05.07.2017
Optimization-based control methods applied to a laboratory-scale tower crane

Project focus

• Real-time implementation of optimization-based control methods
• Constrained model predictive control
• Path planning
• Path-following control

Description

Tower cranes are widely-used and constitute an interesting field of application for modern control theory. An important task is to control the position of the hook by suppressing the oscillating motion of the cable at the same time. Another possible goal is the rejection of disturbances such as different load masses or external forces induced by wind.

Different control concepts are developed to cope with theseand further  goals. The resulting controllers are tested on a laboratory tower crane. The focus lies on optimization-based control methods, in particular model predictive control (MPC). MPC is able to systematically take into account system constraints and to achieve an optimal behavior of the closed-loop system in the sense of the underlying objective functional. This includes for example the minimization of the energy consumption of the actuators.

To avoid collisions with obstacles, it is required that the hook or rather the load mass follows a given collision-free path as accurately as possible. This task can be tackled from two different directions.

• Trajectory tracking control: The time evolution along the geometric path is fixed in advance. The controller has to achieve the tracking of the time-parameterized trajectory. This task was implemented in the CLIC-project (Closed-Loop Integration of Cognition, Communication and Control, 2009-2010). Another goal of this project was to generate a collision-free path based on information from a distributed image processing system in real-time. The integration of all components is carried out by means of a synchronous communication structure. Therefore, it is also possible to account for moving obstacles.
  

  Trajectory tracking for collision avoidance, desired trajectory (green) vs. actual trajectory (red) of the crane hook.

  The other partners in the CLIC-project were the Department of Computer Engineering (TU Wien), the Institute of Networked and Embedded Systems (Alpen-Adria-Universität Klagenfurt) and TTTech Computertechnik AG.

• Path-following control: Within this framework, the time evolution along the geometric path is left as a degree of freedom for the controller. This gives the possibility to prioritize the spatial tracking of the path compared to the overall time it takes to complete the traversal along the path. In the case of disturbances, this allows to correct the resulting deviations before the traversal of the path towards the end-point is continued.
  

  Path-following control with an external disturbance force acting on the crane hook, desired path (blue) vs. actual path (green) of the crane hook.

Selected publications

• M. Böck and A. Kugi, Real-time Nonlinear Model Predictive Path-Following Control of a Laboratory Tower Crane, IEEE Transactions on Control Systems Technology, vol. 22, iss. 4, p. 1461–1473, 2014.
  [BibTex] [Download]

  @Article{Boeck14,
  Title = {Real-time Nonlinear Model Predictive Path-Following Control of a Laboratory Tower Crane},
  Author = {B{\"o}ck, Martin and Kugi, Andreas},
  Journal = {IEEE Transactions on Control Systems Technology},
  Pages = {1461--1473},
  Volume = {22},
  Year = {2014},
  Number = {4},
  Doi = {10.1109/TCST.2013.2280464},
  }

• M. Böck and A. Kugi, Manifold Stabilization and Path-Following Control for Flat Systems with Application to a Laboratory Tower Crane, in Proceedings of the 53rd IEEE Conference on Decision and Control (CDC), Los Angeles, USA, 2014, p. 4529–4535.
  [BibTex] [Download]

  @InProceedings{Boeck14b,
  author = {Martin B{\"o}ck and Andreas Kugi},
  title = {Manifold Stabilization and Path-Following Control for Flat Systems with Application to a Laboratory Tower Crane},
  booktitle = {Proceedings of the 53rd IEEE Conference on Decision and Control (CDC)},
  year = {2014},
  month = {12},
  pages = {4529--4535},
  doi = {10.1109/CDC.2014.7040096},
  address = {Los Angeles, USA},
  }

• M. Egretzberger, K. Graichen, and A. Kugi, Flatness-Based MPC and Global Path Planning Towards Cognition-Supported Pick-and-Place Tasks of Tower Cranes, in Advanced Dynamics and Model-Based of Control Structures and Machines, H. Irschik, M. Krommer, and A. Belyaev, Eds., Wien: Springer, 2011, p. 63–72.
  [BibTex]

