US4466054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved proportional integral-derivative control apparatus
Assignee: Toshiba Corp
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Filing: 1982-05-24
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Granted: 1984-08-14
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Expires: 2002-05-24
Abstract
Abstract A process control apparatus is provided which has a PID controller to which is supplied a sampled signal of a control deviation signal of a process value signal and a reference signal and which generates a PID control signal according to sampled-value PID control constants. A non-linear controller is connected in parallel with the PID controller. A sum signal of the output signals from the PID controller and the non-linear controller is supplied to a process through a holding circuit. The process control apparatus further includes a circuit for identifying the dynamic characteristic of the process according to the sum signal and the sampled signal of the process value, and a circuit for calculating a transfer function of the process in the Laplace operator domain and for determining the sampled-value PID constants of the PID controller according to the dynamic characteristic.
Inventors
- 👤 Takashi Shigemasa
- 👤 Yasuo Takagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 04:42
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; G05B13/0205; G05B13/024; G05B13/0245
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
A process control apparatus comprising: first sampling means for sampling a control deviation signal of a process value signal and a reference signal; PID controlling means for performing a sampled-value PID calculation with respect to an output signal from said first sampling means by using sampled-value PID control constants and for generating a PID control signal; non-linear controller means for converting an output signal from said first sampling means to a non-linear signal; holding means for holding a sum signal of the PID control signal and the non-linear signal and for supplying a hold signal controlling a process value to a process; second sampling means for sampling the process value signal; and control constant generating means for calculating sampled-value PID control constants on the basis of an output signal from said second sampling means and the sum signal of the PID control signal and the non-linear signal and for supplying an operation result to said PID controlling means.
Claim 2
Dependent Claim
158 words
A process control apparatus comprising: first sampling means for sampling a control deviation signal of a process value signal and a reference signal; PID controlling means for performing a sampled-value PID calculation with respect to an output signal from said first sampling means by using sampled-value PID control constants and for generating a PID control signal; non-linear controller means for converting an output signal from said first sampling means to a non-linear signal; holding means for holding a sum signal of the PID control signal and the non-linear signal and for supplying a hold signal controlling a process value to a process; second sampling means for sampling the process value signal; and control constant generating means for calculating sampled-value PID control constants on the basis of an output signal from said second sampling means and the sum signal of the PID control signal and the non-linear signal and for supplying an operation result to said PID controlling means.
Claim 3
Dependent Claim
50 words
A process control apparatus according to claim 1, wherein said non-linear controller means comprises a relay which produces a signal v*(k) given: v*(k)=Ar·sign(e*(k)) where Ar is a constant, and e*(k) is an output signal from said first sampling means, sign(e*(k)) being 1 if e*(k)≧0 and sign(e*(k)) being -1 if e*(K)<0.
Claim 4
Dependent Claim
24 words
A process control apparatus according to claim 1, wherein said first sampling means and said second sampling means operate in synchronism with each other.
Claim 5
Dependent Claim
110 words
A process control apparatus according to claim 1, wherein said control constants generating means comprises: a circuit for identifying a pulse transfer function of the process by recursively calculating a quotient which is obtained by dividing the output signal from said second sampling means by the sum signal of the PID control signal and the non-linear control signal, a transfer function generating circuit for converting an output signal from the identifying circuit to a transfer function of the process in a Laplace operator domain, and a control constant generating circuit for generating sampled-value PID control constants on the basis of the transfer function generated by the transfer function generating circuit.
Claim 6
Dependent Claim
21 words
A process control apparatus according to claim 4, wherein said identifying circuit performs identification by a recursive approximation maximum likelihood filter.
References Cited (Backward Citations)
US3490691A
Cited
US3552428A
Cited
US3578957A
Cited
GB2015771A
Cited
US4232364A
Cited
US4265263A
Cited
US4346433A
Cited
US4349868A
Cited
US4368510A
Cited
US4407013A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-14 | 1988-02-13 | 1988-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-14 | 1992-02-13 | 1992-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-14 | 1996-02-13 | 1996-08-14 | $7700.00 | Window Closed / Lapsed |