DSpace Arşivi :: by Yazar "Toz, Metin" değerine göre listeleniyor

Yazar "Toz, Metin" seçeneğine göre listele

Listeleniyor 1 - 20 / 20

5 Eksenli Manipülatörün Eklem Uzayında Yörünge Planlaması
(2017) Uzuner, Sabri; Akkuş, Nihat; Toz, Metin
Bu çalışmada eğitim amaçlı kullanılmak üzere dönel eklemlere sahip 5 Serbestlik Dereceli (SD) bir seri robot manipülatörü gerçekleştirilmiştir. Robot 150 gr taşıma kapasiteli ve eklem hareketleri rahat, sürtünmesiz ve titreşimsiz olarak hareket edebilmesine imkân sağlayacak özelliklerde,radyo kontrollü R/C Servo motorlar kullanılmıştır. Eklem uzayında yörünge planlaması yapabilmek için robotun ters kinematik problemi çözülmüş ve yörünge planlaması üçüncü dereceden bir polinom kullanılarak gerçekleştirilmiştir. Tasarlanan 5 eksenli manipülatörün kullanıcı tarafından rahat ve basit bir şekilde kullanılması amacıyla Visual BASIC programında görsel bir arayüz hazırlanmıştır. Son olarak geliştirilen mekanizmanın öğrenciler tarafından yapılan robotlarla ilgili uygulamalarda başarıyla kullanıldığı gözlemlenmiştir
5-DOF serial robot manipulator design, application and inverse kinematic solution through analytical method and simple search technique
(2020) Uzuner, Sabri; Akkus, Nihat; Toz, Metin
In this study a five Degrees of Freedom (DOF) serial robot manipulatorwas designed and implemented. The inverse kinematics problem, whichhas not exact analytical solution (only one inverse kinematic solutionfor a predefined end effector position in three dimensional space), of therobot mechanism was solved by using the combination of the analyticalmethod and a simple search method. In order to use the proposedmethod in real-time applications, the method is designed so that it canbe used to solve the inverse kinematics problem for the next point of theend-effector while the mechanism is working. Moreover, so that tocontrol the implemented mechanism, a user interface program waswritten by using Visual Basic programming language. Finally, theproposed inverse kinematic solution method was tested on two differenttrajectories, an arc shaped trajectory that composed of 58 points and alinear trajectory divided into 29 points. The obtained results revealedthat the proposed method can be used successfully in solving the inversekinematic problem of the designed mechanism.
Asimetrik üç serbestlik dereceli bir düzlemsel paralel robot mekanizmasının kinematik analizi
(2018) Toz, Metin
Bu çalışmada üç Serbestlik Derecesine (SD) sahip bir düzlemsel paralel robot mekanizmasının kinematik analizi gerçekleştirilmiştir. Seçilen mekanizmanın diğer düzlemsel mekanizmalardan farkı asimetrik bacak yapısına sahip olmasıdır. Asimetrik yapıyı elde etmek için 3-RPR (R:Dönel eklem, P: Aktif prizmatik eklem) yapısındaki simetrik bir düzlemsel robot mekanizmasının bir bacağı RRR (R: Aktif dönel eklem) tipi bacak ile değiştirilmiş ve bu sayede RPR2RRR1 adını verdiğimiz asimetrik düzlemsel paralel robot mekanizması elde edilmiştir. Bu mekanizma için ters kinematik, Jacobian matrisi ve tekil noktalardan bağımsız çalışma uzayı analizi ile ilgili hesaplamalar gerçekleştirilmiştir. Ayrıca bu mekanizmanın performansı simetrik düzlemsel bir paralel robot mekanizması olan 3-RPR mekanizması ile karşılaştırılmıştır. Elde edilen sonuçlara göre önerilen mekanizmanın çalışma uzayının hem uç işlevci tarafından ulaşılabilinen nokta sayısı hem de yönelim açısının sınır değerleri yönünden 3-RPR mekanizmasından daha iyi olduğu gösterilmiştir.
