CORE GROUPS

Theory of Dynamical Systems

MEMBERS: Zoltán Szabó DSc (Head), Zsolt Bíró, PhD, László Gerencsér, DSc, Máté Mánfay, Tamás Péni, PhD

The Systems and Control Research Laboratory is the leading research center in Hungary in the field of mathematical systems and control theory that represents the Hungarian basic and applied research in the field being on the international level. The members of the Laboratory contribute to the advancement of systems and control theory and to the application of the accumulated knowledge in the field by outstanding basic research that is on the international level.

The scope of activity in the group is to include forefront research in specific fields of system and control theory. This scope includes topics that are traditionally related to successful R&D activities of SZTAKI in this area, and these are extended with some of the new emerging theoretical and application approaches inspired by progresses in information technology and smart instrumentations.

More specifically the group focuses on the following research issues:

•   System theory, system identification and fault detection

•   Nonlinear, adaptive and robust systems and control theory

•   Advanced signal and image processing

•   Control systems engineering

Robust and nonlinear control, LTV, LPV and bilinear systems

In the approach of the problems of nonlinear control systems, the special representation of nonlinearities in form of Linear Parameter Varying (LPV) representations of dynamic models and has gained increasing attention in the past years, LPV design playing a central role in modern control theory. Investigations in the theory of LPV systems related to system concepts, invertability questions and their applications to a wide range of control applications stay in the focus of our research. The classical notions of system theory, like controllability and observability, have been investigated for time-varying nonlinear systems enabling a model with linear structure: for example for affine linear time or parameter-varying (LTI/LPV) systems with a given structure. The theoretical and practical problems related to the inversion of the system play a central role in the design of nonlinear controllers. The possibilities of (q)LPV modeling have been investigated and they have been successfully applied for practical problems.

Linear Hybrid Systems

Motivated by the need of dealing with physical systems that exhibit a more complicated behavior than those normally described by classical continuous and discrete time domains, hybrid systems are getting very popular nowadays. Reconfigurable control systems, more precisely switching between different controllers generate a lot of theoretical and practical questions related to stability, performance and implementation. It is a decisive question how nonlinear problems can be reduced to the linear framework. In this respect our main purpose is to examine the behavior of nonlinear switching systems that can be linearized using a suitable feedback especially in the context of the bimodal systems.

Fault detection and isolation

The basic objective of a fault detection methodology for dynamic systems is to provide techniques for detection and isolation of failed components in an attempt to prevent catastrophic malfunctions in the system liable to cause destruction of the equipment, endangering the crew or the operational personnel, or in any way constituting a potential threat to the safety or the natural environment. Fault detection and estimation are tightly coupled subjects. For solving the health monitoring and failure detection problem effectively the solution of a robust estimation problem is crucial. One of the major concerns in designing failure detection systems is detection performance i.e., the ability to detect and identify faults promptly with minimal delays and false alarms even in the presence of uncertainty. Finding a trade-off between sensitivity and disturbance attenuation of the methods is an important design issue.

Fault tolerant and reconfigurable control

Fault tolerant control is a field promoting the joint implementation of advanced control and fault detection ideas. A common practice when designing fault tolerant control scheme is to make use of two basic modules: fault detection and fault accommodation where special controllers are implemented to minimize the impact on the system performance. This extended control scheme should guarantee graceful and gradual degradation in performance in case of failures. Development of integrated control and failure detection methods within the scheme of the fault tolerant control architecture is an important design quality.

AERO_GNC: Aerospace Guidance, Navigation and Control

MEMBERS: Bálint Vanek (Head), Márk Lukátsi, István Réti

Associated members: Péter Bauer, István Gőzse, Tamás Péni

Student members: András Erdő, Bálint Zsiga

Research Projects: ADDSAFE (EU FP7, terminated), RECONFIGURE (EU FP7, current), ACTUATION 2015 (EU FP7, current), Sense and Avoid (ONR, current), Safety Critical UAS Avionics (Internal, self-supported, current).

