Digital PID control apparatus

摘要

In the digital PID (P:proportional, I:integral, D:derivative) control apparatus of the present invention, in which a deviation is obtained from a controlling amount of an object to be controlled, and a target value, a velocity type PI control operation is carried out on the deviation, a velocity type D control operation is carried out on the deviation or the controlling amount, these velocity type control operation outputs are synthesized, and then converted into a position type manipulation signal, and this signal is supplied to the object to be controlled, the derivation processing unit includes the judgment unit for judging whether K=2x DELTA t/( DELTA t+2 eta xTD)1 by using a control operation period DELTA t, a derivative time TD and a derivative gain 1/ eta , and the operation unit which carries out a lagged derivative operation by a bilinear transfer method when K1.