| 摘要 |
PURPOSE:To perform the automatic bumpless transfer, by using a rate limiter which has the proportional aging characteristics of output to an input. CONSTITUTION:When a control mode command device 21 is selected to the back pressure control from the front pressure control, the output of a PI controller 14 is selected by a changeover switch 20. In this case, the output of a rate limiter 30 keeps at first the output of a PI controller 12 for front pressure, and therefore a changeover switch 37 is set at the M side by the output of an AND element 36. Thus the output of the switch 37 has no sudden change. Then the output of the limiter 30 approximates to the output of the controller 14, and the switch 37 is changed to the N side by the output of the element 36. As a result, the output of the controller 14 is sent to an operating device 18. Thus the control mode is automatically switched with no bump. In such a way, the bumpless transfer is automatically carried out. |
