Method for ascertaining control variables for active profile and flatness control elements for a rolling stand and profile and average flatness values for hot-rolled metal strip

A method for hot rolling a metal strip and ascertaining control variables for active profile and flatness control elements for at least one rolling stand, comprising:

• hot rolling the metal strip in a plurality of i=1 . . . I successive passes through the at least one rolling stand;
• individually adjusting active profile and flatness control elements of the at least one rolling stand for each pass;
• and
• ascertaining profile and center flatness values for the metal strip by the following steps:
• a1) specifying a target profile value and a target center flatness after a last pass and process-related center flatness thresholds for the metal strip after individual passes (i), wherein an interval range or a singular target center flatness value is specified for the target center flatness after the last pass;
• a2) specifying pass-specific interval ranges in each case for the target center flatness of the metal strip after a predetermined pass (k) with i=1<k<I and for the target center flatness values after the subsequent passes (i) with k<i≤I−1, wherein the interval ranges lie in each case within the center flatness thresholds;
• b) inputting specifications into a technological model for simulating the hot rolling;
• and
• c) successively calculating control variables for the active profile and flatness control elements and a calculated profile value (Cx) and a calculated center flatness value for the individual passes (i) with assistance of the technological model based on of the specifications,
• wherein the successively calculating of the control variables for the profile and flatness control elements and of the profile and center flatness values for the metal strip for the individual passes with the assistance of the technological model is carried out, with additional consideration of the respective specified pass-specific interval ranges for the target center flatness of the metal strip for the passes k≤i≤I.