Murat Lüy

Control of Pitch Angle of Wind Turbine by Fuzzy Pid Controller

AbstractThis article presents a study on set of PID parameters of blade pitch angle controller of wind turbine with fuzzy logic algorithm. Three individual control methods were used to control the wind turbine pitch angle. These control methods are conventional PI, fuzzy and fuzzy PID. With the use of these control methods, the system was protected from possible harms in high wind speed region and maintained changing of nominal output power. It was aimed to the control the wind turbine blade pitch angle in different wind speeds and to hold the output power stable in the set point by simulation of controllers with Matlab/Simulink Software. By evaluating the steady state time of output power received from the simulation results and steady state errors, the performances of the control systems have been measured and compared with one another. As a result of these simulation comparisons, it is clear that fuzzy PID controller performed better than PI and Fuzzy Controller.

WELDING PROCESS OPTIMIZATION WITH ARTIFICIAL NEURAL NETWORK APPLICATIONS

Correct detection of input and output parameters of a welding pro- cess is significant for successful development of an automated welding operation. In welding process literature, we observe that output parameters are predicted according to given input parameters. As a new approach to previous efforts, this paper presents a new modeling approach on prediction and classification of welding parameters. 3 different models are developed on a critical welding process based on Artificial Neural Networks (ANNs) which are (i) Output parameter prediction, (ii) Input parameter prediction (reverse application of output prediction model) and (iii) Classification of products. In this study, firstly we use Pareto Analysis for determining uncontrollable input parameters of the welding process based on expert views. With the help of these analysis, 9 uncontrollable parameters are determined among 22 potential parameters. Then, the welding process of ammu- nition is modeled as a multi-input multi-output process with 9 input and 3 output parameters. 1st model predicts the values of output parameters according to given input values. 2nd model predicts the values of correct input parameter combina- tion for a defect-free weld operation and 3rd model is used to classify the products whether defected or defect-free. 3rd model is also used for validation of results obtained by 1st and 2nd models. A high level of performance is attained by all the methods tested in this study. In addition, the product is a strategic ammunition in the armed forces inventory which is manufactured in a limited number of countries in the world. Before application of this study, the welding process of the product could not be carried out in a systematic way. The process was conducted by trial- and-error approach by changing input parameter values at each operation. This caused a lot of costs. With the help of this study, best parameter combination is found, tested, validated with ANNs and operation costs are minimized by 30%.

Backpropagation Neural Network Applications for a Welding Process Control Problem

The aim of this study is to develop predictive Artificial Neural Network (ANN) models for welding process control of a strategic product (155 mm. artillery ammunition) in armed forces’ inventories. The critical process about the production of product is the welding process. In this process, a rotating band is welded to the body of ammunition. This is a multi-input, multi-output process. In order to tackle problems in the welding process 2 different ANN models have been developed in this study. Model 1 is a Backpropagation Neural Network (BPNN) application used for classification of defective and defect-free products. Model 2 is a reverse BPNN application used for predicting input parameters given output values. In addition, with the help of models developed mean values of best values of some input parameters are found for a defect-free weld operation.

Position Estimation with Fuzzy Logic Based Dead Reckoning for GPS-Denied Environment

T he importance of security precautions has been increased as a consequence of raised terrorist incidents. Terrorist acts that move into the city from country sides have made tracking of security and military personnel more important. GPS signals, densely utilized for this tracking, pose a problem in signal blockage situation and GPS-denied environments. The main goal of this research is that to develop a practical positioning system for walking military personnel in GPS denied environments. The system is very useful for GPS signal blockage environments, such as tunnels, thick-walled structures and dense high rise buildings, etc. Proposed system contains a 6-degree of freedom (DOF) inertial measurement unit (IMU) and digital compass attached to the military personnel’s shoe. Tri-axis accelerometer and gyroscope measurements are obtained by IMU. These measurements are applied to fuzzy logic algorithms and total displacement for each step is calculated. Digital compass is utilized to determine direction of personnel. Thus, current location has been estimated with the known starting point.

Laser Obstacle Sensor based System Design on Light Railway Systems

Gunumuzde yerlesim bolgelerindeki nufusun cok yogun oldugu yerlerde toplu ulasim araclari ve ozellikle demiryollari cok onemli hale gelmistir. Bu durum demiryollarindaki guvenlik onlemlerini de onemli hale getirmektedir. Bu baglamda calismada hafif rayli sistemlerdeki ulasimda onemli yere sahip olan kaza onleme ve sisteminin guvenli bir sekilde durdurulmasi uzerine calisilmistir. Hafif rayli sistemlerde ulasim sisteminde olusabilecek kaza tehditlerinin basinda tramvayin onune cikabilecek engellerin algilanmasi, bu durumun tren guvenlik sistemince tanimlanmasi ve gerekli guvenlik mekanizmasinin calistirilmasi gerceklestirilmistir. Tren raylari uzerine bilerek ya da bilmeyerek birakilan cisimler, guzergâh uzerinde yuruyen insanlar, trafikteki diger araclar algilanmakta ve gelistirilen yazilimla degerlendirilmektedir. Degerlendirme cisimlerin hiz, konum ve buyukluk olarak gozlemlenmesi ve carpma olasiligina karsi surucunun uyarilmasi devaminda fren mekanizmasinin devreye girmesi saglanmaktadir. Calisma bir proje1 cercevesinde gercek zamanli olarak Bursa’da Durmazlar Makine Sanayi A.Ş. tarafindan uretilmis bir tramvay icin gelistirilmis ve test araci olarak kullanilmistir. Calismada insan sagligina zararsiz sinif-1 lazer sinyaller ureten bir tarayici tramvay uzerinde kullanilarak yol guzergahindaki nesneleri tarama islemi yatay duzlemde ve iki boyutlu olarak gerceklestirilmistir. Tramvay guvenlik sistemine lazer tarayici sisteminin entegrasyonu ile tarama alani surucuye on panelde gorsel olarak sunulmus ve sistem, surucu uyarilari ve otomatik frenleme sistemiyle donatilmistir.