US5834918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-tuning tracking controller for permanent-magnet synchronous motors
Assignee: Georgia Tech Research Corp
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Filing: 1996-04-01
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Granted: 1998-11-10
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Expires: 2016-04-01
Abstract
Abstract A self-tuning tracking controller for permanent-magnet synchronous motors is disclosed, providing for velocity or position trajectory tracking even when both the electrical and mechanical parameters of the motor, amplifier, and load are initially unknown. A time-scale simplification of a full-order mathematical model of the motor leads to a discrete-time design model that is reduced-order and that evolves in a mechanical time-scale which is substantially slower than the electrical time-scale, permitting implementation of the self-tuning tracking controller with a lower sampling frequency (and at a lower cost) than is typically expected. A piecewise-linear parameterization of the motor torque-angle characteristic functions allows for identification of higher-order harmonics with a degree of accuracy which is selectable by the user, without requiring more computation than traditional single-term sinusoidal descriptions. Excellent performance is achieved, even with very poor initial motor parameter knowledge.
Inventors
- 👤 David G. Taylor
- 👤 Kenneth R. Shouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:30
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/20; H02P6/34
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
95 words
A method for recursively estimating the parameters of a motor drive system, comprising the steps of: (a) selecting initial parameter estimates; (b) applying stator phase voltages; (c) measuring the rotor position, rotor velocity, and stator phase currents; (d) determining regressor vectors and associated output signals from the rotor position, rotor velocity, stator phase currents, and stator phase voltages; (e) determining estimation error signals from the parameter estimates, the regressor vectors, and the associated output signals; (f) updating the parameter estimates from the estimation error signals and the regressor vectors; (g) repeating steps (b) through (f).
Claim 2
Independent Claim
95 words
A method for recursively estimating the parameters of a motor drive system, comprising the steps of: (a) selecting initial parameter estimates; (b) applying stator phase voltages; (c) measuring the rotor position, rotor velocity, and stator phase currents; (d) determining regressor vectors and associated output signals from the rotor position, rotor velocity, stator phase currents, and stator phase voltages; (e) determining estimation error signals from the parameter estimates, the regressor vectors, and the associated output signals; (f) updating the parameter estimates from the estimation error signals and the regressor vectors; (g) repeating steps (b) through (f).
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the motor drive system consists of an electronic power converter, a permanent-magnet synchronous motor, and a mechanical load.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein the updated parameter estimates of step (f) are provided to a control system for purposes of guiding the instantaneous values of rotor position.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein the updated parameter estimates of step (f) are provided to a control system for purposes of guiding the instantaneous values of rotor velocity.
Claim 6
Dependent Claim
29 words
The method of claim 1 wherein the updated parameter estimates of step (f) are provided to a control system for purposes of guiding the instantaneous values of electric torque.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein the stator phase voltages of step (b) are determined in part from the parameter estimates of step (a) and step (f).
Claim 8
Dependent Claim
39 words
The method of claim 1 wherein the motor drive system is equipped with a shaft-mounted sensor to measure the rotor position and rotor velocity of step (c), and electrical sensors to measure the stator phase currents of step (c).
Claim 9
Dependent Claim
35 words
The method of claim 1 wherein the regressor vectors and associated output signals of step (d) are determined using a linearly parameterized predetermined model of the motor drive system, the model having unknown parameter values.
Claim 10
Dependent Claim
21 words
The method of claim 8 wherein the associated output signals represent the combined resistive and back-emf voltages and the electric torque.
Claim 11
Dependent Claim
23 words
The method of claim 8 wherein the predetermined model of the motor drive system is derived under the assumption of small stator inductances.
Claim 12
Dependent Claim
24 words
The method of claim 8 wherein the predetermined model of the motor drive system is derived under the assumption of large stator current gains.
Claim 13
Dependent Claim
29 words
The method of claim 1 wherein the estimation error signals of step (e) are determined by subtracting products of regressor vectors and parameter estimates from the associated output signals.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein the updated parameter estimates of step (f) comprise mechanical parameter estimates and electrical parameter estimates.
Claim 15
Dependent Claim
22 words
The method of claim 13 wherein the mechanical parameter estimates are associated with rotor inertia, load torque, cogging torque, and/or friction coefficients.
Claim 16
Dependent Claim
23 words
The method of claim 13 wherein the electrical parameter estimates are associated with stator inductances, stator resistances, electric torque coefficients, and/or back-emf coefficients.
Claim 17
Dependent Claim
38 words
The method of claim 13 wherein the updated parameter estimates are computed sequentially using a nested updated method, with the electrical parameter estimates computed first in independent fashion and the mechanical parameter estimates computed second in dependent fashion.
Claim 18
Dependent Claim
20 words
The method of claim 1 wherein the updated parameter estimates of step (f) are computed using a gradient update method.
Claim 19
Dependent Claim
14 words
The method of claim 17 wherein the gradient update method includes a normalization factor.
Claim 20
Dependent Claim
14 words
The method of claim 17 wherein the gradient update method includes a deadzone function.
Claim 21
Dependent Claim
18 words
The method of claim 17 wherein the regressor vectors of step (d) include piecewise approximations of nonlinear functions.
Claim 22
Dependent Claim
13 words
The method of claim 20 wherein the piecewise approximation are piecewise linear approximations.
Claim 23
Dependent Claim
13 words
The method of claim 20 wherein the piecewise approximations are piecewise polynomial approximations.
Claim 24
Dependent Claim
20 words
The method of claim 20 wherein only those parameters corresponding to the active segments of the piecewise approximations are updated.
References Cited (Backward Citations)
US4025837A
Cited
US4129813A
Cited
US4369400A
Cited
US4481457A
Cited
US4670698A
Cited
US4609855A
Cited
US4701839A
Cited
US4733149A
Cited
US4800325A
Cited
US5038090A
Cited
US5124625A
Cited
US5089757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-09 | 2002-05-11 | 2002-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-09 | 2006-05-11 | 2006-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-09 | 2010-05-11 | 2010-11-10 | $7700.00 | Window Closed / Lapsed |