Hol-I-Wood PR

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 project Hol-I-Wood PR 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. Read more →

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

In continuous strip processing line, steel strips are thermally and mechanically processed as well as surface coated (e.g. galvanized). In this project, observer and control concepts for continuous galvanizing lines are developed. Additionally, controllers for laboratory facilities to develop new process technologies (e.g. laboratory furnaces) are designed. Read more →

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

Rough-rolled steel plates are rolled in a tandem hot rolling mill to strip with a final thickness. This thickness should accurately and uniformly correspond with the desired value. To satisfy this requirements and to ensure a stable strip travel, model-based control concepts are developed in this project. Read more →

Flatness control in heavy plate rolling

In heavy plate rolling, the heated plates are plastically deformed between two work rolls. Here, asymmetries in the roll gap may cause up- or downward bending of the ends of the plates. This so-called ski effect affects the flatness of the plates and may entail problems in subsequent processing steps. A model-based control concept and an improved speed controller for the roll drives can avoid such ski-ends and thus increase the quality of the plates. Read more →

Modeling and control of hot levelers

Levelers are used in the production of steel plates in rollings mills to improve the flatness of the products. After rolling and cooling, a leveling machine reduces remaining flatness errors and residual stresses in the plates. This happens by alternate plastic bending of the plate material between the work rolls of the leveler. Read more →

Modeling, observer design, control, and optimization of strip annealing furnaces

In the steel industry, continuous strip annealing furnaces are used for the heat treatment of strip products. To meet the high demands on the quality of the final product, the strip has to be heated to a predefined target temperature while it moves through the furnace. This is a challenging control task because an annealing furnace is a complex, nonlinear, thermodynamical multi-input-multi-output system and many process variables cannot be measured. Read more →

Modeling and control of a four-high heavy plate rolling mill

In heavy plate rolling, the heated plate is plastically deformed between two work rolls. Various measures avoid or minimize the deflection of the work rolls and thus the lateral non-uniformity of the product thickness profile. A mathematical deflection model yields the plate exit thickness, which cannot be directly measured. A model-based feedforward strategy compensates the disturbances observed in the previous rolling pass. Read more →

Lateral guiding and shape control in heavy plate rolling

In the rolling process of heavy plates, contour errors (deviations from the desired straight contour in the top view) and a lateral off-center position of the plate in the rolling mill may occur. Tailored continuum-mechanics models explain the reasons for these errors. The errors are monitored in real time by a camera-based measurement system. Model-based control strategies ensure that contour errors are avoided and that the plate moves straight through the rolling mill. Read more →

Modeling, observer design, and control of continuous slab reheating furnaces

In the steel industry, products are reheated in continuous reheating furnaces as a preparation for rolling. The reheating process requires large amounts of energy and incurs high costs. The temperature during this process is decisive for the product quality. Based on mathematical process models, state observers and controllers for the non-measureable product temperature are developed. The nonlinear model-predictive multi-input multi-output controller ensures a high accuracy, minimized energy consumption, and reduced CO2-emissions of the reheating process. Read more →

Thermal model and optimal time scheduling of hot rolling

In a heavy-plate rolling mill, hot slabs are rolled out. The plate temperature depends significantly on the process times and it directly influences the product quality. Mathematical models are used for better prediction and control of the product temperature. These models are also useful for an optimization of the processing times. Read more →