István Varga

István Varga
Budapest University of Technology and Economics · Department of Control for Transportation and Vehicle Systems

Professor

About

77
Publications
29,271
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822
Citations

Publications

Publications (77)
Article
Full-text available
Road traffic congestion has become an everyday phenomenon in today's cities all around the world. The reason is clear: at peak hours, the road network operates at full capacity. In this way, growing traffic demand cannot be satisfied, not even with traffic-responsive signal plans. The external impacts of traffic congestion come with a serious socio...
Article
Full-text available
A közúti közlekedési torlódások mára gyakorlatilag mindennapossá váltak a nagyvárosok útjain a világ minden táján. A jelenség magyarázata egyértelmű: a közlekedési hálózatok kapacitása csúcsidőben telítődik, így a fokozódó igények nem szolgálhatók ki megfelelően még akkor sem, ha pl. forgalomfüggő jelzőlámpás irányítás működik. Mindezek eredményeké...
Article
Full-text available
Urban commuters have been suffering from traffic congestion for a long time. In order to avoid or mitigate the congestion effect, it is significant to know how the introduction of autonomous vehicles (AVs) influence the road capacity . The effects that AVs bring to the macroscopic fundamental diagram (MFD) were investigated through microscopic traf...
Article
Full-text available
Traffic control of urban areas is a current research topic. Different pricing regimes such as cordon pricing, time‐based average cost zone pricing, distance‐based average cost zone pricing or marginal cost zone pricing have been investigated so far. The economical best solution, however, cannot be used due to the lack of information. In the study,...
Article
A set-theoretical approach is presented for a multi-objective control design of the local ramp metering problem. Two control objectives are specified: first, the optimization of traffic performance, by the minimization of total time spent. Second, the emission factor of CO2 needs to be minimized. The optimal state for traffic emission, however, lie...
Book
https://mersz.hu/tettamanti-luspay-varga-road-traffic-modeling-and-simulation
Article
Nowadays transportation represents an important field for CPS applications due to the rapid development of highly automated or autonomous vehicles, e.g. warehouse vehicles, airport people movers, public transport, etc. These vehicles are usually designed to circulate on fixed routes independently of the actual state of the network in order to fulfi...
Article
In this work a control system is developed and analyzed for the suppression of moving jamwaves and the reduction of pollutant concentrations near motorways. The system is based on the second-order macroscopic freeway traffic model METANET, joined by an emission dispersion model, introduced in a previous work of the authors. For the control tasks de...
Article
The paper investigates a traffic-responsive control method applicable at isolated signalized intersections. The proposed strategy involves three basic parts: a traffic model, a reconfigurable regulator, and a congestion detection filter. Road traffic dynamics is modeled by the well-known store-and-forward approach. The controller is based on the ef...
Article
Full-text available
A full methodology of short-term traffic prediction is proposed for urban road traffic network via Artificial Neural Network (ANN). The goal of the forecasting is to provide speed estimation forward by 5, 15 and 30 min. Unlike similar research results in this field, the investigated method aims to predict traffic speed for signalized urban road lin...
Conference Paper
Full-text available
The knowledge of road traffic parameters is of crucial importance to ensure state-of-the-art traffic services. Due to the widespread of today's information communication technologies the classical approach of road traffic detection has fundamentally changed. Beside or instead of traditional static traffic sensors the so called floating car data (FC...
Article
Full-text available
https://ercim-news.ercim.eu/en109/special/recar-hungarian-research-centre-for-autonomous-road-vehicles-is-on-the-way
Article
Full-text available
The Research Center for Autonomous Road Vehicles (RECAR) was founded in 2015 upon the initiative of the Faculty of Transportation Engineering and Vehicle Engineering of Budapest University of Technology and Economics. The research center is supported by industrial partners and other academic partners targeting research and educational purposes. In...
Article
Full-text available
A set-theoretical approach is presented for a multi-objective control design of the local ramp metering problem. Two control objectives are specified: first, the optimization of traffic performance, by the minimization of total time spent. Second, the emission factor of CO2 is minimized. The optimal state for traffic emission however lies in the un...
Article
Full-text available
Autonomous vehicular technology significantly stresses the issue of safety. Although the use of driverless cars raises considerable expectations of a general improvement in safety, new challenges concerning the safety aspects stem from the changing context. On the one hand, the paper addresses regulatory issues raised by the impact of technological...
Article
Full-text available
In the near future, autonomous vehicles will face with new challenges in several fields. One of the most exciting changes will be represented by the network-wide optimal traffic control. When driverless vehicles take over the road, classical road signalization schemes will become superfluous. Accordingly, the paper’s aim is to propose a control des...
Article
Full-text available