AERO_GNC conducts research in the field of both manned and unmanned aerospace vehicles. The main research themes are guidance, navigation, control, fault detection and safety critical avionics systems. Key to the group is to work on the boundary between advanced theoretical concepts and challenging industrial applications. Core to the research activities are model based control design and estimation, which are based on, linear, nonlinear or linear parameter-varying (LPV) framework. Control methods are applied to various applications, ranging from inner-loop electro mechanical actuator position control to small unmanned aerial vehicle waypoint guidance, and to reconfigurable control algorithms for commercial airlines. Estimation methods are used mainly in two topics: navigation, where multiple sensor sources are fused to provide high precision position, velocity and attitude information for the autopilot, and in fault detection and isolation, where potential actuator or sensor faults are detected, based on the available measurements taking advantage of analytical redundancy. The control and monitoring algorithms, together with a vision based sense and avoid system, are also combined, in a safety critical avionics architecture to provide a platform for future integration of UAVs into the common airspace. The group is actively involved in international research collaborations with industrial partners such as Airbus, UTC Aerospace, research agencies like DLR, ONR and universities such as University of Minnesota, TUHH. 

Vehicle Dynamics and Control Group

MEMBERS: Péter Gáspár DSc (Head), Balázs Németh, Gábor Rödönyi, PhD

Student members: András Mihály, Balázs Varga, András Lang

The Systems and Control Laboratory provides solutions in the field of vehicle control systems analysis and design. The main directions of research include integrated vehicle control design methods, reconfigura-ble and fault-tolerant control systems architectures, the control of coordinated platoon systems and con-trol methods of intelligent unmanned vehicle systems. 

Integrated control of road vehicles

Research in the functional integration possibilities of active vehicle components is aimed at integrating the components of the suspension, steering, braking and driveline subsystems in order to guarantee performance demands, achieve better management of different resources and eliminate harmful interference between them. Using integrated control the operation of a partial control system is also extended with a fault-tolerant and reconfigurable structure.

Supervisory decentralized architecture

The research also focuses on a multi-layer supervisory decentralized architecture. The performance specifications are guaranteed by the local controllers, while the coordination of these components is provided by the supervisor. The supervisor has information about the current operational mode of the vehicle and it is able to make decisions about the necessary interventions into the vehicle components. These decisions are propagated to the lower layers through predefined interfaces encoded as suitable scheduling signals.

Components of Vehicle Control 

A method is developed for the design of the construction of a variable-geometry suspension system, which affects the design of robust suspension control.  In the control solution a predefined road trajecto-ry required by the driver with a steering command is followed. The variable geometry suspension system allows us to modify the mechanical geometry and set up an efficient structure. The lateral and longitudinal dynamics are combined in a trajectory tracking system which is able to track road geometry with a predefined reference velocity. The control system manipulates the front steering, braking and driving. Although the selection of the actuator is usually performed by using practical considerations, a theory-based method is developed in a weighting strategy.

Cooperative Control of a Vehicle Platoon System

The focus of the research is the design of a vehicle platoon system. In our approach, the platoon has a non-autonomous leader vehicle, i.e., this first vehicle is driven by a human driver, and some subordinate vehicles following the leader vehicle at some small pre-specified distances between them are driven au-tomatically by driver assistance systems. Usually, two performance goals are set for a platoon system: a) to improve safety compared to that of the individual transports, b) to reduce the total fuel consump-tion. The longitudinal controller is responsible for the stabilization of the platoon, which is characterized formally by the string stability theorem.

Measurement and Control Technology Group

MEMBERS: Alexandros Soumelidis PhD (Head), Ferenc Schipp, DSc (prof. emeritus), Zoltán Fazekas, CSc, Ádám Bakos, Ernő Simonyi, Gergely Regula, István Gőzse


The Measurement and Control Technology Group is devoted to elaborate some significant topics of control science and technology such as sensing, measurement, actuation, and signal processing, modeling, identification both in theoretical and implementation level. The main activities of the group are concentrated on

• Sensing, measurement, and data acquisition,
• Signal processing, image processing, detection, diagnostics, system identification,
• Control system realizations,
• Embedded system design in the field of measurement and control.

 Main subjects of the research:

• Signal and systems theory, signal processing for system identification and control (A. Soumelidis, F. Schipp in collaboration with Prof. J. Bokor),
• Surface representations and reconstruction, detection methods by image processing (A. Soumelidis, Z. Fazekas, F. Schipp, E. Simonyi),
• Control design methodologies for aerospace and automotive systems, including identification and control design of electric drives, servo systems, etc. (A. Soumelidis, A. Bakos, G. Regula, I. Gőzse),
• Vehicle control methodologies, navigation and guidance solutions, smart sensors, sensor fusion, individual and cooperative control strategies (A. Soumelidis, G. Regula, Á. Bakos, E. Simonyi). 

