Zuhtu Hakan Akpolat

Speech recognition using a wavelet packet adaptive network based fuzzy inference system

Abstract In this paper, an expert speech recognition system is presented. This paper especially deals with the combination of feature extraction and classification for real speech signals. A Wavelet packet adaptive network based fuzzy inference system (WPANFIS) model is developed in this study. WPANFIS consists of two layers: wavelet packet and adaptive network based fuzzy inference system. The wavelet packet layer is used for adaptive feature extraction in the time–frequency domain and is composed of wavelet packet decomposition and wavelet packet entropy. The performance of the developed system is evaluated by using noisy speech signals. Test results showing the effectiveness of the proposed speech recognition system are presented in the paper. The rate of correct classification is about 92% for the sample speech signals.

A software tool: Type-2 fuzzy logic toolbox

The concept of type‐2 fuzzy set was initially proposed as an extension of classical (type‐1) fuzzy sets. Type‐2 fuzzy sets are very useful in circumstances where it is difficult to determine an exact membership function for a fuzzy set; hence they are very effective for dealing with uncertainties. However, type‐2 fuzzy sets are more difficult to use and understand than type‐1 fuzzy sets. Even in the face of these difficulties, type‐2 fuzzy logic has found applications in many fields. In this article, a new Type‐2 Fuzzy Logic Toolbox written in MATLAB programming language is introduced. The main aim is to help the user to understand and implement type‐2 fuzzy logic systems easily. Type‐2 Fuzzy Logic Controller Block is also prepared for use in SIMULINK. Since general type‐2 fuzzy logic systems are very complicated, they are not preferred in applications. Thus, only interval type‐2 fuzzy logic systems are considered in the proposed Type‐2 Fuzzy Logic Toolbox. Since MATLAB Fuzzy Logic Toolbox users are familiar with its windows, all the menus of the developed software are prepared in the same format of the MATLAB Fuzzy Logic Toolbox.

Modeling and implementation of a biomimetic robotic fish

In this study, design and implementation of a remote-controlled, 4-joints flapping mechanism and autonomous-swimming biomimetic robotic fish are presented. The propulsive model of the robotic fish is given considering the biological fish structure. The motion control of the robotic fish is performed by using speed and position control. The forward speed of the robotic fish can be adjusted by changing oscillation frequency, oscillation amplitude and length of the oscillation mechanism. Its position is controlled by implementing different joints angles.

Type-2 Fuzzy Sliding Mode Control of A Four-Bar Mechanism

Abstract This paper describes a new control scheme for the robust crank angular speed control of a four-bar mechanism driven by a DC motor. The proposed control method is based on type-2 fuzzy logic and sliding mode control (SMC) technique. Type-2 fuzzy control (FC) systems are characterized by type-2 membership functions which are useful in circumstances where it is difficult to determine an exact membership function. They are also very effective to handle uncertainties because type-2 fuzzy systems can model them and minimize their effects. SMC is a robust control method against parameter variations and external disturbances. Type-2 fuzzy logic and SMC can be combined to use the advantages of both methods and thus to improve the effectiveness of the controllers. One of the most important advantages of the use of SMC with type-2 FC is to reduce the number of fuzzy rules and thus to obtain a simpler and more practical control algorithm to use in real applications. To show the effectiveness of the proposed controller, simulation results of the Type-2 FC and Type-2 FSMC systems are presented in the paper.

Type-2 fuzzy reaching law speed control of an electric drive

Abstract In this paper, a new control scheme is described for the robust speed control of electrical drives. The proposed control method is based on type-2 fuzzy logic and Sliding Mode Control (SMC) technique. In the design of the proposed controller, Reaching Law Control (RLC) approach—a SMC design method—is used. Takagi-Sugeno-Kang (TSK) fuzzy system and interval type-2 fuzzy sets are preferred due to their suitability for control applications. Non-singleton fuzzification is employed because of its effectiveness on uncertainties. The control performance is tested under inertialfrictional variations and external load torque disturbances. To show the effectiveness of the new control approach, simulation results of the SMC and type-2 fuzzy SMC (T2FSMC) systems are presented together.

