Steel shape control method and a steel plate shape control device

(A) by performing a first numerical analysis, sets a target corrective shape of the steel plate of the electromagnet located in the curved shape, the running steel sheets with magnetic corrected so that (B) electromagnets positioned in steel plate target corrective shape when brought into, the steel sheet shape is measured, (C) calculates the steel plate shape of the nozzle positions on the basis of the steel sheet shape, (D) if the warpage amount of the steel sheet shape of the nozzle position is not less than the first upper limit value , and re-sets the target corrective shape the curved shape of the smaller amount of warpage, the repeated (B) and (C) step, (E) if the warpage amount of the steel sheet shape of the nozzle position is lower than the upper limit value, (F) by performing the second numerical analysis to calculate the vibration of the steel plate of the nozzle position, (G) when the amplitude of the vibration is a second upper limit value or more, the amplitude is less than the second upper limit adjusting the control gain of the electromagnet until the steel plate shape control Law.