Martin Steinberger

Saturated Super-Twisting Algorithm: Lyapunov based approach

A saturated control Super-Twisting Algorithm is presented. Lyapunov level curves are used for the design of the saturation of Super-Twisting Algorithm.

Modeling and feedback linearization based control of an electromagnetic clutch actuator

In automotive clutch applications the use of purely electromagnetic actuators is not yet very common. Their dynamics are nonlinear and often subject to kinematic constraints. Therefore their accurate control is a challenging task. In this paper, a plant model of an electromagnetic clutch actuator is developed from the corresponding physical principles. On this basis, a position controller for the electromagnets armature utilizing feedback linearization is presented. It allows smooth and fast armature movement without introducing unwanted torque jerks into the drive train. The effectiveness of the control strategy is shown in simulations where it is compared to a conventional PID controller.

Input Matrix Factorizations for Constrained Control Allocation

Control allocation (CA) is part of a hierarchical control architecture and distributes the desired control effort of a controller among a set of redundant actuators as it is used, for example, to meet high reliability requirements. Before applying CA, a factorization of a linear plants input matrix must be carried out. This paper investigates the influence of this factorization on two common algorithms for constrained CA: direct allocation and redistributed pseudoinverse (RPINV). It is shown why the factorization does not affect the first method, whereas it influences the latter one as soon as the number of actuator saturations exceeds a certain threshold. On this basis a modification of RPINV is proposed, which allows the prioritization of virtual control vector components. If the actuator saturations prevent an exact solution, the errors of those components with high priority are preferentially forced to zero. Finally simulations demonstrate the main results.

Sliding Mode Based Platooning With Non-Zero Initial Spacing Errors

This letter presents a novel approach to unidirectional formation control of multiple vehicles with non-zero initial spacing errors. It is based on concepts of first-order sliding mode control. A combination of two adaptive sliding surfaces enables collision-free platooning with asymptotic convergence to constant distance spacings. It is an attractive feature of the proposed algorithm that only position and velocity of the preceding vehicle are used so that no car-to-car communication is necessary.

The 2017 Summer School on Sliding Mode Control [Conference Reports]

T he 2017 International Summer School on Sliding Mode Control took place at the Institute of Automation and Control, Graz University of Technology, Austria, September 4–8, 2017. The summer school was organized by Martin Horn, Martin Steinberger (Graz University of Technology), and Leonid Fridman (Universidad Nacional Autónoma de México). It was supported by the IEEE Control Systems Society (CSS) Technical Committee on Variable Structure and Sliding Mode Control. The school is the first stage of preparation for the 15th International Workshop on Variable Structure Systems, which will take place in Graz, Austria, June 9–11, 2018 (see www.vss-graz.com). The goal of the school was to promote basic techniques and recent results of sliding mode control and observation among students and researchers from Europe. The 22 participants came from universities and companies (Samsung SDI Battery systems, LAM Research, Virtual Vehicle,

Model Predictive Temperature Control of a Distribution System for Chemicals

In semiconductor manufacturing tight temperature control of chemicals is crucial for meeting clean application requirements. The use of multiple chemistries as well as various configuration options makes precise temperature control a challenging task. In this paper a generic solution for the temperature control in a single wafer manufacturing machinery for wet-chemical processing based on a model predictive control technique is presented. The developed control strategy is implemented and evaluated on a real world unit with realistic wafer cleaning recipes.

Model predictive output integral sliding mode control

A combination of model predictive control with output integral sliding mode techniques is proposed. The output integral sliding mode controller protects the nominal control provided by the predictive controller against matched perturbations. The entire concept exploits output information only. The control strategy is tested in the laboratory on a mass positioning system.

A new method to compute generalized inverses for control allocation

Modern mechatronic systems are often equipped with a set of redundant actuators due to different operating points and high reliability requirements. One possibility to deal with such systems incorporates a separation between the control task and the distribution of the control effort among the actuators (so-called control allocation). In case of a linear plant model a factorization of the input matrix has to be carried out. The relationship between factorizations can be described by means of invertible transformation matrices. This work investigates the impact of factorization on the computation of generalized inverses and their usage for control allocation. Based on these results a new method for generating generalized inverses, which allow a more effective usage of the available actuators, is developed.

Saturated Super-Twisting Algorithm based on Perturbation Estimator

A Saturated Sliding Mode Controller based on Super-Twisting Algorithm and Perturbation Estimator is presented. With the implementation of the perturbation estimator, Saturated Super-Twisting Algorithm is able to use the entry range of control signal to compensate Lipschitz perturbations ensuring the global finite-time stability of the origin at the maximum rate of convergence that the saturated control signal can offer.

Sliding Mode Applications on Hydraulics and Pneumatics

Dipl.-Ing. Dr. Martin Steinberger Die vorliegende Ausgabe der e&i ist dem Themenschwerpunkt „Sliding Mode Applications on Hydraulics and Pneumatics“ gewidmet. Es handelt sich hierbei um ein Schwerpunktheft, das vom Fachbereich „Automatisierungs-, Regelungstechnik und Mechatronik“ der österreichischen Gesellschaft für Mess-, Automatisierungsund Robotertechnik, kurz GMAR, gestaltet wurde. Das Ziel dieses Heftes besteht darin, einen Überblick über die Anwendung moderner strukturvariabler Methoden zur Regelung und Beobachtung hydraulischer und pneumatischer Systeme zu geben. Diese Methoden der nichtlinearen Regelungstheorie zeichnen sich dadurch aus, dass gewisse Klassen von Störungen vollständig unterdrückt werden können. Zusätzlich erlauben diese Verfahren die Rekonstruktion von einwirkenden Störungen bzw. die robuste Schätzung interner Systemgrößen. Diese Eigenschaften ermöglichen den Einsatz von strukturvariablen Konzepten zur Regelung, Schätzung von Zustandsgrößen, Parameterschätzung sowie zur Fehlerdetektion und -identifikation in komplexen dynamischen Systemen. Sliding Mode Control ist ein klassisches Verfahren der Regelungstechnik, dessen Robustheit auf dem schaltenden Charakter der Regelgesetze basiert. Der daraus resultierende „unruhige“ Verlauf der Stellgrößen wird dabei häufig als ein Nachteil der Methodik angesehen. In den letzten Jahrzehnten gelang es, Algorithmen zu entwickeln, die bei weitgehender Minderung des oben genannten Nachteils die Vorzüge der ursprünglichen Sliding Mode-Konzepte besitzen. Heute stellt der Bereich der strukturvariablen Systeme auch in Österreich ein äußerst aktives Forschungsgebiet dar. Diesem Umstand wird auch dadurch Rechnung getragen, dass vom Institut für Regelungsund Automatisierungstechnik der Technischen Universität Graz im Jahr 2017 eine internationale Sommerschule für strukturvariable Systeme im Schloss Seggau (Steiermark) und im Jahr 2018 der „15. internationale Workshop für strukturvariable Systeme (VSS2018)“ in Graz ausgerichtet wird.