  @Incollection{Egretzberger11e,
  Title = {Flatness-Based MPC and Global Path Planning Towards Cognition-Supported Pick-and-Place Tasks of Tower Cranes},
  Author = {M. Egretzberger and K. Graichen and A. Kugi},
  Booktitle = {Advanced Dynamics and Model-Based of Control Structures and Machines},
  Publisher = {Springer},
  Year = {2011},
  Address = {Wien},
  Editor = {H. Irschik and M. Krommer and A. Belyaev},
  Pages = {63--72},
  Doi = {10.1007/978-3-7091-0797-3_8},
  }

• K. Graichen, M. Egretzberger, and A. Kugi, Suboptimal model predictive control of a laboratory crane, in 8th IFAC Symposium on Nonlinear Control Systems (NOLCOS), Bologna, Italy, 2010, p. 397–402.
  [BibTex]

  @InProceedings{Graichen10,
  author = {K. Graichen and M. Egretzberger and A. Kugi},
  title = {Suboptimal model predictive control of a laboratory crane},
  booktitle = {8th IFAC Symposium on Nonlinear Control Systems (NOLCOS)},
  year = {2010},
  pages = {397--402},
  doi = {10.3182/20100901-3-IT-2016.00140},
  address = {Bologna, Italy},
  }

• K. Graichen, M. Egretzberger, and A. Kugi, Ein suboptimaler Ansatz zur schnellen modellprädiktiven Regelung nichtlinearer Systeme, at – Automatisierungstechnik, vol. 58, p. 447–456, 2010.
  [BibTex]

  @Article{Graichen10c,
  Title = {Ein suboptimaler {A}nsatz zur schnellen modellpr{\"a}diktiven {R}egelung nichtlinearer {S}ysteme},
  Author = {K. Graichen and M. Egretzberger and A. Kugi},
  Journal = {at -- Automatisierungstechnik},
  Pages = {447--456},
  Volume = {58},
  Year = {2010},
  Doi = {10.1524/auto.2010.0860},
  }

Project partners and funding

The CLIC-project received funding from the FIT-IT program of the Austrian Research Promotion Agency (FFG) (project no. 819482). Besides ACIN, the following partners were involved:

• Department of Computer Engineering (TU Wien)
• Institute of Networked and Embedded Systems (Alpen-Adria-Universität Klagenfurt)
• TTTech Computertechnik AG

  04.07.2017
Hol-I-Wood PR

Project focus

• Time optimal process flow
• Visual position control
• Flexible production systems

Description

The correction of natural wood defects, such as resin galls or loose dead knots, interrupts the automatized production flow in timber industry. The human workforce is key for detection and classification of wood defects as well as for their correction.

The “Holonic Integration of Cognition, Communication and Control for a Wood Patching Robot”, in short “Hol-I-Wood PR”, project aims at automatizing this monotone and laborious work. The resulting innovative “wood patching”-plant is going to be integrated into the shutter board production line of our partner company.

A multi-sensor system scans the shutter boards and collects the defect data, like position and contour of the loose dead knot given in Fig. 1. A patching robot repairs the defects by drilling a hole and sealing it with one or more patches, see Fig. 2. One wood scanner is able to supply several production lines, which are connected via junctions. In this process, a variety of optimization problems do occur, which have to be solved in real-time.

To start with, the minimum number of patches and their arrangement have to be calculated for each defect. The arrangement of the patches is severly restricted, since one has to ensure the proper connection between the patches and the shutter board.
The next task is to compute the time optimal robot path between the patch locations. This challenging combinatorial optimization problem, similar to the so-called “Travelling Salesman Problem”, moreover is time variant, since the shutter boards are flexibly allocated to the individual production lines. Consequently, the patch locations are announced to the patching robot as a (more or less) continuous flow of patch locations.
Following the allocation of the shutter board to a specific patching robot, it requests the shutter board data from a data base, moves the board by means of time optimal trajectory planning and visual position control along the desired path and places the patches.
For this purpose, position data of the board delivered by the camera network and position data acquired from standard sensors, which all have different precision and sampling time, must be merged.

Due to the natural tolerances of wood and the rough production environement in saw mills, the automation design has to be robust, fault tolerant and flexible. This is achieved by modern observer and control concepts.

Furthermore, the Automation and Industrial Control Systems group of ACIN ensures maximum capacity utilization by means of flexible shutter board assignment, redirection or even buffering between the individual production lines. In case of malfunction of one or more patching robots, the shutter boards are redirected instantaneously in order to prevent unnecessarily high loss of production.

