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Prof. Dr. László Juhász

  • Modelling, parameter identification, and simulation of mechatronics systems
  • Control of mechatronics systems
  • Model-based control design and testing
  • Model-based control design for FPGA-based controller
  • Mathematics

Faculty of Electrical Engineering and Media Technology

Professors

Dean

E 206

0991/3615-532

0991/3615-297

Sortierung:
Contribution
  • Đ. Garabandić
  • T. Petrović
  • László Juhász

Robust decentralised control of parallel DC/DC converters.

In: Proceedings of the VIIIth Symposium Power Electronics '95. pg. 563-570

  • (1995)
Contribution
  • László Juhász
  • Đ. Garabandić
  • M. Živanov

Digital regulation of the BUCK DC/DC converter.

In: Proceedings of the IX Symposium Power Electronics '97 (22.-24.10.1997, Novi Sad, Serbien). pg. 513-521

  • (1997)
Journal article
  • M. Peruničić
  • László Juhász
  • A. Sadibašić

The dynamics of a conical gravity flow tank.

In: Chemical Industry (Belgrad, Serbien) vol. 51 pg. 24-27

  • (1997)
Contribution
  • László Juhász
  • Đ. Garabandić
  • M. Živanov

BUCK DC/DC converter controlled by microcontroller.

In: Proceedings of INDEL '97 (24.-26.09.1997, Banja Luka, Bosnien und Herzegowina). pg. 135-140

  • (1997)
Journal article
  • M. Peruničić
  • László Juhász

Dynamics of a spherical gravity flow tank.

In: Documenta Chemica Yugoslavica vol. 39 pg. 85-88

  • (1997)
Contribution
  • László Juhász
  • A. Vujanić
  • N. Adamović
  • T. Lozanovski
  • L. Nagy
  • B. Borovac

Platform for micropositioning with piezo-actuators.

In: Proceedings of the 3rd International Symposium 'Interdisciplinary Regional Research (Hungary, Romania, Yugoslavia)' [Novi Sad, Jugoslawien, 24.-25.09.1998]. pg. 103-106

  • (1998)
Journal article
  • M. Peruničić
  • László Juhász

Contribution to analysis of proportional and proportional-integral liquid-level control in cylindrical flow tank.

In: Documenta Chemica Yugoslavica vol. 40

  • (1998)
Contribution
  • László Juhász
  • T. Lozanovski
  • N. Adamović
  • A. Vujanić
  • L. Nađ
  • B. Borovac

Realisation testing of platform for micro positioning using piezo-actuators.

In: Proceedings of ETRAN '98 (01.-05.06.1998, Vrnjačka Banja, Jugoslawien). (IV) pg. 285-288

  • (1998)
Contribution
  • L. Nađ
  • László Juhász

Design of CMOS buffers for driving large capacitive loads using PsPICE.

In: Proceedings of ETRAN '98 (01.-05.06.1998, Vrnjačka Banja, Jugoslawien). (IV) pg. 35-38

  • (1998)
Journal article
  • László Juhász
  • M. Peruničić
  • T. Kuljanin

Simulational dynamic model of a chemical reactor.

In: Chemical Industry (Belgrad, Serbien) vol. 52 pg. 279-285

  • (1998)
Contribution
  • László Juhász
  • N. Pekarić-Nađ
  • L. Nađ

EMI-oriented macromodel for operational amplifier μA741.

In: Proceedings of ETRAN '98 (01.-05.06.1998, Vrnjačka Banja, Jugoslawien). (IV) pg. 49-52

  • (1998)
Journal article
  • László Juhász
  • S. Markov
  • L. Nađ
  • B. Borovac
  • A. Vujanić
  • N. Adamović

Moving platform for sample micropositioning.

In: Chemical Industry vol. 54 pg. 243-257

  • (2000)
Contribution
  • László Juhász
  • A. Vujanić
  • N. Adamović
  • L. Nagy
  • B. Borovac

Development of Platform for Micro-Positioning Actuated by Piezo-Legs.

In: Proceedings of the 2000 IEEE International Conference on Robotics and Automation (ICRA) [24.-28.04.2000, San Francisco, CA, USA]. (4) pg. 3647-3653

  • (2000)
Journal article
  • László Juhász
  • A. Vujanić
  • N. Adamović
  • L. Nagy
  • B. Borovac

A platform for micropositioning based on piezo legs.

