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Fuzzy control of the electrohydraulic actuatorSampson, Eric Bowyer 20 May 2005 (has links)
Industrial applications increasingly require actuators that offer a combination of high force
output, large stroke and high accuracy. The ElectroHydraulic Actuator (EHA) was designed by Drs. Habibi and Goldenberg originally as a high-performance actuator for use in robotics. However, it was determined that the EHA had the potential to achieve high positional accuracy. Little research has been performed in the area of high-accuracy hydraulic positioning systems. Therefore, the objective of this study to achieve nano-scale positional accuracy with the EHA while maintaining large stroke and high force output. It was planned to achieve this objective through modification of the prototype EHA and the use of fuzzy control.
During this research project, both hardware and control system modifications to the EHA were
performed. A high-precision optical encoder position sensor with a 50 nm resolution was mounted on the inertial load to directly measure the position of the load. A number of device drivers were written to interface the MATLAB real-time control environment with the optical encoder and servo motor amplifier. A Sugeno-inference fuzzy controller was designed and implemented in MATLAB. For comparison purposes, a switched-gain controller and a proportional controller were also implemented in the control environment.
The performance of the fuzzy controller was compared to the switched-gain controller and
the proportional controller in a number of tests. First, the regulatory and tracking performance
of the EHA with an inertial load of 20 kg was examined. It was determined in the regulatory
tests that the positional accuracy of the EHA with the fuzzy controller was excellent, achieving
a steady state error of 50 ± 25 nm or less for step inputs in the range 5 cm to 200 nm. The
positional accuracy during the tracking tests was found to be reduced compared to the regulatory
tests since the actuator did not have sufficient time to settle to final accuracy due to the timevarying input signals. In all cases, it was found that the positional accuracy of the EHA with the fuzzy controller was significantly greater than with the switched-gain and proportional controllers for both regulatory and tracking signals. Testing with the inertial load eliminated or changed was not performed because the position sensor was mounted to the load, making it unfeasible to alter the load during the time frame of this study.
The regulatory and tracking performance of the EHA with an inertial load of 20 kg plus external
resistive loads of 90 to 280 N were investigated. It was found that the positional accuracy of the
EHA decreased with the application of an external load to 3.10 ± 0.835 µm for a 1 cm step input
(90 N load) and 8.45 ± 0.400 µm for a 3 cm step input (280 N load). Again, the positional accuracy
of the EHA decreased during the tracking tests relative to the regulatory tests, for the reason stated above. This implies that the positional accuracy of the EHA with a resistive load is in the microscale, rather than the nano-scale as was put forth as the objective of this study. Nevertheless, the positional accuracy of the EHA with the fuzzy controller was found to be significantly greater than with the switched-gain and proportional controllers. It is postulated that the increase in positional error observed during the external load tests was due to an increase in cross-port leakage, relative to
the inertial load tests, caused by the pressure differential induced across the actuator by the external load. Methods of reducing the increase in positional error caused by external loads on the EHA remains an area for future study.
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Implementation of A Swing System Based on Fuzzy ControlSi Tou, Tat-seng 11 August 2011 (has links)
none
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Visual Servo Control and Path Planning of Ball and Plate SystemChou, Chin-Chuan 02 September 2009 (has links)
This thesis presents a visual servo control scheme for a ball-and-plate
system with a maze. The maze built on the plate forms obstacles for the ball
and increases variety and complexity of its environment. The ball-and-plate
system is a two degrees-of-freedom robotic wrist with an acrylic plate attached
as the end effector. By using image processing techniques, the ball¡¦s position is
acquired from the visual feedback, which was implemented with a webcam and
a personal computer. A fuzzy controller, which provides dexterity of the robotic
wrist, is designed to decide the slope angles of the plate to guide the ball to a
designated target spot. Using the method of distance transform, the path
planning based on the current position of the ball is conducted to find the
shortest path toward the target spot. Besides, a relaxed path, appears to be more
suitable for actual applications, is provided by the obstacle¡¦s expansion
approach.
Experimental results show that the presented control framework
successfully leads the ball to pass through the maze and arrive at target spot.
The visual servo control scheme works effectively in both stabilization and
tracking control. Based on this preliminary achievement, further improvement
and deeper exploration on related research topics can be carried on in the
future.
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[en] ADAPTIVE HEURISTIC CONTROLLERS / [pt] CONTROLADORES HEURÍSTICOS ADAPTATIVOSRICARDO GUTIERRES 27 December 2006 (has links)
[pt] Um controlador Heurístico Adaptativo baseia-se num
conjunto de regras lingüísticas para conduzir um processo
com modelo impreciso ou complexo ao estado desejado. O
comportamento do processo deve respeitar os requisitos de
performance predefinidos. Para satisfazer estes objetivos,
a estrutura interna do controle sofre mudanças para adequá-
la as condições vigentes no processo.
Os métodos de adaptação abordados consideram a modificação
de uma estrutura matricial interpretada como as correções
incrementais, compatíveis com os ajustes a serem efetuados
sobre o processo, ou como regras, constituídas por
variáveis nebulosas, que requerem manipulações adicionais
para produzir a saída do controlador. Em qualquer dos
casos, a adaptação é realizada a partir de uma Tabela de
Índices de Performance. Para facilitar a sua obtenção é
implementado um procedimento, que fornece a representação
matricial das regras lingüísticas, concatenadas na forma
de um Algoritmo Lingüístico de Controle.
O comportamento dinâmico do Sistema, composto pelos
Controladores Heurísticos e por processos com modelos
distintos, é considerado para Tabelas de índices de
Performance com várias dimensões. As regras lingüísticas,
correlacionadas com estas tabelas, foram elaboradas com
diversas classes de atributos.
As simulações realizadas concentram-se sobre os parâmetros
dos controladores, que influenciam significativa-
Os estudos abordam também o comportamento da estrutura
interna destes controladores e o seu desempenho em termos
da velocidade de atuação sobre o processo. / [en] A heuristic Controller uses a set of linguistic rules,
which are derived from expertise or human operators´
skills, in order to achieve control of processes that have
inaccurate or complex models.
An adaptative Heuristic Controller adjusts the set of
rules in an automatic and continuous way, aiming to
achieve prescribed objectives indicated by a performance
measure.
The adaptative procedures modify a matrix, the elements of
which are either incremental corrections or numeric rules
associated with fuzzy variables. In both cases a
Performance Index Table and a learning method are employed
to correct that matrix. The Performance Table is a matrix
calculated from a set of linguistic rules.
The controllers are implemented with different Performance
Tables, considering various sets of linguistic values and
quantization levels.
The dynamic behaviour of overdamped and underdamped
processes is investigated. The performance of simulated
systems is analyzed with respect to relevant parameters
that affect their behaviour.
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Rotational Double Inverted PendulumLi, Bo 30 August 2013 (has links)
No description available.
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Advanced servo control of a pneumatic actuatorThomas, Michael Brian January 2003 (has links)
No description available.
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Intelligent control and force redistribution for a high-speed quadruped trotPalmer, Luther Robert, III 27 March 2007 (has links)
No description available.
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Integrating Collision Avoidance, Lane Keeping, and Cruise Control With an Optimal Controller and Fuzzy ControllerGrefe, William Kevin 11 May 2005 (has links)
This thesis presents collision avoidance integrated with lane keeping and adaptive cruise control for a car. Collision avoidance is the ability to avoid obstacles that are in the vehicle's path, without causing damage to the obstacle or car. There are three types of collision avoidance controllers, passive, active, and semi-active. This thesis is designed using active collision avoidance controllers.
There are two controllers developed for collision avoidance in this paper. They are an optimal controller and a fuzzy controller. The optimal vehicle trajectory, which maximizes the distance to an obstacle and changes lanes, is derived. The optimal collision avoidance controller is a closed loop controller; with the decisions based on the current state. The fuzzy controller makes decisions based on the system rules. A simulation environment was created to compare these two controllers as viable solutions for collision avoidance.
The environment uses MATLAB/Simulink for simulation of the vehicle as well as the optimal and fuzzy controllers. The simulation incorporates system blocks of the kinematics of a car, navigation, states, control law, and velocity controller. Once the controllers are fully developed and tested in the simulation environment, they are implemented and tested on the platform vehicle. This verifies the real world performance
of the controllers.
The platform vehicle is a modified radio controlled car. This car is completely autonomous. The car has onboard sensors that allow it to follow a white piece of tape as well as detect obstacles. / Master of Science
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Έλεγχος ανεμογεννήτριας επαγωγικής μηχανής βραχυκυκλωμένου κλωβού με ασαφή λογικήΚόκκοτας, Κωνσταντίνος 13 October 2013 (has links)
Ένα από τα σύγχρονα προβλήματα που απασχολούν του την κοινωνία είναι το ενεργειακό πρόβλημα, απόρροια της σταδιακής εξάντλησης των συμβατικών πηγών ενέργειας. Μία ιδιαίτερα ελκυστική λύση, αποτελεί η αξιοποίηση των ανανεώσιμων πηγών ενέργειας και ειδικά του ανέμου που παρέχει την αιολική
ενέργεια. Η παρούσα διπλωματική εργασία έχει ως θέμα τον έλεγχο ανεμογεννήτριας επαγωγικής μηχανής βραχυκυκλωμένου κλωβού(SCIG) με χρήση ασαφούς λογικής. Ο έλεγχος με ασαφή λογική είναι ταχέως
αναπτυσσόμενος καθώς πλησιάζει πολύ στην ανθρώπινη λογική. Βασιστήκαμε πάνω σε ένα ήδη υπάρχον μοντέλο μη-γραμμικού ελέγχου για αυτό το είδος ανεμογεννήτριας και το μετατρέψαμε κατάλληλα για την σταδιακή εφαρμογή της ασαφούς λογικής. Το σύστημα προσομοιώθηκε με τη βοήθεια της εφαρμογής Simulink του λογισμικού Matlab. Τα αποτελέσματα παρουσιάζονται μέσω διαγραμμάτων και εξάγονται τα ανάλογα συμπεράσματα. / One of the current issues that concern the society is the energy problem of the gradual depletion of conventional energy sources. A particularly attractive solution is the exploitation of renewable energy sources, especially wind providing the wind. This thesis will deal with controlling wind turbine induction motor squirrel cage (SCIG) using fuzzy logic. The control with fuzzy
logic is rapidly growing as it approaches the human sense. We relied on an existing model of nonlinear control for this type turbine and turned it suitable for the application of fuzzy logic. The system was simulated with the help of application Simulink software Matlab. The results are presented through diagrams and the relative conclusions are extracted.