Applications

The repair of defects increases the wood’s value, regardless of the final product. In the case of shutter boards their usability is ensured, whereas in the case of furniture or window frames their appearance is improved.

Considering a more general context, similar tasks, e.g., optimal path planning, positioning of parts that are merely moved via friction or maximum capacity utilization, occur in a wide range of production chains.

Selected publications

• M. W. Hofmair, M. Melik-Merkumians, M. Böck, M. Merdan, G. Schitter, and A. Kugi, Patching process optimization in an agent-controlled timber mill, Journal of Intelligent Manufacturing, vol. 28, iss. 1, p. 69–84, 2017.
  [BibTex] [Download]

  @Article{Hofmair14,
  Title = {Patching process optimization in an agent-controlled timber mill},
  Author = {Hofmair, Matthias Wolfgang and Melik-Merkumians, Martin and B\"ock, M. and Merdan, M. and Schitter, G. and Kugi, A.},
  Journal = {Journal of Intelligent Manufacturing},
  Pages = {69--84},
  Volume = {28},
  Year = {2017},
  Number = {1},
  Doi = {10.1007/s10845-014-0962-z},
  ISSN = {1572-8145},
  }

• M. W. Hofmair, Process Optimization and Control of a Patching Plant for Shuttering Panels, A. Kugi and K. Schlacher, Eds., Aachen: Shaker Verlag, 2016, vol. 32.
  [BibTex]

  @Book{Hofmair16,
  Title = {Process Optimization and Control of a Patching Plant for Shuttering Panels},
  Author = {Hofmair, M. W.},
  Editor = {A. Kugi and K. Schlacher},
  Publisher = {Shaker Verlag},
  Year = {2016},
  Address = {Aachen},
  Series = {Modellierung und Regelung komplexer dynamischer Systeme},
  Volume = {32},
  ISBN = {978-3-8440-4745-5},
  Organization = {Institute f{\"u}r Automatisierungs- und Regelungstechnik (TU Wien) und Regelungstechnik und Prozessautomatisierung (JKU Linz)},
  }

• M. W. Hofmair, M. Böck, and A. Kugi, Time-Optimal Trajectory Generation, Path Planning and Control for a Wood Patching Robot, in Proceedings of the 2015 IEEE Conference on Control Applications (CCA), Sydney, Australia, 2015, p. 459–465.
  [BibTex]

  @InProceedings{Hofmair15,
  author = {Hofmair, Matthias Wolfgang and B\"ock, Martin and Kugi, Andreas},
  title = {Time-Optimal Trajectory Generation, Path Planning and Control for a Wood Patching Robot},
  booktitle = {Proceedings of the 2015 IEEE Conference on Control Applications (CCA)},
  year = {2015},
  publisher = {IEEE},
  month = {9},
  pages = {459--465},
  doi = {10.1109/CCA.2015.7320672},
  address = {Sydney, Australia},
  }

Project partners and funding

Together with ACIN three further public research institutions as well as four industry partners from five countries of the European Union collaborated in the “Hol-I-Wood PR” project:

• Lip Opazne Plosce Bohinj Doo (Slovenia)
• Lulea Tekniska Universitet (Sweden)
• MiCROTEC (Italy)
• Springer (Austria)
• Technische Universität München (Germany)
• TTTech (Austria)

The project was funded by the 7^th Framework Programme of the European Commission.

• Project acronym: Hol-I-Wood PR
• Project title: Holonic Integration of Cognition, Communication and Control for a Wood Patching Robot
• Project number: 284573

  29.06.2017
Modeling, observer design, and control of continuous strip processing lines

  29.06.2017
Optimal Control of pneumatic linear drives

Project focus

• Optimal control of nonlinear MIMO systems
• Energy saving
• Experimental verification

Description

The demands on today’s production regarding progressive flexibility and cost reduction as well as resource-efficiency require new approaches in each part of a production line.

Nowadays, pneumatics is popular in various industries, in particular in automation technology, pneumatic actuators are widly used.

Future pneumatic linear drives have to realize fast point-to-point positioning with high accuracy and minimal sensor effort at minimum energy consumption. The use of an inexpensive, discrete distance measurement, instead of a costly continuous position sensor, represents a challenge for the controller design for point-to-point movements. The lack of continuous position information must be compensated by an intelligent control of the drive.