Development activities and services (participation in the R&D projects of the Laboratory):

• Design and realization of measurements and data acquisition with dSpace, NI data acquisition systems, and customized measurement devices,
• Embedded control system design and realization: applying 8-16-32-bit microcontrollers, microcomputers (AVR, ARM, PowerPC), and FPGA,
• High precision and high reliability electronic design; sensors, power electronics, digital and hybrid solutions, sensor and actuator development for aerial and automotive vehicles,
• Testing methodologies, test systems design, simulation and hardware-in-the-loop based solutions. 

Industrial I&C Systems Group

MEMBERS: Tamás Bartha, PhD (Head), István Varga PhD, Gábor Szederkényi DSc, Krisztián Szabó, Alfréd Csikós, Attila Gábor 

Associated members: Prof. Katalin Hangos DSc

The Industrial Instrumentation and Control Systems (IICS) Group deals with the different technological and architectural aspects of safety-critical industrial systems, with a special focus on (nuclear) power generation systems. The group works frequently in cooperation with the Paks Nuclear Power Plant, but it has carried out projects also in the fields of aviation and road transport systems. The research and development scope of the group includes the full life-cycle of the industrial I&C systems from the specification, the design, through the implementation. The expertise of the group comprises the architectural and technological design of control and safety systems, (formal) verification of the control system specification and design, safety and reliability analysis, test system design and realization, fault detection and diagnosis, testing and validation of the final product, and the computer security aspects of the industrial I&C systems. 

A short list of the more significant projects completed by members of the IICS group (in chronological order, the details can be found on the Project page): 

• Compilation of the probabilistic and deterministic safety requirements for the refurbishment of the Control Rod Control System (CRCS), and the Reactor’s Power Control System (RPC) 
• Strengthening cyber security of digital I&C Systems in Hungarian nuclear installations by improving regulations (joint work together with the Hungarian Atomic Energy Authority) 
• Modeling and identification of the primary and secondary circuits of the Paks NPP units (the process and the current controllers) 
• Paks NPP Primary Pressure Controller refurbishment 
• Survey of the typical control problems in the Paks NPP and recommendation for the control theoretic solution methodologies 
• Status and actual risk monitoring for the Paks NPP Reactor Protection System 
• Development, testing and deployment of the Universal Test System for the Paks NPP Reactor Protection System 
• Paks NPP Unit Computer Refurbishment Project 
• Participation in the Paks NPP Reactor Protection System Refurbishment Project 
• Development of dependable architectures and techniques for electronic brake systems 

PEN3C: Research Group on Pervasive Networks for Cooperative Control and Communication

MEMBERS: András Edelmayer DSc (Head), József Kovács, László Virág, András Takács

Research Projects: ITSSv6 (EU FP7, recent), sensITSv6 (Internal, self-supported, current)

PEN3C conducts research in the field of pervasive networks with applications to cooperative systems, where communication and ubiquitous networking are the enabling technology factors. PEN3C provides software and hardware solutions and services designed for intelligent vehicles and the transportation infrastructure. Special focus is taken on V2X (Vehicle-to-Vehicle and Vehicle-to-Infrastructure) communications systems research and development, as part of the next generation Intelligent Transportation Systems (ITS), i.e., Cooperative Transportation Systems (CTS). PEN3C provides solutions of communication fully compliant with the emerging harmonized ISO/ETSI/IEEE ITS communications architecture, including a variety of communication interfaces and technologies. Embedment of ultra-low-power sensor networks in the V2X communication architectures and use-case scenarios is in the forefront of the research. PEN3C is the core developer and integrator of the emerging new communication protocols, such as the ones constituting the ETSI G5 technology (including Wave and CALM FAST-based safety critical communications), mobile IPv6 and Geonetworking protocols, the CALM protocols and standards. 

ASSOCIATED GROUPS

Associated Research Group of Hungarian Academy of Sciences on Systems and Control Theory

MEMBERS: László Keviczky, academician (Head), Csilla Bányász, PhD