A fuzzy approach for the network congestion problem

In the recent years, the unpredictable growth of the Internet has moreover pointed out the congestion problem, one of the problems that historicallyha ve affected the network. This paper deals with the design and the evaluation of a congestion control algorithm which adopts a FuzzyCon troller. The analogyb etween Proportional Integral (PI) regulators and Fuzzycon trollers is discussed and a method to determine the scaling factors of the Fuzzycon troller is presented. It is shown that the Fuzzycon troller outperforms the PI under traffic conditions which are different from those related to the operating point considered in the design

Hybrid Takagi‐Sugeno Fuzzy FED PID Control of Nonlinear Systems

The new method of proportional‐integral‐derivative (PID) controller is proposed in this paper for a hybrid fuzzy PID controller for nonlinear system. The important feature of the proposed approach is that it combines the fuzzy gain scheduling method and a fuzzy fed PID controller to solve the nonlinear control problem. The resultant fuzzy rule base of the proposed controller contains one part. This single part of the rules uses the Takagi–Sugeno method for solving the nonlinear problem. The simulation results of a nonlinear system show that the performance of a fed PID Hybrid Takagi‐Sugeno fuzzy controller is better than that of the conventional fuzzy PID controller or Hybrid Mamdani fuzzy FED PID controller

Power Quality Enhancement of DFIG Based Wind Energy System Using Priority Control Strategies

A. BOUZEKRI T. ALLAOUI, M. DENAI, 'Power Quality Enhancement of DFIG Based Wind Energy System Using Priority Control Strategies', Journal of Electrical Engineering, Vol. 15 (4): 139-145, 2015.The integration of intermittent renewable energy sources into the electric grid presents some challenges in terms of power quality issues, voltage regulation and stability. Power quality relates to those factors which affect the variability of the voltage level and distortion of the voltage and current waveforms which can cause severe adverse effects to the electric grid. The paper focuses on the design and evaluation of a priority control strategy for improving the quality of energy of a grid-connected variable speed Doubly Fed Induction Generator (DFIG) wind energy conversion system. The aim of priority control is to manage the priority among three different controls: active stator power control; reactive stator power control and harmonic rotor current control by using the active shunt filter with SRF method harmonic compensation, and to have a high performance and robustness; an adaptive-fuzzy PI control are including for currents rotor control. The simulation model was developed in Matlab/Simulink environment. The results show that the proposed control scheme can effectively reduce the Total Harmonic Distortion (THD) in the grid currents.Peer reviewedFinal Published versio

Review on decomposed fuzzy PID structure for power inverters regulation

The aim of this paper is to critically review prominent decomposed Fuzzy PID control structures. Structural construction and output control laws of these controllers will be discussed. Their merits and drawbacks are highlighted. Based on the critical discussions, a new structure of Fuzzy PID controller is proposed. It is based on cascaded structure, which yields simpler design flow and parameters tuning. Other advantages of the proposed Fuzzy PID structure are the reduction of tuning parameters and rules of the Fuzzy controller. In addition, the proposed structure allows the usage of signed distance method. The application of the method reduces the computation burden significantly as the power inverter regulation needs very fast and precise computation

Fuzzy-PID Position Control of a Three Fingered Robot Hand for Grasping Varying Loads / Norshariza Mohd Salleh ...[et al.]

In previous study, PID control was used to control the joint’s motor position of a three fingered robot hand. However, it can be observed that PID control alone could not cater the nonlinearities caused by varying weight loads and friction from the gears. Both the settling time and rise time increased as the weight exceeded 20g, thus deteriorated the transient response performance. Therefore, this paper discusses the development of an intelligent system with PID control namely Fuzzy-PID control for a 6-DOF robot hand. The proposed control is capable of tuning the PID gains automatically when different loads are applied. Fuzzy Inference System was established based on the previous investigation on the effects of varying loads with the transient response parameters where the settling time and rise time have been taken as inputs and PID gains as the outputs. The proposed control specifically focused on one of the 2-DOF robotic finger. The same control inputs were applied to the motors of the other two fingers to provide synchronous motion. Finally, the proposed control was verified in real-time experiments for varying weight loads from 0g to 100g with 20g increments in terms of percent of overshoot, settling time, rise time and steady state error. From the experimental results, Fuzzy-PID control proved that it is capable to improve TS by the maximum of 17.75% and the maximum of 1.21% of TR compared to PID control only. No significant improvement was observed for percentage of overshoot and steady state error. Furthermore, the proposed control has successfully applied for random weights grasping by the 6-DOF robot hand with TS and TR improvement of 14.51% for joint 1, 9.82% for joint 2 and 3.54% of joint 1 and 2.69% of joint 2 respectively compared to PID control. Hence, the proposed Fuzzy-PID can be applied for grasping objects with different weight in future work

