| 摘要 |
PURPOSE:To improve response characteristics by performing control arithmetic on the basis of a desired value greater than a final desired value when a detected value is less than the final desired value by more than a prescribed value. CONSTITUTION:The DO (dissolved oxygen amount) detected value of a detector 6 is sent to an operator 9 together with a desired value from a switch 11 and the arithmetic output is further sent to an operator 10. The operator 10 is applied with the output of an air-measuring detector 3 and drives a control valve 4 according to the deviation from the output of the operator 9, controlling the amount of a blast. The DO detected value is compared by a comparator 7 with the output of a multiplier 8 which multiplies the output of a desired value setter 12 by a constant (m) (>1) and when it is less than the value, the switch is changed over to a setter 13 side. In the setter 13, the said multiplication result is held, so an approximation to the desired value is obtained with good response characteristics. According to the approximation, the switch 11 is changed over to a setter 12 side, preventing an overshoot. |
