US5283729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tuning arrangement for turning the control parameters of a controller
Assignee: Fisher Rosemount Systems Inc
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Filing: 1991-08-30
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Granted: 1994-02-01
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Expires: 2011-08-30
Abstract
Abstract A system is provided for tuning at least one control parameter of a controller in a control loop wherein the system includes an oscillation function not in series with the controller for selectively causing the control loop to oscillate at a tuning frequency, while the controller is in control of the process. While oscillating at the tuning frequency, a tuner is responsive to the tuning gain of the control loop and its tuning frequency for determining control parameters for tuning the controller.
Inventors
- 👤 Sheldon G. Lloyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:19
CPC Classifications
G; G05; G05B; G05B11/00; G05B11/01; G05B11/36; G05B11/42; G05B13/00; G05B13/02; G05B13/0205; G05B13/024; G05B13/025
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
135 words
A system for tuning for at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: a tuning loop including oscillation causing means and said process, said oscillation causing means being outside of said control loop, said oscillation causing means for selectively causing said control loop to oscillate at a tuning frequency while said controller m is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and, tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 2
Independent Claim
135 words
A system for tuning for at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: a tuning loop including oscillation causing means and said process, said oscillation causing means being outside of said control loop, said oscillation causing means for selectively causing said control loop to oscillate at a tuning frequency while said controller m is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and, tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 3
Dependent Claim
49 words
The system of claim 1 wherein said oscillation causing means comprises nonlinear element means and wherein said control loop and said tuning loop are arranged so that said nonlinear element means is selectively operated in parallel with said controller means, said nonlinear element means having a nonlinear relay response.
Claim 4
Dependent Claim
56 words
The system of claim 1 wherein said oscillation causing means comprises nonlinear element means and wherein said control loop and said tuning loop are arranged so that said nonlinear element means is selectively operated as a feedback from said process to an input of said controller means, said nonlinear element means having a nonlinear relay response.
Claim 5
Dependent Claim
19 words
The system of claim 1 wherein said oscillation causing means comprises nonlinear element means having a nonlinear relay response.
Claim 6
Dependent Claim
30 words
The system of claim 4 wherein said nonlinear element means causes said control loop to oscillate at a critical frequency at which said control loop has a phase of -180°.
Claim 7
Dependent Claim
67 words
The system of claim 5 wherein said tuning means comprises gain scheduling means for selecting at least one of a plurality of tuned parameters dependent upon a scheduling variable, at least a different one of said plurality of tuned parameters corresponding respectively to a different one of a plurality of values of said scheduling variable, said controller means operating with said at least one selected tuned parameter.
Claim 8
Dependent Claim
68 words
The system of claim 5 wherein said control loop can be represented by a transfer function having a frequency dependent gain curve when it is plotted on a Nyquist chart and wherein said tuning means comprises means for selecting said frequency dependent gain curve such that every point of said frequency dependent gain curve is more than a predetermined distance away from a point -1.0+j0.0 on the chart.
Claim 9
Dependent Claim
38 words
The system of claim 5 wherein said control loop has a control loop phase and wherein said tuning means senses said control loop phase for adjusting said control loop phase so that said control loop phase is -180°.
Claim 10
Dependent Claim
56 words
The system of claim 5 wherein said tuning means comprises filter means for receiving said error and for providing a filter output having a response substantially centered upon said critical frequency, and amplifier means responsive to said filter output for driving said nonlinear element means so that said tuning means can continuously tune said controller means.
Claim 11
Dependent Claim
59 words
The system of claim 4 wherein said tuning means comprises filter means for receiving said error and for providing a filter output having a response substantially centered upon said tuning frequency, and amplifier means responsive to said filter output for driving said nonlinear element means so that said tuning means can continuously tune said at least one control parameter.
Claim 12
Independent Claim
131 words
A system for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: nonlinear element means having a nonlinear relay response, said nonlinear elements means arranged to operate in parallel with said controller means for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 13
Independent Claim
131 words
A system for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: nonlinear element means having a nonlinear relay response, said nonlinear elements means arranged to operate in parallel with said controller means for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 14
Dependent Claim
30 words
The system of claim 11 wherein said nonlinear element means causes said control loop to oscillate at a critical frequency at which said control loop has a phase of -180°.
Claim 15
Dependent Claim
59 words
The system of claim 11 wherein said tuning means comprises filter means for receiving said error and for providing a filter output having a response substantially centered upon said tuning frequency, and amplifier means responsive to said filter output for driving said nonlinear element means so that said tuning means can continuously tune said at least one control parameter.
Claim 16
Independent Claim
133 words
A system for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error between a process variable and a set point, said system comprising: nonlinear element means having a nonlinear relay response, said nonlinear element means arranged to operate as a feedback from said process to an input of said controller means for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one parameter.
Claim 17
Independent Claim
133 words
A system for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error between a process variable and a set point, said system comprising: nonlinear element means having a nonlinear relay response, said nonlinear element means arranged to operate as a feedback from said process to an input of said controller means for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and tuning means responsive to said tuning gain and to said tuning frequency for tuning said at least one parameter.
Claim 18
Dependent Claim
30 words
The system of claim 14 wherein said nonlinear element means causes said control loop to oscillate at a critical frequency at which said control loop has a phase of -180°.
Claim 19
Dependent Claim
59 words
The system of claim 14 wherein said tuning means comprises filter means for receiving said error and for providing a filter output having a response substantially centered upon said tuning frequency, and amplifier means responsive to said filter output for driving said nonlinear element means so that said tuning means can continuously tune said at least one control parameter.
Claim 20
Independent Claim
126 words
A method for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: initiating an oscillation causing means, not in series with said controller means, for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and activation a tuning means that is responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 21
Independent Claim
126 words
A method for tuning at least one control parameter of a controller means, said controller means operating in series with a process in a control loop and controlling said process in response to an error defined as the difference between a process variable and a set point, said system comprising: initiating an oscillation causing means, not in series with said controller means, for selectively causing said control loop to oscillate at a tuning frequency while said controller means is in control of said process, said control loop having a tuning gain while said control loop is oscillating at said tuning frequency; and activation a tuning means that is responsive to said tuning gain and to said tuning frequency for tuning said at least one control parameter.
Claim 22
Dependent Claim
31 words
The method of claim 17 wherein said oscillation causing means comprises nonlinear element means selectively operated in parallel with said controller means, said nonlinear element means having a nonlinear relay response.
Claim 23
Dependent Claim
38 words
The method of claim 17 wherein said oscillation causing means comprises nonlinear element means selectively operated as a feedback from said process to an input of said controller means, said nonlinear element means having a nonlinear relay response.
Claim 24
Dependent Claim
19 words
The method of claim 17 wherein said oscillation causing means comprises nonlinear element means having a nonlinear relay response.
Claim 25
Dependent Claim
30 words
The method of claim 20 wherein said nonlinear element means causes said control loop to oscillate at a critical frequency at which said control loop has a phase of -180°.
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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) | 1997-01-31 | 1997-08-02 | 1998-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-31 | 2001-08-02 | 2002-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-31 | 2005-08-02 | 2006-02-01 | $7700.00 | Window Closed / Lapsed |