Mehmet Turan Söylemez

Istanbul Technical University · Railway Systems Engineering

Günümüzde sürdürülebilir ve temiz enerji kullanan elektrikli araçların yaygınlaşmasıyla birlikte, bu araçların şarj planlaması ve en uygun şarj istasyonlarının belirlenmesi hayati bir ihtiyaç haline gelmiştir. Bu çalışmada, elektrikli araç kullanıcılarına en uygun şarj istasyonlarını öneren ve şarj planlamasını optimize eden bir derin q-öğrenme tab...

Günümüz büyük şehirlerinde ekonomik, sosyolojik ve ekolojik açıdan pek çok sıkıntıyı beraberinde getiren trafik problemi, dünyamız için en büyük problemlerden birisi haline gelmiştir. Araçların trafikte en çok vakit kaybettiği bölgelerden biri de trafik kavşaklarıdır. Bu kavşaklar üzerinde kaybedilen zamanı minimize etmeyi amaçlayan pek çok çalışma...

In contemporary times, the issue of traffic congestion has become a paramount concern affecting a broad spectrum of society. However, when it comes to emergency vehicles, particularly ambulances, this matter takes on even greater significance. This study addresses a research endeavor aimed at mitigating traffic risks for emergency situations. The p...

This paper extends the characteristic ratio approach using novel inequalities to ensure zero/low overshoot for linear‐time‐invariant systems with zeros. The extension provided by this paper is based on the maximally‐flatness property of a transfer function, where the square‐magnitude of the transfer function is ensured to be a low‐pass filter. In o...

Traffic intersections act as pivotal junctions where various streams of traffic intersect and intersecting movements occur. When traffic volumes are high, intersections that are efficiently designed and equipped with intelligent traffic control systems can optimize the movement of vehicles. Accordingly, the time spent by vehicles at intersections i...

Trafik sıkışıklığı sorununun önümüzdeki yıllarda daha karmaşık hale gelmesi beklenmektedir. Trafik sıkışıklığı problemlerinin en yoğun şekilde yaşandığı alanlar trafik kavşaklardır. Bu sorunu hafifletmek için bir kavşak kontrol yöntemi gereklidir. Bu çalışmada, kavşaklardaki trafik sıkışıklığını ortadan kaldırmak için üretilen akıllı kontrol sistem...

Günümüzde, trafik sorunu herkesi yakından ilgilendirmektedir. Fakat acil durum araçları söz konusu olduğunda, bu konu daha da önem kazanmaktadır. Bu çalışma, acil durumlar için trafik riskini azaltmayı amaçlayan bir araştırmayı ele almaktadır. Araştırmanın temel amacı, Derin Q-Öğrenimi yöntemini kullanarak ambulansların hastaları en hızlı ve en uyg...

Bu çalışmada, iki giriş iki çıkışlı sistemler için ayrık zaman düzleminde oransal-integral oransal-çift gecikmeli (PI-PR2) kontrolör yapısı önerilmiştir. Tasarım yöntemi olarak kontrol sistemlerinde sıkça karşılaşılan baskın kutup atama yaklaşımı kullanılmıştır. İki giriş iki çıkışlı sistem bir ayrıştırıcı ile iki alt sisteme bölünmüş ve her bir al...

Traffic congestion is a major concern for many metropolises. Although it is difficult to regulate traffic flow because of numerous complexities and uncertainties, the traffic congestion problem must be mitigated in order to reduce the environmental problems related to traffic and the time lost on the roads in big cities. Intelligent traffic control...

Demiryolu teknolojisinin gelişmesiyle birlikte emniyet ve konfor kavramları hiç olmadığı kadar önem kazanmıştır. Bu kapsamda yapılan sistem mühendisliği Güvenilirlik, Emre Amadelik, Bakım Yapılabilirlik ve Güvenlik (RAMS) analizleri ile işletilen sistemin güvenilir, elverişli, sürdürülebilir ve emniyetli bir şekilde işletilmesi garanti altına alınm...

In this paper, a decentralized proportional–integral proportional–retarded (PI-PR) controller design method is proposed for two-input two-output (TITO) systems in discrete-time domain. The well-known dominant pole assignment (DPA) approach is used as the basis of the proposed approach. The controller design starts with the decoupling of a given TIT...

