US4358723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring the rotation of a work table
Assignee: NEISE MODERN TOOLS Inc A CORP OF NEW YORK
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Filing: 1980-08-29
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Granted: 1982-11-09
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Expires: 2000-08-29
Abstract
Abstract A device for measuring the rotation of a member includes an angular error sensor having a movable sensor element connected to the rotatable member and a pair of guadrature-spaced stationary elements for inducing the error in the sensor element. A detector measures the polarity and amplitude of the error and delivers it to a processor that accumulates successive error signals. The accumulated signal is averaged, corrected and displayed as the measurement. Also the accumulated signal is used to control a set of multiplier devices that create different driving signals from a single signal source for application to the guadrature elements of the error sensor. The output of these multiplier devices is controlled by the processor such that the error signal is driven toward zero.
Inventors
- 👤 Jule A. Scholl
- 👤 Paul F. Fitts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:39
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/121; G01; G01D; G01D1/00; G01D1/02; H; H03; H03M; H03M1/00; H03M1/12; H03M1/22; H03M1/66; H03M1/668
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
223 words
Apparatus for measuring the rotation of a member, comprising: an angular error sensor means including a movable sensor element and at least one pair of elements forming at least one stationary arrangement, said stationary elements having a quadrature spaced relation to each other, said movable element being connected to said member for rotation therewith, said stationary quadrature elements being adapted to receive a first signal for one element and a second signal phase-shifted by 90° from the first signal for the other element, and said movable sensor element being adapted to produce an error signal based on the angular position of the movable element with respect to the stationary arrangement; detector means for detecting the polarity and amplitude of the error signals; processor means for accumulating the error signals in a raw data counter and applying a correction signal to the accumulated error signals in the raw data counter to form a linearized signal; display means for displaying the value of the corrected signal; signal generator means for creating an alternating current signal; and means for attenuating the alternating current to generate both the first and second reference signals, said means for attenuating being controlled by the value of the contents of the raw data counter of said processor means such that the error signal from the sensor means is driven toward zero.
Claim 2
Dependent Claim
223 words
Apparatus for measuring the rotation of a member, comprising: an angular error sensor means including a movable sensor element and at least one pair of elements forming at least one stationary arrangement, said stationary elements having a quadrature spaced relation to each other, said movable element being connected to said member for rotation therewith, said stationary quadrature elements being adapted to receive a first signal for one element and a second signal phase-shifted by 90° from the first signal for the other element, and said movable sensor element being adapted to produce an error signal based on the angular position of the movable element with respect to the stationary arrangement; detector means for detecting the polarity and amplitude of the error signals; processor means for accumulating the error signals in a raw data counter and applying a correction signal to the accumulated error signals in the raw data counter to form a linearized signal; display means for displaying the value of the corrected signal; signal generator means for creating an alternating current signal; and means for attenuating the alternating current to generate both the first and second reference signals, said means for attenuating being controlled by the value of the contents of the raw data counter of said processor means such that the error signal from the sensor means is driven toward zero.
Claim 3
Dependent Claim
34 words
Apparatus as claimed in claim 1 wherein the sensor means is a multiple pole resolver, the elements are windings of the resolver and the stationary arrangement is at least one pole of the resolver.
Claim 4
Dependent Claim
12 words
Apparatus as claimed in claim 2 wherein the resolver has 180 poles.
Claim 5
Dependent Claim
24 words
Apparatus as claimed in claims 2 or 3 wherein the stationary windings are in the form of cross-connected segments to reduce one-turn flux errors.
Claim 6
Dependent Claim
16 words
Apparatus as claimed in claims 1 or 2 wherein said detector means is a synchronous detector.
Claim 7
Dependent Claim
14 words
Apparatus as claimed in claims 1 or 2 wherein said processor is a microprocessor.
Claim 8
Dependent Claim
32 words
Apparatus as claimed in claim 1 or 2 wherein said means for attenuating are two linear multiplying digital to analog converters which are controlled according to a linear function by the processor.
