US5760562A
Expired / Lapsed
US
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Apparatus and method for generating digital position signals for a rotatable shaft
Assignee: PacSci Motion Control Inc
•
Filing: 1997-06-05
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Granted: 1998-06-02
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Expires: 2017-06-05
Abstract
Abstract An apparatus and method for generating digital electrical signals which are representative of the angular position and rotational velocity of a rotatable shaft component in a servomechanism includes a resolver which is connected to the rotatable component. The resolver generates analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of the electrical angular or position of the motor. The output signals from the resolver are fed to a digital signal processing circuit which employs software algorithm techniques to define a plurality of tasks which are implemented sequentially to obtain the desired angular position and velocity signals. First, the sine and cosine signals are read from the resolver through respective analog-to-digital converters. The sine and cosine signals are demodulated by multiplication with the excitation signal, and the undesired higher frequency components are deleted by filtering. Then, the demodulated sine and cosine signals are conditioned to insure quadrature and to correct for amplitude and offset variations. Next, an electrical angular position signal for the rotatable member is determined by combining the demodulated and conditioned sine and cosine signals, and a correction is made for repeatable harmonic errors. A calculation is then made to determine the rotational velocity of the rotatable member. The electrical angular position signal is next corrected for velocity related errors to generate an actual electrical position signal. Lastly, an actual mechanical position signal for the rotatable member is calculated.
Inventors
- 👤 Lane L. Woodland
- 👤 Daryl J. Marvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:17
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/33; G08; G08C; G08C19/00; G08C19/38; G08C19/46; G05B2219/00; G05B2219/30; G05B2219/37; G05B2219/37313; G05B2219/37473
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
104 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to insure quadrature and to correct for amplitude variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 2
Independent Claim
104 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to insure quadrature and to correct for amplitude variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 3
Dependent Claim
46 words
The method defined in claim 1 wherein the steps of demodulating the sine and cosine signals, adaptively conditioning the demodulated sine and cosine signals, determining a velocity signal, determining an actual electrical position signal, and determining an actual mechanical position signal, are all embodied as software.
Claim 4
Dependent Claim
27 words
The method defined in claim 1 comprising the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 5
Dependent Claim
26 words
The method defined in claim 1 comprising the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 6
Dependent Claim
29 words
The method defined in claim 1 wherein the amplitude of the demodulated sine and cosine signals is corrected based upon updated amplitude information by defining initial conditions for amplitude.
Claim 7
Dependent Claim
29 words
The method defined in claim 1 including the step of determining a value for an electrical angle of the movable member, using the adaptively conditioned sine and cosine signals.
Claim 8
Dependent Claim
16 words
The method defined in claim 6 including the step of correcting the value for harmonic errors.
Claim 9
Independent Claim
104 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to insure quadrature and to correct for offset variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 10
Independent Claim
104 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to insure quadrature and to correct for offset variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 11
Dependent Claim
46 words
The method defined in claim 8 wherein the steps of demodulating the sine and cosine signals, adaptively conditioning the demodulated sine and cosine signals, determining a velocity signal, determining an actual electrical position signal, and determining an actual mechanical position signal, are all embodied as software.
Claim 12
Dependent Claim
27 words
The method defined in claim 8 comprising the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 13
Dependent Claim
26 words
The method defined in claim 8 comprising the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 14
Dependent Claim
29 words
The method defined in claim 8 wherein the offset of the demodulated sine and cosine signals are corrected based upon updated offset information by defining initial conditions for offset.
Claim 15
Dependent Claim
29 words
The method defined in claim 8 including the step of determining a value for an electrical angle of the movable member, using the adaptively conditioned sine and cosine signals.
Claim 16
Dependent Claim
16 words
The method defined in claim 13 including the step of correcting the value for harmonic errors.
Claim 17
Independent Claim
102 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to correct for amplitude and offset variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 18
Independent Claim
102 words
A method for generating signals which are representative of the position and velocity of a movable member comprising: generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; demodulating the sine and cosine signals by multiplication with the excitation signal; adaptively conditioning the demodulated sine and cosine signals to correct for amplitude and offset variations; determining a velocity signal for the movable member; determining an actual electrical position signal for the movable member; and determining an actual mechanical position signal for the movable member.
Claim 19
Dependent Claim
46 words
The method defined in claim 15 wherein the steps of demodulating the sine and cosine signals, adaptively conditioning the demodulated sine and cosine signals, determining a velocity signal, determining an actual electrical position signal, and determining an actual mechanical position signal, are all embodied as software.
Claim 20
Dependent Claim
27 words
The method defined in claim 15 comprising the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 21
Dependent Claim
26 words
The method defined in claim 15 comprising the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 22
Dependent Claim
29 words
The method defined in claim 15 wherein the offset of the demodulated sine and cosine signals are corrected based upon updated offset information by defining initial conditions for offset.
Claim 23
Dependent Claim
29 words
The method defined in claim 15 including the step of determining a value for an electrical angle of the movable member, using the adaptively conditioned sine and cosine signals.
Claim 24
Dependent Claim
16 words
The method defined in claim 20 including the step of correcting the value for harmonic errors.
Claim 25
Independent Claim
152 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to insure quadrature and to correct for amplitude variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 26
Independent Claim
152 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to insure quadrature and to correct for amplitude variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 27
Dependent Claim
32 words
The apparatus defined in claim 22 wherein the software based circuit executes the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 28
Dependent Claim
31 words
The apparatus defined in claim 22 wherein the software based circuit executes the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 29
Dependent Claim
29 words
The apparatus defined in claim 22 wherein the amplitude of the demodulated sine and cosine signals are corrected based upon updated amplitude information by defining initial conditions for amplitude.
Claim 30
Independent Claim
152 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to insure quadrature and to correct for offset variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 31
Independent Claim
152 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to insure quadrature and to correct for offset variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 32
Dependent Claim
32 words
The apparatus defined in claim 26 wherein the software based circuit executes the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 33
Dependent Claim
31 words
The apparatus defined in claim 26 wherein the software based circuit executes the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 34
Dependent Claim
33 words
The apparatus defined in claim 26 wherein the offset of the demodulated sine and cosine signals are corrected based upon updated amplitude and offset information by defining initial conditions for amplitude and offset.
Claim 35
Independent Claim
150 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to correct for amplitude and offset variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 36
Independent Claim
150 words
An apparatus for generating signals which are representative of the position and velocity of a movable member comprising: a resolver for generating analog electrical output signals which are representative of an excitation signal modulated by both the sine and cosine of an electrical angular position of the movable member; and a software based circuit for correcting time varying errors in the sine and cosine signals and converting the corrected signals to digital electrical output signals which are representative of the position and velocity of the movable member, said software based circuit being effective to demodulate the sine and cosine signals by multiplication with the excitation signal, adaptively condition the demodulated sine and cosine signals to correct for amplitude and offset variations, determine a velocity signal for the movable member, determine an actual electrical position signal for the movable member, and determine an actual mechanical position signal for the movable member.
Claim 37
Dependent Claim
32 words
The apparatus defined in claim 30 wherein the software based circuit executes the additional step of introducing a predetermined phase shift into the excitation signal before demodulating the sine and cosine signals.
Claim 38
Dependent Claim
31 words
The apparatus defined in claim 30 wherein the software based circuit executes the additional step of removing extraneous higher frequency components from the sine and cosine signals after demodulating the signals.
Claim 39
Dependent Claim
35 words
The apparatus defined in claim 30 wherein the amplitude and offset of the demodulated sine and cosine signals are corrected based upon updated amplitude and offset information by defining initial conditions for amplitude and offset.
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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) | 2001-06-01 | 2001-12-01 | 2002-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-01 | 2005-12-01 | 2006-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-01 | 2009-12-01 | 2010-06-02 | $7700.00 | Window Closed / Lapsed |