Кафедра автоматизації виробничих процесів (ДМетІ)
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UK: Кафедра автоматизації виробничих процесів (Дніпровський металургійний інститут, ДМетІ)
EN: Department of Automation of Production Processes (DMetI)
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Browsing Кафедра автоматизації виробничих процесів (ДМетІ) by Author "Boyko, O."
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Item Automatic Compensation of the Mill RolL Eccentricity in Terms of Limited Speed of Hydraulic Compression Devices(Dnipro University of Technology, Dnipro, 2025) Boyko, O.; Kuvaiev, Victor; Potap, Oleg; Potap, M.; Rybalchenko, Maria O.ENG: Purpose. To reduce deviation of vertical dimension (thickness) of rolled products from the specified value by enhancing the accuracy and shortening the setup time of an eccentricity compensation subsystem of mill rolls based on substantiation of an eccentricity compensation method. This method is based on an active search algorithm to determine the actual eccentricity parameters in real time, taking into account the actual response time of hydraulic compression devices (HCD) and investigating its effectiveness through simulation computer modelling. Methodology. The research was based on the analytical determination of the frequency characteristics of the AGC system in sheet metal rolling, considering the actual response time of HCD of a rolling mill as well as a comprehensive model of a rolling process in a quarto mill with rolling movement and an automatic thickness control system (ATCS) that compensates for eccentricity. The study was conducted by comparing the results of computer simulation modelling of the improved ATCS, whose algorithm took into account the HCD response time, with the performance indicators of the previous system, which did not consider this factor. Findings. It has been established that under the AGC thickness control conditions, the measured amplitude of a variable component of thickness does not match the amplitude of eccentricity due to the finite response time of HCD. The frequency characteristics of the AGC system have been determined analytically, taking into account the actual response time of HPD in a rolling mill. An improved procedure for determining the actual eccentricity amplitude in real time has been substantiated, which involves a temporary reduction in the HCD speed within the initial rolling section. A structure for an automated control system has been proposed for practical implementation of this procedure. It has been demonstrated that the proposed solutions allow for a threefold reduction in thickness variations caused by eccentricity compared to the corresponding performance indicators of the known eccentricity compensation systems with the AGC thickness control. Originality. The influence of the HCD response time on the accuracy of AGC thickness control systems for rolled products has been established. An approximate linear relationship has been identified between the ratio of the amplitude of thickness fluctuations caused by eccentricity and the amplitude of roll gap fluctuations relative to the roll speed and HCD response time under the AGC algorithm thickness control conditions. The improved procedure for determining the actual eccentricity amplitude in real time has been substantiated. Practical value. The effectiveness is substantiated of implementing an improved active search algorithm for determining the eccentricity parameters of mill rolls under the limited HCD response conditions in real time. This approach allows for a threefold reduction in the sheet thickness variability caused by roll eccentricity compared to the performance indicators of the known AGC thickness control systems, thereby ensuring the production of high-precision rolled products in Ukrainian sheet rolling mills.Item Minimization of Dynamic Changes in the Tension of Long Products behind the Outlet Cage in Rolling Stock Production in Coils(Dnipro University of Technology, Dnipro, Ukraine, 2022) Boyko, O.; Kuvaiev, Victor; Beshta, D.; Potap, Oleg; Matsiuk, S.ENG: Purpose. Justification of technical solutions as to the reduction of the amplitude and reduction of the dynamic change duration in the tension of the rolling stock at the exit of the output cage when moving to winding a new layer to an acceptable level in terms of its effect on the resulting profile of the rolled product through the control of the rotation frequency of an output cage. Methodology. The conducted research was based on a complex model of the process of rolled steel winding with a Garrett-type winder and the tension of rolled steel in the area of the exit cage-winder. To control the actual amount of tension at the output cage exit, it is suggested to use the amount of free deflection of the rolled steel directly behind the cage. The research was carried out by simulating the process of rolled steel winding according to the basic control scheme and control schemes that predict the influence on both drives, i.e. the winder drive and the output cage drive according to the actual value of tension, in various combinations with further analysis and comparison of the obtained results. Findings. It was established that the correction for the deviation of the actual rolling tension in the finishing cage-winder area from the specified value of the winding current of the winder electric drive does not eliminate rolling tension when switching to the next layer winding and the oscillating form of the transition process, which are characteristic of the basic rolling winding scheme. In turn, the correction of the rotation frequency of the output cage rolls drive reduces the amplitude of the roll tension jerk by almost half with a simultaneous reduction in the time of the transition process and readjustment when switching to a new layer winding. Originality. It has been shown for the first time that the introduction of the roll tension control circuit by correcting the high speed rolling mode of the output cage ensures minimization of dynamic changes in the rolled steel tension when switching to a new layer winding and reduces the probability of local tightening of rolled steel profile. Practical value. The use of the described technical solutions in the control system of the section of rolled products winding of the small-grade wire mill DSDS 250/1506 PJSC “ArcelorMittal Kryvyi Rih” ensures the improvement of the commercial proper ties of the winding of rolled products produced on the rolling mill.