US 4,882,526 A · Adaptive process control system

Abstract

An adaptive process control system comprises a controller of an I-P type generating a manipulating variable signal with a feed forward circuit responsive to the set-point signal r(t), an integrator responsive to a difference between a process variable signal y(t) and set-point signal r(t), and a feedback circuit responsive to the process variable signal y(t). An identification signal generator superposes a persistantly exciting identification signal h(t) to the control system. A frequency characteristic identifying circuit receives a discrete controlled data u(k) and y(k), estimates the parameters of the ARMA model by the least square method to identify the pulse transfer function, and obtains the transfer function in the continuous system as the frequency characteristics of gain and phase. A controller parameter calculating circuit calculates the controller parameters of the controller, such as integration gain K, proportional gain f.sub.o, and feed forward gain f.sub.f, using the frequency characteristics of gain and phase, and the overshoot, gain and phase margins, and attenuation ratio. The controller parameters are supplied via a switch to the controller.

Claims12

Dependent claims

An adaptive process control system comprising:

set point means for generating a set-point signal which represents a target value of a process variable signal of a process to be controlled;
controller means for generating a manipulating signal which controls the process variable signal in accordance with the set-point signal, the process variable signal, and controller parameters;
tuning means for superposing a persistently exciting identification signal on at least one of the set-point signal and the manipulating signal;
frequency characteristic identifying means for estimating an autoregressive moving average model of the process from sampling data of the process variable signal and sampling data of the manipulating signal by using a least square method, during a period in which said tuning means outputs the identification signal, identifying a pulse transfer function of the process, and obtaining a frequency characteristic of gain and phase of the process based on the pulse transfer function;
and
controller parameter calculating means for adjusting the controller parameters of the controller means so that the frequency characteristics of gain and phase satisfy predetermined gain and phase margins.

3 more elements

Dependencies are inferred from the claim text.

Adaptive process control system

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Adaptive process control system

Life of this patent

Abstract

Claims12