Edge drop control device

An edge drop control device, comprising:

• low response actuators provided in a rolling stand that rolls a strip, including a first low response actuator and a second low response actuator, and making a different amount of change to each of roll gaps at edges of the strip according to a combination of operation of the first low response actuator based on a correction manipulated amount A and operation of the second low response actuator based on a correction manipulated amount B;
• a high response actuator provided in the rolling stand, having a higher response than the first low response actuator and the second low response actuator, and making a same amount of change to each of the roll gaps at the edges of the strip based on a correction manipulated amount C;
• an edge drop meter provided at least either upstream or downstream of the rolling stand and measuring an edge drop amount for each of the both edges of the strip;
• and
• a processor configured to:
• calculate a calculated manipulated amount A_calc of the first low response actuator and a calculated manipulated amount B_calc of the second low response actuator for bringing a difference between the measured edge drop amount and a target amount close to zero without using the high response actuator;
• calculate a calculated manipulated amount C_calc of the high response actuator for bringing a difference between the measured edge drop amount and the target amount to zero without using the low response actuators;
• when a determination condition is established, output the calculated manipulated amount A_calc as the correction manipulated amount A to the first low response actuator and outputting the calculated manipulated amount B_calc as the correction manipulated amount B to the second low response actuator;
• and
• when the determination condition is not established, output the calculated manipulated amount C_calc as the correction manipulated amount C to the high response actuator.