Patent US2307583A successfully refreshed from Google Patents.
US3854081A
Expired / Lapsed
US
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Servo error signal generator for numerical control systems
Assignee: Bendix Corp
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Filing: 1973-05-14
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Granted: 1974-12-10
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Expires: 1993-05-14
Abstract
Abstract A position error signal generator for use in position servo control systems wherein means are provided for generating a ramptype reference voltage having an amplitude which varies linearly with time between predetermined positive and negative values, means for producing a precisely located sample strobe signal which is shifted in time according to the shift in phase of a position signal and means for using the strobe signal to sample the linear reference such that the amplitude of the sampled signal is representative of a position error. In the preferred embodiment, means are provided for inverting half cycles of the linear reference voltage so as to effectively double the sampling rate but without loss of polarity significance as between leading the lagging error conditions. The subject device produces an essentially dc error signal which does not require filtering but which may be directly applied to the preamplifier of an N/C servo drive.
Inventors
- 👤 R Benaglio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:10
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/33; G05B2219/00; G05B2219/30; G05B2219/34; G05B2219/34188; G05B2219/41; G05B2219/41363
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
195 words
In a numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a stored program, a servo positioning apparatus comprising: first means operatively associated with said controlled element for producing a periodic signal quantity which varies in phase according to the position error of said controlled element relative to a commanded position; second means for producing a periodic reference signal in the form of an electrical voltage having an amplitude which varies linearly between maximum and minimum values over a period which is related to the period of said periodic signal quantity from said first means and of fixed phase and having a characteristic which varies substantially linearly over the period thereof, and third means interconnected with said first and second means for sampling and holding a quantity related to the instantaneous characteristic of said reference signal quantity upon the occurrence of said periodic signal quantity from said first means whereby the character of said reference quantity at the sample time represents the position error of said controlled element said first means including means for producing a sample strobe for each of said first periodic signal quantities.
Claim 2
Dependent Claim
195 words
In a numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a stored program, a servo positioning apparatus comprising: first means operatively associated with said controlled element for producing a periodic signal quantity which varies in phase according to the position error of said controlled element relative to a commanded position; second means for producing a periodic reference signal in the form of an electrical voltage having an amplitude which varies linearly between maximum and minimum values over a period which is related to the period of said periodic signal quantity from said first means and of fixed phase and having a characteristic which varies substantially linearly over the period thereof, and third means interconnected with said first and second means for sampling and holding a quantity related to the instantaneous characteristic of said reference signal quantity upon the occurrence of said periodic signal quantity from said first means whereby the character of said reference quantity at the sample time represents the position error of said controlled element said first means including means for producing a sample strobe for each of said first periodic signal quantities.
Claim 3
Dependent Claim
41 words
Apparatus as defined in claim 1 including inverter means for inverting substantially half cycles of said reference signal quantity at times related to said sample strobes whereby the sampled amplitudes are of consistent polarities for a given character of position error.
Claim 4
Dependent Claim
51 words
Apparatus as defined in claim 1 wherein said first means comprises a resolver for producing a substantially sinusoidal output quantity and a zero crossing detector connected to receive said output quantity for producing a substantially square waveform output having a phase which varies accordingly to the phase of the resolver output.
Claim 5
Dependent Claim
41 words
Apparatus as defined in claim 1 including gate means connected to receive said periodic signal quantity from said first means and operative to produce an alarm signal whenever said periodic signal quantity varies in periodicity by more than a predetermined amount.
Claim 6
Dependent Claim
41 words
Apparatus as defined in claim 4 wherein said gate means includes a retriggerable monostable signal generator having a period greater than the period of said periodic signal quantity, and logic gate means connected to receive the output of said signal generator.
Claim 7
Dependent Claim
40 words
Apparatus as defined in claim 1 wherein said second means comprises an integrator circuit having two inputs and an output, one of said inputs being connected to receive a periodic reference waveform which, when integrated, produces said linearly varying character.
Claim 8
Dependent Claim
41 words
Apparatus as defined in claim 6 including first and second precision voltage sources of opposite polarity and switch means connected between said sources and said one input to alternately apply the opposite polarity voltages from said sources to said one input.
