I. Eksin - Academia.edu (original) (raw)

Papers by I. Eksin

Transactions of the Institute of Measurement and Control, 2009

ABSTRACT In this study, a sliding mode controller with a linear time-varying sliding surface is p... more ABSTRACT In this study, a sliding mode controller with a linear time-varying sliding surface is proposed for high-order systems by generalizing the co-ordinate transformed sliding surface design algorithm devised by the authors for second-order systems. The sliding mode control law is formulated for the sliding surface that has been defined by using a time-varying function. The equivalent control term of the proposed controller is expressed as a sum of the equivalent control term of the conventional sliding mode controller and an additive signal, which is a linear function of system tracking error vector and a time-dependent monotonous function. Simulations are performed on a third-order non-linear model with external disturbances and parameter variations. The performance of the sliding mode controller with the proposed design methodology is compared both with a conventional sliding mode controller and with another sliding mode controller that also uses an additive term in the control law to minimize the reaching time. The simulation results have shown that the proposed method has improved the robustness and the transient response with respect to related sliding mode controllers.

IEEE Transactions on Systems, Man, and Cybernetics, 1995

2013 XXIV International Conference on Information, Communication and Automation Technologies (ICAT), 2013

ABSTRACT The peak observer method is firstly proposed and used for PID type fuzzy logic controlle... more ABSTRACT The peak observer method is firstly proposed and used for PID type fuzzy logic controllers. In this study, the peak observer method is adapted and then implemented to the classical PI control structure. The basic principle of the method is to change the controller parameters of the system using the peak values of the system response in order to improve system performance. Firstly, the peak observer method is reconsidered on a simple internal model control based classical PI controller. Later, the peak observer method is further developed and a new structure called model based peak observer is proposed and the parameters of PI controller are further tuned for a much better performance. The performances of the proposed methods are tested and compared on different systems based on simulations.

ECMS 2006 Proceedings edited by: W. Borutzky, A. Orsoni, R. Zobel, 2006

2011 11th International Conference on Intelligent Systems Design and Applications, 2011

ABSTRACT In this paper, a fuzzy-sliding model reference learning controller is proposed in which ... more ABSTRACT In this paper, a fuzzy-sliding model reference learning controller is proposed in which optimal scaling factors are assigned for the fuzzy sliding mode controllers. As the name of this study suggest the method is a breeding or hybrid combination of the fuzzy-sliding mode control (FSMC) and fuzzy model reference learning control (FMRLC) which inherits the benefits of these two methods. The main advantage of the proposed controller is that the number of rules has been reduced dramatically in comparison with the traditional FMRLC since fuzzy-sliding mode controllers are invoked in place of standard fuzzy logic controllers. The input and output scaling factors of fuzzy sliding mode controllers are adjusted using big bang - big crunch optimization method to provide an optimal result. The simulations for the proposed method are done on the inverted pendulum system. The results of these simulations demonstrate that the FS-MRLC achieves a robust performance with minimum number of fuzzy rules.

2011 IEEE 12th International Symposium on Computational Intelligence and Informatics (CINTI), 2011

ABSTRACT There are various ways to interpret uncertainty on membership functions of interval type... more ABSTRACT There are various ways to interpret uncertainty on membership functions of interval type-2 fuzzy sets. In this study, Granular Interval Type-2 Membership Functions (GIT2 MFs) are introduced. The footprint of uncertainty of GIT2 MFs is formed by using rectangular interval type-2 fuzzy granules. GIT2 MFs provide more degrees of freedom and flexibility in design procedure of interval type-2 membership functions. Therefore, interval type-2 fuzzy logic systems using GIT2 MFs have more potential to model and handle uncertainties. By using GIT2 MFs, uncertainties on the grades of membership functions can be represented independently for any region in the universe of discourse. Thus, it provides the designer to form highly nonlinear, discontinuous or hybrid membership functions which are formed as a combination of type-1 and type-2 characteristics. This makes it possible to model any desired discontinuity and nonlinearity on the universe of discourse or in any input-output mapping. The effectiveness of the proposed GIT2 MFs is demonstrated through simulations on modeling a nonlinear system having dead zone. The simulation results show that the fuzzy system using proposed GIT2 MFs is superior to the fuzzy system using conventional interval type-2 membership functions.