In this study, it is aimed to design discrete time PI, PID and PIR controllers with the dominant pole region assignment method in order to have time domain characteristics of the closed loop system in the desired interval. First of all, determination of the boundary functions for the regions where the dominant and non-dominant poles of the closed-l...

Solving traffic congestion is one of the most important and complex problems, as it causes chaos in metropolitans, especially during rush hours. Traditional methods that continue to be used have proven to be inadequate, and as a result, the developing technology has affected all areas as well as the solutions to the traffic control problem. Intelli...

Multi-agent system applications, which started in the mid-1980s, are used in many areas such as e-commerce, e-health, information systems, robotic systems, traffic, transportation systems. One of the biggest reasons why multi-agent systems are so preferred is that they are more durable and work more efficiently than other systems. Although multi-ag...

Robustness analysis of disturbance observer (DOB)-based control systems under parametric uncertainty is addressed in this study. A spherical polynomial family-based approach is adopted to analyse how much uncertainty can be tolerated, and to capture a unified framework for different cases including non-minimum phase plant and different nominal and...

In metropolises, problems such as waste of time due to traffic congestion, and climate change are exposed. One of the main causes of climate change is traffic congestion, as it increases the amount of CO2 released. In this study, traffic congestion problem is focused on an intersection. By using the data on the number of vehicles on the roads of th...

In this study, a centralized automatic block controller that ensures fail-safe interlocking in open line and between the exit routes facing each other of two neighbouring stations are developed for fixed block signalling systems. In this way, a protected track form is created that ensures protection against following and opposing movements across t...

Traffic density in big cities is an important factor that reduces the quality of human life. With the increasing population of metropolitans and the inability of their infrastructures to handle this density, the traffic density is gradually increasing. As a result, passengers lose time in more traffic and the amount of emissions and hence air pollu...

A vast number of contemporary studies investigate to resolve traffic congestion in completely autonomous vehicle scenarios. In scenarios when autonomous vehicles approach an intersection at which there are no traffic signals, they are able to drive in a coordinated manner without colliding and minimizing the consumption of fuel or electricity, whic...

The traffic problem is a significant concern for many metropolitans around the world. Controlling the flow of traffic is problematic in terms of many complexities and uncertainties. Despite this situation, this problem needs to be solved as it reduces the productivity and living standards. Modern traffic control methods offer a more effective solut...

Günümüzde, birçok metro hattı projesinde sinyalizasyon sistemi olarak haberleşme tabanlı tren kontrolü (CBTC) sistemleri kullanılmaktadır. Otomasyon seviyesi-2 (GoA2) veya üzerinde bir otomasyon seviyesine sahip sinyalizasyon sistemi trenleri, önceden tanımlanmış hız profillerini dikkate alarak sürmekte ve tren trafiğini yönetmektedir. CBTC sisteml...

In this study, a new discrete proportional integral–proportional retarded (D-PI–PR) controller design method is proposed. The proposed controller involves replacing the PD controller in the classical PI–PD control structure with a PR controller in discrete time and is implemented using dominant pole assignment, which is carried out by help of the m...

In this paper, a novel robust PID controller design technique is proposed for the parametric uncertain systems via the dominant pole assignment approach. In the closed‐loop, it is aimed that two poles are placed in the desired (dominant) region, and it is guaranteed that the remaining (unassigned) poles are located far away from the dominant pole r...

Traffic is an important factor affecting human life quality in crowded cities. Increasing population and increasing individual vehicle ownership lead to an increase in traffic density. This leads to an increase in the time lost for travelers and pollution. Intersections are areas that cause more traffic density because of design making hurdles. Tra...

Traffic congestion is one of the leading causes of loss of productivity and low living standards in urban areas. The effectiveness of transport systems is a priority for modern society. The regions with the highest traffic density in cities are those with traffic intersections. Intelligent traffic light applications reduce waiting time in traffic....

Nowadays, most of the new metro systems deploy Communication Based Train Control system with grade of automation level 2 or above in which signaling system is driving the trains as per pre-defined speed profiles based on a set of performance parameters. IEEE Std. 1474 standard specifically names train acceleration, train coasting, and train braking...

Controlling rail voltage especially in DC electrified railways is an important issue for safety and economic reasons. A new possibility has started to arise in controlling the rail voltages with the increased usage of current limiting function in the railway vehicles. In some cases, it could actually be possible to isolate (weaken) catenary/3 rd ra...

Traffic density is a growing drawback with the crowding of cities in contemporary societies. As a consequence of financial and technological innovations, the living standards of people are improving yet this increases the number of cars and traffic density accordingly. Thus, the density of traffic is reducing the quality of life for individuals in...

This paper focuses on the design of the so called sky-hook controller, which is used to isolate vibrations on suspension systems. The design of the sky-hook controller is posed as a single input-single output static output feedback control problem. The design of the sky-hook controller is posed using the generalized plant with the sparse structure...

An autonomous emergency braking (AEB) system is a driver assistance system that helps to avoid or mitigate the damages of rear-end collisions. This is achieved by alerting the driver through collision warnings to induce driver initiated braking. If the driver does not react to the warnings issued by the system, then the AEB system starts applying t...

One of the most important problems today is the traffic congestion problem. The traffic problem is one of the main causes of loss of productivity and low living standards, especially in large cities. With the development of technology, the use of road vehicles is increasing. With the increasing number of vehicles, the efficiency of transportation i...

This paper is about autonomous emergency braking (AEB) system which is a driver assistance system that is mandated to be installed on certain categories of vehicles. AEB system aims to prevent rear end collisions or to diminish the damages and injuries in case such collisions are inevitable. This paper present an adaptive AEB system that is based o...

Quadrotor also referred to as quadcopter has an increasing reputation nowadays as a practical rotorcraft and an unmanned aerial vehicle (UAV). The high number of degrees of freedom makes stability a serious issue as well as a performance criterion. Although, many different methods and strategies of control are applied to different models of quadrot...

In railway transport, braking and traction forces mainly depend on the normal force and the adhesion coefficient between the wheel and the rail. Regarding the restrictions on controlling the normal force, maximization of adhesion coefficient seems to be the only way of increasing braking and tractive efforts. Moreover, efficient utilization of adhe...

In this paper, a robust control strategy of a railway traction system with induction motor is proposed. The control problem is divided into sub-loops such as, current loop, acceleration loop, speed loop and position loop. A conventional PI controller is designed for the current loop, which is a very fast loop in comparison to the other mechanical l...

Guaranteeing the stability is one of the fundamental problems of control engineering. In most of the dynamical systems, parameter uncertainties can not be avoided. Thus, it is crucial from a practical point of view to propose generic methods for analyzing the stability of uncertain parameter systems. In this study, the extension of previously propo...

The aim of this study is to introduce a novel approach for robust model predictive control (MPC) design based on stabilizing parameter spaces. In order to determine the stabilizing parameter regions, a Lyapunov equation based approach is proposed for nominal systems. In addition to the free controller parameters, it is also possible to determine bo...

In this paper, a digital PI-PD controller design method is proposed for arbitrary order systems with or without time-delay to achieve desired transient response in the closed-loop via dominant pole placement approach. The digital PI-PD controller design problem is solved by converting the original problem to the digital PID controller design proble...

In this study, firstly, the model of railway traction electric drive systems is derived analytically along with the indirect vector control approach. In such systems, there are several disturbance and uncertainty sources like varying total weight, weight distribution, environmental conditions, voltage irregularities etc. Furthermore, resistive forc...

Dominant roots of the closed loop characteristic equation play a crucial role in terms of the performance of Linear Time Invariant (LTI) systems. Within the scope of this study, a dominant pole placement approach which has two main phases is proposed for PI/PID type controllers. In the first phase, characteristic equation is partitioned into its do...

This paper presents a method to design PI and PID controllers in continuous time domain through dominant pole region assignment so that the closed-loop time domain characteristics remain within the desired interval. Firstly, parametrization of the PI controllers which assign the dominant pole pair to the desired region is given. The sub-region, in...

Today, there exist two main paradigms for the control of multi-component systems. These are central control and agent-based control paradigms. In systems with central control, the decisions are made by a central controller and the other unit performs the assigned task by giving feedback to the center after performing the task given by the central c...

