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Full-Text Articles in Engineering
A Nonlinear Disturbance Observer Scheme For Discrete Time Control Systems, Mehmet Önder Efe, Coşku Kasnakoğlu
A Nonlinear Disturbance Observer Scheme For Discrete Time Control Systems, Mehmet Önder Efe, Coşku Kasnakoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a modification to the original disturbance observer based control (DOBC) scheme byredefining the lowpass filter using a nonlinear element. The proposed technique improves the disturbance predictionperformance for both small and large magnitude disturbance signals. The contribution of the current work is to unfoldthe stability and performance conditions under the proposed modification. A comparative set of simulation studies arediscussed and it is seen that the proposed modification results in smaller disturbance prediction error energy and smallertracking error energy when the plant model is discrete time and uncertain.
An Enhanced Bandwidth Disturbance Observer Based Control- S-Filter Approach, Mehmet Önder Efe, Coşku Kasnakoğlu
An Enhanced Bandwidth Disturbance Observer Based Control- S-Filter Approach, Mehmet Önder Efe, Coşku Kasnakoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
A continuous time enhanced bandwidth disturbance observer based control (DOBC) scheme is proposed in this paper. The classical Q -filter is implemented in feedback form and a signum function is inserted into the loop. The loop with this modification becomes capable of detecting small magnitude matched disturbances and we present an in depth discussion of the stability and performance issues comparatively. The proposed approach is called S-filter approach and the results outperform the classical approach under certain conditions. The contribution of the current paper is to advance the subject area to nonlinear filters for DOBC loops with guaranteed stability and …
Combined System Identification And Robust Control Of A Gimbal Platform, Mehmet Baskin, Mehmet Kemal Leblebi̇ci̇oğlu
Combined System Identification And Robust Control Of A Gimbal Platform, Mehmet Baskin, Mehmet Kemal Leblebi̇ci̇oğlu
Turkish Journal of Electrical Engineering and Computer Sciences
Gimbaled imaging systems require very high performance inertial stabilization loops to achieve clear image acquisition, precise pointing, and tracking performance. Therefore, higher bandwidths become essential to meet recent increased performance demands. However, such systems often posses flexible dynamics around target bandwidth and time delay of gyroscope sensors which put certain limit to achievable bandwidths. For inertial stabilization loops, widely used design techniques have difficulty in achieving large bandwidth and satisfying required robustness simultaneously. Clearly, high performance control design hinges on accurate control-relevant model set. For that reason, combined system identification and robust control method is preferred. In the system identification …
Hybrid Control Of Five-Phase Permanent Magnet Synchronous Machine Using Space Vector Modulation, Djamel Difi, Khaled Halbaoui, Djamel Boukhetala
Hybrid Control Of Five-Phase Permanent Magnet Synchronous Machine Using Space Vector Modulation, Djamel Difi, Khaled Halbaoui, Djamel Boukhetala
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims to study the hybrid control of a five-phase permanent-magnet synchronous machine improved by the space vector modulation (SVM) technique. The torque ripples and currents will therefore be reduced. This control is based on the theory of hybrid dynamic systems (HDS), its discrete component is the voltage inverter which has a finite number of states controlling the continuous component that represents the machine. The results of the simulation made on MATLAB/Simulink are presented and discussed in order to check the performance of the strategy of the studied control. They show, in particular, the main advantages of this control …
Robust Optimal Stabilization Of Balance Systems With Parametric Variations, Salman Zaffar, Attaullah Memon
Robust Optimal Stabilization Of Balance Systems With Parametric Variations, Salman Zaffar, Attaullah Memon
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a method of robust optimal stabilization for balance systems such as rocket and missile systems, Segway human transportation systems, and inverted pendulum systems. Constant-gain controllers such as linear-quadratic regulators may not guarantee stability let alone optimality for balance systems affected by parametric variations. The robust stability and robust performance achieved through the proposed variable-gain controller are better than those of the linear-quadratic regulator. The proposed controller consists of two components, one of which is designed offline for nominal values of parametric variations and one of which is updated online for off-nominal values of parametric variations. A salient …
Wide-Range Reliable Stabilization Of Time-Delayed Power Systems, Hisham M. Soliman, Abdellah Benzaouia, Hassan Yousef
Wide-Range Reliable Stabilization Of Time-Delayed Power Systems, Hisham M. Soliman, Abdellah Benzaouia, Hassan Yousef
Turkish Journal of Electrical Engineering and Computer Sciences
No abstract provided.
