| 摘要 |
<p>PURPOSE:To prevent the time lag and to improve the accuracy of thickness control, by detecting time lag of the thickness control signal according to the difference between the average value of thickness deviations on the exit side and the aim thickness value. CONSTITUTION:The mean square circuit 7 calculates the average value of the thickness deviation signal DELTAh, and this average value is compared by the comparator 5 with the reference value 6 in respect of the magnitude. When the average value is larger than the reference value, the discriminator 4 sends a signal, for putting the signal generating time of the feedforward signal generator 1 forward by a specified time, to the timing device 2. Then, the deviation signal DELTAh is generated by the thickness deviation detector, and is again sent to the mean square circuit 7. Hereupon, if this value of mean square of the deviation DELTAh is larger than the former value, the discriminator 4 sends a signal, for putting back the generating time of the feedforward signal by a specified time, to the timing device 2; and if above value of mean square of DELTAh is smaller than the former value, the discriminator 4 sends a signal, for putting the generating time of the feedforward signal forward by additional specified time, to the timing device 2; thus the control is continued until the average value of DELTAh becomes smaller than the reference value.</p> |
