METHOD OF CONTROLLING AN ACTUAL TENSION TO BRING IT TO A DESIRED TENSION BY MEANS OF A MODEL OF THE CONTROLLED TENSION PATH OF AN ADAPTED TENSION CONTROLLER

摘要

Method of controlling an actual tension to bring it to a desired tension by means of a model of the controlled tension path of an adapted tension controller. While a rolled material (1) runs at a rolled material speed (v) through a section of a path (2) that is delimited by a front conveying element (3) and a rear conveying element (4), it is subjected to an actual tension (Z), which is to be controlled to bring it to a desired tension (Z*). The actual tension (Z) and the desired tension (Z*) are fed to a tension controller (5). Arranged upstream of the tension controller (5) is an adaptation element (5') of the controlled tension path, by means of which a current controller characteristic (P, T) is dynamically determined for the tension controller (5) in dependence on static and dynamic data of the rolled material (1) and the conveying elements (3, 4). The current controller characteristic (P, T) is stipulated for the tension controller (5), and so, on the basis of the actual tension (Z) and the desired tension (Z*) together with the current controller characteristic (P, T), the tension controller (5) determines a manipulated variable (S) for a final control element influencing the actual tension (Z) and outputs the manipulated variable (S) to the final control element. The adaptation element (5') comprises a pre-evaluation block (7), which is used for determining parameters (Po, To, V, ai, bi, Ai, Bi) that describe an optimum control characteristic (Po, To) or are used as a basis, together with a predetermined specification, for determining the optimum control characteristic (Po, To), with which the tension controller (5) corrects deviations - for example an abrupt change in the desired tension (Z*) - optimally over time with a defined transient response. The adaptation element (5') determines the current controller characteristic (P, T) in dependence on the optimum controller characteristic (Po, To).