Design And Implemention Of Automatic Gauge Control Of Cold Rolling Mill

With the rapid development of the national economy and improvement of control means which based on computer technology and power electronics etc, it has promoted the production precision and relative technology of plate and strip products in industry.For the gauge control system, currently it just apply the automated intelligence system into AGC control system, and the automated intelligence system by simulating the human brain deal with some real things, the control method is based on the actual data to optimize the process control. Depending on the actual situation of the equipment itself, it can adopt the mass flow calculation to achieve the thickness control. The control strategy to be used in the thickness control system of the cold rolling mill is divided into two layers to control, the first layer is adjusted according to the proportional integral which the actual thickness value and the deviation of a given value, but this deviation can’t exceed the limit of the output of the controller. If the deviation exceeds the limit of the output of the controller, and the thickness of the board didn’t reach the target of the control accuracy, the system will automatically adjust the second layer control. The second layer controller used as a control signal that the first layer controller overflow part is used as the need to adjust, second layer controller is also proportional integral adjustment for this part of the signal, so the more the first layer of overflow, then the higher the control accuracy of the second layer.This paper introduces Automatic thickness control theory and control methods, depending on the ability of the cold rolling mill stand, it indicates the main designing idea. And it focuses on not only the hardware and software but also realization about them. For the electrical part, the control system is updated, such as application of SIEMENS’s PLC-400, and added the external testing equipment which thickness gauge, X-ray thickness gauge and the shape meter etc of the plate thickness measuring instrument. PLC-400 is mainly used for controlling the thickness of the system, used to handle all kinds of input and output signals, user’s program, and logic and process control of mill housing, which is the core of the thickness control system.Through the transformation of the AGC system and the programming controller, which will be able to effectively solve the market demand and high accuracy requirements of the plate and strip products.