Aziz Sezgin - Academia.edu (original) (raw)

Papers by Aziz Sezgin

Journal of Vibration and Control, Aug 14, 2013

MATEC web of conferences, 2012

In this study, the effect of vehicle vibrations on human beings is investigated. The computations... more In this study, the effect of vehicle vibrations on human beings is investigated. The computations were made with the help of a simulation program using a full vehicle model with driver and the results were evaluated using international ISO 2631 standard. The physical model of the investigated system is formed by a full-vehicle model and a driver. The road roughness is used as an input to the system and the responses are compared with the related standard. Finally, the results are discussed.

Journal of Vibroengineering, 2012

Vehicle vibrations affect the health and comfort of the driver and passengers considerably. The a... more Vehicle vibrations affect the health and comfort of the driver and passengers considerably. The aim of this study is to analyze the effects of vertical vehicle vibrations on the driver. To achieve this goal, a human biodynamic model with 11 degrees of freedom was incorporated into a full vehicle model and this combined human-vehicle model was subjected to the road disturbance. After dynamic analysis of the proposed model, root mean square (RMS) acceleration responses of the human body parts over a certain frequency range were obtained. Physiological effects of the vibrations on the human body were analyzed using the criteria specified in International Organization for Standardization (ISO) 2631. Then, in order to observe the effectiveness of a controller on the vibration isolation of human body, sliding mode controller was applied to the model. Comparison of the vibration effects for the uncontrolled and controlled cases of the human-vehicle model was presented. It can be concluded from the results that sliding mode controller considerably reduces whole body vibrations compared with the uncontrolled case and thereby improves the ride comfort satisfactorily.

World Academy of Science, Engineering and Technology, International Journal of Mechanical and Mechatronics Engineering, Jun 2, 2016

Sliding mode controller for a vehicle active suspension system is designed in this study. The wid... more Sliding mode controller for a vehicle active suspension system is designed in this study. The widely used quarter car model is preferred and it is aimed to improve the ride comfort of the passengers. The effect of the actuator time delay, which may arise due to the information processing, sensors or actuator dynamics, is also taken into account during the design of the controller. A sliding mode controller was designed that has taken into account the actuator time delay by using Smith predictor. The successful performance of the designed controller is confirmed via numerical results.

Sakarya University Journal of Science, Feb 28, 2023

Mobile robot concept is one of the most commonly used nonholonomic system for industrial and acad... more Mobile robot concept is one of the most commonly used nonholonomic system for industrial and academic autonomous applications. There are many types of mobile robot design concepts and control strategies which have been continuously developed by researchers. In this study, two wheeled differential drive mobile robot (DDMR) is used for trajectory tracking study under different conditions. Reference trajectory, dynamic and kinematic motion models of DDMR are defined as mathematical expressions in computer software. For tracking the reference trajectory, error between current pose and reference pose was decreased by sliding mode controller (SMC) and proportional–integral–derivative controller (PID) with kinematic based backstepping controller (KBBC) respectively. A reference path which consists of sinusoidal and linear parts tracked by both controller combinations in first simulation to examine controller tracking performances. In order to examine and compare; responsiveness, stability and robustness of the controllers, an additional mass which affects motion dynamics of DDMR vertically added to the mobile robot body during trajectory tracking application. All results and discussions are comparatively stated at the end of the study with related error figures and evaluations.

World Academy of Science, Engineering and Technology, International Journal of Mathematical, Computational, Physical, Electrical and Computer Engineering, Oct 3, 2015

We consider the problem of stabilization of an unstable heat equation in a 2-D, 3-D and generally... more We consider the problem of stabilization of an unstable heat equation in a 2-D, 3-D and generally n-D domain by deriving a generalized backstepping boundary control design methodology. To stabilize the systems, we design boundary backstepping controllers inspired by the 1-D unstable heat equation stabilization procedure. We assume that one side of the boundary is hinged and the other side is controlled for each direction of the domain. Thus, controllers act on two boundaries for 2-D domain, three boundaries for 3-D domain and "n" boundaries for n-D domain. The main idea of the design is to derive "n" controllers for each of the dimensions by using "n" kernel functions. Thus, we obtain "n" controllers for the "n" dimensional case. We use a transformation to change the system into an exponentially stable "n" dimensional heat equation. The transformation used in this paper is a generalized Volterra/Fredholm type with "n" kernel functions for n-D domain instead of the one kernel function of 1-D design.