Relay Sliding Mode Control Based On The Input-Output Model, Şölen Kumbay Yildiz, Hüseyi̇n Demi̇rci̇oğlu
Relay Sliding Mode Control Based On The Input-Output Model, Şölen Kumbay Yildiz, Hüseyi̇n Demi̇rci̇oğlu
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the relay sliding mode control method based on the input-output model proposed in previous studies is revisited. Sliding conditions under ideal operating conditions are reformulated to fortify the theoretical background. Some additional issues, namely the effects of disturbances and measurement noise on the sliding mode conditions, are addressed and analyzed in detail. Finally, the theoretical results are put to the test by detailed simulation examples.
Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi
Robust Speed Controller Design For Induction Motors Based On Ifoc And Kharitonov Theorem, Bijan Moaveni, Mojtaba Khorshidi
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, robust PI controllers are designed to control the speed of induction motors based on a vector control strategy. The design methodology defines the robust stability and robust performance regions in the $k_{p}-k_{i}$ (PI controller coefficients) plane using the Kharitonov theorem. In the control system design procedure, a nonlinear induction motor is modeled as an uncertain linear model. The procedure of modeling the uncertainties is presented. The required scientific foundations for designing a robust PI controller are also introduced in the general case while the necessary equations are derived. In the final step, the design procedure for a …
Design Of Adaptive Compensators For The Control Of Robot Manipulators Robust To Unknown Structured And Unstructured Parameters, Recep Burkan
Design Of Adaptive Compensators For The Control Of Robot Manipulators Robust To Unknown Structured And Unstructured Parameters, Recep Burkan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a new adaptive-robust control approach for robot manipulators is developed. The adaptive-robust control law is not only robust to unknown structured parameters but also robust to unknown unstructured parameters such as unstructured joint friction and disturbances. The bounded disturbances and unstructured model are taken into account in a dynamic model and it is assumed that the structured and unstructured parameters are unknown. The structured and unstructured parameters are distinguished between parameters and these parameters are treated separately. Next, new parameter estimation functions are developed for each of the 2 uncertainty groups. After that, the developed dynamic adaptive …
Design Parameters And Uncertainty Bound Estimation Functions For Adaptive-Robust Control Of Robot Manipulators, Recep Burkan
Design Parameters And Uncertainty Bound Estimation Functions For Adaptive-Robust Control Of Robot Manipulators, Recep Burkan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a parameter and uncertainty bound estimation functions for adaptive-robust control of robot manipulators are developed. A Lyapunov function is defined and parameters and uncertainty bound estimation functions are developed based on the Lyapunov function. Thus, stability of an uncertain system is guaranteed and uniform boundedness of the tracking error is achieved. As distinct from previous parameter and bound estimation laws, the parameters and uncertainty bounds are updated as a function of a combination of trigonometric function depending on robot parameters and tracking error. Based on the same Lyapunov function, a robust control law is also defined and …
Decentralized Robust Load-Frequency Control Of Power System Based On Quantitative Feedback Theory, Aidin Sakhavati, Gevork Gharehpetian, Seyed Hossein Hosseini
Decentralized Robust Load-Frequency Control Of Power System Based On Quantitative Feedback Theory, Aidin Sakhavati, Gevork Gharehpetian, Seyed Hossein Hosseini
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims at investigating the problem of Load Frequency Control (LFC) in interconnected power systems in order to obtain robustness against uncertainties. A design method for a robust controller, based on Quantitative Feedback Theory (QFT), has been presented in this paper. For a two-area power system, the simulation results show that the system response with the proposed QFT controller exhibits transient response beyond PI controllers. It is also shown that the transient response of the tie line power can also be improved.
Modeling And Control Of Flow Problems By Adaptation-Based Linear Parameter Varying Models, Coşku Kasnakoğlu
Modeling And Control Of Flow Problems By Adaptation-Based Linear Parameter Varying Models, Coşku Kasnakoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper a systematic modeling and control approach for flow problems is considered. A nonlinear Galerkin model is obtained from the partial differential equations (PDEs) describing the flow; and a Linear Parameter Varying (LPV) model is constructed to approximate the Galerkin model, where the parameter variation of the LPV model is controller by an adaptation mechanism. The LPV model is then treated as a surrogate on which the control design is carried out, where the parameter variations provide a range of uncertainty in which the control design must perform satisfactorily. It is shown that if certain conditions are met, …