Adaptive control of a dynamic system or process

An industrial control system having an adaptive control in which a control means compares at least one parameter of the control system with at least one predetermined value to produce an output signal to control each parameter and in which each parameter can be described mathematically as having dominant eign values and which utilize a rate of change of phase with frequency criterion under the following conitions:

• ##EQU17## and (1), (2) and (3) are equal and where the transfer function corresponding to the linear differential equation is expressed as ##EQU18## where j is the complex operator .sqroot.-1 and
• A=C.sub.o -C.sub.2 .omega..sup.2 +C.sub.4 .omega..sup.4 -C.sub.6 .omega..sup.6 + . . .
• B=C.sub.1 .omega..sup.1 -C.sub.3 .omega..sup.3 +C.sub.5 .omega..sup.5 -C.sub.7 .omega..sup.1 + . . .
• and .omega. is the angular frequency in radians per second;
• .phi. the phase lag of z relative to y and the modulus M=.vertline.z/y.vertline. are given by ##EQU19## said industrial control system further comprising a memory means having stored therein the values for at least one control parameter based on a rate of change of phase with frequency criterion;
• means for measuring the current value of each control parameter;
• and means for comparing a stored control parameter with the current value of each parameter to produce an output signal, and means, responsive to said output signal, for controlling the industrial system to produce a desired optimum performance thereof.