DYNAMIC MODEL AND SIMULATION OF ONE ACTIVE JOINT ROBOTIC FISH

This study considers the dynamic model of one active joint robotic fish by using Lagrange method and simulation of the robotic fish model in MATLAB/SimMechanics environment. Compared results of these two different models are given in the study. The mathematical model of the system is derived from Lagrange energy equations of the robotic fish inspired from a real carangiform fish. The Computer Aided Design (CAD) model of the robotic fish is designed by using SolidWorks and it is transferred to the SimMechanics environment. The hydrodynamic effects, which are linear and nonlinear drag force, are also adapted and head motion, one active joint, and one passive joint angles found by using MATLAB Simulink environment. Obtained results for joint angles from both dynamic and SimMechanics models are compared and proved with animation video of the robotic fish.

Design and Control of Diving Mechanism for the Biomimetic Robotic Fish

This paper focuses on generating nonlinear mathematical model of the robotic fish and design a novel diving mechanism for the robotic fish prototype. For this purpose, diving behavior of a real fish is analyzed by using Kineova 8.20. The designed diving mechanism model is constructed by using moving of the sliding mass and dynamic model of robotic fish behavior is performed completely. The diving mechanism is also rearranged by adapting to the robotic fish prototype in order to obtain simple and better design performance. Hence, three dimensional motions results are obtained by using the nonlinear mathematical model and diving mechanism of the robotic fish with different diving angles.

Robust Control of a Robot Arm Using an Optimized PID Controller

In this study, Scorbot ER-V Plus robot arm is drawn on SolidWorks environment. The 3D solid model of the robot arm is converted into SimMechanics form. The electric motor actuating the system is controlled by using a PID controller with a low pass filter. The controller parameters are optimized by using sinusoidal reference and external disturbances corresponding to total uncertainties including parameter variations and load torque. The inverse kinematic is used to obtain joint angels from determined trajectory. Desired trajectory is achieved by applying the obtained joint angles. The proposed optimized controller provides a robust control performance and the simulation results are presented in the paper.

FARKLI KUYRUK MODELLERİNE SAHİP BİR ROBOT BALIĞIN FSI ANALİZİ

Bu calismada, akiskan icerisinde hareket edebilen ve farkli kuyruk yapilarina sahip olan robot baliga akiskan tarafindan etki eden hiz, basinc, kinetik enerji ve girdap degerlerinin bulunmasi amaclanmistir. Belirtilen amaca ulasmak icin Hesaplamali Akiskanlar Dinamigi (HAD) yazilimlarindan biri olan ANSYS paket programi kullanilmistir. Analizler icin carangiform yuzus moduna sahip baliklar ornek alinarak bir robot balik modeli ve 3 farkli kuyruk modeli SolidWorks paket programinda tasarlanmistir. Olusturulan robot balik modelleri icin Akiskan-Yapi Analizi (FSI) yontemi tercih edilmistir. Analizlerin sonuclarina gore kuyruklarin yuzey alanlarinin akiskanda olusturdugu hiz, basinc, kinetik enerji ve girdap degerlerini nasil etkiledigi incelenmistir. FSI analizlerindeki basinc, girdap ve kinetik enerji degerlerine bakildiginda olusturulan robot balik modeli icin en uygun kuyruk yapisinin girintili kuyruk yapisi oldugu sonucuna varilmistir.

Link length optimization of a biomimetic robotic fish based on Big Bang — Big Crunch algorithm

This paper is concerned with the link length optimization method of a biomimetic Carangiform robotic fish with multi-link propulsion mechanism. Motion characteristic of a real fish depends on the body traveling wave and propulsion mechanism of the robotic fish should imitates the traveling wave function. In order to imitate the body traveling wave with minimum error, intersection method is used and Big Bang - Big Crunch (BB-BC) optimization algorithm is adapted to this method. BB-BC algorithm is a heuristic and evolutionary optimization method. BB-BC is preferred in many nonlinear engineering problems because of the low computation time and very fast convergence speed. As a results, optimum link lengths and endpoints of the each joint are determined by using this combined method. Numerical results show that precise fitting effects and link length optimization can improve the propulsion efficiency of the robotic fish. Also, optimum links are proportioned according to actual size of a real Carangiform carp fish in the main axis and free swimming gaits of the real carp are proved.