US5220265A
Expired / Lapsed
US
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Discrete-type repetitive control method and an apparatus therefor
Assignee: Fanuc Corp
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Filing: 1991-04-20
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Granted: 1993-06-15
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Expires: 2011-04-20
Abstract
Abstract A discrete-type repetitive control unit which enables stable repetitive control even if a state variable of a controlled object is not observable, using time delay elements (Z -1 ). The number of time delay elements is equal to or greater than a value obtained by dividing a cycle period of a cyclic target input by a period of sampling the deviation between a controlled object output and the cyclic target input. Periodically applied to each of the time delay elements is a sum obtained by adding the product of the deviation and a first gain (h1, - - - , hn) associated with the time delay element, to the product of an input (u(k)) of the controlled object and a second gain (m1, - - - , mn) associated with the time delay element, and to an output (Wn(n+n), - - - , W1(k+1)) of a preceding element. The control unit periodically applies to the controlled object a sum (u(k)) obtained by adding the product of the deviation and a third gain (h0) to an output (W1(k)) of the last time delay element. The control unit achieves a stable operation of the controlled object with the flexibility to respond to variation in the cycle period of the target input and without causing a delay in following the target input which periodically changes in a single changing pattern.
Inventors
- 👤 Mitsuhiko Araki
- 👤 Keiji Sakamoto
- 👤 Yasusuke Iwashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:34
CPC Classifications
G; G05; G05B; G05B21/00; G05B21/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
207 words
A discrete-type repetitive control method comprising the steps of: (a) receiving a cyclic target input; (b) periodically sampling an input of a controlled object and a deviation between the cyclic target input and an output of the controlled object; (c) multiplying the deviation sampled in step (b) times each of a plurality of a first gains associated with a plurality of time delay elements to produce a first product associated with each time delay element; (d) multiplying the input of the controlled object times each of a plurality of second gains associated with the time delay elements to produce a second product associated with each time delay element; (e) multiplying the deviation sampled in step (b) times a third gain to produce a third product; (f) applying, to each of the time delay elements, numbering not less than a value obtained by dividing the input cycle period by the sampling period, a sum of the first product associated with the time delay element, the second product associated with the time delay element and an output of a preceding time delay element, when one exists; and (g) periodically applying, to the controlled object, a sum of the third product and an output of a final time delay element.
Claim 2
Dependent Claim
207 words
A discrete-type repetitive control method comprising the steps of: (a) receiving a cyclic target input; (b) periodically sampling an input of a controlled object and a deviation between the cyclic target input and an output of the controlled object; (c) multiplying the deviation sampled in step (b) times each of a plurality of a first gains associated with a plurality of time delay elements to produce a first product associated with each time delay element; (d) multiplying the input of the controlled object times each of a plurality of second gains associated with the time delay elements to produce a second product associated with each time delay element; (e) multiplying the deviation sampled in step (b) times a third gain to produce a third product; (f) applying, to each of the time delay elements, numbering not less than a value obtained by dividing the input cycle period by the sampling period, a sum of the first product associated with the time delay element, the second product associated with the time delay element and an output of a preceding time delay element, when one exists; and (g) periodically applying, to the controlled object, a sum of the third product and an output of a final time delay element.
Claim 3
Dependent Claim
23 words
The discrete-type repetitive control method according to claim 1, wherein at least one of the first gains and the second gains is zero.
Claim 4
Dependent Claim
216 words
A discrete-type repetitive control unit for controlling a controlled object in accordance with a cyclic target input, comprising: time delay elements, numbering not less than a value obtained by dividing a cycle period of the cyclic target input by a sampling period of a sampled deviation between an output of the controlled object and the cyclic target input, said time delay elements connected in series with each other and each producing an output; first gain elements, each corresponding to one of said time delay elements, operatively connected to receive the sampled deviation and producing an output; second gain elements, each operatively connected to receive an input of the controlled object, corresponding to one of said time delay elements and producing an output; first adder elements, each operatively connected to supply an output to a corresponding time delay element and to receive the output from corresponding first and second gain elements and from a preceding time delay element except when the corresponding time delay element is a first time delay element; a third gain element operatively connected to receive the sampled deviation and producing an output; and a second adder element operatively connected to supply the input of the controlled object and to receive the output of a last time delay element and the third gain element.
Claim 5
Dependent Claim
216 words
A discrete-type repetitive control unit for controlling a controlled object in accordance with a cyclic target input, comprising: time delay elements, numbering not less than a value obtained by dividing a cycle period of the cyclic target input by a sampling period of a sampled deviation between an output of the controlled object and the cyclic target input, said time delay elements connected in series with each other and each producing an output; first gain elements, each corresponding to one of said time delay elements, operatively connected to receive the sampled deviation and producing an output; second gain elements, each operatively connected to receive an input of the controlled object, corresponding to one of said time delay elements and producing an output; first adder elements, each operatively connected to supply an output to a corresponding time delay element and to receive the output from corresponding first and second gain elements and from a preceding time delay element except when the corresponding time delay element is a first time delay element; a third gain element operatively connected to receive the sampled deviation and producing an output; and a second adder element operatively connected to supply the input of the controlled object and to receive the output of a last time delay element and the third gain element.
Claim 6
Dependent Claim
43 words
The discrete-type repetitive control unit according to claim 3, further comprising: a sampling circuit, operatively connected to the first and third gain elements and to receive the cyclic target input and the output of the controlled object for periodically producing the sampled deviation.
Claim 7
Dependent Claim
28 words
The discrete-type repetitive control unit according to claim 3, wherein at least one of said first gain elements and said second gain elements has a gain of zero.
Claim 8
Dependent Claim
45 words
The discrete-type repetitive control unit according to claim 3, wherein the number of said time delay elements is equal to an integer obtained by dividing the cycle period of the cyclic target input by the sampling period of the deviation and rounding up any remainder.
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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) | 1996-06-14 | 1996-12-14 | 1997-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-14 | 2000-12-14 | 2001-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-14 | 2004-12-14 | 2005-06-15 | $7700.00 | Window Closed / Lapsed |