Bu çalışma, zaman gecikmeli sistemler için parametre uzayı yaklaşımını kullanarak oransal-integral (PI) kontrolör parametrelerinin kararlı kılan değerlerini hesaplamak için bir yöntem önermektedir. Bu yöntem, PI kontrolör parametre uzayındaki kararlılık sınırları üzerine kuruludur. Kökleri sol yarı düzlemde bulunan kararlı bir karakteristik polinom...

Süspansiyonlar yol yüzeyindeki bozuklukların araç üzerine olan etkisini minimize etmek için üretilmiş sistemlerdir ve pa-sif, yarı aktif ve aktif olmak üzere üçe ayrılırlar. Bu çalışmada aktif süspansiyon sistemi sırasıyla gecikmeli rezonatör (GR), dogrusal kuadratik regülatör (LQR) ve model öngörülü kont-rolör (MPC) tarafından kontrol edilmiştir....

This paper introduces a new lightweight tool for simulative error propagation analysis of Simulink models. The tool allows a user to inject different types of faults that are common for embedded control systems and analyze error propagation to critical system parts and outputs. The intended workflow comprises the following three steps: (i) setup fa...

Efficient slip and slide control systems are crucial in railway transportation since maximization of adhesion utilization and minimization of operating costs mainly depend on performance of such control systems. In order to improve adhesion characteristics, slip and slide control systems should hold the slip ratio at its optimum value which is dete...

Permanent magnet synchronous motors (PMSMs) are widely used in industry due to their high torque per volume ratio, low noise, efficiency and wide stable operation region. Especially in home appliance applications, obtaining high torque using small motors and low audible noise has crucial importance. Therefore, conventional DC motors have been repla...

In this study, a new method is proposed in order to analytically determine the stability boundaries of discrete time linear systems. The stability conditions of discrete time systems are reformulated in this method to derive an equation that includes the products of all eigenvalues, that can be checked more easily than conditions on every single ei...

This work focuses on a quadrocopter model, which was developed by QuanserTM and named as Qball X4. First, mathematical model of the Qball X4 is obtained. Then, a conventional PID control technique is presented. This PID control parameters come from Qball user manual. After the presentation of conventional PID control, as an extension of the convent...

In this study, a Lyapunov Equation based stability mapping approach is proposed for MIMO systems in order to determine stability regions. Since the proposed approach is independent of the controller type and the number of the control variables, it is also applicable for SISO systems. In standard Lyapunov Equation approach, the designer should solve...

This paper provides a topology based analysis for the average consensus problem regarding various configurations and possibilities. Consensus problem which can be defined as the agreement of the agents in a multi-agent topology is a common problem in various fields of science, technology and engineering. The main subject focused on within the scope...

In this paper, a simple derivation for an all-stabilizing proportional controller set for first-order bi-proper systems with time delay is proposed. In contrast to proper systems, an extremely limited number of studies are available in the literature for such bi-proper systems. To fill this gap in the literature, broader aspects of the stabilizing...

Many Parameter Space Approach (PSA) based methods have been proposed previously to determine the stabilizing controller parameter spaces for discrete-time systems. The PSA approach is based on sweeping over the whole range of singular frequencies which leads to an expensive numerical computation to find the boundaries of the stability region. These...

In this study, a new approach is proposed to determine controller parameter spaces that achieve integrity for multivariable systems. Integrity refers to the property that the closed-loop system remains stable against arbitrary failures of certain subsystems in order to increase the reliability of industrial systems. The proposed approach is based o...

Yapılan bu çalı¸şmada matematiksel modeli elde edilen Qball X4 dört pervaneli rotor sisteminin, verilen referansı nasıl takip ettiği ve bu referans takibinin iyile¸ştirilmesi için kullanılan yöntemler anlatılmı¸stır. Ba¸şlangıçta referans takibi için klasik PID yöntemi kullanılmı¸ş olup, daha sonra ise PID tipli bulanık kontrolör tasarlanmı¸ştır. B...