Chaos-based Vortex Search algorithm for solving inverse kinematics problem of serial robot manipulators with offset wrist
(Elsevier, 2020) Toz, Metin
Vortex Search (VS) algorithm is a single-solution-based optimization algorithm that requires the high maximum number of iterations (NOI) to solve optimization problems. In this study, two methods were proposed to reduce the required maximum NOI of the VS algorithm. These methods are based on using ten chaos maps with the VS algorithm and provide improvements in the exploration and exploitation abilities of the algorithm for reducing the required maximum NOI. Ten chaos-based VS algorithms (CVSs) were obtained by combining these methods with the VS algorithm. The performances of the CVS algorithms were tested by fifty benchmark functions. The results were evaluated in terms of some statistical values and a pairwise statistical test, Wilcoxon Signed-Rank Test. According to the results, it was found that the CVS algorithm obtained by using the Gauss-Mouse chaos map was the best algorithm. And also, it was shown that the proposed CVS algorithm performs better than the classical VS algorithm, even when its maximum NOI was ten times less than the maximum NOI of the VS algorithm. Additionally, the effects of the proposed methods in the exploration and the exploitation abilities of the VS algorithm were visually shown and a comparison about algorithm processing time was presented. In order to test the performance of the proposed CVS algorithm in solving the real-world optimization problems, the inverse kinematics problem of a six Degrees Of Freedom (DOF) serial robot manipulator with offset wrist was solved with both the proposed CVS algorithm and the VS algorithm for two different types of trajectories. The results showed that the proposed algorithm outperforms the VS algorithm in terms of the objective function values and position errors of the end-effector of the serial robot manipulator. (C) 2020 Elsevier B.V. All rights reserved.
A Comparative Study for Computational Cost of Fundamental Robot Manipulators
(Ieee, 2011) Toz, Metin; Küçük, Serdar
The computational cost of the dynamic equations is very important in real time control applications of industrial robot manipulators. Basically, the computational cost depends on the joint properties, the method used for deriving the dynamic equations and the algorithm efficiency. In this study, the dynamic equations for the sixteen three and six degrees of freedom fundamental robot configurations were derived using Newton-Euler (N-E), Lagrange-Euler (L-E) and Hamiltonian (H) methods in symbolic form. The computational costs of these dynamic equations for both three and six degrees of freedom manipulators are obtained. Some comparisons considering the joint properties, the method and the workspace geometries of the manipulators are performed and some important conclusions are summarized.
Data Clustering Based on FCM and WOA
(Ieee, 2018) Arslan, Hatice; Toz, Metin
In this article, we have proposed a new hybrid clustering algorithm based on Fuzzy C Means (FCM) and Whale Optimization Algorithm (WOA) using chaotic map. The random selection of the initial cluster centers in the FCM algorithm is a disadvantage for the algorithm. To reduce this disadvantage, the BOA algorithm, which is improved performance with chaotic maps, is used to optimize the initial cluster centers. The proposed hybrid algorithm is tested for four different sets of data and better results are obtained from the FCM algorithm.
DATA CLUSTERING BASED ON FUZZY C-MEANS AND CHAOTIC WHALE OPTIMIZATION ALGORITHMS
(Yildiz Technical Univ, 2019) Arslan, Hatice; Toz, Metin
Clustering is the process of sub-grouping data according to certain distance and similarity criteria. One of the most commonly used clustering algorithms in the literature is the Fuzzy C-Means (FCM) algorithm based on the fuzzy clustering principle. Although FCM is an efficient algorithm, random selection of initial cluster centers is a disadvantage since it easier trap the algorithm into local optimum. This problem can be solved by approaching the clustering problem as an optimization problem. In this article, Whale Optimization Algorithm (WOA), a global optimization algorithm developed by inspiration from hunting behaviors of humpback whales, has been improved with chaos maps using an adaptive normalization method and chaotic WOA algorithms are proposed. They are then hybridized with FCM algorithm. The performances of the proposed chaotic optimization algorithms are tested with thirteen different benchmark functions. Results are evaluated with means and standard deviations of the objective function values and with the Wilcoxon Sign Rank Test at 0.05 significance level. The clustering performances of the proposed hybrid algorithms measured according to the objective function, the Rand Index and the Adjusted Rand Index values and compared with the K-Means, FCM and some of the other hybrid algorithms for six different data sets selected from the UCI Repository database. In addition, the new hybrid clustering algorithms are improved by using Chebyshev distance function instead of the classical Euclidean distance for the FCM algorithm in order to increase their data clustering performances. As a result, it has been seen that the used chaos functions improve the optimization performance of WOA algorithm, integrating chaotic WOA algorithms with FCM algorithm enhances the disadvantages of FCM algorithm and changing the distance function increases clustering performance of the proposed algorithms.
