Design And Application Of Automatic Gauge Control System For Heavy Plate Mill In Shouqin Company

The medium plate is a heavy steel material in national economy progress, it is an essential part of steel products in our country's modernization construction, and it is widely used in large diameter long distance oil and gas pipeline, shipbuilding, large span beam, boiler, pressure vessel, machinery manufacturing, offshore platform petroleum and chemical industry etc. The medium plate production level and the level of medium plate material are hallmarks of national iron and steel industry and level of steel material.In recent years, China's iron and steel enterprises importing foreign advanced plate production line, the equipment level and the technical level are in leading position in the world, but the attendant result is medium plate overcapacity, intense market competition. With the development of production and the progress of technology, user will have more higher requirement for thickness accuracy, and more rigorous demand on various different plates, especially in the automotive industry, electronic industry, pressure vessel and other area.Based on Shouqin medium plate as the background, this thesis mainly research and application on the Shouqin thickness control system.Firstly, the recent development of heavy plate in the domestic market introduced. The thickness control system is an important way to directly generate economic benefits and improve the ability of market competition, and the subject has ben established.Secondly, described the general situation of the process equipment mill in Shouqin and application and development of AGC control technology, then the detailed design of the rolling mill control system from two aspects of hardware and software, construction of factory automation network, through the network, the PLC hardware, the automation components and actuators are combined together, realizes the data exchange and action.Completed the design of the Shouqin mill AGC system, and introduced the " Screwdown System Processing" and "Digital Screwdown Control" control function of the rolling mill under screwdown system. Studied function structure and control principle of the electric gauge control system, hydraulic gauge control system and automatic thickness control system. In order to further improve the thickness control precision,the thickness monitoring control system is designed. And The AGC control system mathematical model is established, the workings of AGC system was discussed.PID controller design method is discussed, and on the basis of the mathematical model of rolling mill hydraulic AGC system, and adopts digital PID controller to control the hydraulic AGC system, the stability of the control effect is obtained. Requirements for hydraulic AGC system response speed, high control precision, strong anti-jamming capability, etc, according to the fuzzy control theory to design the adaptive fuzzy PID controller, and has carried on the simulation, the simulation results show that the adaptive fuzzy PID controller of control effect is superior to the conventional PID controller, and when the object properties change adaptability is stronger, smaller overshoot, accelerate the stable time, improve the system stability and robustness.Finally, this thesis also analyzed and improved to the practice problem of AGC control system. Introduced the roll gap calibration principle and the calibration process, the static deviation problems in the process of rolling mill calibration are analyzed and improved. The principle and process of mill bounce are introduced, the mill bounce curve is studied, when the rolling force from the beginning of the 2000 tons, roll gap and rolling force into linear distribution, this phase control of thickness is the most accurate, is the most easy to control. The roll system deformation problems are analyzed and improved,It's study found that the roll bending force in certain circumstances, plate width, bending the greater the effect of vertical thickness difference. Eventually the control level of the current thickness of Shouqin company are introduced.