The era of autonomous vehicles infer new challenges in several fields. When autonomous vehicles take over the road in a large volume, consumer preferences around car-ownership will transform, traffic modeling and control will need correction, and moreover hackers will appear. These are just a few impacts which are expectable in the near future. Acc...
Conference Paper
The paper presents a Sum-of-Squares programming-based method for the analysis of the nonlinear urban network gating problem. The goal of the analysis is the determination of the maximum control input by which the stability of the system is guaranteed and traffic congestion is avoided. The urban traffic dynamics is modeled as a parameter-dependent p...
Article
This work suggests a framework for modeling the traffic emissions in urban road traffic networks that are described by the Network Fundamental Diagram (NFD) concept. Traffic emission is formalized in finite spatiotemporal windows as a function of aggregated traffic variables, i.e. Total Travel Distances (TTDs) in the network and network average spe...
Article
Full-text available
In the recent decade, computer simulation has been developed enormously in all engineering fields and has become a basic step of design. Accordingly, simulation plays a fundamental role in road traffic engineering offering a basis for the effective analysis of intelligent traffic control systems. A reliable simulator is able to provide effective an...
Article
The paper presents a joint state and unmeasured input estimation technique for a special class of nonlinear second order macroscopic traffic model. The freeway traffic system is transformed into a quasi and affine approximate Lin- ear Parameter Varying (LPV) form. Observer design technique is formulated using off-line optimization problem subjected...
Article
Full-text available
Recently, computer simulation aided work has become a standard routine in all engineering fields. Accordingly, simulation plays a fundamental role even in road traffic engineering. A reliable simulator is able to provide effective analysis of a given traffic network if the applied simulation scenarios properly converge to the real-word situation. T...
Article
Full-text available
This work proposes a nonlinear model predictive controller for the urban gating problem. The system model is formalized based on a research on existing models of the network fundamental diagram and the perimeter control systems. For the existing models, modifications are suggested: additional state variables are allocated to describe the queue dyna...
Conference Paper
In this work a control system is developed for the limitation of pollutant concentrations of rural areas near motorways. The controlled system is based on the second-order macroscopic model description of the freeway traffic, extended by an emission dispersion model, introduced in [1]. The control of the system is realized by ramp metering, optimiz...
Conference Paper
This work suggests a NMPC controller for the urban perimeter control problem. The system model is based on the mathematical formalization of the problem, proposed in [1] expanded by describing the queue dynamics at the perimeter gates. For the extended model a multicriteria control problem is formalized: the conventional control objective of traffi...
Article
Full-text available
Signaling data of cellular phones can be used as valuable information for state-of-the-art traffic applications especially in urban areas. The traces of mobiles like handovers and location area updates may be efficiently utilized in the field of road traffic measurement and forecasting or even traffic control. By detecting and processing the locomo...
Patent
Full-text available
A method and a device for determining a travel information are provided, said method comprising the steps of (i) receiving information about a cell change, in particular a cell change event related to at least one mobile subscriber device traversing a plurality of cells,wherein said cells are located along or in the vicinity of a path of a transpor...
Article
The aim of the presented research is to elaborate a traffic-responsive optimal signal split algorithm taking uncertainty into account. The traffic control objective is to minimize the weighted link queue lengths within an urban network area. The control problem is formulated in a centralized rolling-horizon fashion in which unknown but bounded dema...
Article
Full-text available
The knowledge of road traffic parameters is of crucial importance to ensure state-of-the-art traffic services either in public or private transport. In our days, a plethora of road traffic data are continuously collected producing historical and real-time traffic information as well. The available information, however, arrive from inhomogeneous sen...
Conference Paper
In this work a modeling approach is introduced for the dispersion of motorway traffic emissions. The process model is developed for a distributed parameter system, and is derived based on the conservation law within the balance volumes between the road and the rural area, specified by the wind direction. Parallel to the wind, plug flow is considere...
Conference Paper
In this work a novel controller design method is suggested for motorway shockwave management using ramp metering and variable speed limit (VSL) control. The proposed controller has a feedforward-feedback control structure that is designed for a motorway arterial model. For the feedback design the nonlinear model predictive control is used. The feed...
Article
The paper presents the design of cruise control systems considering road and traffic information during the design of speed trajectories. Several factors are considered such as road inclinations, traffic lights, preceding vehicles, speed limits, engine emissions and travel times. The purpose of speed design is to reduce longitudinal energy, fuel co...
Article
Full-text available
In this paper a real-time macroscopic modeling framework of road traffic emissions is suggested based on an average-speed emission model. A model function is created to describe the spatiotemporal distribution of motorway traffic emissions using loop detector data only which is suitable for emission dispersion and immission modeling. The proposed m...
Conference Paper
In this paper a multicriteria ramp metering control is designed considering three criteria: traffic performance and the local– and global effects of traffic emission. For real-time emission modeling a macroscopic modeling framework is proposed using an average-speed emission model. Based on the proposed model function cost functions regarding the g...
Data
The paper focuses on the simulation of signal control problems based on VISSIM microscopic simulator VISSIM is a commonly used software in practice for diverse problems related to road traffic control. Beyond the standard use of VISSIM, advanced options are available. VISSIM COM interface and VISSIM DLL API may be used as well providing freedom to...
Conference Paper
A well-organized platoon control may have advantages in terms of increasing highway capacity and decreasing fuel consumption and emissions. The paper proposes the design of the velocity of platoon. In the velocity design several factors must be taken into consideration such as fuel consumption, road inclinations, emissions and traveling time. Since...
Article
Full-text available
The rapid growth of mobile phone communications has induced novel and emerging technologies in the past decades. Signaling data of cellular phones can be used as valuable information for state-of-the-art traffic applications especially in urban areas. The paper focuses on the applicability for estimating the traces of traveling mobiles in the trans...
Article
Full-text available
The paper focuses on the simulation of signal control problems based on VISSIM microscopic simulator. VISSIM is a commonly used software in practice for diverse problems related to road traffic control. Beyond the standard use of VISSIM, advanced options are available. VISSIM COM interface and VISSIM DLL API may be used as well providing freedom to...
Article
Full-text available
The paper contributes to the analysis of freeway traffic flow dynamics by set theoretic methods. First, the macroscopic, non-linear and second-order model of freeway traffic flow dynamics is transformed to an equivalent and quasi Linear Parameter Varying (LPV) representation by steady-state centering and state variable factorization. Second, a poly...
Article
In this paper a complex traffic emission modeling approach is suggested: based on the considerations of macroscopic traffic flow modeling and an average speed emission model, a macroscopic emission model is formed. The proposed methodology leads to two functions to evaluate traffic emission: a model for actually realized emissions and one for the e...
Conference Paper
The paper contributes to the derivation and analysis of accelerations in freeway traffic flow models. First, a solution based on fluid dynamics and on pure mathematical manipulations is given to express accelerations. The continuous-time acceleration is then approximated by a discrete-time equivalent. By applying continues time microscopic and macr...
Article
In the paper a novel non-linear modeling formalism is suggested for freeway traffic flow. A second-order macroscopic model has been transformed into a Linear Parameter Varying (LPV) model. The paper proposes two LPV descriptions for traffic modeling: the first one covers completely the non-linear macroscopic dynamics, while the second one is an app...
Article
The paper presents the design of a pressure controlling tank located in the primary circuit of a Nuclear Power Plant. All steps from modeling through control design to implementation are detailed. Based on first engineering principles a second-order Wiener model is formulated and its unknown parameters are identified. The control design is based on...
Article
Full-text available
The paper investigates a distributed control system scheme for urban road traffic management. The control algorithm is based on model predictive control (MPC) involving Jacobi iteration algorithm to solve constrained and nonlinear programming problem. The signal controllers of traffic network constitute a network of computers. They can distribute t...
Article
Full-text available
The paper investigates a designing method for urban traffic management system. A busy traffic area was chosen for test field in the 10 th district of Budapest. The control algorithm is based on model predictive control (MPC). The control aim is to relieve traffic congestion, reduce travel time and improve homogenous traffic flow. Theory and realiza...
Conference Paper
This paper presents the design and implementation of a pressure controller for the pressurizer of the primary circuit in the Paks Nuclear Power Plant (NPP) in Hungary. The controlled process is part of a highly safety-critical environment, therefore strict reliability requirements are imposed on both the hardware and the software of the controller....
Conference Paper
Full-text available
The implementation of a dynamic inversion based controller of the pressure controlling tank located in the primary circuit of the Paks Nuclear Power Plant (NPP) in Hungary is presented in this paper The implemented controller has a distributed structure including measurement and control PLCs, a continuous power controller and a special supervisor m...
Conference Paper