Development of derivation of inverse Jacobian matrices for 195 6-DOF GSP mechanisms
(2016) Toz, Metin; Küçük, Serdar
One of the key issues in robotics is finding high-performance manipulator structures. To evaluate the performance of a parallel manipulator, researchers mostly use kinematic performance indices (such as condition number, minimum singular value, dexterity, and manipulability), which are based on inverse Jacobian matrices. Driving the inverse Jacobian matrix of even one parallel manipulator is a very cumbersome process. However, in this paper, general equations for the inverse Jacobian matrices of 195 GSP mechanisms are symbolically derived by considering 4 basic leg types having 1 angular and 4 distance constraints. With the help of these general equations, the development of the inverse Jacobian matrix for a GSP mechanism can be achieved by defining only the leg connection points on the base and moving platforms with minimum cost. Having derived the inverse Jacobian matrices, one can directly compute kinematic performance indices to measure and compare the manipulator performance of the 195 GSP mechanism. These analyses may yield new high-performance GSP mechanisms for use in engineering, medical device design, and other applied branches. Two different mechanisms (symmetrical and asymmetrical) are given as examples to describe the methodology for deriving the inverse Jacobian matrices. Finally, 2 numerical examples are given for illustrating the practical applications of the procedure.
Development of derivation of inverse Jacobian matrices for 195 6-DOF GSP mechanisms
(Tubitak Scientific & Technical Research Council Turkey, 2016) Toz, Metin; Küçük, Serdar
One of the key issues in robotics is finding high-performance manipulator structures. To evaluate the performance of a parallel manipulator, researchers mostly use kinematic performance indices (such as condition number, minimum singular value, dexterity, and manipulability), which are based on inverse Jacobian matrices. Driving the inverse Jacobian matrix of even one parallel manipulator is a very cumbersome process. However, in this paper, general equations for the inverse Jacobian matrices of 195 GSP mechanisms are symbolically derived by considering 4 basic leg types having 1 angular and 4 distance constraints. With the help of these general equations, the development of the inverse Jacobian matrix for a GSP mechanism can be achieved by defining only the leg connection points on the base and moving platforms with minimum cost. Having derived the inverse Jacobian matrices, one can directly compute kinematic performance indices to measure and compare the manipulator performance of the 195 GSP mechanism. These analyses may yield new high-performance GSP mechanisms for use in engineering, medical device design, and other applied branches. Two different mechanisms (symmetrical and asymmetrical) are given as examples to describe the methodology for deriving the inverse Jacobian matrices. Finally, 2 numerical examples are given for illustrating the practical applications of the procedure.
Dexterous workspace optimization of an asymmetric six-degree of freedom Stewart-Gough platform type manipulator
(Elsevier, 2013) Toz, Metin; Küçük, Serdar
In this paper, an asymmetric Generalized Stewart-Gough Platform (GSP) type parallel manipulator is designed by considering the type synthesis approach. The asymmetric six-Degree Of Freedom (DOE) manipulator optimized in this paper is selected among the GSPs classified under the name of 6D. The dexterous workspace optimization of Asymmetric parallel Manipulator with tEn Different Linear Actuator Lengths (AMEDIAL) subject to kinematics and geometric constraints is performed by using the Particle Swarm Optimization (PSO). The condition number and Minimum Singular Value (MSV) of homogenized Jacobian matrix are employed to obtain the dexterous workspace of AMEDLAL. Finally, the six-DOF AMEDLAL is also compared with the optimized Traditional Stewart-Gough Platform Manipulator (TSPM) considering the volume of the dexterous workspace in order to demonstrate its kinematic performance. Comparisons show that the manipulator proposed in this study illustrates better kinematic performance than TSPM. (C) 2013 Elsevier B.V. All rights reserved.
Dimensional optimization of 6-DOF 3-CCC type asymmetric parallel manipulator
(Taylor & Francis Ltd, 2014) Toz, Metin; Küçük, Serdar
In this paper, dimensional optimization of a six-degrees-of-freedom (DOF) 3-CCC (C: cylindrical joint) type asymmetric parallel manipulator (APM) is performed by using particle swarm optimization (PSO). The 3-CCC APM constructed by defining three angle and three distance constraints between base and moving platforms is a member of 3D3A generalized Stewart-Gough platform (GSP) type parallel manipulators. The dimensional optimization purposes to find the optimum limb lengths, lengths of line segments on the base and moving platforms, attachment points of the line segments on the base platform, the orientation angles of the moving platform, and position of the end-effector in the reachable workspace in order to maximize the translational and orientational dexterous workspaces of the 3-CCC APM, separately. The dexterous workspaces are obtained by applying condition number and minimum singular values of the Jacobian matrix. The optimization results are compared with the traditional GSP manipulator for illustrating the kinematic performance of 3-CCC APM. Optimizations show that 3-CCC APM have superior dexterous workspace characteristics than the traditional GSP manipulator.