In this project, low-cost switching valves are used to control linear pneumatic drives. The aim of this project is to design an optimal control strategy for the valves in order to accomplish a point-to-point motion of the piston actuator. Here, time-optimal and energy-efficient positioning of the piston is required, which is robust against fluctuations in the supply pressure and changing load forces.

Applications

• Production lines
• Handling systems

Selected publications

• A. Pfeffer, T. Glück, and A. Kugi, Soft Landing and Disturbance Rejection for Pneumatic Drives with Partial Position Information, in Proceedings of the 7th IFAC Symposium on Mechatronic Systems & 15th Mechatronics Forum International Conference, Loughborough, UK, 2016, p. 559–566.
  [BibTex] [Download]

  @InProceedings{Pfeffer16a,
  author = {Pfeffer, A. and Gl\"uck, T. and Kugi, A.},
  title = {Soft Landing and Disturbance Rejection for Pneumatic Drives with Partial Position Information},
  booktitle = {Proceedings of the 7th IFAC Symposium on Mechatronic Systems \& 15th Mechatronics Forum International Conference},
  year = {2016},
  volume = {49},
  number = {21},
  month = {9},
  pages = {559--566},
  doi = {10.1016/j.ifacol.2016.10.661},
  address = {Loughborough, UK},
  issn = {2405-8963},
  }

  29.06.2017
Modeling, observer and control design of a tandem hot strip rolling mill

  28.06.2017
Nonlinear control and protection concepts for Smart Power ICs

Project focus

• Mathematical modeling of a Smart Power IC
• Development of model-based digital control and protection functions
• Implementation and verification on a testbench

Description

Smart Power ICs are used for switching medium and high current loads in low-voltage automotive and industrial applications. Figure 1 shows exemplarily the application range of the PROFET™ Smart Power IC Series from Infineon.

 

  26.06.2017
Backstepping-based observer design for parabolic PDEs with varying parameters

Project focus

• State estimation for scalar linear PDEs with spatially and time-varying parameters defined on a one-dimensional spatial domain and time-varying boundary conditions
• State estimation to systems governed by parabolic PDEs defined on a higher-dimensional spatial domain
• State estimation for quasi-linear parabolic PDEs with locally Lipschitz nonlinearities
• Efficient numerical implementation in view of real-time applications

Description

Model-based control and advanced process monitoring usually require full state information. This is in particular evident if control strategies are utilized by means of state feedback or if algorithms based on full state knowledge are applied to improve the insight into the system behavior, e.g., for diagnostic or error detection purposes. In general, the complete state information cannot be directly measured. This is especially true for distributed-parameter systems, i.e., systems governed by partial differential equations (PDEs). In this case, the measurement information is typically limited to a finite number of spatially discrete sensors, or for spatially higher-dimensional systems by the fact that measurements are usually available only at the boundary of the spatial domain. Therefore, an observer is required to estimate the state variables from the knowledge of measured input and output variables as well as the mathematical model of the system.

This project is concerned with the state observer design for systems governed by parabolic PDEs with boundary sensing. For this, a distributed-parameter Luenberger-type state observer is applied with observer corrections entering both the PDE and the boundary conditions. Thereby, the backstepping method is utilized and extended to determine the output injection weights to ensure the exponential de­cay of the resulting observer error dynamics and hence an accurate state es­ti­ma­tion.

Selected publications

• L. Jadachowski, T. Meurer, and A. Kugi, Backstepping Observers for linear PDEs on Higher-Dimensional Spatial Domains, Automatica, vol. 51, p. 85–97, 2015.
  [BibTex]

  @Article{Jadachowski14a,
  author = {Jadachowski, L. and Meurer, T. and Kugi, A.},
  title = {{Backstepping Observers for linear PDEs on Higher-Dimensional Spatial Domains}},
  doi = {10.1016/j.automatica.2014.10.108},
  pages = {85--97},
  volume = {51},
  journal = {Automatica},
  year = {2015},
  }

• L. Jadachowski, T. Meurer, and A. Kugi, Backstepping Observers for Periodic Quasi-Linear Parabolic PDEs, in Proceedings of the 19th IFAC World Congress, Cape Town, South Africa, 2014, p. 7761–7766.
  [BibTex]

