Cold rolling mill rolling condition calculation method, cold rolling mill rolling condition calculation device, cold rolling method, cold rolling mill, and steel sheet manufacturing method

A cold rolling mill rolling condition calculation device for a cold rolling mill having at least one rolling stand, the at least one rolling stand having a rolling mill exit side, the device comprising an arithmetic device having an arithmetic processing section configured to:

• estimate a rolling constraint condition with respect to a target steady rolling condition of a roll target material, by inputting second multi-dimensional data to a prediction model,
• the prediction model having been trained with explanatory variable and response variable,
• the explanatory variable being first multi-dimensional data generated based on non-steady rolling performance data, among past rolling performance in rolling a roll material by the cold rolling mill, the roll material including a welded portion where a preceding material and a succeeding material are welded to each other, the non-steady rolling performance data being rolling performance data acquired when the welded portion passes through the rolling mill exit side of the at least one rolling stand, and
• the response variable being steady rolling performance data and rolling constraint condition data during steady rolling, the steady rolling performance data being data indicating a target rolling speed during steady rolling of a roll material rolled in the past, and
• the second multi-dimensional data having been generated based on non-steady rolling performance data of the roll target material;
• and
• change the target steady rolling condition so that the estimated rolling constraint condition satisfies a predetermined condition.