COMPARISON OF DIFFERENT CONTROL CONCEPTS FOR COLD ROLLING TANDEM MILLS

It is shown that in recent years, the control concepts for cold rolling tandem mills have been continuously improved. This development was favored by new and more efficient measuring devices - for instance for measuring roll separating force, gage, tensile stresss, and tensile stress distribution over the strip width - and control equipment such as hydraulic screwdown systems and roll bending systems. The control concepts are based on continuity equations for mass flow. However, the conclusions drawn may differ as shown by the example of a rigid speed control system and a noninteractive control concept.