2010 Volume 96 Issue 10 Pages 601-607
During acceleration and deceleration in cold rolling, variation in friction between a strip and the rolls can adversely affect strip thickness accuracy. Though automatic gauge and tension control is being introduced, constant tension references are insufficient for adequate control over a wide range of rolling speeds. Therefore, we have optimized tension references which vary depending on rolling speed. In order to limit maximum tension to an acceptable value, the optimization problem is composed in a multi level way by using an approximate surface. Moreover, the lowest level optimization problem is decomposed into sub-problems to obtain a solution stably and quickly. Experimental results with a 5-stand tandem cold mill showed a decrease in off-gauge length.
