US5587898A
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Method and apparatus for fuzzy control
Assignee: Siemens AG
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Filing: 1995-03-02
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Granted: 1996-12-24
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Expires: 2015-03-02
Abstract
Abstract In a method and apparatus for fuzzy control in contrast to standard methods and arrangements, no sharp quantity is processed as an input quantity of the fuzzy controller; instead, an input quantity is supplied that is affected with a probability density distribution. Thus it is not a sharp value but the probability density distribution of an input value whose membership degree is determined in the inference procedure of the fuzzy controller. This procedure offers advantages, particularly given asymmetrical distribution densities. First, one thus obtains a better response behavior of the controller and, second, the disadvantages that would occur given a pre-filtering of the signal, such as information losses, are avoided.
Inventors
- 👤 Rainer Palm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:56
CPC Classifications
G; G06; G06N; G06N7/00; G06N7/02; G06N7/04; Y; Y10; Y10S; Y10S706/00; Y10S706/90
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
101 words
A method for fuzzy control of a device, comprising the steps of: forming a control difference comprising at least one unsharp quantity having varying values with a probability density distribution of said values; supplying said control difference to a fuzzy controller; in said fuzzy controller, normalizing said probability density distribution to a predetermined value to obtain a normalized probability density distribution; conducting a fuzzy logic inference procedure in said fuzzy controller using said normalized probability density distribution to determine a membership degree of said probability density distribution to form a manipulated quantity; and controlling said device dependent on said manipulated quantity.
Claim 2
Independent Claim
101 words
A method for fuzzy control of a device, comprising the steps of: forming a control difference comprising at least one unsharp quantity having varying values with a probability density distribution of said values; supplying said control difference to a fuzzy controller; in said fuzzy controller, normalizing said probability density distribution to a predetermined value to obtain a normalized probability density distribution; conducting a fuzzy logic inference procedure in said fuzzy controller using said normalized probability density distribution to determine a membership degree of said probability density distribution to form a manipulated quantity; and controlling said device dependent on said manipulated quantity.
Claim 3
Dependent Claim
29 words
A method as claimed in claim 1 comprising the additional step of formulating said probability density distribution of said at least one unsharp quantity over a fixed time interval.
Claim 4
Dependent Claim
38 words
A method as claimed in claim 2 comprising the additional steps of: formulating a control error after controlling said device with said manipulated quantity; and subtracting said control error from said unsharp quantity in formulating said control difference.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 2 comprising the steps of: defining a control event; and formulating said probability density distribution during said control event.
Claim 6
Dependent Claim
40 words
A method as claimed in claim 2 comprising the additional step of formulating said probability density distribution during a control event by repeated analysis of said control difference, each analysis resulting in an analyzed value, and numbering said analyzed values.
Claim 7
Dependent Claim
53 words
A method as claimed in claim 1 wherein the step of formulating said control difference is further defined by formulating said control difference as a probability density distribution of only one value comprising a spatial distribution of values occurring within a fixed spatial region of a spatially occurring quantity of said fuzzy controller.
Claim 8
Dependent Claim
87 words
A method as claimed in claim 1 wherein the step of conducting said inference procedure includes formulating a membership function on the basis of which said membership degrees are determined, and comprising the additional steps of: identifying an intersection of said membership function with at least one input set to said inference procedure according to the Mamdani method and defining a membership value of said intersection as an intersection value; employing said intersection value in a conclusion portion of said inference procedure for forming said manipulated quantity.
Claim 9
Independent Claim
128 words
A method as claimed in claim I wherein the step of conducting said inference procedure includes formulating a membership function on the basis of which said membership degree is determined, and comprising the additional steps of: identifying an intersection of said membership function with at least two input sets to said inference procedure in a condition part of said inference procedure according to the Takagi-Sugeno method, and identifying an intersection value set of the membership values of the intersections; identifying a center of area value of said membership function as a sharp input value for a conclusion part of said inference procedure according to the Takagi-Sugeno method; and forming a product of each input value and a minimum value of said intersection value for forming said manipulated quantity.
Claim 10
Independent Claim
112 words
An apparatus for fuzzy control of a device, comprising: means for forming a control difference comprising at least one unsharp quantity having varying values with a probability density distribution of said values; means for supplying said control difference to a fuzzy controller; said fuzzy controller comprising means for normalizing said probability density distribution to a predetermined value to obtain a normalized probability density distribution; means for conducting a fuzzy logic inference procedure in said fuzzy controller using said normalized probability density distribution to determine a membership degree of said probability density distribution to form a manipulated quantity; and said fuzzy controller comprising means for controlling a device dependent on said manipulated quantity.
Claim 11
Independent Claim
112 words
An apparatus for fuzzy control of a device, comprising: means for forming a control difference comprising at least one unsharp quantity having varying values with a probability density distribution of said values; means for supplying said control difference to a fuzzy controller; said fuzzy controller comprising means for normalizing said probability density distribution to a predetermined value to obtain a normalized probability density distribution; means for conducting a fuzzy logic inference procedure in said fuzzy controller using said normalized probability density distribution to determine a membership degree of said probability density distribution to form a manipulated quantity; and said fuzzy controller comprising means for controlling a device dependent on said manipulated quantity.
Claim 12
Dependent Claim
23 words
An apparatus as claimed in claim 9 wherein said means for conducting said inference procedure comprises means for conducting a Mamdani inference procedure.
Claim 13
Dependent Claim
23 words
An apparatus as claimed in claim 9 wherein said means for conducting an inference procedure comprises means for conducting a Takagi-Sugeno inference procedure.
Claim 14
Dependent Claim
21 words
An apparatus as claimed in claim 9 wherein said fuzzy controller comprises a sliding mode fuzzy controller with a boundary layer.
References Cited (Backward Citations)
US5410613A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-12-24 | 2000-06-24 | 2000-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-24 | 2004-06-24 | 2004-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-24 | 2008-06-24 | 2008-12-24 | $7700.00 | Window Closed / Lapsed |