Study On Strategy Of Strip Automatic Gauge Control For Continuous Tandem Cold Mill

The accuracy of strip gauge are one of the most important quality target of strip production. Automatic Gauge Control is called AGC for short. Meanwhile, it's a important means to achieve the high accuracy in modern tandem cold rolling. The function of the AGC system in tandem cold mill is to get the well-proportioned lengthways thickness of steel strip. Presently, for meeting the continuous advance to the production quality in car and electric equipment section and so on, the AGC system which has been developed into many control modes has become the indispensable control system in the modern steel strip production and the request to it become higher and higher.The dissertation gives the AGC system structure based on the deep analyse and research on Smith-AGC system and Smith-AGC integrated thickness control strategy in the four stands of BenXi tandem cold mill, whose key control algorithm, computing model are reasoned as well as its physical meaning analyse. The dissertation also analyzes the Smith prediction strategy, the rationality of Smith-AGC structure and the stability of Smith-AGC system.Smith predictor is an effective method to compensate for time delays, but it is sensitive to the change of the parameters, which often causes systems unstable. Aimed at this problem, the dissertation gives an improved Smith prediction control system, which is added a one-order integral factor in Smith system's main feedback channels. And from the emulation of the Simulink and the nyquist criterion, the improved system is proved that it has many advantages. For example, fast response, small overshoot, better robust performance and so on.