  @InProceedings{Jadachowski14,
  author = {Jadachowski, L. and Meurer, T. and Kugi, A.},
  booktitle = {Proceedings of the 19th IFAC World Congress},
  title = {Backstepping Observers for Periodic Quasi-Linear Parabolic {PDE}s},
  doi = {10.3182/20140824-6-ZA-1003.01246},
  pages = {7761--7766},
  address = {Cape Town, South Africa},
  month = {8},
  year = {2014},
  }

• L. Jadachowski, T. Meurer, and A. Kugi, State Estimation for Parabolic PDEs with Reactive-Convective Non-Linearities, in Proceedings of European Control Conference ECC 2013, Zürich, Switzerland, 2013, p. 1603 – 1608.
  [BibTex] [Download]

  @InProceedings{Jadachowski13,
  author = {L. Jadachowski and T. Meurer and A. Kugi},
  title = {State Estimation for Parabolic PDEs with Reactive-Convective Non-Linearities},
  booktitle = {Proceedings of European Control Conference ECC 2013},
  year = {2013},
  month = {7},
  pages = {1603 -- 1608},
  url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6669588},
  address = {Z\"{u}rich, Switzerland},
  }

• L. Jadachowski, T. Meurer, and A. Kugi, An Efficient Implementation of Backstepping Observers for Time-Varying Parabolic PDEs, in Proceedings MATHMOD 2012 Vienna, Wien, Austria, 2012, p. 798–803.
  [BibTex]

  @InProceedings{Jadachowski12,
  author = {L. Jadachowski and T. Meurer and A. Kugi},
  title = {{An Efficient Implementation of Backstepping Observers for Time-Varying Parabolic PDEs}},
  booktitle = {Proceedings MATHMOD 2012 Vienna},
  year = {2012},
  editor = {Troch, I. and Breitenecker, F.},
  month = {2},
  pages = {798--803},
  doi = {10.3182/20120215-3-AT-3016.00141},
  address = {Wien, Austria},
  }

• L. Jadachowski, T. Meurer, and A. Kugi, State Estimation for Parabolic PDEs with Varying Parameters on 3-Dimensional Spatial Domains, in Proceedings of the 18th IFAC World Congress, Milano, Italia, 2011, pp. 13338-13343.
  [BibTex]

  @InProceedings{Jadachowski11,
  author = {L. Jadachowski and T. Meurer and A. Kugi},
  title = {{S}tate {E}stimation for {P}arabolic {PDE}s with {V}arying {P}arameters on 3-{D}imensional {S}patial {D}omains},
  booktitle = {Proceedings of the 18th IFAC World Congress},
  year = {2011},
  month = {8},
  pages = {13338-13343},
  doi = {10.3182/20110828-6-IT-1002.02964},
  address = {Milano, Italia},
  }

• L. Jadachowski, T. Meurer, and A. Kugi, State Reconstruction in Higher Dimensional PDEs with Spatially Varying Parameters, PAMM, Proceedings in Applied Mathematics and Mechanics, vol. 11, iss. 1, p. 813–814, 2011.
  [BibTex]

  @Article{Jadachowski11a,
  Title = {{State Reconstruction in Higher Dimensional PDEs with Spatially Varying Parameters}},
  Author = {L. Jadachowski and T. Meurer and A. Kugi},
  Journal = {PAMM, Proceedings in Applied Mathematics and Mechanics},
  Pages = {813--814},
  Volume = {11},
  Year = {2011},
  Number = {1},
  Doi = {10.1002/pamm.201110395},
  }

Applications

• State estimation for heating-up and cooling-down processes in steel industry
• System diagnostics and error detection in fixed-bed tubular reactors in chemical engineering

Funding

TU Wien Doktorandenkolleg PDETech

Partners

Prof. Dr.-Ing. habil. Thomas Meurer

  20.06.2017
Flatness control in heavy plate rolling

Project focus

• Development of models of the visco-plastic material deformation in the roll gap
• Modeling of flatness defects occurring in heavy plate rolling
• Control design for improved flatness accuracy

Description

In heavy plate rolling, the customer demands on product thickness and flatness quality steadily increase. The quality is primarily influenced by the rolling process at reversing mill stands. Here the heavy plates are rolled out to a certain product thickness in consecutive passes. To increase the product quality, physical models serve as a basis for optimized control concepts.

To achieve the desired plate thickness, a precise product tracking of the heavy plate is necessary. To this end, an analytical forward slip model based on visco-plastic material behavior is deduced. The resulting partial differential equations are solved by appropriate coordinate transformations to obtain closed form solutions.

 

When heavy plates are rolled, an unwanted bending of the plate ends may occur. This flatness defect is called ski-effect, cf. Fig. 1. Asymmetric rolling conditions (amongst others temperature and friction) with respect to the plates mid-plane cause this phenomenon. Using the Upper Bound Method, a semi-analytical model can be obtained to describe the ski formation.

 

Based on the ski model, nonlinear control strategies are designed to improve the flatness quality. In particular, a MIMO-control concept for the main drives of the rolling mill is developed to control the circumferential speed difference between the upper and lower work roll. By means of the semi-analytical ski-model the necessary speed difference for avoiding temperature-provoked ski-ends is computed.

Selected publications

• T. Kiefer, R. Heeg, and A. Kugi, Modellbasierte Dicken- und Ebenheitsregelung in Grobblechwalzwerken, at – Automatisierungstechnik, vol. 56, iss. 8, p. 416–426, 2008.
  [BibTex] [Download]

  @Article{Kiefer08b,
  Title = {Modellbasierte {D}icken- und {E}benheitsregelung in {G}robblechwalzwerken},
  Author = {T. Kiefer and R. Heeg and A. Kugi},
  Journal = {at -- Automatisierungstechnik},
  Pages = {416--426},
  Volume = {56},
  Year = {2008},
  Number = {8},
  Doi = {10.1524/auto.2008.0720},
  }

• T. Kiefer and A. Kugi, Model-based control in front-end bending in hot rolling processes, in Proceedings of the 17th IFAC World Congress, Seoul, Korea, 2008, p. 1645–1650.
  [BibTex]

  @InProceedings{Kiefer08,
  author = {T. Kiefer and A. Kugi},
  title = {Model-based control in front-end bending in hot rolling processes},
  booktitle = {Proceedings of the 17th IFAC World Congress},
  year = {2008},
  month = {7},
  pages = {1645--1650},
  doi = {10.3182/20080706-5-KR-1001.00280},
  address = {Seoul, Korea},
  }

• T. Kiefer and A. Kugi, An Analytical Approach for Modelling Asymmetrical Hot Rolling of Heavy Plates, Mathematical and Computer Modelling of Dynamical Systems, vol. 14, iss. 3, p. 249–267, 2008.
  [BibTex] [Download]

  @Article{Kiefer08a,
  Title = {An Analytical Approach for Modelling Asymmetrical Hot Rolling of Heavy Plates},
  Author = {T. Kiefer and A. Kugi},
  Journal = {Mathematical and Computer Modelling of Dynamical Systems},
  Pages = {249--267},
  Volume = {14},
  Year = {2008},
  Number = {3},
  Doi = {10.1080/13873950701844915},
  }

• T. Kiefer and A. Kugi, Modelling and Control of Front End Bending in Heavy Plate Mills, in Proceedings of the 12th IFAC Symposium on Automation in Mining, Mineral and Metal Processing, Quebec City, Canada, 2007, p. 231–236.
  [BibTex]

  @InProceedings{Kiefer07,
  author = {T. Kiefer and A. Kugi},
  title = {Modelling and Control of Front End Bending in Heavy Plate Mills},
  booktitle = {Proceedings of the 12th IFAC Symposium on Automation in Mining, Mineral and Metal Processing},
  year = {2007},
  month = {8},
  pages = {231--236},
  doi = {10.3182/20070821-3-CA-2919.00034},
  address = {Quebec City, Canada},
  }

Applications

• Automation of rolling mills

  20.06.2017
Modeling and control of hot levelers

Project focus

• Modeling, identification and analysis of the mechanical and hydraulic components of the leveler
• Optimal, active compensation of the elastic deformation
• Design of control strategies for the dynamic positioning of the leveler

Description

Hot levelers are used in hot rollings mills for steel plates. After rolling and cooling, a leveling machine reduces remaining flatness errors and residual stresses in the plates. Between the work rolls of the hot leveler, the plates undergo plastic deformations through alternating excessive bending.

The leveling forces can reach several meganewtons and lead to deformations of the leveler in the range of several millimeters. For quality reasons, these deformations have to be compensated, e.g., by means of actuators or a bending mechanism. At the same time, overloading the leveler must be avoided.

The modeling and analysis of the mechanical and hydraulic configuration of the leveler are of interest. Essential parts of the mathematical model are the elastic deflection of the machine as well as friction forces which occur in the hydraulic actuators and the joints of the bending mechanism.

The work rolls are modeled as Euler-Bernoulli beams. They are elastically supported by the support rolls, the sub-frames, and the posts, where the deflection models of these components are represented by compliance matrices. The deflection model was validated by measurements with instrumented plates. A reduced finite-dimensional model is used to determine an optimal deflection compensation. By means of an optimization algorithm the adjustment of the actuators is calculated such that the desired plate curvature is optimally reached. With the optimization approach the mechanical load is directly constrained and thus overloading the leveler is avoided. For the calculation of the leveling load a nonlinear leveling model is used.

The precise adjustment of the rolls by means of the bending mechanism is crucial for an effective deflection compensation. Based on a validated mathematical dynamical model of the mechanism, a control law was developed, which reliably adjusts the rolls even under friction and operating loads.

The developed solution has been successfully implemented at an industrial hot leveler for heavy plates.

Selected publications

• R. Brauneis, M. Baumgart, A. Steinboeck, and A. Kugi, Deflection Model Of A Multi-Actuator Gap Leveler, in Proceedings of the 20th IFAC World Congress, Toulouse, France, 2017, pp. 11295-11300.
  [BibTex] [Download]

  @InProceedings{Brauneis17,
  author = {Brauneis, R. and Baumgart, M. and Steinboeck, A. and Kugi, A.},
  title = {Deflection Model Of A Multi-Actuator Gap Leveler},
  booktitle = {Proceedings of the 20th IFAC World Congress},
  year = {2017},
  volume = {50},
  number = {1},
  month = {7},
  pages = {11295-11300},
  doi = {10.1016/j.ifacol.2017.08.1647},
  address = {Toulouse, France},
  issn = {2405-8963},
  }

• M. Baumgart, A. Steinboeck, T. Kiefer, and A. Kugi, Modelling and experimental validation of the deflection of a leveller for hot heavy plates, Mathematical and Computer Modelling of Dynamical Systems, vol. 21, iss. 3, p. 202–227, 2015.
  [BibTex] [Download]

  @Article{Baumgart15a,
  Title = {Modelling and experimental validation of the deflection of a leveller for hot heavy plates},
  Author = {Baumgart, M. and Steinboeck, A. and Kiefer, T. and Kugi, A.},
  Journal = {Mathematical and Computer Modelling of Dynamical Systems},
  Pages = {202--227},
  Volume = {21},
  Year = {2015},
  Number = {3},
  Doi = {10.1080/13873954.2014.941881},
  }

• M. Baumgart, A. Steinboeck, A. Kugi, G. Raffin-Peyloz, L. Irastroza, and T. Kiefer, Optimal Active Deflection Compensation of a Hot Leveler, in Proceedings of the IFAC Workshop on Automation in the Mining, Mineral and Metal Industries, Gifu, Japan, 2012, p. 30 – 35.
  [BibTex]

  @InProceedings{Baumgart12,
  author = {M. Baumgart and A. Steinboeck and A. Kugi and G. Raffin-Peyloz and L. Irastroza and T. Kiefer},
  title = {{O}ptimal {A}ctive {D}eflection {C}ompensation of a {H}ot {L}eveler},
  booktitle = {Proceedings of the IFAC Workshop on Automation in the Mining, Mineral and Metal Industries},
  year = {2012},
  month = {9},
  pages = {30 -- 35},
  doi = {10.3182/20120910-3-JP-4023.00009},
  address = {Gifu, Japan},
  }

• M. Baumgart, A. Steinboeck, A. Kugi, B. Douanne, G. Raffin-Peyloz, L. Irastroza, and T. Kiefer, Modeling and Active Compensation of the Compliance of a Hot Leveler, steel research international, vol. Special Edition ICTP2011, p. 337–342, 2011.
  [BibTex]

  @Article{Baumgart11a,
  Title = {{Modeling and Active Compensation of the Compliance of a Hot Leveler}},
  Author = {M. Baumgart and A. Steinboeck and A. Kugi and B. Douanne and G. Raffin-Peyloz and L. Irastroza and T. Kiefer},
  Journal = {steel research international},
  Pages = {337--342},
  Volume = {Special Edition ICTP2011},
  Year = {2011},
  }

• M. Baumgart, A. Steinboeck, A. Kugi, G. Raffin-Peyloz, B. Douanne, L. Irastorza, and T. Kiefer, Active compliance compensation of a hot leveler, in Proceedings of the 4th International Conference on Modelling and Simulation of Metallurgical Processes in Steelmaking, STEELSIM, METEC InSteelCon 2011, Düsseldorf, Germany, 2011.
  [BibTex]

  @InProceedings{Baumgart11,
  author = {M. Baumgart and A. Steinboeck and A. Kugi and G. Raffin-Peyloz and B. Douanne and L. Irastorza and T. Kiefer},
  title = {Active compliance compensation of a hot leveler},
  booktitle = {Proceedings of the 4th International Conference on Modelling and Simulation of Metallurgical Processes in Steelmaking, STEELSIM, METEC InSteelCon 2011},
  year = {2011},
  month = {6},
  address = {D\"usseldorf, Germany},
  }

Applications

• Rolling mill automation
• Press equipment/forming machinery

  19.06.2017
Noreia

Project focus

• Development and Construction of highly sophisticated PVD deposition plant
• Highly flexible and recipe based programming method for reproducible lot size one hard coatings
• Component-based design and programming approaches for modular plant construction

Description

Project Noreia entitles the design and development of a highly sophisticated PVD deposition plant, which consider state of the art developments in automation and control as well as deposition techniques. The design and development is conducted in a framework between the Institute of Materials Science and Technology (Prof. Paul H. Mayrhofer) and the Faculty of Electrical Engineering and Information Technology within the TU Wien.
The aim of the cutting-edge concept is to connect the advantages of industrial deposition plants and labor scale systems to provide an ideal setup for application oriented coating development. Industrial processes are always qualified through high deposition rates and optimal target erosion which is strongly linked to enhanced target power densities and at least larger target geometries. Labor scale deposition systems protrude through Ultra High Vacuum (UHV) conditions and a huge variety in process controlling as well as individual target powering and positing to deposit most diverse coating architectures. Noreia combines all these aspects within one system.

In addition, Noreia is equipped with state of the art magnetron systems powered by High Power Impulse Magnetron Sputter (HiPIMS) generators to combine the advantageous of DC magnetron sputtering and arc-evaporation without their drawbacks of shadowing effects and macro particles. A load lock system gives the possibilities for an easy substrate exchange as well as UHV conditions. To precisely influence the deposition parameters such as bias voltage or substrate temperature and hence film properties, Noreia is provided with an innovative substrate heating and powering system to control nucleation and film growth.

All deposition parameters such as target powering, substrate heating, gas flow, pressure control, cooling system, etc. are controlled through a Programmable Logic Controller (PLC) to provide the user highest possible comfort in usage as well as a highest freedom to influence the deposition process.

Application areas

• Component-based automation systems
• Flexible manufacturing systems

Related publications

• M. Melik-Merkumians, M. Baierling, and G. Schitter, A Service-Oriented Domain Specific Language Programming Approach for Batch Processes, in Proceedings of 2016 IEEE 21th Conference on Emerging Technologies & Factory Automation, 2016.
  [BibTex]

  @InProceedings{TUW-251132,
  Title = {A Service-Oriented Domain Specific Language Programming Approach for Batch Processes},
  Author = {Melik-Merkumians, Martin and Baierling, Matthias and Schitter, Georg},
  Booktitle = {Proceedings of 2016 IEEE 21th Conference on Emerging Technologies {\&} Factory Automation},
  Year = {2016},
  Note = {Vortrag: 21st IEEE International Conference on Emerging Technologies and Factory Automation (ETFA 2016), Berlin; 2016-09-06 -- 2016-09-09},
  Doi = {10.1109/ETFA.2016.7733729},
  Eid = {68},
  ISBN = {978-1-5090-1314-2},
  Keywords = {SOA, DSL, Batch Process, ISA-88, IEC 61499, component based automation, service based automation},
  Numpages = {9}
  }

Project partners

• Project leader: TU Wien – Prof. Paul Heinz Mayrhofer
• Pfeiffer Vacuum Austria GmbH
• GSA Elektrotechnik und Engineering GmbH
• Beckhoff Automation GmbH
• MKS Instruments Deutschland GmbH
• Gencoa Ltd
• SMC Pneumatic GmH
• VAT Vakuumventile AG
• Advanced Energy Industries