In: Mechatronics vol. 11 pg. 869-897

  • (2001)

DOI: 10.1016/S0957-4158(00)00059-3

show abstract

In this paper, we describe the development and prototype testing of a platform for micropositioning having three legs made of piezo tubes. Each piezo tube has four outer electrodes and one common inner electrode on its walls. By appropriate polarization of outer(s) electrode(s) with respect to the inner electrode, due to the inverse piezo effect, the tube wall will change its longitudinal dimension and the tube will bend in the corresponding direction. The platform motion is performed by successive slow bending and quick stretching of the tubes (i.e., legs). At this stage of development, the platform is connected by five wires to a power supply and a PC. The range of platform motion is limited only by the length of the wires connecting it to the power source. Electronic circuits for generating appropriate voltage signals are designed to be as simple as possible. This enabled the complete electronics and microcontroller for motion control to be placed onboard. The microcontroller is capable of realizing all operations needed for the motion execution and the communication with PC (containing the information about motion direction and step amplitude) can be done using a standard RS-232 interface. It was experimentally verified that, though being of a simple design, the platform allows a positioning accuracy which is below Full-size image (<1 K). Even more accurate positioning (below Full-size image (<1 K)) can be achieved in the “only bending” mode by simultaneous bending of all legs in a desired direction and without executing the legs' stretching. The platform capability to accomplish controlled complex motion using different motion velocities was demonstrated. Using a joystick, translation and rotation are easily achievable and the motion can be controlled in real time. Platform loading capacity allows some additional devices like a gripper, or any another device for a particular application to be mounted onboard. This enables the platform's potential use in a wide variety of applications.
Journal article
  • D. Skobalj
  • Z. Zavargó
  • László Juhász

Water temperature distribution in a vertical cross-section of a wet counterflow cooling tower.

In: Hungarian Journal of Industrial Chemistry vol. 30 pg. 1-5

  • (2002)
Contribution
  • László Juhász
  • F. Schütte
  • K. Diekstall

Use of rapid control prototyping (RCP) and hardware in the loop (HIL) technology for development and tests of Aerospace applications.

In: Konferenzband der AIRTEC 2007 ('Supply on the wings'; 2. Internationale Zulieferermesse für die Luft- und Raumfahrt) [24.-25.10.2007, Frankfurt am Main].

  • (2007)
Contribution
  • László Juhász
  • F. Schütte
  • S. Lillwitz

AFDX for Airplanes.

In: Konferenzband der Aerospace Testing International 2007.

  • 2007 (2007)
Contribution
  • László Juhász
  • A. Kiffe
  • J. Maas

Modellierung und Regelung eines hybriden Nanopositionierungssystems.

In: Konferenzband des Internationalen Forums Mechatronik (ifm) 2009 (10.-11.11.2009, Linz, Österreich). pg. 161-174

  • 10.-11.11.2009 (2009)
Contribution
  • László Juhász
  • A. Kiffe
  • J. Maas

FPGA-Based Interface for Control of a Hybrid Micropositioning Stage.

In: Proceedings of the 35th Annual Conference of the IEEE Industrial Electronics Society (IECON-2009) [03.-05.11.2009, Porto, Portugal]. pg. 2862-2867

  • (2009)
Contribution
  • László Juhász
  • A. Kiffe
  • J. Maas
  • B. Borovac

FPGA-Based Interface for Fast Data Exchange between a Rapid Control Prototyping System and a Hybrid Micropositioning Stage.

In: Proceedings of the 53rd Conference for Electronics, Telecommunications, Computers, Automatic Control and Nuclear Engineering (15.-19.06.2009, Vrnjačka Banja, Serbien).

  • (2009)
Contribution
  • László Juhász
  • J. Maas
  • J. Tasevski
  • B. Borovac

Multiplicative and Additive Piezoelectric Hysteresis Compensation Methods for Real-Time Micropositioning Applications.

In: Proceedings of the 54th Conference for Electronics, Telecommunications, Computers, Automatic Control and Nuclear Engineering (Juni 2010, Donji Milanovac, Serbien).

  • (2010)
Contribution
  • László Juhász
  • T. Fichtner
  • A. Kiffe
  • J. Maas

Model-Based State-Space Control of Hybrid Micropositioning Systems.