The paper investigates a model predictive control (MPC) strategy specialized in urban traffic management in order to relieve traffic congestion, reduce travel time and improve homogenous traffic flow. Over the theory the realization of the control method is also presented. To validate the effectiveness of the controller a busy traffic network was c...
Article
The problem of modelling the complex behaviour of freeway flow leads to a nonlinear macroscopic model. Unfortunately, high dimensional non-linear characteristics could not be performed easily. The paper's purpose is to introduce a new, general modelling formalism for freeway traffic flow modelling, respectively control. Linear Parameter Varying (LP...
Article
Full-text available
The paper proposes some new methods for traffic control systems design. The goal was to find solutions that make possible to give constraints in course of the estimation process of the road traffic parameters and the traffic controller system design. The proposed solutions are built on the constrained Moving Horizon Estimation and the Fault Detecti...
Conference Paper
The modeling and identification of a pressure controlling tank located in the primary circuit of the Paks Nuclear Power Plant in Hungary is presented in this paper. The main goal of the identification procedure is to produce a physically meaningful process model which is simple enough but still applicable for controller design. Based on first engin...
Article
Robust model predictive control of an industrial pressurizer is presented in this paper. The physical model of the pressurizer is based on first engineering principles and the model parameters have been previously identified from measured data. To satisfy the hard constraints on the state variables and the input even in the presence of disturbances...
Conference Paper
This paper presents the concept and practical realization of the testing and diagnostic methodology for a reactor protection system in a nuclear power plant. The test concept utilizes the highly redundant nature of these systems to conduct tests during the normal operation of the monitored process. The diagnostic concept uses a simple rule-based ex...
Article
Full-text available
The paper suggests the necessity of the estimation of unmeasured variables of traffic systems. The presented method proposes constrained state estimation of unmeasured traffic variable such as turning rates. The weighted constrained state approach uses moving horizon along the state trajectory which permits to handle equality and inequality constra...
Article
The paper presents a method for the constrained Moving Horizon Estimation of origin-destination (OD) matrices for traffic networks. in traffic systems split ratios are important parameters for OD estimation and for control problems as well. The paper treats the general constrained Moving Horizon Estimation problem for traffic systems modelled in te...
Article
Full-text available
The paper introduces a risk monitoring solution for a NPP protection system. The two main functions of the solution, the Status Monitoring System and the Risk Monitoring System are described, as well as the possible improvements to enhance system performance and shorten the response time.
Article
This paper presents the concept and practical realization of the testing methodology of safety-critical supervisory systems. The test concept utilizes the highly redundant nature of these systems to conduct test during the normal operation of the monitored process. The described principles have been implemented in the form of microcomputer-based te...
Article
This paper presents the development of an experimental system for the visual detection of unintended lane-departures of commercial road vehicles. If such event is detected, a warning signal is sent to the driver and a message to the supervisor system. The supervisor can intervene in the motion of the vehicle while it monitors the driver’s activity...
Article
Certain variables of dynamic system can not be mea-sured, however they play an important role for control system strategies. In such a situation the approximation, computer based simulation of these variables could be useful for further techniques. There are some estimation methods which can determine the traffic flow in a traffic network. Based on...
Article
Full-text available
A simple dynamic model in physical coordinates and the corresponding parameter estimation procedure for the primary circuit dynamics and premodeling studies of the secondary circuit of VVER-type pressurized water reactors are presented in this paper. The primary uses of the model are control oriented dynamic model analysis and high level controller...
Article
A kutatás elsődleges célkitűzése volt a folytonos idejű nemlineáris állapotegyenletekkel leírt modellekben szereplő paramétereknek bemenet-kimenet mérési adatok segítségével történő becslése, az úgynevezett grey-box identifikációs probléma megoldása. Kutatásaink során a folytonos idejű lineáris változó paraméterű (LPV) modelleken alapuló szürkedobo...
Article
A kutatás során a hibrid rendszerek egy osztályára, amit lineáris kapcsoló üzemű rendszerekenek neveznek, rendszerelméleti erdményeket dolgoztunk ki. A munka során elsősorban az alapvető rendszer tulajdonságok, mint a megfigyelhetőség és irányithatóság feltételeivel és ellenőrzésük módszereivel foglalkoztunk. A kapcsoló üzemű rendszerek egy fontos...

Projects

Projects (4)
Project
The project aims: - to develop Scenario-in-the-Loop (SciL) simulation (mixed reality) framework for testing and proving of autonomous vehicles; - to support and provide R&D at ZalaZone automotive proving ground.
Project
Impact of a automated/autonomous vehicles to classical traffic flow theories and modeling techniques. Traffic control via automated/autonomous vehicles.
Project
Data fusion technique for efficient traffic estimation. Kalman filtering and AI based methods for traffic estimation.