Developing Digital Observer of Angular Gaps in Rolling Stand Mechatronic System

Abstract

Algorithms for monitoring the rolling mill mechatronic system state should be developed on the basis of modern digital technologies. Developing digital shadows (observers) of system state parameters in the periodic measurement mode is promising. This study relevance is defined by frequent emergency breakdowns of rolling stand mechanical transmissions. Most breakdowns are caused by worn end clutches (heads) of countershafts (spindles) transmitting rotation from the motor to the rolls. This is caused by elastic oscillations due to closing angular gaps when the metal enters the stand. The spindle joint angular gap increases over time with the mill operation. Therefore, it is an important diagnostic parameter that allows for an estimation of the transmission serviceability. In this regard, the problem of monitoring the angular gaps in the rolling stand mechatronic systems is relevant. The paper considers developing an observer of angular gaps in the spindle joints of the ‘electric drive-stand’ mechatronic system of the plate Mill 5000 of Magnitogorsk Iron and Steel Works PJSC (MMK PJSC). The monitored signal (angular gap) is calculated with the mathematical processing of the motor’s physical parameters (speed and electromagnetic torque), measured at a given frequency. The gap is determined indirectly by integrating the speed during its closing. To achieve this, the speed is controlled according to the triangular tachogram at no load. The stand’s electromechanical system modes have been studied using mathematical simulation. The observer’s practical use expediency has been reasoned. The structure of the observer-based angular gap monitoring information system is given. The system has been full-scale tested on Mill 5000, which has confirmed the developed algorithm efficiency. The study’s contribution is a justified and implemented concept of a relatively simple technical solution that can be commercially implemented without extra costs. The angular gap calculation algorithm does not involve complex mathematical techniques and can be implemented in industrial rolling mill controllers. Monitoring is automated without human involvement, which eliminates the human factor. The solution has a specific practical focus and is recommended for implementation at operating rolling mills.

Physical Modeling of a Water Hydraulic Proportional Cartridge Valve for a Digital Twin in a Hydraulic Press Machine

“…Alternatively, the problem of estimating the parameters in Equation ( 17) can be formulated by accordingly referring to Equation (4.1) in [35] as min θ∈R 8 1…”

“…Karandaev et al (2021) developed a digital twin for the purpose of mirroring and controlling metal behavior in wire-rolling processes [7]. Gasiyarova et al ( 2021) developed an observer of angular gaps in a rolling stand's mechanical transmission, where this observer contained information about the transmission's failure, which was achieved by considering the algorithm's computational cost for real-time monitoring [8]. A comparison of some types of behavioral models used for digital twins of a ring-rolling machine was investigated in Bautista and Rönnow (2023); specifically, autoregressive with exogenous variables (ARX), autoregressive moving average with exogenous variables (ARMAX), and orthonormal basis function (OBF) models were investigated [9].…”

Method for Defining Parameters of Electromechanical System Model as Part of Digital Twin of Rolling Mill

“…Therefore, it is fair to assume that the main roll drive lines (main lines) are two-mass electromechanical systems with elastic constraints and angular gaps in the spindle joints. This assumption is valid for most stands of plate and wide-strip hot mills [31,55].…”

Telemetry System to Monitor Elastic Torque on Rolling Stand Spindles

“…Figure3ashows the spindle design photo[49]. It is connected to the roll using a head of a special design (Figure3b)[23], attached to the working shaft, as shown in Figure3a.…”

“…read by the IBA PDA, and the signals from pressure sensors in the hydraulic cylinders of the vertical balancing of spindles [52]. In combination with a system for recording angular gaps in spindle joints [49], this will allow the building of a universal system for diagnostic monitoring of the main stand line mechatronic equipment conditions. Attention should also be paid to the development of techniques and algorithms for calculating fatigue wear and the life of spindles based on a set of measured parameters.…”