Andreas Steinboeck
Vienna University of Technology
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Andreas Steinboeck.
IEEE Transactions on Control Systems and Technology | 2011
Andreas Steinboeck; Knut Graichen; Andreas Kugi
A dynamic optimization method is developed for temperature control of steel slabs in a continuous reheating furnace. The work was stimulated by the need for furnace control concepts that are computationally undemanding, robust, accurate, and capable of non-steady-state operating scenarios, where the properties and the temperature goals of slabs may vary significantly. The proposed hierarchical control structure is based on a continuous-time switched nonlinear model and uses the furnace zone temperatures as intermediate control variables. Consistent approximation is applied to obtain a parametric optimization problem that can be efficiently solved with the quasi-Newton method. Constraints on system states and control variables are considered by penalty terms in the cost function and saturation functions, respectively. The optimization method plans temperature trajectories for both the furnace and the slabs, which may be useful for open-loop control and feedforward branches of two-degrees-of-freedom control structures. The capabilities of the method are demonstrated in an example problem.
Mathematics and Computers in Simulation | 2011
Andreas Steinboeck; Daniel Wild; Thomas Kiefer; Andreas Kugi
Abstract: A flexible solution method for the initial-boundary value problem of the temperature field in a one-dimensional domain of a solid with significantly nonlinear material parameters and radiation boundary conditions is proposed. A transformation of the temperature values allows the isolation of the nonlinear material characteristics into a single coefficient of the heat conduction equation. The Galerkin method is utilized for spatial discretization of the problem and integration of the time domain is done by constraining the boundary heat fluxes to piecewise linear, discontinuous signals. The radiative heat exchange is computed with the help of the Stefan-Boltzmann law, such that the ambient temperatures serve as system inputs. The feasibility and accuracy of the proposed method are demonstrated by means of an example of heat treatment of a steel slab, where numerical results are compared to the finite difference method.
ieee industry applications society annual meeting | 2016
Katharina Prinz; Andreas Steinboeck; Martin Klaus Müller; Andreas Ettl; Andreas Kugi
The most common and well proven control strategy for thickness control in industrial rolling mills is the automatic gauge controller (AGC). However, it is still unclear how to use AGC for the control of asymmetries in lateral direction. How should the controller react to different thickness estimations at both sides of the mill. Such laterally asymmetric rolling conditions may originate from strip track-off, asymmetric friction in the mill stand, or a wedge-shaped entry profile of the strip thickness. In this paper, two different versions of AGC are compared and a feedforward approach is developed for lateral asymmetries of the entry thickness profile. Simulation studies based on a validated mill stand model demonstrate the benefit of combining AGC with a feedforward controller to compensate for asymmetries.
IEEE Transactions on Industry Applications | 2017
Katharina Prinz; Andreas Steinboeck; Martin Klaus Müller; Andreas Ettl; Andreas Kugi
The most common and well proven control strategy for thickness control in industrial rolling mills is the automatic gauge controller (AGC). However, it is still unclear how to use AGC for the control of asymmetries in lateral direction. How should the controller react to different thickness estimations at both sides of the mill? Such laterally asymmetric rolling conditions may originate from strip track-off, asymmetric friction in the mill stand, or a wedge-shaped entry profile of the strip thickness. In this paper, three control approaches are discussed. Two different setups of AGC are compared and a feedforward (FF) approach is developed for lateral asymmetries of the entry thickness profile. Simulation studies based on a validated mill stand model demonstrate the benefit of combining AGC with a feedforward controller to compensate for asymmetries.
IFAC Proceedings Volumes | 2014
Andreas Steinboeck; G. Mühlberger; Andreas Kugi
Abstract A mathematical model of a strip-looper system of a hot strip tandem rolling mill is developed using Hamiltons principle and the Galerkin weighted residual method. Several nonlinearities are considered and the effects of bending and dynamic forces on the accuracy of the model are studied. Based on the model, an estimator for the strip tension is proposed. Finally, an impedance controller for the strip tension and the looper position is designed. It can be used in the whole operating range of the system, which is also demonstrated in a simulation scenario.