Bu calismada, statik kosegen bir on kontrolor ile kontrol edilen Iki Girisli Iki Cikisli (TITO) sistemlerin kosegen baskinligi ve kararliligi problemleri ele alinmistir. Bu amacla, oncelikle standart kosegen baskinlik tanimina agirlik katsayilari eklenmistir. Ardindan, agirliklandirilmis kosegen baskinligin saglanmasi ve istenen baskinlik oranlarin...

In the dominant pole placement approach, it is important non-dominant poles to be located far away from the dominant pole pair. Otherwise, predicting the closed-loop system transient response is difficult and satisfying the performance criteria becomes very challenging. It is known that PI and PID controllers are well-known and commonly used contro...

This paper presents a simple PI tuning method for first order plus dead time (FOPDT) systems. Firstly, stabilizing PI parameters region is found for these kinds of systems. Then, optimal point of this region is selected using the Big Bang Big Crunch optimization algorithm and this work is extended to FOPDT systems that contain parameter uncertainty...

In this paper, the real time tracking performance of the fuzzy PID controller has been evaluated on nonlinear 3-DOF helicopter system. Quanser 3-DOF helicopter system has been utilized as experimental setup. Three separate fuzzy PID controller have been employed so as to control three state of the system. The dynamics of the system has been altered...

The main issue in controlling safety-critical systems such as nuclear power reactors or railway interlocking systems is to provide high safety and reliability where the risk ratio is at the highest level because small errors might result in hazardous accidents (e.g., death or injury of many people). The N-version programming technique, where N-diff...

In this study, diagonal dominance of two input two output systems are discussed by considering the standard and weighted diagonal dominance conditions separately. In addition, sufficient conditions using static diagonal controllers are derived for fixed frequencies. Derived results can be easily extended for a given frequency range. An algorithm is...

In this study, diagonal dominance of parametric uncertain two input two output systems are discussed. Controller gain regions of the static diagonal controller that guarantee the standard and the weighted diagonal dominance of a TITO system are determined non-conservatively for the nominal system. An algorithm is proposed to determine static contro...

It is important to know how far non-dominant poles can be located away from the dominant poles since the closed-loop system transient response may not be as expected, if the non-dominant poles are not placed far enough from the dominant pole pair. Even if the arbitrary pole assignment is possible with a full state feedback or an output feedback con...

Interlocking system is the most crucial part of the railway signaling system that ensures safe travel and transportation. In fixed block signaling systems (or namely, conventional railway systems), train movements are mainly rely on route reservation procedure. Identification of these routes including all prohibitions and the relations between rail...

In this paper, two methods for calculating all robustly stabilizing PI controllers for continuous time single-input single-output linear time invariant systems with multiplicative uncertainties are given. The first method which is based on parameter space approach is a geometric oriented method. The second method utilizes a generalization of Nyquis...

This paper presents a method for PID controller design which can achieve dominant pole assignment using two of the controller parameters. The non-dominant poles are restricted on the left of the line s = σH, where σH is the minimum feasible value, called as the feasibility border. It is obvious that a dominant pole assignment is not practical if σH...

Pole assignment is a well-established controller synthesis technique used in control engineering. An important drawback of the pole assignment technique is poor numerical accuracy of the resulting compensators especially for high order systems, when fixed precision arithmetic is used in calculations. Obviously there are several parameters that affe...

This paper will present several tools for model manipulation, model-order reduction, analysis, and the design/synthesis of control systems, developed in the symbolic algebra environment Mathematica. New control objects have been introduced in the framework of Mathematica's Control System Professional package, with several new associated transformat...

In this paper, a simple root locus based graphical method is proposed to calculate all stabilizing (destabilizing) proportional controller set which provides time-delay independent stability for single input single output (SISO) systems with time-delay. In other words, for the gains belong to this set, if the delay-free system is stable, the time-d...

Ensuring the system safety at all times is most important in railway systems where small failures may result in a large number of casualties and property loss. Although there are various design methods, safety precautions, and recommendations of the railway-related safety standards, sometimes the occurrence of accidents cannot be prevented. In this...

Most of the multivariable control systems include interactions between different input-output pairs. The control problem becomes more complex in case of significant interactions because single loop control solutions cannot be applied directly. In such cases, reducing the interactions with a pre-compensator can be accepted as the first step of desig...