In: Proceedings of the 5th IFAC Symposium on Mechatronic Systems (September 2010, Cambridge, MA, USA). pg. 324-331

  • (2010)
Contribution
  • László Juhász
  • A. Kiffe
  • J. Maas

Friction and Hysteresis Compensation of a Hybrid Micro-Positioning System.

In: Proceedings of the 12th International Conference on New Actuators (ACTUATOR 10) [14.-16.06.2010, Bremen]. pg. 268-271

  • (2010)
Contribution
  • J. Maas
  • László Juhász

Adaptive Regelung für piezoelektrisch-basierte Hybridsysteme.

In: Konferenzband der SPS/IPC/Drives 2011 (Nürnberg). pg. 93-101

  • (2011)
Journal article
  • László Juhász
  • J. Maas

FPGA-Based Control of Piezoelectric Actuators.

In: Serbian Journal of Electrical Engineering vol. 8 pg. 181-201

  • (2011)

DOI: 10.2298/SJEE1102181J

Contribution
  • László Juhász
  • J. Maas

Online Controller Optimization for Hybrid Micropositioning Systems.

In: Proceedings of the IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM) [03.-07.07.2011, Budapest, Ungarn]. pg. 820-825

  • (2011)
Contribution
  • László Juhász
  • J. Maas

State-Space Control of Hybrid Micropositioning Systems for Industrial Applications.

In: Konferenzband der VDI-Mechatroniktagung 2011 (31.03.-01.04.2011, Dresden). pg. 31-36

  • (2011)
Journal article
  • László Juhász
  • J. Maas
  • B. Borovac

Parameter identifications and hysteresis compensation of embedded piezoelectric stack actuators.

In: Mechatronics vol. 21 pg. 329-338

  • (2011)

DOI: 10.1016/j.mechatronics.2010.12.006

show abstract

A novel method for the identification of embedded piezoelectric stack actuator parameters in combination with a real-time capable hysteresis compensation measure is presented. The presented algorithms are based on the Maxwell resistive capacitor model and are particularly useful for the identification of piezoelectric actuators embedded in a high-precision micropositioning system where the disassembly of the complete system for separate actuator identification is not recommended or not possible. The parameter identification can be performed in a fully automated way and enables the adaptation of the compensation routine to the changed circumstances (temperature difference, wearing of actuators) as well. The hysteresis compensation method proposed here does not require significant CPU or memory resources. It can be implemented as an additional task on the already existing controller or a low-budget FPGA. As an example, the proposed method was validated experimentally by the parameter identification and hysteresis compensation of the piezoelectric actuators incorporated in a commercially available hybrid micropositioning system. The achieved experimental results are in very good agreement with the theoretical ones.
Contribution
  • F. Schütte
  • László Juhász
  • A. Tenge

Integration of EtherCAT in Advanced Test Systems - Solutions and Challenges.

In: EtherCAT in Mobile Applications (ETG) 2013.

  • (2013)
Journal article
  • László Juhász
  • J. Maas

Control of Hybrid Nanopositioning Systems for Trajectory-Tracking Applications.

In: Mechatronics vol. 23 pg. 617-629

  • (2013)

DOI: 10.1016/j.mechatronics.2013.06.008

show abstract

In many industrial applications positioning systems are required to follow trajectory paths in the range of several centimeters and featuring at the same time a nanometre-range precision. Neither pure piezoelectric stages nor standard positioning systems with motor and spindle are able to meet such requirements as a single actuator, because of the small operation range on the one hand and inadequacies like backlash and friction on the other hand. Hybrid positioning systems, realized as a combination of a “coarse” and a “fine” actuator, aim to solve this problem. The wide range of applications enables a considerable market potential for such devices, but yields changing control requirements due to the high variety of possible positioned objects and positioning tasks and requires therefore a high-performance control system. In this paper a model-based control design for piezoelectric hybrid nanopositioning systems is presented. The proposed control consists of a multivariable state-feedback control on the basis of a novel plant representation offering a sufficient robustness. The designed control is realized and experimentally tested with a commercially available hybrid nanopositioning system featuring a DC drive, representing the coarse actuator, and a piezoelectric actuator utilized as fine actuator.
Patent
  • László Juhász

Computerimplementiertes Verfahren zur Berechnung und Ausgabe von Steuerimpulsen durch eine Steuereinheit.