Hybrid FCM-WOA Data Clustering Algorithm
(Ieee, 2018) Arslan, Hatice; Toz, Metin
In this work, we propose a hybrid clustering algorithm that integrates Fuzzy C-Means (FCM) and Whale Optimization Algorithm (WOA) using the Chebshev distance function. The FCM algorithm uses Euclidean distance to measure the similarity between the data. To avoid the existing disadvantages of the Euclidean distance, all distances in the FCM algorithm is calculated with the Chebsyhev distance function. The BOA algorithm is used to optimize the initial cluster centers. The proposed hybrid algorithm is tested with three different sets of data selected from UCI Machine Learning Repository database. As a result, it is seen that the clustering performance of the proposed algorithm is much better than the FCM algorithm.
An improved form of the ant lion optimization algorithm for image clustering problems
(2019) Toz, Metin
This paper proposes an improved form of the ant lion optimization algorithm (IALO) to solve image clusteringproblem. The improvement of the algorithm was made using a new boundary decreasing procedure. Moreover, a recentlyproposed objective function for image clustering in the literature was also improved to obtain well-separated clusters while minimizing the intracluster distances. In order to accurately demonstrate the performances of the proposed methods, firstly, twenty-three benchmark functions were solved with IALO and the results were compared with the ALO and a chaos-based ALO algorithm from the literature. Secondly, four benchmark images were clustered by IALO and the obtained results were compared with the results of particle swarm optimization, artificial bee colony, genetic, and Kmeans algorithms. Lastly, IALO, ALO, and the chaos-based ALO algorithm were compared in terms of image clustering by using the proposed objective function for three benchmark images. The comparison was made for the objective function values, the separateness and compactness properties of the clusters and also for two clustering indexes Davies– Bouldin and Xie–Beni. The results showed that the proposed boundary decreasing procedure increased the performance of the IALO algorithm, and also the IALO algorithm with the proposed objective function obtained very competitive results in terms of image clustering.
INVERSE KINEMATIC SOLUTION OF A 6 DOF SERIAL ROBOT MANIPULATOR WITH OFFSET WRIST BY USING ALO ALGORITHM
(Yildiz Technical Univ, 2017) Toz, Metin
The inverse kinematic problem is one of the most difficult problems to solve analytically for the serial robot manipulators. Its solution is highly related to the types and numbers of the joints of the manipulators. In this study the inverse kinematic problem of a six Degrees Of Freedoms (DOF) serial robot manipulator with offset wrist is solved by using Ant Lion Optimization (ALO) algorithm. In order to evaluate the performance of the algorithm, five workspace points are randomly selected and the inverse kinematic problem of the manipulator for these points are solved by the ALO algorithm. The obtained results are assessed according to the positioning error and the solution time. It is shown that the ALO algorithm can be effectively used for the solution of the inverse kinematic problem of the serial robot manipulators in terms of the both of the evaluating criteria.
A NOVEL IMAGE CLUSTERING ALGORITHM BASED ON DS and FCM
(Ieee, 2015) Toz, Metin; Toz, Güliz
Image clustering, the separation process of the image to the clusters which have pixels with similar properties is one of the most important sections of the image processing procedures. In this study we developed a novel image clustering algorithm by combining Differential Search algorithm (DS) which is a new optimization algorithm and Fuzzy Clustering Algorithm (FCM). Combining procedure was realized by minimizing the objective function of FCM by DS. As for testing purposes 3 brain MRI images were clustered by the new algorithm and the classical FCM. Both of the algorithms were compared in terms of objective function values. According to the results, the new algorithm out performs the classical FCM algorithm in terms of image clustering.