Performance comparison of optimal fractional order hybrid fuzzy PID controllers for handling oscillatory fractional order processes with dead time

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Fuzzy logic based PID controllers have been studied in this paper, considering several combinations of hybrid controllers by grouping the proportional, integral and derivative actions with fuzzy inferencing in different forms. Fractional order (FO) rate of error signal and FO integral of control signal have been used in the design of a family of decomposed hybrid FO fuzzy PID controllers. The input and output scaling factors (SF) along with the integro-differential operators are tuned with real coded genetic algorithm (GA) to produce optimum closed loop performance by simultaneous consideration of the control loop error index and the control signal. Three different classes of fractional order oscillatory processes with various levels of relative dominance between time constant and time delay have been used to test the comparative merits of the proposed family of hybrid fractional order fuzzy PID controllers. Performance comparison of the different FO fuzzy PID controller structures has been done in terms of optimal set-point tracking, load disturbance rejection and minimal variation of manipulated variable or smaller actuator requirement etc. In addition, multi-objective Non-dominated Sorting Genetic Algorithm (NSGA-II) has been used to study the Pareto optimal trade-offs between the set point tracking and control signal, and the set point tracking and load disturbance performance for each of the controller structure to handle the three different types of processes

Pengaturan Kecepatan Motor Induksi Tiga Fasa Dengan Beban Rem Magnetik Menggunakan Metode Fuzzy PD Plus Integral

Pengaturan kecepatan motor induksi tiga fasa dibuat untuk mengatur putaran motor yang tidak linear, yang diakibatkan oleh gangguan beban, noise, dan banyak faktor lainnya. Tetapi ada beberapa kekurangan apabila motor dalam keadaan dinamis dimana keadaan motor dapat berubah secara terus-menerus, hal ini karena pengaruh dari beberapa faktor yang mengganggu dari beban dan noise. Sehingga dibutuhkan kontroler yang mampu menjaga plant agar tetap stabil. Pada Tugas Akhir ini untuk menjaga kestabilan plant digunakan kontroler Fuzzy PD plus kontroler Integral. Kontroler Fuzzy PD plus kontroler Integral merupakan gabungan dari dua kontroler, yaitu kontroler Fuzzy PD dan kontroler Integral. Kontroler ini unggul dalam bekerja dengan sistem non-linear dan juga tanpa memperhatikan beban, kontroler mampu mendekati nilai referensi sehingga tidak membutuhkan model matematis plant. Hasil pengujian antara simulasi dan implementasi menunjukkan bahwa hasil dari simulasi memiliki nilai % error steady state dan settling time 5% sebesar 0,044% dan 0,3 detik sedangkan hasil dari implementasi sebesar 0,015% dan 0,11 detik. ========== Speed control of three phase induction motor was made for motor’s rotation that aren’t linear caused by dynamic load, noise, and another factor. But there is some disadvantage if motor in dynamic condition where the condition of motor always change, this was caused by some factor that disturb from load and noise. Therefore controller is needed in order plant stable. In this final project , to keep stabilize the plant, PD Fuzzy plus Integral Controller was used. PD Fuzzy plus Integral Controller is composited by two controller, that is PD Fuzzy and Integral Controller. Advantages of t his controller is neglect load, controller able to approach setpoint value, so that model math plant is not needed and also controller have most superior with non -linear system . Result of experiment between simulation and implementation indicate that result from simulation has value of %error steady state and settling time 5% is 0.044% and 0. 3 second whereas result from implementation is 0.015% and 0. 11 secon