkumné a laboratorní využití / Wind Turbine Model for Research and Laboratory Applications

Števček, Tomáš January 2015 (has links)
A major portion of this thesis is devoted to the Whisper 200 wind turbine model in Matlab-Simulink environment. The turbine is installed at the Department of Electrical Power Engineering, FEEC BUT. In the model, several types of simulations can be executed. On that basis, the power curve and mathematical relationships between wind speed and other physical quantities, such as RPM, electic current, and voltage, were obtained. Comparisons of the simulations' results with measurement data illustrate adequate agreement, but limitations of the model remain significant, as is exhaustively documented and commented upon in the thesis. As a partial advancement towards elimination of the model's deficiencies, conditions for substantial performance improvements of the dynamic simulation have been elaborately derived.
107

Řízení laboratorního modelu nestabilního balancujícího vozidla / Control of laboratory model of unstable balancing vehicle

Horák, Petr January 2011 (has links)
This diploma thesis is a part of HUMMER project. The project deals with three student’s development of two-wheeled unstable vehicle Segway type and its diminished laboratory model. This thesis deals with reviviscence of laboratory model, design of its control and realization of its actuating (a more detailed breakdown of tasks in the project is shown below). At the beginning of the work is presented reviewed study. The first part of study deals with similar models in the world, their construction and way of control. In the next part of reviewed study follows description of a real model and derivation of model basic equations, in the last part of search is given principle of operation of some used sensors. The next step was the selection and design of required electronics. In this capture are described all designed electronic modules and used sensors. There are also given parameters of used batteries and motors. The next task was the estimation of system parameters. The estimation was made by sections, in the capture is in detail described way of measuring data and structuring of estimation model. The penultimate step was design of PID and LQR controller using I/O card MF 624 and their comparing. Following thing was choice of better regulator and its implementation to the microprocessor. The last step was the realization of actuating driving of model by joystick and supreme PC.
108

Simulace kombinace dvou kniplů Active Side Stick a algoritmus potlačení pilotem indukovaných oscilací / Twin Active Side Stick Configuration Model and Pilot-Induced Oscillations Suppression Algorithm

Vadlejch, Filip January 2012 (has links)
Diplomová práce se zabývá představením, popisem a vytvořením modelu postranní řídicí páky pilota s aktivní silovou zpětnou vazbou firmy Honeywell International Inc. v prostředí MATLAB Simulink. Dále pak představením problému pilotem indukovaných oscilací a možnostmi jejich předcházení, detekce a potlačení. Model řídicí páky se silovou zpětnou vazbou je použit pro potlačení detekovaných oscilací v simulaci letounu.
109

Využití knihovny HAM-Tools pro simulaci tepelného chování rodinného domu / HAM-Tools library use for the simulation of the thermal performance of the house

Zábojník, Jakub January 2015 (has links)
In terms of master’s thesis HAM-Tools library designed for MATLAB/Simulink was modified for the use in simulations of houses in the Czech Republic. Modified library and its parts were described in detail and tested by the simulation of the one-zone and two-zones models of the house. The simulations of models with same parameters were also realized in program TRNSYS. The corresponding results achieved in mentioned simulation tools were compared to each other. The one-zone model created by using HAM-Tools library is tested by the simulation of ventilating, heating, cooling, and sources of moisture. A demonstration of the practical use of the simulation is carried out in the thesis, namely by examining the influence of the insulation thickness on the thermal performance of the house (resp. its heat loss) on real atmospheric conditions. Among others, available resources of meteorological data are mentioned and compared to each other. The function for processing of the meteorological data to a file compatible with the HAM-Tools library was created. It was also created a material data file containing commonly used materials of building structures in the Czech Republic and their parameters.
110

Ukázky regulací s prediktivním řízením / Examples of governings with predictive controls

Šalda, Zbyněk January 2015 (has links)
This thesis deals with model predictive control principally Based Predictive Control (MPC). The first part describes the principle of predictive control, cost function, the choice of a constraints in regulation and the choice of weights. In the next section is an analysis system: a system with non-minimal phase (control water turbine), oscillating systems (trolley frame control) and system with a time-delay . In all of these systems is performed classical feedback control using PID control and concurrently regulation with the MPC. MPC is selected as the solution fy Mathworks Model Predictive Control Toolbox and Simulink. The results are then analyzed using the criteria of quality control.

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