Altan Onat

Eskişehir Technical University · Department of Electrical and Electronics Engineering

Discrete simulation of Power Electronic Converters (PECs) can be important for several purposes such as condition and health monitoring, controller design, and analysis of these devices. In this study, an improved Trapezoidal Rule with Second Order Backward Differentiation Formula (TR-BDF2) and Predictor-Corrector (PC) approach is proposed for the...

This paper proposes a parameter estimation method for DC-DC converters based on the Simulated Annealing algorithm. The proposed method is demonstrated on a buck converter modeled in state-space form, and simulation results show its effectiveness in estimating the converter parameters with parametric uncertainties. Compared to other population-based...

Anti-slip control systems are essential for railway vehicle systems with traction. In order to propose an effective anti-slip control system, adhesion information between wheel and rail can be useful. However, direct measurement or observation of adhesion condition for a railway vehicle in operation is quite demanding. Therefore, a proportional–int...

In this study, a vehicle based method, which considers the use of velocity sensors mounted on a vehicle, is proposed for this purpose. It includes the use of a mathematical model of the vehicle and a joint unscented Kalman filter. Methodology has been tested based on the measurements obtained from a full scale wheel on roller type test rig which re...

It can be life-saving to monitor the respiratory rate (RR) even for healthy people in real-time. It is reported that the infected people with coronavirus disease 2019 (COVID-19), generally develop mild respiratory symptoms in the early stage. It will be more important to continuously monitor the RR of people in nursing homes and houses with a non-c...

Adhesion and creep force models play an important role in the realistic simulation of railway vehicle systems. These models are mainly based on experiments and they are determined heuristically. In previous studies, no metric is defined to demonstrate the level of agreement between these models and measurements. This study aims to provide such metr...

When the above article was first published online, the subcaptions written on Figures 2, 8, 9, 10, 11 must be deleted. These have now been corrected for both online and print.

Loading conditions of railway vehicles both affect the vehicle and substructure directly. There are approaches to determine the load of a railway vehicle, the first one is to statically weigh the vehicle, the second approach is to place sensors along the track and dynamically weigh the vehicle at certain sections and the third one is to design spec...

Unscented Kalman filter (UKF) is one type of the sigma point Kalman filters and it is based on unscented transformation (UT). UKF is used for parameter estimation of various dynamic systems and for such purpose either joint unscented Kalman filtering (JUKF) or dual unscented Kalman filtering (DUKF) schemes are considered. JUKF is based on estimatin...

Model-based condition monitoring is an increasingly important area for rail transportation. The key elements of such condition monitoring methodologies are low-cost vehicle sensors and intelligent algorithms. In this study, a swarm intelligence-based multiple models approach is proposed to detect different friction conditions by using velocity meas...

Statically weighing a railway vehicle is the traditional way to determine the weight of a railway vehicle. Recently, approaches for dynamically weighing railway vehicles are proposed and such approaches are based on replacing sensors to track sections. In this study, the possibility of estimating loading conditions is discussed by using only vehicl...

Monitoring the conditions of railway vehicle systems plays an important role in the maintenance of safety and performance of railway vehicles. Rolling radius is one of the properties that should be monitored continuously for the predictive maintenance of a railway vehicle since it changes with time due to wheel wear. In this study, a model-based co...

On board diagnosis and condition monitoring become a primary concern for railway vehicles so that necessary actions can be taken before a catastrophic consequence. Especially, the main aim is to diagnose and monitor such conditions by using vehicle-mounted sensors. In this study, a particle swarm intelligence based multiple model approach is propos...

Track experiments and tests for railway vehicles are challenging tasks. In order to realize methods and validate models which are developed for railway vehicle systems, roller-rig test equipments are widely used. In this study, a torsional dynamic model of a tram wheel test stand, which has a wheel on roller configuration and has been used for rese...

In this dissertation, the use of model based filtering techniques for wheelsets of railway vehicles is presented. Especially, this dissertation provides the application of a parameter estimation scheme by using dynamic response of a conventional wheelset, a vehicle and a tram wheel on a test stand with a novel methodology. In the context, firstly, an...

In recent years, there has been an increasing interest in designing intelligent vehicles such that they can take necessary actions according to the environmental changes around them and they can inform decision makers about these changes. For safer and cheaper transport, dynamic modelling of these vehicles and identification of such changes in envi...

Model based filtering is fast becoming a key instrument for maintenance and condition monitoring of railway vehicles. This study presents the use of linear Kalman filtering scheme to identify vertical secondary suspension of a railway vehicle by using the vertical vibrations of a vehicle due to vertical track irregularities. As well as the use of l...

Globally, maintenance tasks for railway vehicles have generally calendar based schedules. However, apparent changes may occur in vehicle structure and environment. Suspension malfunction and substantial change in adhesion conditions can be given as an example for such situations. Since these kinds of changes may affect especially safety, necessary...

In railway vehicles the observation of lateral and yaw response of a wheelset has great importance as it is directly related with safety and deformation of wheel/rail. In previous studies about the lateral and yaw response of a wheelset, the mathematical models proposed do not consist of tractive effort and torsional dynamics. In this study, these...

This paper presents an approach for the trajectory tracking control of nonholonomic wheeled mobile robots (WMR) by combining one of the existing adaptive control methods and multiple identification models. The overall system includes two types of controllers in the control scheme. A kinematic controller developed by using kinematic model produces t...

This chapter presents a method about trajectory tracking control of a nonholonomic wheeled mobile robot. The main focus of the chapter is to improve the transient response for the trajectory tracking control of mobile robots including dynamic parameter uncertainties. An adaptive combined direct and indirect control scheme is used for compensation o...

Railway vehicle running behavior is mainly determined by the forces that exist between wheel and rail surfaces. These forces are influenced by the nonlinear wheel/rail contact. Furthermore, for better organization of condition monitoring and repair of railway vehicles, better understanding of wheel/rail contact is essential. In this study, analysis...

This paper presents a novel methodology for the trajectory tracking control of nonholonomic wheeled mobile robots using multiple identification models. The overall control system includes two stages. In the first stage, a kinematic controller developed by using kinematic model provides the required linear and angular velocities of the robot for tra...