US4813339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse-width-modulation control of parallel three-way valves to supply single-acting quick-response actuator
Assignee: Hitachi Ltd
•
Filing: 1985-11-06
•
Granted: 1989-03-21
•
Expires: 2005-11-06
Abstract
Abstract Parallel, pulse-width-modulation controlled three-way valves each both supply and exhaust a pressure chamber of a fluid actuator. The phase difference of the oscillator carrier waves of the pulse width modulation input circuit effectively increases the frequency of a net actuator carrier wave so as to quicken the response of the actuator.
Inventors
- 👤 Motoo Uno
- 👤 Ikuo Takeuchi
- 👤 Kazuo Honma
- 👤 Akihiko Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:02
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/20; G05D16/2006; G05D16/2013; G05D16/2026; G05D16/2046; G05D16/2053; F; F15; F15B; F15B11/00; F15B11/02; F15B11/04; F15B11/042; F15B11/0426; F15B11/044; G05D3/00; G05D3/12; G05D3/14; G05D3/18; F15B2211/00; F15B2211/60; F15B2211/63; F15B2211/6303; F15B2211/6306; F15B2211/6313; F15B2211/665; F15B2211/6653; F15B2211/6656; F15B2211/70; F15B2211/705; F15B2211/7051; F15B2211/7052; F15B2211/76; Y; Y10; Y10S; Y10S91/00; Y10S91/01
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
299 words
A control apparatus for an actuator responsive to fluid pressure therein including a plurality of actuator drivers connected to said actuator and controlled in accordance with an error voltage signal indicating the difference between a pressure reference signal and a pressure feedback signal of said actuator and wherein operation of said actuator is controlled by fluid pressure supplied thereto by said plurality of actuator drivers, comprising: pressure reference signal generator means for providing a reference voltage signal corresponding to a pressure refrence; pressure sensor means for providing a pressure signal based on the pressure in said actuator; error voltage producing means, coupled to said pressure reference signal generator means and said pressure sensor means, for producing an error voltage signal as a function of the difference between the reference voltage signal from said pressure reference signal generator means and the pressure signal from said pressure sensor means; oscillator means for generating a plurality of phase-shifted carrier wave signals corresponding in number to the number of said actuator dirvers; and pulse width modulation means, coupled to receive said plurality of carrier wave signals from said oscillator means and said error voltage signal from said error voltage producing means, for producing a plurality of trains of pulse signals corresponding to the number of said drivers, being respectively out-of-phase with each other with a relative phase difference dependent upon the relative phase difference of said carrier wave signals and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of actuator drivers, whereby as a result of said plurality of actuator drivers being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 2
Dependent Claim
299 words
A control apparatus for an actuator responsive to fluid pressure therein including a plurality of actuator drivers connected to said actuator and controlled in accordance with an error voltage signal indicating the difference between a pressure reference signal and a pressure feedback signal of said actuator and wherein operation of said actuator is controlled by fluid pressure supplied thereto by said plurality of actuator drivers, comprising: pressure reference signal generator means for providing a reference voltage signal corresponding to a pressure refrence; pressure sensor means for providing a pressure signal based on the pressure in said actuator; error voltage producing means, coupled to said pressure reference signal generator means and said pressure sensor means, for producing an error voltage signal as a function of the difference between the reference voltage signal from said pressure reference signal generator means and the pressure signal from said pressure sensor means; oscillator means for generating a plurality of phase-shifted carrier wave signals corresponding in number to the number of said actuator dirvers; and pulse width modulation means, coupled to receive said plurality of carrier wave signals from said oscillator means and said error voltage signal from said error voltage producing means, for producing a plurality of trains of pulse signals corresponding to the number of said drivers, being respectively out-of-phase with each other with a relative phase difference dependent upon the relative phase difference of said carrier wave signals and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of actuator drivers, whereby as a result of said plurality of actuator drivers being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 3
Dependent Claim
17 words
A control apparatus for an actuator according to claim 1, wherein said control valves comprise three-way valves.
Claim 4
Dependent Claim
38 words
A control apparatus for an actuator according to claim 1, wherein said actuator comprises a single acting actuator including a fluid chamber and which operates in one direction in response to fluid pressure action in the fluid chamber.
Claim 5
Dependent Claim
36 words
A control apparatus for an actuator according to claim 3, wherein said plurality of actuator drivers comprise control valves which are respectively incorporated in branched pipelines connected in common to the fluid chamber of said actuator.
Claim 6
Dependent Claim
32 words
A control apparatus for an actuator according to claim 4, wherein respective ones of said trains of pulse signals are supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 7
Dependent Claim
17 words
A control apparatus for an actuator according to claim 4, wherein said control valves comprise three-way valves.
Claim 8
Dependent Claim
111 words
A control apparatus for an actuator according to claim 4, wherein said plurality of phase-shifted carrier wave signals are pulse shaped waveforms and said pulse width modulation circuit means comprises a plurality of decrement counters and flip-flop circuits, corresponding in number to the number of said actuator drivers, wherein said decrement counters, responsive to said rectangular carrier wave signals and said error voltage signal, are connected to feed pulses generated therefrom to said flip-flop circuits, and said flip-flop circuits produce respective trains of pulse signals which are respectively phase-shifted and which have duty ratios proportional to said error voltage signal based on respective countdown magnitudes of said plurality of decrement counters.
Claim 9
Dependent Claim
20 words
A control apparatus for an actuator according to claim 7, wherein said error voltage producing means comprises a digital subtractor.
Claim 10
Dependent Claim
31 words
A control apparatus for an actuator according to claim 8, wherein respective ones of said trains of pulse signals supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 11
Dependent Claim
81 words
A control apparatus for an actuator according to claim 4, wherein said plurality of phase-shifted carrier wave signals are triangular shaped waveforms and said pulse width modulation circuit means comprises a plurality of comparators, corresponding in number to the number of said actuator drivers for producing respective trains of phase-shfited pulse signals, each having respective duty ratio proportional to said error voltage signal, in response to a respective one of said triangular shaped carrier wave signals and said error voltage signal.
Claim 12
Dependent Claim
20 words
A control apparatus for an actuator according to claim 10, wherein said error voltage producing means comprises an operational amplifier.
Claim 13
Dependent Claim
31 words
A control apparatus for an actuator according to claim 11, wherein respective ones of said trains of pulse signals supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 14
Dependent Claim
17 words
A control apparatus for an actuator according to claim 12, wherein said control valves comprise three-way valves.
Claim 15
Dependent Claim
218 words
A control apparatus for a single action actuator having a fluid chamber, including a plurality of control valves for operating the actuator and width are controlled in accordance with an error voltage signal producing means between a pressure reference signal and a pressure feedback signal corresponding to the pressure in said fluid chamber of the actuator and wherein operation of the actuator is controlled by fluid pressure in response to said plurality of control valves, comprising: an oscillator for generating a plurality of phase-shifted carrier wave signals corresponding to the number of said control valves; and a plurality of pulse width modulation circuits, responsive to said carrier wave signals and said error voltage signal, for outputting a plurality of phase-shifted trains of pulse signals having a relative phase difference dependent upon the relative phase difference of said plurality of carrier wave signals and being equal in number to the number of said control valves and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of control valves, whereby as a result of said plurality of control valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 16
Dependent Claim
218 words
A control apparatus for a single action actuator having a fluid chamber, including a plurality of control valves for operating the actuator and width are controlled in accordance with an error voltage signal producing means between a pressure reference signal and a pressure feedback signal corresponding to the pressure in said fluid chamber of the actuator and wherein operation of the actuator is controlled by fluid pressure in response to said plurality of control valves, comprising: an oscillator for generating a plurality of phase-shifted carrier wave signals corresponding to the number of said control valves; and a plurality of pulse width modulation circuits, responsive to said carrier wave signals and said error voltage signal, for outputting a plurality of phase-shifted trains of pulse signals having a relative phase difference dependent upon the relative phase difference of said plurality of carrier wave signals and being equal in number to the number of said control valves and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of control valves, whereby as a result of said plurality of control valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 17
Dependent Claim
31 words
A control apparatus for an actuator according to claim 14, wherein respective ones of said trains of pulse signals supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 18
Dependent Claim
107 words
A control apparatus for an actuator according to claim 14, wherein said plurality of phase-shifted carrier wave signals are pulse shaped waveforms and said pulse width modulation circuit means comprises a plurality of decrement counters and flip-flop circuits, corresponding in number to the number of said control valves, wherein said decrement counters, responsive to said rectangular carrier wave signals and said error voltage signal, are connected to feed pulses generated therefrom to said flip-flop circuits, and said flip-flop circuits produce respective phase-shifted trains of pulse signals having respective duty ratios proportional to said error voltage signal based on respective countdown magnitudes of said plurality of decrement counters.
Claim 19
Dependent Claim
32 words
A control apparatus for an actuator according to claim 16, wherein respective ones of said trains of pulse signals are supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 20
Dependent Claim
17 words
A control apparatus for an actuator according to claim 14, wherein said control valves comprise three-way valves.
Claim 21
Dependent Claim
32 words
A control apparatus for an actuator according to claim 18, wherein said plurality of three-way valves are respectively incorporated in branched pipelines connected in common to the fluid chamber of said actuator.
Claim 22
Dependent Claim
83 words
A control apparatus for an actuator according to claim 14, wherein said plurality of phase-shifted carrier wave signals consist of triangular shaped waveforms and said plurality of pulse width modulation circuits comprise a plurality of comparators, corresponding in number to the number of said control valves for producing respective trains of phase-shifted pulse signals, each having a duty ratio proportional to said error voltage signal, in response to a respective one of said triangular shaped carrier wave signals and said error voltage signal.
Claim 23
Dependent Claim
145 words
A control apparatus for an actuator according to claim 20, wherein said plurality of pulse width modulation circuits include a first comparator, responsive to said error voltage signal and a first of said plurality of carrier wave signals, supplying a first of said plurality of control valves with a respective first train of pulses having a duty ration proportional to said error voltage signal and a second comparator, responsive to said error voltage signal and a second of said plurality of carrier wave signals, supplying a second one of said plurality of control valves with a second train of pulses phase-shifted with respect to said first train of pulses and having a duty ratio proportional to said error voltage signal and being phase-shifted relative to said first train of pulses in dependence upon the relative phase difference of said first and second carrier wave signals.
Claim 24
Dependent Claim
31 words
A control apparatus for an actuator according to claim 21, wherein respective ones of said trains of pulses are supplied to respective ones of said control valves via corresponding power amplifiers.
Claim 25
Dependent Claim
26 words
A control apparatus for an actuator according to claim 22, wherein said first and second carrier wave signals having a relative phase shift of about 180°.
Claim 26
Dependent Claim
24 words
A control apparatus for an actuator according to claim 23, wherein said first and second control valves comprise first and second three-way valves, respectively.
Claim 27
Dependent Claim
33 words
A control apparatus for an actuator according to claim 24, wherein said first and second three-way valves are respectively incorporated in branched pipelines connected in common to the fluid chamber of said actuator.
Claim 28
Dependent Claim
288 words
A control apparatus for an actuator responsive to fluid pressure therein including a plurality of three-way valves connected to said actuator and controlled in accordance with an error voltage signal indicating the difference between a pressure reference signal and a pressure feedback signal of said actuator and wherein operation of said actuator is controlled by fluid pressure supplied thereto by said plurality of three-way valves, comprising: pressure reference signal generator means for providing a reference voltage signal corresponding to a pressure reference; pressure sensor means for providing a pressure signal based on the pressure in said actuator; error voltage producing means, coupled to said pressure reference signal generator means and said pressure sensor means, for producing an error voltage signal as a function of the difference between the reference voltage signal from said pressure reference signal generator means and the pressure signal from said pressure sensor means; oscillator means for generating a plurality of phase-shifted carrier wave signals corresponding in number to the number of said three-way control valves; and pulse width modulation means, coupled to receive said plurality of carrier wave signals from said oscillator means and said error voltage signal from said error voltage producing means, for producing a plurality of trains of pulse signals corresponding to the number of said three-way control valves, being respectively out-of-phase with each other and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of three-way control valves, whereby as a result of said plurality of three-way control valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 29
Dependent Claim
288 words
A control apparatus for an actuator responsive to fluid pressure therein including a plurality of three-way valves connected to said actuator and controlled in accordance with an error voltage signal indicating the difference between a pressure reference signal and a pressure feedback signal of said actuator and wherein operation of said actuator is controlled by fluid pressure supplied thereto by said plurality of three-way valves, comprising: pressure reference signal generator means for providing a reference voltage signal corresponding to a pressure reference; pressure sensor means for providing a pressure signal based on the pressure in said actuator; error voltage producing means, coupled to said pressure reference signal generator means and said pressure sensor means, for producing an error voltage signal as a function of the difference between the reference voltage signal from said pressure reference signal generator means and the pressure signal from said pressure sensor means; oscillator means for generating a plurality of phase-shifted carrier wave signals corresponding in number to the number of said three-way control valves; and pulse width modulation means, coupled to receive said plurality of carrier wave signals from said oscillator means and said error voltage signal from said error voltage producing means, for producing a plurality of trains of pulse signals corresponding to the number of said three-way control valves, being respectively out-of-phase with each other and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of three-way control valves, whereby as a result of said plurality of three-way control valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 30
Dependent Claim
34 words
A control apparatus for an actuator according to claim 26, wherein said plurality of three-way control valves are respectively incorporated in branched pipelines connected in common to control the fluid pressure in said actuator.
Claim 31
Dependent Claim
203 words
A control apparatus for a single action actuator having a fluid chamber, including a plurality of three-way control valves for operating the actuator and which are controlled i n accordance with an error voltage signal producing means between a pressure reference signal and a pressure feedback signal corresponding to the pressure in said fluid chamber of the actuator and wherein operation of the actuator is controlled by fluid pressure in response to said plurality of three-way control valves, comprising: an oscillator for generating a plurality of phase-shifted carrier wave signals corresponding to the number of said control valves; and a plurality of pulse width modulation circuits, responsive to said carrier wave signals and said error voltage signal, for outputting a plurality of phase-shifted trains of pulse signals equal in number to the number of said three-way control valves and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of three-way control valves, whereby as a result of said plurality of three-way valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 32
Dependent Claim
203 words
A control apparatus for a single action actuator having a fluid chamber, including a plurality of three-way control valves for operating the actuator and which are controlled i n accordance with an error voltage signal producing means between a pressure reference signal and a pressure feedback signal corresponding to the pressure in said fluid chamber of the actuator and wherein operation of the actuator is controlled by fluid pressure in response to said plurality of three-way control valves, comprising: an oscillator for generating a plurality of phase-shifted carrier wave signals corresponding to the number of said control valves; and a plurality of pulse width modulation circuits, responsive to said carrier wave signals and said error voltage signal, for outputting a plurality of phase-shifted trains of pulse signals equal in number to the number of said three-way control valves and each having a duty ratio proportional to said error voltage signal for respectively controlling each of said plurality of three-way control valves, whereby as a result of said plurality of three-way valves being controllably actuated by said plurality of phase-shifted trains of pulse signals, there results in enhanced control of said actuator by effectively increasing the frequency of the carrier wave for said actuator.
Claim 33
Dependent Claim
32 words
A control apparatus for an actuator according to claim 28, wherein said plurality of three-way valves are respectively incorporated in branched pipelines connected in common to the fluid chamber of said actuator.
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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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |