## 1 Introduction  
Today, at least 12 plate Mills 5000 are operated worldwide, five of which are in Japan, three in Germany, three in the Russian Federation, and one in Shanghai (BAOSTEEL, China). They are designed to produce flats of up to 5 m in width and up to 36 m in length. Such rolling mills are the main suppliers of rolled products for large diameter pipes, used to build oil and gas pipelines. High product quality is the most important requirement to rolling production units. The requirement is also relevant for heavy-plate rolling mills, including Mill 5000 at PJSC \"Magnitogorsk Iron and Steel Works\" (MMK PJSC). The key quality requirement is the geometric precision of the finished sheet or plate and minimum edge trimming. This is attained by automated electric drives and process parameter control systems. The most commonly occurring feed (intermediate product between plate slab and ready sheet) defect are the bend in the motion plane (defect \"camber\" Figure 1b) and its lateral shift at the output of the stand [1; 2; 3]. Horizontal bend is induced in the strip by strain difference in cross section (Figure 1a) which leads to elongation difference. Such differential elongation manifests itself as feed strain causing lateral and angular shift as shown in Figure 1b [3]. Both defects cause the loss of output product quality, and at larger deviations they can lead to the mill emergency shutdown. This explains the relevance of conducting the research, intended for the elimination of specified drawbacks. Many authors' works prove the relevance of the issue. Thus, paper [4] presents a case study of a mill operated by Tata Steel (Port Talbot, Wales), which shows that the longitudinal shape of the feed is a distorted passage from the passage during roughing. Paper [5] shows the curve of the axial shift of the feed at Mill 2250 (China) as a function of the length of rolled feed. The plate deviates by as much as 15 mm from the rolling axis, which the paper states is unacceptable for this grade of product. Paper [6] presents a similar study for Mill 1580. Online camber measurement is utilized to prevent accidents such as collisions with the guiding rail or runoff from the roller table. These measurements control the force of the hydraulic screw-downs (SD) or the side guides [2]. However, camber measurement equipment, which is usually based on light sensors [7], can be installed on a unit-by-unit basis and is not available on every rolling mill. Solutions to the problem are covered in patents [8; 9]. The research of most authors, including [10; 11], showed that the feed cross section and, correspondingly, the sheet final form depend on the difference of forces formed by a hydraulic cylinder at driving (DS) and operated sides (OS). The references suggest various technical solutions for increasing the precision and expanding functional possibilities of the control systems for roll gap misalignment. Thus, in [12], to minimize DS-OS differences in relation to roll shift level, a control system with the use of the model predictive controller (MPC) was developed. The tilt controller responds to the pressure deviations in the initial phase of the gap misalignment. Control is based on measuring the difference of torsional forces on OS-DS without the application of additional control and measurement instrumentation. In real time operation, this model calculates the incline corrections, minimizing the force difference during bending at the compliance of maximum action limitations. It is stated that MPC application can bring about some advantages comparing  
Figure 1: Asymmetry (misalignment) of roll gap (**a**), camber and feed axial shift (**b**). with conventional controllers (PI or PID) because of the function of forecasting force difference along the gap width. The controller has been implemented in the Level 1 software of the hot strip mill of Tata Steel in IJmuiden, the Netherlands. However, according to [12], this technical solution is at the approach stage and has not been industrially introduced yet.