In conventional railway systems (or fixed-block railway signaling systems), railway lines are divided into subsections, called railway blocks, which start and end with a signal. In order to prevent collisions, only one train is allowed in each railway block at a time. Since the occupancy of the next block is indicated by the signals, train drivers...

Guaranteed dominant pole placement problem has already been considered in the literature (Journal of Process Control 19(2009):349–352). For the systems that are higher-order or have dead-time, pole placement procedure with PID controllers via modified Nyquist plot and root-locus has been proposed. Based on this idea, the dominant pole placement pro...

This paper presents a symbolic PI tuning method for first orders systems with time delay based on Pade approximation. The presented method is very easy to use like well-known methods such as Ziegler-Nichols and Cohen-Coon. Besides its easiness, the method performs a faster step response and no overshoot. Furthermore, it provides a good robust perfo...

Systems with inverse response are difficult to be identified because of the existence of at least one zero at the right half s-plane. However, it is important to obtain the transfer function as accurately as possible for such systems to be able to provide the desired performance using a controller. If the system has dead-time, the design problem be...

Since the overall capacity of railway lines are not used effectively in fixed-block railway systems, moving-block railway systems are introduced to increase the transport capacity and to reduce the headway times. CBTC (Communication Based Train Control) systems and ERTMS (European Rail Traffic Management System) application level 3 are regarded as...

When compared with the other transportation systems, railway systems are economical, safer and more environment friendly. Despite all these features, investments on railways in Turkey remained quite restricted in comparison to other European countries. The initial construction costs of railways are high and developing its signaling system also requ...

Signalling systems play a vital role for safe and efficient transportation on railways. In parallel,development of signalling systems requires a lot of attention. The relevant standards insist on using formal methods such as automata and Petri Nets in the design of software for such crucial systems. In this study, the Unified Modelling Language (UM...

Interlocking systems that can be regarded as the main decision making component of fixed block railway signaling systems, are directly responsible for ensuring the safe movements of trains. Software of an interlocking system depends on the interlocking table of the related railway yard. Although there are tools for automatic interlocking table gene...

Although there are many methods for the calculation of all stabilizing PID controllers for a given linear time invariant system, this problem is still time-consuming. Moreover, if there is a time delay or uncertainty in the system, the problem gets more complex. The power of computer algebra tools can be utilized in finding all stabilizing PID cont...

In order to optimize and to standardize the train traffic across Europe, railway people developed new standards known as European Rail Traffic Management System (ERTMS) that has three levels from conventional rails (level 1) to high speed rails (level 3). The use of this standard is not limited only in Europe and became a widely used standard in As...

The main issue in controlling safety-critical systems such as nuclear power reactors or railway signalization systems where risk ratio is at the highest level because small errors might result in hazardous accidents (e.g. death or injury of several people) is to satisfy safety-related standards and provide high-safety with high-reliability. In orde...

It is vital that an interlocking system is thoroughly tested before its deployment. The conduction of the tests of an interlocking system on the real field is cumbersome and expensive. It is necessary that fast and efficient methods are utilized to test the hardware and the software of interlocking systems before its final installation. In this man...

An optimization method is proposed to obtain a CDM controller that provides a fast transient response while keeping the control signal below a predetermined limit. In order to determine the performance of the proposed method, a brushless DC motor has been controlled with a Coefficient Diagram Method (CDM) based controller and an optimal PI controll...

In this paper, a new simple derivation of all stabilizing proportional controllers, for first order linear time invariant systems with time‐delay, is presented. Although several results based on the Hermite‐Biehler theorem for finding such a set of controllers exist, the aim of this article is to present a shorter and more instructive derivation, w...

Signalization and interlocking design is one of the most crucial components that provide safe travelling and transportation on railways. In order to satisfy the requirements of CENELEC (European Committee for Electrotechnical Standardization) standards that are used for railways, there is a need of formal methods. While providing these standards, P...

Interlocking systems are the core components of railway signalization systems. They ensure the safe movement of the trains on railway tracks by being the main decision making unit of the railway signalization systems. Therefore it is crucial to predetermine the errors in interlocking systems. In this work a new environment designed to test the reli...