Claim 9
Dependent Claim
77 words
Apparatus as claimed in claim 7 wherein said linear function is a trapezoid such that during two quarters of a cycle one converter is linearly increased or decreased in multiplying factor, while the other converter is held constant at a maximum or minimum level, and during the other two quarters of a cycle the other converter is linearly increased or decreased in multiplying factors while the one converter is held constant at a maximum or minimum level.
Claim 10
Dependent Claim
72 words
Apparatus as claimed in claims 1 or 2 wherein the accumulated error signals are averaged over a period of time to form an average value signal, the correction signal is from a linearization table of values chosen to compensate for driving the resolver with signals modulated according to a linear function instead of a sine function, and the correction signal is added to the average value signal to form the linearized signal.
Claim 11
Dependent Claim
38 words
Apparatus as claimed in claim 9 wherein the linearization table contains sixty-four values spread over one quadrant of operation and further including interpolation means for linearly interpolating between the sixty-four values and repeating the values for other quadrants.
Claim 12
Dependent Claim
42 words
Apparatus as claimed in claims 1 or 9 further including a table of sensor inherent correction values and means for adding the sensor correction values to the linearized signal, said sensor correction values being related to the inaccuracies manufactured into the resolver.
Claim 13
Dependent Claim
18 words
Apparatus as claimed in claim 1 wherein the member is a rotating work table of a machine tool.
Claim 14
Dependent Claim
19 words
Apparatus as claimed in claim 1 further including a keyboard means for inserting off set data into the display.
Claim 15
Independent Claim
141 words
A method of measuring the rotation of a member comprising the steps of: generating an error signal in a sensor means having a movable sensing element and quadrature spaced stationary elements; detecting the amplitude and polarity of the error signal; updating a raw data counter with the error signal in a direction determined by the polarity of the error signal and by an amount determined by the amplitude of the error signal; generating a reference signal and applying it to two multiplier circuits; controlling the multiplying factors of the two multiplying circuits in response to the contents of the raw data counter in a linear fashion so as to generate a first signal and a second signal which is phase shifted by 90° from the first; and applying the first and second signals to the quadrature elements of said sensor means.
Claim 16
Independent Claim
141 words
A method of measuring the rotation of a member comprising the steps of: generating an error signal in a sensor means having a movable sensing element and quadrature spaced stationary elements; detecting the amplitude and polarity of the error signal; updating a raw data counter with the error signal in a direction determined by the polarity of the error signal and by an amount determined by the amplitude of the error signal; generating a reference signal and applying it to two multiplier circuits; controlling the multiplying factors of the two multiplying circuits in response to the contents of the raw data counter in a linear fashion so as to generate a first signal and a second signal which is phase shifted by 90° from the first; and applying the first and second signals to the quadrature elements of said sensor means.
Claim 17
Dependent Claim
22 words
The method of claim 14 wherein the sensor means is a multiple pole resolver and the elements are windings of the resolver.
Claim 18
Dependent Claim
32 words
The method of claim 14 wherein the step of detecting the amplitude and polarity of the error signal is accomplished a synchronous detection based on a phase-shifted version of the reference signal.
Claim 19
Dependent Claim
66 words
The method of claim 14 further including the steps of averaging the contents of the raw data counter over a period of time to obtain an average count, applying a linearization correction to the average counts to obtain a linearized count compensated for driving the resolver with linear signals, and displaying a true count, related to the linearized count, as the angular position of the member.
Claim 20
Dependent Claim
43 words
The method of claim 17 further including the step of applying an inherent sensor error correction to the linearized count to create a corrected count compensated for errors in the manufacture of the resolver, said true count being related to the corrected count.
Claim 21
Independent Claim
26 words
The method of claims 14 or 18 further including the step of changing the format of the data prior to display in response to operator command.
Claim 22
Independent Claim
52 words
The method of claims 14, 17, or 18 further including the steps of generating a new position signal count from a keyboard, subtracting the new position count from the corrected count to produce an off set count, and adding the off set count to the corrected count to produce the true count.
References Cited (Backward Citations)
US3562740A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |