Search results for " fuzzy"

showing 10 items of 209 documents

Adaptive type-2 fuzzy logic control of a bioreactor

2010

Two adaptive type-2 fuzzy logic controllers with minimum number of rules are developed and compared by simulation for control of a bioreactor in which aerobic alcoholic fermentation for the growth of Saccharomyces cerevisiae takes place. The bioreactor model is characterized by nonlinearity and parameter uncertainty. The first adaptive fuzzy controller is a type-2 fuzzy-neuro-predictive controller (T2FNPC) that combines the capability of type-2 fuzzy logic to handle uncertainties, with the ability of predictive control to predict future plant performance making use of a neural network model of the nonlinear system. The second adaptive fuzzy controller is instead a self-tuning type-2 PI cont…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciAdaptive neuro fuzzy inference systemEngineeringAdaptive controlNeuro-fuzzybusiness.industryApplied MathematicsGeneral Chemical EngineeringNonlinear dynamicBioreactorAdaptive controlPID controllerControl engineeringGeneral ChemistryFuzzy control systemFuzzy logicDefuzzificationIndustrial and Manufacturing EngineeringType-2 fuzzy logic controlControl theoryProcess controlbusinessStabilityProcess control; Adaptive control; Type-2 fuzzy logic control; Stability; Nonlinear dynamics; BioreactorChemical Engineering Science
researchProduct

Nonlinear fuzzy control of a fed-batch reactor for penicillin production

2012

Abstract The process of penicillin production is characterized by nonlinearities and parameter uncertainties that make it difficult to control. In the paper the development and testing of a multivariable fuzzy control system that makes use of type-2 fuzzy sets for the control of pH and temperature are described. The performance of the type-2 fuzzy logic control system (T2FLCS) is compared by simulation with that of a type-1 fuzzy logic control system (T1FLCS) and that of a control system with traditional proportional-integral-derivative (PID) controllers proposed in the literature. The fuzzy controllers are optimized using an ANFIS algorithm. The best results are obtained with the T2FLCS pa…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciAdaptive neuro fuzzy inference systemEngineeringbusiness.industryGeneral Chemical EngineeringMultivariable calculusFuzzy setnon linear systemPID controllerControl engineeringFuzzy control systemFuzzy logicComputer Science ApplicationsNonlinear systemControl theorytype-2 fuzzy logic controllerControl systemfed batch fermentoruncertaintybusinessComputers & Chemical Engineering
researchProduct

Control of a Non-isothermal CSTR by Type-2 Fuzzy Logic Controllers

2009

The paper describes the application of a type-2 fuzzy logic controller (FLC) to a non-isothermal continuous stirred tank reactor (CSTR) characterized by the presence of saddle node and Hopf bifurcations. Its performance is compared with a type-1 fuzzy logic controller performance. A full analysis of the uncontrolled CSTR dynamic was carried out and used for the feedback-feedforward fuzzy controllers development. Simulation results confirm the effectiveness and the robustness of the type-2 FLCs which outperform their type-1 counterparts, particularly when uncertainties are present in the system.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciComputer scienceContinuous stirred-tank reactorSaddle-node bifurcationFuzzy logicIsothermal processType-2 fuzzy logic controllerFuzzy logic controllerNon-isothermal CSTRControl theoryRobustness (computer science)BifurcationNon-linear system.Bifurcation
researchProduct

Experimental Comparison of Type-1 and Type-2 Fuzzy Logic Controllers for the Control of Level and Temperature in a Vessel

2011

Abstract The objective of this experimental study is to compare the performance of type-1 and type-2 fuzzy logic controllers on a real system where the control of liquid level and temperature are considered. By the use of genetic algorithms it is possible to optimize the fuzzy sets of each fuzzy controller assuring high control performance. The experimental results show that a better control in terms of robustness can be achieved by type-2 fuzzy logic controllers.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciFuzzy classificationNeuro-fuzzyComputer scienceControl engineeringFuzzy control systemFuzzy logicDefuzzificationFuzzy electronicsControl theoryFuzzy set operationsFuzzy numberType-1 fuzzy logic controller type-2 fuzzy logic controller genetic algorithms.
researchProduct

Control of a nonlinear continuous bioreactor with bifurcation by a type-2 fuzzy logic controller

2008

The object of this paper is the application of a type-2 fuzzy logic controller to a nonlinear system that presents bifurcations. A bifurcation can cause instability in the system or can create new working conditions which, although stable, are unacceptable. The only practical solution for an efficient control is the use of high performance controllers that take into account the uncertainties of the process. A type-2 fuzzy logic controller is tested by simulation on a nonlinear bioreactor system that is characterized by a transcritical bifurcation. Simulation results show the validity of the proposed controllers in preventing the system from reaching bifurcation and instable or undesirable s…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciGeneral Chemical EngineeringControl (management)MathematicsofComputing_NUMERICALANALYSISProcess (computing)Control engineeringInstabilityStability (probability)Computer Science ApplicationsNonlinear systemTranscritical bifurcationControl theoryBioreactorType-2 fuzzy logic controller Bifurcation Nonlinear systems Stability BioreactorNonlinear Sciences::Pattern Formation and SolitonsBifurcationMathematics
researchProduct

Control of a non-isothermal continuous stirred tank reactor by a feedback–feedforward structure using type-2 fuzzy logic controllers

2011

A control system that uses type-2 fuzzy logic controllers (FLC) is proposed for the control of a non-isothermal continuous stirred tank reactor (CSTR), where a first order irreversible reaction occurs and that is characterized by the presence of bifurcations. Bifurcations due to parameter variations can bring the reactor to instability or create new working conditions which although stable are unacceptable. An extensive analysis of the uncontrolled CSTR dynamics was carried out and used for the choice of the control configuration and the development of controllers. In addition to a feedback controller, the introduction of a feedforward control loop was required to maintain effective control…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciInformation Systems and ManagementComputer scienceNon-linear systemsFeed forwardContinuous stirred-tank reactorFuzzy logicInstabilityIsothermal processComputer Science ApplicationsTheoretical Computer ScienceType-2 fuzzy logic controllerNonlinear systemNon-isothermal CSTRArtificial IntelligenceControl and Systems EngineeringControl theoryRobustness (computer science)Control systemBifurcationType-2 fuzzy logic controller; Non-isothermal CSTR; Bifurcation; Non-linear systemsSoftware
researchProduct

Development of a predicitive type-2 neurofuzzy controller

2009

A controller that combines the main characteristics and advantages of three different control methodologies is proposed for the control of systems with nonlinearities and uncertainties. A neural network predictive control approach is implemented modifying the output of a controller with a fuzzy logic structure that uses type-2 fuzzy sets. Neural networks are also used to optimize the membership function parameters. The proposed controller is tested by simulation for the control of a bioreactor characterized by bifurcation and parameter uncertainty.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciPredictive control Type-2 fuzzy logic systems Neurofuzzy control
researchProduct

A design methodology for adaptive type-2 fuzzy controllers

2011

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciType-2 fuzzy controller adapative control
researchProduct

Adaptive Type-2 Fuzzy Logic Control of Non-Linear Processes

2011

The main objective of this study is to provide a valid and effective approach for the design and development of an adaptive type-2 fuzzy controller (AT2FLC), based on the analysis of the nonlinear process dynamics and the use of an ANFIS technique for the optimization of the controller. The performance of the obtained AT2FLC, characterized by a few number of rules, is higher than the performance of a traditional type-2 fuzzy controller with a larger rule base. The proposed controller is particurarly suitable for the control of processes characterized by uncertainty and time varying parameters.

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicilcsh:Computer engineering. Computer hardwareComputingMethodologies_DOCUMENTANDTEXTPROCESSINGAdaptive controllcsh:TP155-156Non-linear processeslcsh:TK7885-7895Adaptive control; Type-2 fuzzy control;Non-linear processesType-2 fuzzy controllcsh:Chemical engineeringComputingMilieux_MISCELLANEOUSComputingMethodologies_COMPUTERGRAPHICS
researchProduct

Stability analysis of type-2 fuzzy logic controllers

2009

The application of the direct Lyapunov method to the stability analysis of systems controlled by type-2 fuzzy logic controllers (FLC) is presented. The method is an extension of a method proposed for type-1 fuzzy systems. It is usually applied to systems described by state equations and controlled by fuzzy controllers using state variables as inputs but has been extended to controllers that have the error and the integral of error of the controlled variable as inputs. The proposed method allows to modify the controller rule base so that the controlled system is stable in the operating range defined by the manipulative variable constraints. The method is applied to the stability analysis of …

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi Chimicilcsh:Computer engineering. Computer hardwareStability Type-2 fuzzy systems Lyapunov methodlcsh:TP155-156lcsh:TK7885-7895lcsh:Chemical engineering
researchProduct