Levente Czégé’s research while affiliated with University of Debrecen and other places

In this paper, focusing on a designated route of public transport in Debrecen, we examine the possibilities of creating a driving cycle representative for the route. The background of the work is, that in the framework of a larger-scale research project we examine the possibility of how to reduce the bus’s emissions by modifying the drive chain of the current diesel vehicle. A dynamic model suitable for performing the calculations was developed, in which the movement of the vehicle in traffic is described by the driving cycle. The data provided by the data acquisition equipment of the bus on the designated route is available for the creation of the special driving cycle. In this paper, we look for the answer to the question: how the difference in data density affects the driving cycle and how it modifies the parameters describing its representativeness. KeywordsReal traffic dataMicro-trip methodDriving cycleUrban bus route

In the literature it has been proven several times, that the common driving cycles are not accurate enough to estimate the fuel and energy consumption data or emission data for vehicles, especially for public transport vehicles, such as buses. One can find driving cycles for buses, but the special driving environment in Debrecen, Hungary cannot be accurately represented by them. As a part of a project focusing on the determination of fuel and energy consumption of vehicles by dynamic simulation, a study has been carried out for determining driving cycles, which are representative for Debrecen. In this paper the development of a driving cycle for city buses in Debrecen is presented. Typical bus routes were selected in the town for the study, the vehicles were instrumented with an appropriate data collecting system. These onboard units were used to collect data such as travelled distance, speed and acceleration on several vehicles in the real-world traffic. We used special purpose software to pre-process and filter the collected data. After pre-processing a statistical evaluation of the data was carried out. Using a version of the widely spread micro-trip method of driving cycle development, a Bus Driving Cycle has been constructed for Debrecen.

Due to the technological progress, new approaches such as model-based design are spreading in the development process in the automotive industry to meet the increased requirements related to lower fuel consumption and reduced emission. This work is part of a research project which focuses on dynamic modeling of vehicles aimed at analyzing and optimizing the emission and fuel consumption. To model the driver behavior, the simulation control algorithm requires a predetermined speed-time curve as an input. The completeness of this driving cycle is a crucial factor in the simulation, and as far as the legislative driving cycles are not accurate enough, it is indispensable to develop our own one representing our narrower area and driving conditions. This article considers two common drive cycle design methods, comparing the micro-trip-based approach and the Markov-chain approach. The new driving cycle has been developed applying the Markov-chain approach and compared to a driving cycle introduced in our recent paper using the micro-trip method. The comparison basis is the Speed-Acceleration Probability Distribution, which sufficiently reflects the dynamic behavior of the vehicle, and the root mean square error, including parameters such as the average speed, average cruising speed, average acceleration, average deceleration, root mean square acceleration, and idle time percentage. The representative Bus Driving Cycle for Debrecen is prepared to be applied in the vehicle dynamics simulation for evaluating and improving the fuel economy of vehicles, selecting the proper power source for various applications and the optimization of the powertrain and the energy consumption in researches to be continued.

Ebben a tanulmányban egy állandó útvonalon közlekedő tehergépjármű mozgását leíró menetciklus létrehozását tárgyaljuk. Kiválasztottunk egy jellemző szállítási útvonalat, ahol olyan tehergépjárművek közlekednek, melyek fel vannak szerelve megfelelő adatgyűjtő berendezéssel. Hosszú távon gyűjtöttük a jármű mozgását leíró adatokat, majd az adatokat egy saját fejlesztésű célszoftver segítségével szűrtük és készítettük elő, végül a tisztított adatokat statisztikai eljárások alkalmazásával dolgoztuk fel.

The goal of this paper is to give an overview of the literature of construction techniques of driving cycles. Our motivation for the overview is the future goal of constructing our own driving cycles for various types of vehicles and routes. This activity is part of a larger project focusing on determination of fuel and energy consumption by dynamic simulation of vehicles. Accordingly, the papers dealing with sample route determination, data collection and processing, driving cycle construction procedures, statistical evaluation of data are in our focus.

This article presents the modelling of interconnected companies’ logistic processes with Tecnomatix Plant Simulation by Siemens. It has two main parts. The first contains the details of recognition including simulation. The second part presents the modelling with Tecnomatix Plant Simulation. My publication is supported by the EFOP3.6.1-16-2016-00022 project. The project is co-financed by the European Union and the European Social Fund.

Diagnosis of bearings with advanced methods gained remarkable roles in the previous years. This article focuses on the manufacturing defects and methods to reveal and classify them. During manufacturing several faults could emerge because of the grinding operation, tool wear and chatter vibration. Inproper handling of the bearing parts because of the collosion to each other and the storing box that causes deformation. To reveal these problems several methods are applied in industry. For deeper surface analysis nitric acid can be used to initate the finished surface of the roller then natrium-carbonate that nautralize the elements. Vibration analysis in its standard Fourier form is not a new achivement but other mathematical tools could be applied to condition monitoring such as wavelet transform. It is an efficient tool for analyzing the vibration signal of the bearings because it can detect the sudden changes and transient impulses in the signal caused by faults on the bearing elements. In this article five different wavelets, Daubechies, Gaussian, Coiflet, Mexican hat, Meyer are compared according to the Energy to Shannon Entropy ratio criteria to reveal their efficiency for fault detection.