EP0256842A2
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EP
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Adaptive process control system
Assignee: Toshiba Corp
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Filing: 1987-08-11
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Granted: —
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Expires: 2007-08-11
Abstract
Abstract An adaptive process control system comprises a controlling signal generator (2) of an I-P controller with a feed forward circuit (3) responsive to the set-point signal r(t), an integrator (4) responsive to a difference between a controlled signal y(t) and set-point signal r(t), and a feedback circuit (5) responsive to the controlled signal y(t). An identification signal generator (6) superposes a persistantly exciting identification signal h(t) to the control system. A frequency characteristic identifying circuit (10) receives a discrete controlled data u(k) and y(k), estimates the parameters of the ARMA model by the method of least squares to identify the pulse transfer function, and obtains the transfer function in the continuous system as the frequency characteristics of gain and phase. A control parameter calculating circuit (12) calculates the control parameters of the controlling signal generator (2), such as integration gain K, feedback gain f o , and feed forward gain f f , using the frequency characteristics of gain and phase, and the overshoot, gain and phase margins, and attenuation ratio. The control parameters are supplied via a holder (15) to the controlling signal generator (2).
Inventors
- 👤 Yutaka Patent Division Iino
- 👤 Takashi Patent Division Shigemasa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 08:36
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; G05B13/0205; G05B13/024; G05B13/025; G05B13/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
161 words
An adaptive process control system comprising: controller means (2) with control parameters for generating a controlling signal which controls a controlled signal of a process according to a set-point signal, the controlled signal, and the control parameters; tuning means (6) for supplying a persistently exciting identification signal to either of the set-point signal and the controlling signal; characterized by further comprising; frequency characteristic identifying means (10) for estimating an autoregressive moving average model of the process from sampling data of the controlled signal and sampling data of the controlling signal by using a method of least squares, during a period in which said tuning means supplies the identification signal, identifying a pulse transfer function of the process, and obtaining a frequency characteristics of gain and phase of the process based on the pulse transfer function; and control parameter calculating means (12) for adjusting said control parameters so that the frequency characteristics of gain and phase satisfy predetermined gain and phase margins.
Claim 2
Dependent Claim
161 words
An adaptive process control system comprising: controller means (2) with control parameters for generating a controlling signal which controls a controlled signal of a process according to a set-point signal, the controlled signal, and the control parameters; tuning means (6) for supplying a persistently exciting identification signal to either of the set-point signal and the controlling signal; characterized by further comprising; frequency characteristic identifying means (10) for estimating an autoregressive moving average model of the process from sampling data of the controlled signal and sampling data of the controlling signal by using a method of least squares, during a period in which said tuning means supplies the identification signal, identifying a pulse transfer function of the process, and obtaining a frequency characteristics of gain and phase of the process based on the pulse transfer function; and control parameter calculating means (12) for adjusting said control parameters so that the frequency characteristics of gain and phase satisfy predetermined gain and phase margins.
Claim 3
Dependent Claim
81 words
An adaptive process control system according to claim 1, characterized in that said controller means (2) includes an I-P controller with feed forward comprising a feed forward circuit (3) responsive to only the set-point signal r(t), an integrator (4) responsive to a difference between the controlling signal y(t) and the set-point signal r(t), and a feedback circuit (5) responsive to only the controlling signal y(t), said I-P controller serving as a P-I controller if the feed forward gain is appropriately adjusted.
Claim 4
Dependent Claim
39 words
An adaptive process control system according to claim 1, characterized in that said tuning means (6) includes means for generating an identification signal h(t) comprised of one of an M-series signal, a rectangular wave signal, and a pulse signal.
Claim 5
Dependent Claim
37 words
An adaptive process control system according to claim 1, characterized in that said tuning means (6) includes means for generating an identification signal when a difference between the set-point signal and the controlling signal exceeds a threshold.
Claim 6
Dependent Claim
45 words
An adaptive process control system according to claim 1, characterized in that said frequency characteristic identifying means (10) includes means for identifying a pulse transfer function of the process using the data in which the sampling data are repeatedly arranged in a time axis direction.
Claim 7
Dependent Claim
37 words
An adaptive process control system according to claim 1, characterized in that said frequency identifying means (10) includes means for correcting an error of the controlling signal data and the controlled signal data due to the sampling.
Claim 8
Dependent Claim
62 words
An adaptive process control system according to claim 1, characterized in that said control parameter calculating means (12) includes means for designating an overshoot of the process and an attenuation ratio of the process, and means for calculating the control parameters so that the frequency characteristics of gain and phase satisfy predetermined gain and phase margins, the overshoot, and the attenuation ratio.
Claim 9
Dependent Claim
99 words
An adaptive process control system characterized by comprising: first calculating means (40) for receiving a characteristic coefficient of a reference model exhibiting a desired response of a process, and calculating gain and phase margins of the reference model; and second calculating means (42) for receiving the calculated gain and phase margins from said first calculating means (40), a transfer function of the process, and a signal representing a compensation mode of the process, and calculating control parameters for the process so that gain and phase margins of the process coincide with those calculated by said first calculating means (40).
Claim 10
Dependent Claim
99 words
An adaptive process control system characterized by comprising: first calculating means (40) for receiving a characteristic coefficient of a reference model exhibiting a desired response of a process, and calculating gain and phase margins of the reference model; and second calculating means (42) for receiving the calculated gain and phase margins from said first calculating means (40), a transfer function of the process, and a signal representing a compensation mode of the process, and calculating control parameters for the process so that gain and phase margins of the process coincide with those calculated by said first calculating means (40).
Claim 11
Dependent Claim
32 words
An adaptive process control system according to claim 8, characterized in that said second calculating means (42) calculates the control parameters depending on an I-PD compensation mode or a PID compensation mode.
Claim 12
Dependent Claim
98 words
An adaptive process control system comprising: means for receiving an input signal to a process and an output signal from the process at a sampling period, and identifying a pulse transfer function using an autoregressive moving average model of the process; characterized by further comprising; means for calculating frequency characteristics of gain and phase of the process according to the identified pulse transfer function, the sampling period, and a compensation transfer function for removing the difference between the pulse transfer function and a transfer function in the continuous system of the process, which is caused by the sampling.
Claim 13
Dependent Claim
98 words
An adaptive process control system comprising: means for receiving an input signal to a process and an output signal from the process at a sampling period, and identifying a pulse transfer function using an autoregressive moving average model of the process; characterized by further comprising; means for calculating frequency characteristics of gain and phase of the process according to the identified pulse transfer function, the sampling period, and a compensation transfer function for removing the difference between the pulse transfer function and a transfer function in the continuous system of the process, which is caused by the sampling.
References Cited (Backward Citations)
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