Claim 9
Dependent Claim
66 words
Apparatus as defined in claim 1 wherein said third means includes a first stage having signal storage means operative to receive the sampled character of said linearly varying signal quantity, and a second stage connected to the first stage and having signal storage means operated complementally therewith to receive and hold the cumulative sampled quantities to produce a substantially continuous output quantity representing said position error.
Claim 10
Dependent Claim
19 words
Apparatus as defined in claim 8 wherein said signal storage means of the first and second stages include capacitors.
Claim 11
Dependent Claim
39 words
Apparatus as defined in claim 8 wherein said third means further comprises control means having an input connected to Receive said periodic signal quantity, and first and second complementary outputs connected to control said first and second stages, respectively.
Claim 12
Dependent Claim
174 words
In a numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a stored program, a servo positioning apparatus comprising: first means operatively associated with said controlled element for producing a periodic signal quantity which varies in phase according to the position error of said controlled element relative to a commanded position; second means for producing a periodic reference signal quantity of fixed phase and having a characteristic which varies substantially linearly over the period thereof, and third means interconnected with said first and second means for sampling and holding a quantity related to the instantaneous characteristic of said reference signal quantity upon the occurrence of said periodic signal quantity from said first means whereby the character of said reference quantity at the sample time represents the position error of said controlled element, said second element comprising an integrator circuit having two inputs and an output, one of said inputs being connected to receive a periodic reference waveform which, when integrated, produces said linearly varying character.
Claim 13
Dependent Claim
174 words
In a numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a stored program, a servo positioning apparatus comprising: first means operatively associated with said controlled element for producing a periodic signal quantity which varies in phase according to the position error of said controlled element relative to a commanded position; second means for producing a periodic reference signal quantity of fixed phase and having a characteristic which varies substantially linearly over the period thereof, and third means interconnected with said first and second means for sampling and holding a quantity related to the instantaneous characteristic of said reference signal quantity upon the occurrence of said periodic signal quantity from said first means whereby the character of said reference quantity at the sample time represents the position error of said controlled element, said second element comprising an integrator circuit having two inputs and an output, one of said inputs being connected to receive a periodic reference waveform which, when integrated, produces said linearly varying character.
Claim 14
Dependent Claim
41 words
Apparatus as defined in claim 11 including first and second precision voltage sources of opposite polarity and switch means connected between said sources and said one input to alternately apply the opposite polarity voltages from said sources to said one input.
Claim 15
Dependent Claim
176 words
A numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a program of position commands and comprising: a source of position commands, interpolator means for generating a digital pulse count representing the position command, a motor responsive to an input signal quantity of a substantially d.c. character to move the controlled element, first means operatively associated with the controlled element for producing a periodic strobe pulse which varies in phase according to the position error of the controlled element relative to the commanded count, second means for producing a linearly varying ramp voltage of fixed phase, means interconnected with the first and second means for sampling and holding the amplitude of the ramp voltage upon the occurrence of the strobe pulse whereby the amplitude of the ramp voltage at the sample time represents the position error of the controlled element, and means for applying a substantially d.c. signal quantity which is directly proportional to the sampled voltage amplitude to the motor means for moving the controlled element.
Claim 16
Dependent Claim
176 words
A numerical control system for controlling the position of a controlled element within a predetermined coordinate system according to a program of position commands and comprising: a source of position commands, interpolator means for generating a digital pulse count representing the position command, a motor responsive to an input signal quantity of a substantially d.c. character to move the controlled element, first means operatively associated with the controlled element for producing a periodic strobe pulse which varies in phase according to the position error of the controlled element relative to the commanded count, second means for producing a linearly varying ramp voltage of fixed phase, means interconnected with the first and second means for sampling and holding the amplitude of the ramp voltage upon the occurrence of the strobe pulse whereby the amplitude of the ramp voltage at the sample time represents the position error of the controlled element, and means for applying a substantially d.c. signal quantity which is directly proportional to the sampled voltage amplitude to the motor means for moving the controlled element.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |