Cold Rolling Mill Thickness Control System And Applications

The sheet thickness control is a key technology in the sheet rolling industry. The study on the measurement and control system for sheet thickness directly Related to the Product quality and economic efficiency. At Present they have huge advancement with the development of rolling theory, control theory, and artificial intelligence theory and with their application in the rolling process. However, It's still one of researching hotspot problems in strip gauge control accuracy.First, based on the curve of mill elastic deformation and the curve of strip Plastic deformation, this thesis analyzes the influence of various interference factors on the strip exit gauge. The operating principles and control algorithms of the fundamental AGC systems are summarized.Actually, the author based on the specification of the mill, selected the ABB software 800XA, also used the PROFIBUS-DP net to complete the automatic gauge control and other processes. Including the whole system hardware and monitor graphics, this program can complete the data collection, calculation and communication with machines. After debug, the result indicated the mill can run naturally and reach the demands, then write down the values of pressure and thickness. The system's function including closed loop monitoring control, pressure or displacement inner loop control, tilt roll adjustment, displacement inner loop with gauge outer loop, pre-control, and so on. In addition, a new control scheme which connects the pressure inner loop with the gauge outer loop is designed and applied in the AGC system of cold strip reversing mill, thus the effects of import strip thickness fluctuation and roll eccentricity on the export strip thickness are restrained. The real application results in Tong Gang show that this control system can achieve a high precision of±3um, and the maximum rolling velocity is 20.83m/s. And remarkable economic and social benefits have been achieved.The effective control of the sheet thickness Precise and increasing the Product quality can provide a good basis for manufacturing better Products. What's more it is a good advice for the same research.