  • (2015)
Patent
  • László Juhász

Verfahren zur Konfiguration eines für das Testen eines Steuergeräts eingerichteten Testgeräts.

  • (2016)
Patent
  • László Juhász
  • J. Lakemeier

Method for configuring a tester equipped for testing a control unit.

  • 26.01.2017 (2019)
Journal article
  • I. Juhász Junger
  • D. Wehlage
  • R. Döttjer
  • T. Grothe
  • László Juhász
  • C. Grassmann
  • T. Blachowicz
  • A. Ehrmann

Dye-Sensitized Solar Cells with Electrospun Nanofiber Mat-Based Counter Electrodes.

In: Materials vol. 11 pg. 1604

  • (2018)

DOI: 10.3390/ma11091604

show abstract

Textile-based dye-sensitized solar cells (DSSCs) can be created by building the necessary layers on a textile fabric or around fibers which are afterwards used to prepare a textile layer, typically by weaving. Another approach is using electrospun nanofiber mats as one or more layers. In this work, electrospun polyacrylonitrile (PAN) nanofiber mats coated by a conductive polymer poly(3,4-ethylenedioxythiopene) polystyrene sulfonate (PEDOT:PSS) were used to produce the counter electrodes for half-textile DSSCs. The obtained efficiencies were comparable with the efficiencies of pure glass-based DSSCs and significantly higher than the efficiencies of DSSCs with cotton based counter electrodes. The efficiency could be further increased by increasing the number of PEDOT:PSS layers on the counter electrode. Additionally, the effect of the post treatment of the conductive layers by HCl, acetic acid, or dimethyl sulfoxide (DMSO) on the DSSC efficiencies was investigated. Only the treatment by HCl resulted in a slight improvement of the energy-conversion efficiency.
Contribution
  • Amir Samiee
  • J. Sahu
  • Nicolas Tiefnig
  • Michael Wagner
  • A. Baumgartner
  • László Juhász

Model-Driven Engineering in Education.

In: Proceedings of the 2018 18th International Conference on Mechatronics – Mechatronika (ME) (December 5-7, 2018; Brno, Czech Republic). pg. 9-14

  • Eds.:
  • Faculty of Mechanical Engineering, Brno University of Technology
  • Institute of Electrical and Electronics Engineers Inc.

  • (2018)
Journal article
  • László Juhász
  • I. Juhász Junger

Spectral Analysis and Parameter Identification of Textile-Based Dye-Sensitized Solar Cells.

In: Materials vol. 11 pg. 1623

  • (2018)

DOI: 10.3390/ma11091623

Lecture
  • László Juhász
  • J. Sahu
  • Amir Samiee
  • Nicolas Tiefnig
  • Michael Wagner

Model-Driven Engineering in Education: Position Control of an Electronic Throttle Valve.

In: 5th EcETRAN International Conference for Electronics, Telecommunications, Computers, Automatic Control and Nuclear Engineering

Palić, Serbien

  • 11-14.06.2018 (2018)
Lecture
  • Amir Samiee
  • J. Sahu
  • Nicolas Tiefnig
  • Michael Wagner
  • A. Baumgartner
  • László Juhász

Model-Driven Engineering in Education.

In: 18th International Conference on Mechatronics-Mechatronika 2018

Brno University of Technology Brno, Tschechische Republik

  • 5.-7.12.2018 (2018)
Contribution
  • László Juhász
  • Amir Samiee
  • W. Engelbrecht

XCP Service Integration for Model-Based, Automatic Production Code Generation.

In: Proceedings of IEEE EUROCON 2019 -18th International Conference on Smart Technologies. pg. 1-6

  • Eds.:
  • Institute of Electrical and Electronics Engineers Inc.

  • (2019)

DOI: 10.1109/EUROCON.2019.8861774

show abstract

Automated, model-based production code generation is widely used in the development and testing of electronic control units (ECUs). During ECU commissioning, extensive tests of the implemented control algorithms are required. Knowledge of the internal values and states of the ECU software are essential for verifying the correct software functionality by means of complex control algorithms. Calibration and measurement services make it possible to observe the ECU-internal memory values associated with the variables originating from the function model. Furthermore, the final adjustment of control parameters in the production ECU can be performed by means of calibration services. For these reasons, calibration and measurement through service integration is widely applied in both the automotive industry and other industrial fields. Integrating measurement and calibration services is therefore an important task for engineers working with model-based control development and, particularly, ECU production code integration. This paper describes an example integration of the Universal Measurement and Calibration Protocol (XCP) for model-based automatic code generation. The application used for the service integration is the commercially available Motor Control Education Kit (MEDKit) from Emerge-Engineering and dSPACE GmbH. The model-based automatic code generation is performed using the production code generator dSPACE TargetLink. The integration of the XCP on CAN protocol is completed in the scope of student projects. The upgraded MEDKit demonstrator will be used for education purposes in the Deggendorf Institute of Technology.
Contribution
  • Alireza Tajafari Sahebi
  • Amir Samiee
  • László Juhász

