METHOD AND DEVICE FOR ADJUSTING A PID CONTROLLER

摘要

A method for adjusting a PID type controller (11) controlling an industrial process (10), based on the determination of a frequency and a gain causing a free oscillation of the response (y(t)) of said process with a predetermined phase shift, by means of a circuit (15) with a non-linear description function driven by an error signal (e(t)) between a reference (r) and said process response (y(t)), the method including connecting in series with the non-linear circuit (15) a circuit (13) with a linear transfer function and identifying a desired phase shift point causing a stable oscillation of the response (y(t)) of the process (10) by varying the phase shift caused by the linear circuit (13).