Proceedings of IECON '93 - 19th Annual Conference of IEEE Industrial Electronics, 1993

This paper presents a mathematical way of building a fuzzy model of any nonlinear system. The fuz... more This paper presents a mathematical way of building a fuzzy model of any nonlinear system. The fuzzy implications of the system model and the least square identification method have been used to describe the nonlinear systems under study. The phase plane on which the nonlinear system is to be represented has been partitioned into fuzzy subregions and a linear fuzzy system model has been identified for each region. Then it has been observed that the overall system behavior has been characterized quite satisfactorily by using this partitioned fuzzy modelling

... yüzeyi Sezai TOKAT*, İbrahim EKSİN, Müjde GÜZELKAYA İTÜ Elektrik-Elektronik Fakültesi, Kontro... more ... yüzeyi Sezai TOKAT*, İbrahim EKSİN, Müjde GÜZELKAYA İTÜ Elektrik-Elektronik Fakültesi, Kontrol Mühendisliği Bölümü, 34469, Maslak, İstanbul ... x ρ süreksiz kontrol kuralına ait kazanç değerinin parametre belirsizliklerine bağlı alt sınırını verir ve kesin pozitif gerçel bir sayıdır. ...

ABSTRACT In this paper, a systematical methodology is introduced to construct the rule base of an... more ABSTRACT In this paper, a systematical methodology is introduced to construct the rule base of an interval type-2 fuzzy logic controller based on an existing linear PI/PD controller. An easy and rapid generation of the fuzzy rules can be achieved through this technique. In addition, analytical structure of this controller is derived. A closed-fonn of the fuzzy controller output is achieved under the circumstances that the input type-2 membership functions a,re diamond-shaped and a closed-form inference engine is used. Consequently, a linear control law is transformed to a nonlinear structure and certain elaborations can be done on the parameters of the evolved closed output structure. Moreover, the designer can benefit from the nonlinear structure of the proposed controller and the extra degree of freedom of type-2 fuzzy sets. It can be concluded from the results that the proposed controller can be more robust to the parameter uncertainties and eliminate the oscillations much better than type-1 fuzzy logic and linear conventional controllers.

Proceedings of 2003 IEEE Conference on Control Applications, 2003. CCA 2003., 2003

Proceedings of the IEEE International Workshop on Intelligent Motion Control, 1990

ABSTRACT

2008 3rd International Symposium on Communications, Control, and Signal Processing, ISCCSP 2008, 2008

Abstract Fuzzy logic modeling is a powerful tool in representing nonlinear systems. Moreover, inv... more Abstract Fuzzy logic modeling is a powerful tool in representing nonlinear systems. Moreover, inverse fuzzy model can be used as a controller in an open loop fashion to produce perfect control. However, in the case of modeling mismatches and disturbances that might occur on the system, open loop control would not be sufficient. In that case, the modeling errors and disturbances could be compensated by internal model control (IMC) with an on-line model adaptation scheme. The on-line adaptation is usually accomplished ...

Transactions of the Institute of Measurement and Control, 2003

... with a nonlinear time-varying sliding surface Sezai Tokat, IBbrahim Eksin, Mu¨jde Gu¨zelkaya ... more ... with a nonlinear time-varying sliding surface Sezai Tokat, IBbrahim Eksin, Mu¨jde Gu¨zelkaya and M. Turan So¨ylemez Istanbul Technical University, Electrical and Electronics Faculty, Control Engineering Department, 80626 Maslak, Istanbul, Turkey ...

2012 IEEE 13th International Symposium on Computational Intelligence and Informatics (CINTI), 2012

ABSTRACT In this paper, an online tuned set-point regulator with a fuzzy mechanism is proposed. T... more ABSTRACT In this paper, an online tuned set-point regulator with a fuzzy mechanism is proposed. This proposed control structure exploits the advantages of one degree of freedom (1-DOF) and two degree of freedom (2-DOF) control forms. The blending mechanism of the set point regulator mix the filtered and pure reference signals so that the overall performance of the system is ameliorated with respect to load disturbance rejection and set-point following. In the proposed control structure, the PI controller is designed by using Internal Model Control (IMC) methodology. As a result of this chose, the proposed blending mechanism turns out to be a blending constant within the range of zero and one. Consequently, this blending constant can easily be tuned through a fuzzy inference mechanism, where the output signal is naturally the blending constant. First, the effectiveness of the proposed fuzzy adaptive set-point regulator is demonstrated and compared via simulations and then an experimental setup is design to show the applicability of the proposed control approach. The simulation and the experimental results show the benefit of the proposed method over the conventional counterparts.