MRAC Implementation for Electric Throttle Valve.

In: Proceedings of the 2020 10th International Conference on Advanced Computer Information Technologies (ACIT) [September 6-8, 2020; Deggendorf]. pg. 6-12

  • (2020)

DOI: 10.1109/ACIT49673.2020.9208929

show abstract

Design, implementation and testing of a model reference adaptive controller for an electric throttle valve are presented. An important step by design an adaptive controller is to find an adaptation mechanism. For this purpose, we employed the Lyapunov stability theory. The main challenge in this project originates from a certain term in the updating rules. This term contains the angular velocity, which is not measurable directly. Numerical differentiation of the measured angular position yields a noisy signal. To overcome this problem, we used a non-ideal derivative method. The use of a non-linear state observer based on extended Kalman filter could significantly enhance the control quality. This task is currently in progress.
Contribution
  • Shivam Yadav
  • Alireza Tajafari Sahebi
  • László Juhász

Adaptive Model Predictive Controller for Inverted Pendulum.

In: Proceedings of the 2021 11th International Conference on Advanced Computer Information Technologies (ACIT) [September 15-17, 2021; Deggendorf]. pg. 208-213

  • Eds.:
  • Institute of Electrical and Electronics Engineers Inc.

  • (2021)

DOI: 10.1109/ACIT52158.2021.9548562

show abstract

This paper focuses on the design, simulation and implementation of an adaptive model predictive controller of the inverted pendulum. The main objective of the controller is to hold the pendulum at an upright position against the gravity. MPC works using the real-time simulation of the model. The model is designed in MATLAB/Simulink environment. Since an inverted pendulum is a nonlinear single input multi output (SIMO) nonlinear system, it needs to be linearized at each operating point. Thus, linearization of the model is performed around working point. This continuous linearized model is discretized in real-time. This discrete linear model is used for obtaining a predictive model. Optimizer is another essential component of MPC controller, which runs on minimization of Quadratic cost function principle. For rapid control prototyping, dSPACE MicroLabBox (MLBX) is used whereas ControlDesk is used for the recording of the model values in real time environment.
Contribution
  • Christoph Rappl
  • László Juhász

Improving the Plant’s Phase Response by Asymmetrical Lead/Lag Compensation of a given Phase and Slope Deficit.

In: 2024 43rd Chinese Control Conference (CCC). pg. 4232-4239

IEEE

  • (2024)

DOI: 10.23919/CCC63176.2024.10662368

show abstract

A proposal for enhancement of classical lead/lag loop shaping is presented in this work. Although being a rather old method, the Bode-diagram design of phase shifting compensators is still very popular with many users because of its simplicity. In the traditional way, lead or lag filters or PID controllers are used to optimize the phase response of the plant. First the phase deficit is determined at the desired gain crossover frequency ωc of the open loop, then a lead or lag compensator is designed, doing the necessary phase correction at ωc with its phase maximum or minimum. In this new approach, the missing phase amount isn’t generated at the maximum or minimum of the compensator’s symmetrical phase curve, but in its rising or falling area. The positive or negative slope of the controller’s phase response at ωc is hereby used to adjust additionally the slope of the open loop phase to an optimal value. This measure improves the step response of the closed control loop in most cases and often results in an increase of robustness. Interestingly, the design procedure generates in some cases a generalized lead/lag filter, which can be of non-minimum phase type or even instable. The positive effect of the modified design procedure is shown through Monte Carlo Simulations. The design procedure based on this new approach needs strong numerical support, but it can be easily implemented with MATLAB or a similar math package.

Other

A video about a student's project conducted in the lab Model-Based Control-Design and Test

https://nextcloud.th-deg.de/s/F5jnrG2B2YzHL64