JPS6429901A - Pid controller - Google Patents

Abstract

PURPOSE:To improve controllability, by performing the arithmetic operation of a proportional by a first-order lag deviation between a first-order lag preset value in which the arithmetic operation of first-order lag is performed on a preset value and a measured value, and performing the arithmetic operation of an integral term by an ordinary deviation between the preset value and the measured value. CONSTITUTION:The arithmetic operations of the proportional, the integral term, and a differential term are performed at arithmetic parts 4a-4c, respectively, so that a deviation en between measured data (actual measured value xn) corresponding to the operating state of a controlled system 3 measured by a detector 2 and the preset value x0 set in advance can be eliminated, and the output ratio yn of the controlled system 3 can be computed and outputted by multiplying the sum of them by a proportional gain kp. And the arithmetic operation by the first-order lag deviation is applied only on the proportional, and the PID arithmetic operations of the integral term and the differential term by the ordinary deviation not depending on the first-order lag are performed, then, overshoot can be eliminated.