Mühendislik Bilimleri ve Tasarım Dergisi

3B baskı teknolojilerinden biri olan ergiterek yığma ile modelleme (FDM) üretim teknolojisi ve po... more 3B baskı teknolojilerinden biri olan ergiterek yığma ile modelleme (FDM) üretim teknolojisi ve polilaktik asit (PLA) malzemesi kullanarak farklı dolgu deseni ve yönüne sahip çekme testi numuneleri üretilmiş ve dolgu deseni ve yönünün çekme dayanımına olan etkileri incelenmiştir. Beş farklı dolgu deseni (eş merkezli, ızgara, üçgen, 3B altıgen, zik zak) ve üç farklı dolgu desen açısına (0°, 45°, 90°) sahip aynı ağırlıkta 10 adet numune ve bir adet de tam dolu numune FDM teknolojisi ile basılarak toplam 11 adet numune üretilmiştir. Tüm numunelere mekanik çekme testi uygulanmıştır. Mekanik çekme testi sonucunda; ikinci numunenin (90° dolgu desen açılı, eş merkezli), aynı ağırlıktaki diğer numunelere göre daha yüksek dayanıma sahip olduğu tespit edilmiştir. Eş merkezli numunenin aynı ağırlıktaki diğer numunelere göre dayanımının yüksek olması, baskı desen yönünün çekme yönüyle bağlantılı olduğu ve dolayısıyla baskı sırasında baskı desen açılarının ve yönlerinin uygulanan kuvvetler doğrul...

Sliding mode controller for a vehicle active suspension system is designed in this stud... more Sliding mode controller for a vehicle active suspension system is designed in this study. The widely used quarter car model is preferred and it is aimed to improve the ride comfort of the passengers. The effect of the actuator time delay, which may arise due to the information processing, sensors or actuator dynamics, is also taken into account during the design of the controller. A sliding mode controller was designed that has taken into account the actuator time delay by using Smith predictor. The successful performance of the designed controller is confirmed via numerical results.

The actuator time delay problem for a linear active suspension system using the theory of backste... more The actuator time delay problem for a linear active suspension system using the theory of backstepping control design is examined in this study. Time-delay may arise in active suspension systems because of transport phenomenons, information processing, sensors or some mechanical reasons. Designing the controller without taking into account the actuator time delay may degrade the performance of the controller or even destabilize the closed loop control system. It is aimed to improve the ride comfort of passengers without degrading road holding. Therefore, a backstepping controller was designed which takes into account the actuator time delay by combining a first order hyperbolic partial differential equation(PDE) with the linear suspension system. The numerical results confirm the success of the controller.

Uluslararası Muhendislik Arastirma ve Gelistirme Dergisi, 2018

Bu çalışmada seçilen bazı kararsız çok boyutlu dalga denklemleri geri adımlamalı sınır değer kont... more Bu çalışmada seçilen bazı kararsız çok boyutlu dalga denklemleri geri adımlamalı sınır değer kontrol kuramı ile kararlı hale getirilmiştir. Bu amaçla bir boyutlu geri adımlamalı kontrol teorisinden yola çıkılarak çok boyutlu sistemler için kontrolcü tasarımı yapılmış ve hedef sistemler Lyapunov kararlılık analizi ile incelenmiştir. Her boyut için sistemin bir ucundan tutturulup diğer ucundan kontrol uygulandığı düşünülmüştür. Böylelikle iki boyutlu bir sistem için iki adet, üç boyutlu bir sistem için üç adet ve n boyutlu bir sistem için de n adet kontrolcü tasarlanmıştır. Kararsız sistemin üstel kararlı bir hedef sisteme dönüştürülebilmesi için Volterra/Felholm tipi dönüşümler kullanılmıştır.

Journal of Dynamic Systems, Measurement, and Control, 2015

We design a controller for flow-induced vibrations of an infinite-band membrane, with flow runnin... more We design a controller for flow-induced vibrations of an infinite-band membrane, with flow running across the band and only above it, and with actuation only on the trailing edge of the membrane. Due to the infinite length of the membrane, the dynamics of the membrane in the spanwise direction are neglected, namely, we employ a one-dimensional (1D) model that focuses on streamwise vibrations. This framework is inspired by a flow along an airplane wing with actuation on the trailing edge. The model of the flow-induced vibration is given by a wave partial differential equation (PDE) with an antidamping term throughout the 1D domain. Such a model is based on linear aeroelastic theory for Mach numbers above 0.8. To design a controller, we introduce a three-stage backstepping transformation. The first stage gets the system to a critically antidamped wave equation, changing the stiffness coefficient's value but not its sign. The second stage changes the system from a critically antida...

