US4549123A
Expired / Lapsed
US
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Method and an apparatus in tuning a PID-regulator
Assignee: SATT CONTROL INSTRUMENTS AB
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Filing: 1982-08-23
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Granted: 1985-10-22
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Expires: 2002-08-23
Abstract
Abstract PCT No. PCT/SE82/00268 Sec. 371 Date Mar. 21, 1983 Sec. 102(e) Date Mar. 21, 1983 PCT Filed Aug. 23, 1982 PCT Pub. No. WO83/00753 PCT Pub. Date Mar. 3, 1983.In tuning a regulator (2) of the PID-type of a process (1) in a feed back system where the process and the regulator has a transfer function G(s) in common, a method is proposed for bringing the system into self oscillation for measuring the amplitude and frequency of the oscillation and tuning the regulator in dependence of the measurements obtained. A circuit function (NL) having non-linear characteristic and a describing function N(A) is introduced into the system in series to the process for acting on the regulator signal (e). Self oscillation is obtained if G(i omega )xN(A)=-1 for at least one value of the angular frequency omega and the amplitude A of the regulator signal (e). An apparatus for performing the method is disclosed.
Inventors
- 👤 Tore Hagglund
- 👤 Karl J. Astrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:37
CPC Classifications
G; G05; G05B; G05B23/00; G05B23/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
133 words
In tuning a regulator (2) of the PID type of process (1) in a feedback system where the process and the regulator have a transfer function G(s) in common, a method of bringing the system into self-oscillation, whereupon the amplitude and the frequency of said self-oscillation are determined and the regulator is tuned in dependence upon the values determined for the amplitude and the frequency of the self-oscillation, characterized in that for achieving said self-oscillation a non-linear circuit function (NL) which has such a describing function N(A) that G(iω)·N(A)=-1 for at least one value of the angular frequency ω and the amplitude A of an input signal, is connected in series to the process (1), whereupon the circuit function is removed after the amplitude and the frequency of the self-oscillation have been determined.
Claim 2
Dependent Claim
133 words
In tuning a regulator (2) of the PID type of process (1) in a feedback system where the process and the regulator have a transfer function G(s) in common, a method of bringing the system into self-oscillation, whereupon the amplitude and the frequency of said self-oscillation are determined and the regulator is tuned in dependence upon the values determined for the amplitude and the frequency of the self-oscillation, characterized in that for achieving said self-oscillation a non-linear circuit function (NL) which has such a describing function N(A) that G(iω)·N(A)=-1 for at least one value of the angular frequency ω and the amplitude A of an input signal, is connected in series to the process (1), whereupon the circuit function is removed after the amplitude and the frequency of the self-oscillation have been determined.
Claim 3
Dependent Claim
17 words
Method as claimed in claim 1, characterized in that the circuit function (NL) has a relay characteristic.
Claim 4
Dependent Claim
19 words
Method as claimed in claim 1, characterized in that the circuit function (NL) has a relay characteristic and hysteresis.
Claim 5
Dependent Claim
109 words
In tuning a regulator (2) of the PID type of a process (1) in a feedback system where the regulator and the process have a transfer function G(s) in common, an apparatus which is adapted to bring the system into self-oscillation in order to measure the amplitude and the frequency of the self-oscillation, characterized by a means (7, 8; 13-15) which is adapted to realize a non-linear circuit function (NL) having such a describing function N(A) that G(iω)·N(A)=-1 for at least one value of the angular frequency ω and the amplitude A of an input signal, and to temporarily connect said circuit function in series to the process (1).
Claim 6
Dependent Claim
109 words
In tuning a regulator (2) of the PID type of a process (1) in a feedback system where the regulator and the process have a transfer function G(s) in common, an apparatus which is adapted to bring the system into self-oscillation in order to measure the amplitude and the frequency of the self-oscillation, characterized by a means (7, 8; 13-15) which is adapted to realize a non-linear circuit function (NL) having such a describing function N(A) that G(iω)·N(A)=-1 for at least one value of the angular frequency ω and the amplitude A of an input signal, and to temporarily connect said circuit function in series to the process (1).
Claim 7
Dependent Claim
17 words
Apparatus as claimed in claim 4, characterized in that the circuit function (NL) has a relay characteristic.
Claim 8
Dependent Claim
19 words
Apparatus as claimed in claim 4, characterized in that the circuit function (NL) has a relay characteristic and hysteresis.
Claim 9
Dependent Claim
30 words
Apparatus as claimed in claim 4, characterized in that said means comprises an electric circuit (7) and a switch (8) for temporarily connecting the electric circuit to the regulator (2).
Claim 10
Dependent Claim
47 words
Apparatus as claimed in claim 4, wherein the regulator (2) comprises a microcomputer in which the control functions of the regulator are realized by means of algorithms, characterized in that said means consists of said microcomputer (13-15), said circuit function (NL) being realized by an algorithm therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |