Systems and methods for determining rotational position
AssigneeHamilton Sundstrand Corporation
InventorsGary L. Hess, Kanwalpreet Reen
Life of this patent
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Abstract
A resolver system includes a rotatable primary winding, a secondary winding fixed relative to the primary winding, and an analog-to-digital converter electrically connected to the secondary winding. A control module is operatively connected to analog-to-digital converter and is responsive to instructions to apply an excitation voltage with an oscillating waveform to the primary winding, induce a secondary voltage using the secondary winding using the excitation voltage, and acquire a plurality of voltage measurements from the secondary winding separated by a time interval corresponding to π/3 of the excitation voltage oscillating waveform.
Claims16
A resolver system, comprising:
- a rotatable primary winding;
- a secondary winding fixed relative to the primary winding;
- an analog-to-digital converter electrically connected to the secondary winding;
- and
- a control module operably connected to the analog-to-digital converter, the control module being configured to:
- apply an excitation voltage having a periodic waveform to the primary winding;
- induce a secondary voltage having a periodic waveform in the secondary winding using the excitation voltage;
- and
- acquire three or more secondary voltage measurements separated within one-half a period of the periodic waveform of the excitation voltage corresponding to π/3 of one-half the period of the periodic waveform of the excitation voltage from the secondary winding, wherein a root mean square voltage determination is insensitive to an initial phase offset between the periodic waveform of the primary winding and the periodic waveform of the secondary winding, and wherein root mean square voltage
- determination is phase independent, and is defined by
- RMS
- =
- (
- V
- ·
- sin
-
- (
- ϕ
- )
- )
- 2
- +
- (
- V
- ·
- sin
-
- (
- π
- 3
- +
- ϕ
- )
- )
- 2
- +
- (
- V
- ·
- sin
-
- (
- 2
-
- π
- 3
- +
- ϕ
- )
- )
- 2
- 3
- where RMS is root-mean-square, V is voltage, and φ is phase shift.
A method determining rotational position of a rotating component, comprising:
- applying an excitation voltage having a periodic waveform to a primary winding;
- inducing a secondary voltage having a periodic waveform in a secondary winding using the excitation voltage;
- and
- acquiring three or more secondary voltage measurements from the secondary winding separated within one-half a period of the periodic waveform of the excitation voltage corresponding to π/3 of one-half the period of the periodic waveform of the excitation voltage, wherein a root mean square voltage determination is insensitive to an initial phase offset between the periodic waveform of the primary winding and the periodic waveform of the secondary winding, and wherein root mean square voltage
- determination is phase independent, and is defined by
- RMS
- =
- (
- V
- ·
- sin
-
- (
- ϕ
- )
- )
- 2
- +
- (
- V
- ·
- sin
-
- (
- π
- 3
- +
- ϕ
- )
- )
- 2
- +
- (
- V
- ·
- sin
-
- (
- 2
-
- π
- 3
- +
- ϕ
- )
- )
- 2
- 3
- where RMS is root-mean-square, V is voltage, and φ is phase shift.
Dependencies are inferred from the claim text.