Conference on Decision and Control, Dec 1, 2013

We design a controller for flow-induced vibrations of an infinite-band membrane, with flow runnin... more We design a controller for flow-induced vibrations of an infinite-band membrane, with flow running across the band and only above it, and with actuation only on the trailing edge of the membrane. Due to the infinite length of the membrane, the dynamics of the membrane in the spanwise direction are neglected, namely, we employ a 1-D model that focuses on streamwise vibrations. This framework is inspired by a flow along an airplane wing with actuation on the trailing edge. The model of the flow-induced vibration is given by a wave PDE with an anti-damping term throughout the 1-D domain. Such a model is based on linear aeroelastic theory for Mach numbers above 0.8. To design a controller we introduce a 3-stage backstepping transformation. The first stage gets the system to a critically anti-damped wave equation, changing the stiffness coefficient's value but not its sign. The second stage changes the system from a critically anti-damped to a critically damped equation with an arbitrary damping coefficient. The third stage adjusts stiffness arbitrarily. The controller and backstepping transformation map the original system into a target system given by a wave equation with arbitrary positive damping and stiffness.

In this study, the impact of vehicle vibrations on a human body is investigated by comparing comp... more In this study, the impact of vehicle vibrations on a human body is investigated by comparing computations made with the help of a simulation program employing a half-vehicle model with the international ISO 2631 standard. The physical model of the investigated system is formed by combining a half-vehicle model and a human model. The road roughness taken from the literature is used as an input to the established system and the responses are compared with the related standard. As a result, the driver’s dynamic response and the potential psychological or physical problems are commented on.

MATEC Web of Conferences, 2012

Journal of Vibration and Control, 2013

Attenuation of the adverse effects of vehicle vibrations on human health is a challenging problem... more Attenuation of the adverse effects of vehicle vibrations on human health is a challenging problem. One common approach to solve this problem is to use various types of controllers in vehicle suspensions. In this study, in order to decrease the vehicle vibrations and hence improve the ride comfort, a fuzzy logic integrated sliding mode controller was designed. The performance of the controller was tested in a biodynamic human-vehicle combined model. The human body was considered as a lumped parameter model and incorporated into a full vehicle model. The biodynamic responses of a human body to vehicle vibrations were analyzed. Performances of the conventional sliding mode and fuzzy integrated sliding mode controllers were compared with those of a passive control strategy. According to the numerical results, the fuzzy sliding mode controller overcame both classic sliding mode and passive control approaches and decreased vehicle vibrations considerably. It can be deduced from the study ...

In this study we examine the actuator time delay problem for a full vehicle active suspension sys... more In this study we examine the actuator time delay problem for a full vehicle active suspension system using the theory of backstepping control design. It is aimed to improve the ride comfort of passengers in case of actuator time delay, which may arise in active suspension systems because of information processing, sensors or some mechanical reasons. Particularly designing the controller without taking into account the actuator time delay may degrade the performance of the controller or even destabilize the closed loop suspension system. Therefore, we design a backstepping controller that takes into account the actuator time delay by combining a first order hyperbolic partial differential equation (PDE) with the suspension system. The numerical results confirm the success of the controller in improving ride comfort of the passengers while assuring the stability of the system. KeywordsActuator Time Delay, Vehicle Active Suspension System, Distributed Backstepping Control

Journal of Vibration and Control, Aug 14, 2013

MATEC web of conferences, 2012

Journal of Vibroengineering, 2012

World Academy of Science, Engineering and Technology, International Journal of Mechanical and Mechatronics Engineering, Jun 2, 2016

Sakarya University Journal of Science, Feb 28, 2023

World Academy of Science, Engineering and Technology, International Journal of Mathematical, Computational, Physical, Electrical and Computer Engineering, Oct 3, 2015

Mühendislik Bilimleri ve Tasarım Dergisi

Uluslararası Muhendislik Arastirma ve Gelistirme Dergisi, 2018

Journal of Dynamic Systems, Measurement, and Control, 2015

Conference on Decision and Control, Dec 1, 2013

We design a controller for flow-induced vibrations of an infinite-band membrane, with flow runnin... more We design a controller for flow-induced vibrations of an infinite-band membrane, with flow running across the band and only above it, and with actuation only on the trailing edge of the membrane. Due to the infinite length of the membrane, the dynamics of the membrane in the spanwise direction are neglected, namely, we employ a 1-D model that focuses on streamwise vibrations. This framework is inspired by a flow along an airplane wing with actuation on the trailing edge. The model of the flow-induced vibration is given by a wave PDE with an anti-damping term throughout the 1-D domain. Such a model is based on linear aeroelastic theory for Mach numbers above 0.8. To design a controller we introduce a 3-stage backstepping transformation. The first stage gets the system to a critically anti-damped wave equation, changing the stiffness coefficient's value but not its sign. The second stage changes the system from a critically anti-damped to a critically damped equation with an arbitrary damping coefficient. The third stage adjusts stiffness arbitrarily. The controller and backstepping transformation map the original system into a target system given by a wave equation with arbitrary positive damping and stiffness.

MATEC Web of Conferences, 2012

Journal of Vibration and Control, 2013