| 摘要 |
PURPOSE:To facilitate the manual-automatic bumpless changeover and at the same time to avoid the reset wind-up, by performing control using a position type operation and changing the value of integral arithmetic term when an excessive error arises. CONSTITUTION:A processor 1 performs a PI function. A position type control output is calculated on the basis of a measured value Mn, set value SP, proportion gain Kp and input signals of integrating time and differentiating time, respectively. The control output is converted into an analog voltage and applied to a holding capacitor 6. Control is changed from a manual operation to an automatic operation by varying the voltage of the capacitor 6 via a switch 7. Then the integral constant term is set again based on the output of a PI limiter in case a large deviation continues for a long time in order to prevent the reset wind-up. |