A novel mathematical model including the wetness parameter as a variable for prevention of pressure ulcers
(Sage Publications Ltd, 2021) Demircan, Fadime Ogulmus; Yucedag, Ibrahim; Toz, Metin
Pressure ulcers are injuries caused by external conditions such as pressure, friction, shear, and humidity resulting from staying in the same position for a long time in bedridden patients. It is a serious problem worldwide when assessed in terms of hospital capacity, nursing staff employment and treatment costs. In this study, we developed a novel mathematical model based on one of our previous models to prevent pressure ulcers or delay injuries. The proposed model uses a human thermal model that includes skin temperature, hypothalamus temperature, regional perspiration coefficient, and unconsciously loss of water amount. Moreover, in our model, we defined a variable wetness parameter in addition to the parameters, pressure, temperature, and humidity. The proposed model is mathematically defined in detail and tested for a wide range of parameters to show the model's effectiveness in determining the pressure ulcer formation risk. The model is also compared with a model from the literature that based on only the general parameters, pressure, temperature, and humidity. The obtained results showed that the model determines the risk of the occurrence of the pressure ulcer more precisely than the compared one.
Parallel manipulator software tool for design, analysis, and simulation of 195 GSP mechanisms
(Wiley, 2015) Toz, Metin; Küçük, Serdar
In this paper, a new parallel manipulator software tool based on the MATLAB Graphical User Interface (GUI) is developed for design, analysis and simulation of 195 6-DOF General Stewart Platform mechanisms (GSP). The new proposed tool called as GSPDAP uses four basic leg types to design GSP mechanisms. Point or line coordinates required for leg connections are sufficient for GSPDAP to design a GSP mechanism. Once the design of a GSP mechanism is completed, GSPDAP provides the user with several analyses such as inverse kinematics, Jacobian matrix, workspace, and dexterity. It is not necessary for the user to have preliminary knowledge to obtain the inverse kinematics or Jacobian matrix etc. Additionally, GSPDAP generates symbolic equations for the inverse kinematics and the inverse Jacobian matrices of 195 GSP mechanisms. Including 195 parallel manipulator in its library, GSPDAP provides the educational users to profoundly improve the understanding of parallel manipulator fundamentals through interactive simulation. Parallel manipulators are more complex structures than their serial counterparts. Therefore, designing even one parallel manipulator is very cumbersome and expensive issue. In this condition GSPDAP may provide educators and students to design their manipulators in a computer environment with minimum cost. (c) 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:931-946, 2015; View this article online at ; DOI
Personal Space Calculation and Path Planning for Mobile Robots Based on the Turkish Social and Cultural Structure and the Gender
(Ieee, 2018) Tolunbüke, Canberk; Toz, Metin
The introduction of robots into the physical world of humans necessitates complying with the rules of society, such as respect for people's personal space. This study concentrates on the determination of the personal space of the humans when the mobile robots approach them because of the frequent use of these robots in recent years specifically in a service field. For this purpose, unlike other works, gender difference, as well as the rules peculiar to the social and cultural structure of the Turkish society have been taken into consideration instead of general social rules, and thus improvement of the personal space determination is intended to be peculiar to the Turkish society. Moreover, two main rules have been established to be the basis of this proposed method of personal space determination. It is aimed that mobile robots comply with the rules of Turkish society thanks to these main rules in the course of being used. According to study results, sample illustrations are presented by calculating the personal space for groups consisting of one, two, three, four and five persons. As a result of the calculations, the changes between individuals and groups' personal spaces are shown. In addition, a sample path planning application using Ant Lion Optimization (ALO) algorithm is also presented.
Snow Flake Optimization Algorithm
(Ieee, 2018) Akkoyun, Özgün; Toz, Metin
Optimization is the best result finding process under certain constraints for a given problem. In this study, a new population-based optimization algorithm, Snow Flake Optimization Algorithm (SFO), is proposed to model a snowflake falling on the ground. The mathematical formulation of the developed algorithm is given. In addition, 8 benchmark functions are solved with the proposed algorithm and the results are presented in tabular form. According to the results, SFO achieved successful results in solving all functions.
Trajectory Planning of a 5-DOF Serial Robot Manipulator in Joint-Space
(Gazi Univ, 2017) Uzuner, Sabri; Akkuş, Nihat; Toz, Metin
In this study, a five Degrees of Freedom (DOF) serial robot manipulator with revolute joints was designed and realized to be used for educational purposes. The robot has 150 gr payload and the motions of the joints were provided by using radio controlled R/C servo motors with smooth and vibration-free movement. In order to perform the trajectory planning in the joint space the inverse kinematics problem of the robot was solved and a third order polynomial was used for the trajectory planning. So as to present a simple and efficient way to the user for controlling the robot, a visual user interface was also designed by utilizing Visual Basic Programming Language. Finally, it was observed that the designed mechanism has been successfully used by the students for the projects involving robots.

Yazar "Toz, Metin" seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri