Nidec asi automation system for a continuous tandem mill coupled with pickling line

The cold rolling is one of the main sectors for rolling flat products, and a continuous tandem mill is by sureone of the most comprehensive and significant plants in the wide range of the metals industry. A reliablehigh-performance automation system is consequently indispensable to make the most of the mechanical andhydraulic equipment in a process of this type, that must meet requirements in productivity and quality of thefinal coil increasingly stringent.This paper aims to illustrate both the plant and the automation system, focusing on the most significant aspectsrelated to automation developed in the company, from mathematical models to fuzzy regulation algorithms, butwithout neglecting the global architecture of the system.

Fast algorithms for material specific process chain design and analysis in metal forming - final report DFG Priority Programme SPP 1204

The book summarises the results of the DFG-funded coordinated priority programme \"Fast Algorithms for Material Specific Process Chain Design and Analysis in Metal Forming\". In the first part it includes articles which provide a general introduction and overview on the field of process modeling in metal forming. The second part collates the reports from all projects included in the priority programme

Electromagnetic measurements of steel phase transformations

This thesis describes the development of electromagnetic sensors to measure the phase transformation in steel as it cools from the hot austenite phase to colder ferritic based phases. The work initially involved investigating a variety of sensing configurations including ac excited coils, C-core arrangements and the adaptation of commercial eddy current proximity sensors. Finally, two prototype designs were built and tested on a hot strip mill. The first of these, the T-meter was based on a C-shaped permanent magnet with a Gaussmeter measuring the magnetic field at the pole ends. Laboratory tests indicated that it could reliably detect the onset of transformation. However, the sensor was sensitive to both the steel properties and the position of the steel. To overcome this, an eddy current sensor was incorporated into the final measurement head. The instrument gave results which were consistent with material property variations, provided the lift off variations were below 3Hz. The results indicated that for a grade 1916 carbon- manganese steel, the signal variation was reduced from 37% to 2%, and the resulting output was related to the steel property variations. The second of these prototypes was based on a dc electromagnetic E-core, with Hall probes in each of the three poles. 'Cold' calibration tests were used to decouple the steel and the lift-off. The results indicated that there was an error of 3-4% ferrite/mm at high ferrite fractions. At lower fractions the error was higher due to the instrument’s insensitivity to lift-off. The resulting output again showed a relationship with varying steel strip properties. ft was also shown that a finite element model could be calibrated to experimental results for a simple C-core geometry such that the output was sensitive to 0.2% of the range. This is required to simulate the sensor to resolve to 10% ferrite

Application of Alloy 718 in M-1 engine components

Alloy 718 applied to components of M-1 rocket engin

Lyapunov based reference model of tension control in a continuous strip processing line with multi-motor drive

The article describes design and experimental verification of a new control structure with reference model for a multi-motor drive of a continuous technological line in which the motors are mutually mechanically coupled through processed material. Its principle consists in creating an additional information by introducing a new suitable state variable into the system. This helps to achieve a zero steady-state control deviation of the tension in the strip. Afterwards, the tension controller is designed to ensure asymptotic stability of the extended system by applying the second Lyapunov method. The realized experimental measurements performed on a continuous line laboratory model confirm the advantages and correctness of the proposed control structure: it is simple, stable, robust against changes of parameters, invariant to operating disturbances and ensures a high-quality dynamics of the controlled system prescribed by the reference model. To demonstrate effectiveness of the design, the performance of the controller was compared with properties of a standard Proportional Integral Derivative/Proportional Integral (PID/PI) controller designed in frequency domain

Strip tracking in hot strip mills

In the finishing mill, steel strip is rolled from thick slabs through pairs of rollers housed in a continuous train of seven roll stands. As the strip is rolled, unwanted lateral movement, known as strip tracking, can cause the strip to collide with the edge of the mill. Strip tracking control is currently a manual operation, relying on the skill of the operators. When tracking is observed, the stand tilt is adjusted asymmetrically, causing a camber in the strip, steering it towards the centreline. Tracking control can be automated if a reliable measurement of position is available. A vision-based system was developed to measure strip position. Cooling water, steam, high temperatures and electrical noise create a hazardous environment for electronic equipment and hamper image analysis. Hardware was specified to protect all equipment against the environment. A novel image analysis method combining predictive elements, filtering and Bezier curve fitting was created to allow measurements to be made with large amounts of cooling water obscuring the strip edges. The measurement system was designed to integrate with the existing mill systems, using the OPC protocol for communication. The system was created as a development system with only two cameras included, but allowed for additional cameras to be easily added and automatically detected. The results of the system showed that the image analysis techniques were effective, providing an estimated final resolution of 3.5mm/pixel, with measurements ±2mm within 60% confidence. Hardware performance provided good protection of the equipment against the environment but poor quality installation limited overall system performance. A computer model was developed to simulate tracking behaviour in the mill with non-linear variations of strip properties across the strip. The model was not completed to a satisfactory standard capable of producing useful results but the theories described could be developed further.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Book of abstracts of the 14th International Symposium of Croatian Metallurgical Society - SHMD \u272020, Materials and metallurgy

Book of abstracts of the 14th International Symposium of Croatian Metallurgical Society - SHMD \u272020, Materials and metallurgy held in Šibenik, Croatia, June 21-26, 2020. Abstracts are organized in four sections: Materials - section A; Process metallurgy - Section B; Plastic processing - Section C and Metallurgy and related topics - Section D

POINTWISE LINEAR QUADRATIC OPTIMAL CONTROL OF A TANDEM COLD ROLLING MILL

ABSTRACTPOINTWISE LINEAR QUADRATIC OPTIMAL CONTROL OF ATANDEM COLD ROLLING MILLJohn R. Pittner, PhDUniversity of Pittsburgh, 2006The tandem cold rolling of metal strip is a complex multivariable process whose control presents a significant engineering challenge. The present technology generally relies on a control structure wherein the interactive coupling between process variables is partially reduced by several single-input-single-output and single-input-multi-output control loops operating on certain variables to decompose the overall problem into several separate problems to attempt to allow independent adjustment of strip tension and thickness anywhere in the mill. However, while the existing systems generally have been successful in producing an acceptable product, their failure to completely counteract the effects of interactions between process variables has limited their capability for improvement in performance and in robustness to disturbances and uncertainties. Various techniques for improvement have been proposed and some have been implemented. Many of these techniques offer some improvements, but also have shortcomings. Therefore there is a need for a better approach. It is considered that the pointwise linear quadratic optimal control might fulfill this need. This dissertation investigates the theoretical and applied aspects of this technique for control of a tandem cold rolling mill using criteria based on practical applications. A mathematical model of the mill is developed from which nonlinear state space equations are derived. Using these equations, a pointwise linear quadratic optimal controller is developed, and its performance for variations in operating speed and product are confirmed by simulation. Robustness to disturbances and uncertainties is also confirmed by simulation. The results are compared with those using typical industry practice

17. Simpozij „Materijali i metalurgija“ – dopuna „Zbornik sažetaka”

In Metalurgija 63 (2024) 2,303-320 published „ Book of Abstracts “ (224). Deadline for received of Abstracts was November, 30,2023 y. Many authors have request new deadline by March, 25, 2024 y. Organizing committee have accept new deadline. Now it published supplements of 103 Abstracts.U Metalurgiji 63 (2024) 2,303-320 objavljen je Zbornik sažetaka (224). Rok za primitak sažetke je bio 30. studeni 2023. god. Mnogi autori zatražili novi rok do 25.03.2024. Organizacijski odbor Simpozija je prihvatio novi termin. Objavljuje se sada dodatnih još 160 sažetaka