METHOD AND APPARATUS FOR AUTOMATED TUNING OF PID CONTROLLERS

摘要

A method of tuning a PID-regulator (22), or variants thereof, of a plant (10), in which the plant (10) in a feedback system is brought into controlled self-oscillation whereupon the amplitudes and the frequency of the self-oscillation are determined and the controller (22) is tuned in dependence of the values determined for the amplitude and the frequency of the self-oscillation, wherein self-oscillation is induced by connecting in the feedback system a quantiser function (30). Quantiser functions are staircase functions y=Q(x) where an output signal yk, kεN, assumes a predetermined discrete value out of a finite set of discrete values for each of plurality of input signal values XεR within a predetermined interval of input signal values. That is, each discrete output signal value is associated with a plurality of input signal values within a specific one interval.