IFAC Proceedings Volumes | 2011
Andreas Steinboeck; Daniel Wild; Andreas Kugi
Abstract A Lyapunov-based MIMO state feedback controller is developed for slab temperatures in a continuous, fuel-fired reheating furnace. Following an early lumping approach, the computationally simple tracking controller is designed for a nonlinear, switched dynamic model that captures both conductive and radiative heat transfer. The controller modifies reference trajectories of furnace temperatures and is part of a cascade control scheme. Given some nonrestrictive conditions, exponential stability is ensured, even under non-steady state operating conditions. The capabilities of the controller are demonstrated by means of an example problem.
Mathematical and Computer Modelling of Dynamical Systems | 2015
Michael Baumgart; Andreas Steinboeck; Thomas Kiefer; Andreas Kugi
In order to successfully automate levelling processes, in particular for heavy plates, the deflection of the leveller has to be compensated based on a deflection model. In this work, a detailed mathematical deflection model of a hot leveller with bending mechanism and its experimental validation are presented. The roll intermesh profiles are calculated based on the deflection of the work rolls that are elastically supported by support rolls, frames, posts and adjustment screws. The deflection model is suited to compensate the effect of deflection on the roll intermesh and the plate flatness as well as to assess the loads of critical parts, for example the support rolls. A new experimental design to measure the deflection of a leveller is presented and successfully applied for model validation. The work roll deflection is measured directly by means of displacement sensors that are inserted in cut-outs of test plates. These test plates are modelled as linear elastic stripes. For normal load levels, the relative accuracy (repeatability) of the roll intermesh prediction of the model is better than 0.08 mm.
Mathematical and Computer Modelling of Dynamical Systems | 2014
Katrin Speicher; Andreas Steinboeck; Daniel Wild; Thomas Kiefer; Andreas Kugi
During the heavy plate rolling process, different production steps, i.e., roll passes, descaling passes, and air cooling periods, influence the temperature evolution of the plate. All these relevant aspects are covered by a one-dimensional thermal model proposed in this paper. Experiments were conducted in a rolling mill under realistic rolling conditions to parametrise and validate the model. Using pyrometer measurements, a simple model adaption strategy is developed, which can cope with uncertainties in the initial temperature profile. The model provides accurate predictions of the temperature evolution of the plate during the whole rolling process from the plate’s exit of the furnace to the last pass. Thus, it can be used for scheduling the production process. Based on the model, an observer can be designed.
Journal of Dynamic Systems Measurement and Control-transactions of The Asme | 2013
Andreas Steinboeck; Wolfgang Kemmetmüller; Christoph Lassl; Andreas Kugi
In many hydraulic systems, it is difficult for human operators to detect faults or to monitor the condition of valves. Based on dynamical models of an electro-hydraulic servo valve and a hydraulic positioning unit, we develop a parametric fault detection and condition monitoring system for the valve. Our approach exploits the nexus between the spool position, the geometric orifice area, the flow conditions at wearing control edges, and the velocity of the controlled cylinder. The effective orifice area of each control edge is estimated based on measurement data and described by aggregate wear parameters. Their development is monitored during the service life of the valve, which allows consistent tracking of the condition of the valve. The method is suitable for permanent in situ condition monitoring. Flow measurements are not required. Computer simulations and measurement results from an industrial plant demonstrate the feasibility of the method.
IFAC Proceedings Volumes | 2013
Andreas Steinboeck; Daniel Wild; Andreas Kugi
Abstract Several control strategies for reducing the energy consumption of continuous reheating furnaces are reviewed. The energy flows and the efficiencies occurring in such furnaces are analyzed. Moreover, the nexus between energy savings and emission reduction is discussed. A case study of an industrial slab reheating furnace shows how the implementation of a nonlinear model predictive controller for the slab temperatures has reduced the primary energy consumption by 9.6%.