| 摘要 |
PURPOSE:To perform changing over from a manual control or tracking state to automatic control bumpless and smoothly by providing operators to the output side of a controller with output limits, and gradually approaching the output of the controller to limit values at a fixed gradient. CONSTITUTION:The tracking signal EXT is inputted from other controller to a controller 1 to which the set signal SV and the process signal PV are inputted. High selectors H1, H2 and low selectors L1, L2 set the output MV of the controller 1 to limit values HL, LL. Change-over switches SW1, SW2 are changed over to the side A at the time of manual control or tracking and to the side B provided with operators 2a, 2b at the time of automatic control. The operators 2a, 2b have the operating functions shown by the equation (where c0 is an initial value). With such constitution, at the time of changing over to automatic control, the input HL'', LL'' are decreased or increased by a fixed gradient by the operators 2a, 2b, and are made equal to the limit values HL, LL after lapse of a prescribed time, whereby the bumpless and smooth changing-over is accomplished. |