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Autonomous flight control system for an airshipAvenant, Gerrit Christiaan 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In recent years, the use of airships has become popular for observation purposes since they provide
a cost effective alternative to other aircraft. For this project a lateral and longitudinal flight control
system are required for waypoint navigation flight of an 8m long, non-rigid airship. The airship’s
actuators include a rudder, elevator and a propulsion system which can be vectored longitudinally.
Two airship models are evaluated for this project. A chosen model is linearised and a modal
analysis is done. The modal analysis is compared to a previous modal study done on the YEZ-2A
airship and is found to compare well. Each airship mode is discussed and the linear behaviour is
compared to the behaviour of the non-linear model.
A fuzzy logic controller design approach was undertaken for the design of speed, heading and
height controllers. These non-linear controllers were designed for the non-linear model, due to the
following reasons:
Fuzzy logic controllers show tolerance to model inaccuracies.
Complexity of design is simple.
Controllers can be adjusted intuitively.
Fuzzy logic controllers can be combined with conventional control techniques.
Simulation results showed adequate lateral and longitudinal performance, even when subjected
to light wind conditions and disturbances.
The inertial measuring unit implemented in a previous project is used and additional hardware
is designed and implemented for the control of the airship’s actuators. Several improvements are
made to the groundstation software to allow for activation of different controllers as well as for
setting up the desired flight plan.
The controller performance is tested through flight tests and shows adequate performance as
well as controller potential. Although further work is still required for improving the controllers’
performance, this thesis acts as a platform for future research. / AFRIKAANSE OPSOMMING: In die afgelope paar jaar het die gebruik van die lugskepe gewild geword vir waarnemings doeleindes
aangesien dit ’n koste effektiewe alternatief vir ander lugvaartuie bied. In hierdie projek word ’n
laterale en longitudinale beheerstelsel benodig vir merker navigasie vlugte met ’n 8m lang, nierigiede
lugskip. Die lugskip se aktueerders sluit in ’n rigtingroer, hoogteroer asook ’n aandrywing
stelsel wat oorlangs gestuur kan word.
Vir hierdie projek is twee lugskip modelle geïmplementeer. Die gekose model is gelineariseer
en ’n modale analise is gedoen. Die modale analise is met ’n vorige modale studie vir die YEZ-2A
lugskip vergelyk en wys soortegelyke linieêre gedrag. Die lugskip modusse is bespreek en die linieêre
gedrag word met die gedrag van die nie-linieêre model vergelyk.
Daar is op ’n fuzzy logiese beheerder ontwerp besluit vir die ontwerp van spoed, rigting en hoogte
beheerders. Hierdie nie-linieêre beheerders is ontwerp vir die nie-linieêre model a.g.v. die volgende
redes:
Fuzzy logiese beheerders toon toleransie vir modellering of meetfoute.
Kompleksiteit van die ontwerp is eenvoudig.
Beheerders kan intuïtief aangepas word.
Fuzzy logiese beheerders kan met konvensionele beheertegnieke gekombineer word.
Simulasie resultate toon voldoende werkverrigtinge, selfs in die teenwoordigheid van ligte wind
sowel as ander versteurings.
Die inersiële metings eenheid, wat geïmplementeer is in ’n vorige projek, is gebruik en addisionele
hardeware vir die beheer van die lugskip is aktueerders is ontwerp en geïmplementeer. Talle
verbeterings is aangebring aan die grondstasie sagteware vir die aktiveer van die beheerders sowel
as die uitleg van die gekose vlugplan.
Die beheerders se werksverrigtinge is getoets gedurende vlugtoetse en toon voldoende beheer
vermoë sowel as beheerder potensiaal. Alhoewel verdere werk steeds nodig is vir die verbetering
van die beheerders, dien hierdie tesis as ’n platform vir toekomstige navorsing.
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