SIGNAL CONVERTER AND CONTROL DEVICE

• US 20180324011A1
• Filed: 07/13/2018
• Published: 11/08/2018
• Est. Priority Date: 08/05/2015
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: SHIMIZU, Yuji, HIROSHIMA, Akane, ONO, Yutaka
• Granted Patent: US 10,158,507 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2053 using more than one carrier, e.g. carriers with different phases
• CPC Class Codes: H04L 7/0008 Synchronisation information channels, e.g. clock distribution lines

Abstract

A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Claims

1. A method for converting signals by a resolver comprising the steps of:

detecting two-phase signals excited by a carrier signal having a carrier frequency fc;

shifting a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc;

shifting a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc; and

combining the phase-shifted first phase signal with the phase-shifted second phase signal and outputting a phase-modulated signal where the carrier signal is modulated by a rotation angle of the resolver.

2. The method for converting signals according to claim 1, wherein each of the first and second phase shifting includes all-pass filtering.

3. The method for converting signals according to claim 1, wherein relations “

f1=fc/n” and

“

f2=fc×

n”

(where n is an arbitrary positive real number) are satisfied.

4. The method for converting signals according to claim 1, wherein a difference between a phase shift φ

1 by the first phase shifting and a phase shift φ

2 by the second phase shifting is roughly 90°

.

5. The method for converting signals according to claim 1, further comprising the step of:

band-pass filtering that attenuates, for the phase-modulated signal, a signal component outside a predetermined frequency range centered on the carrier frequency fc.

6. The method for converting signals according to claim 1, wherein, for four-phase signals having phases mutually different from one another by roughly 90°

, detected by the resolver excited by the carrier frequency fc, further comprising the steps of;

shifting a phase of a signal obtained by combining first and third phase signals of the resolver, the first and third phase signals having phases different from each other by roughly 180°

, and

shifting a phase of a signal obtained by combining second and fourth phase signals of the resolver, the second and fourth phase signals having phases different from each other by roughly 180°

.

7. The method for converting signals according to claim 1, further comprising the steps of:

generating a correction signal for cancelling out a ripple component caused by the carrier signal of the resolver; and

superposing the correction signal on the phase-modulated signal.

8. The method for converting signals according to claim 1, further comprising the steps of:

synchronously wave-detecting the phase-modulated signal at the carrier frequency fc and outputting a synchronously wave-detected signal;

calculating a ripple component based on a differential value of a synchronously wave-detected signal;

generating a correction signal with a phase and an amplitude by which the ripple component is minimized; and

superposing the correction signal on the phase-modulated signal.

9. A method for controlling a motor comprising the steps of:

detecting two-phase signals excited by a carrier signal having a carrier frequency fc,

shifting a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc;

shifting a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc;

combining the phase-shifted first phase signal with the phase-shifted second phase signal and outputs a phase-modulated signal where the carrier signal is modulated by a rotation angle of the resolver;

synchronously wave-detecting the phase-modulated signal at the carrier frequency fc and outputting a synchronously wave-detected signal; and

controlling the motor based on a synchronously wave-detected signal.

10. The method for controlling a motor according to claim 9, wherein, for four-phase outputs having phases mutually different from one another by roughly 90°

, detected by the resolver excited by the carrier frequency fc, further comprising the steps of;

shifting a phase of a signal obtained by combining first and third phase signals of the resolver, the first and third phase signals having phases different from each other by roughly 180°

; and

shifting a phase of a signal obtained by combining second and fourth phase signals of the resolver, the second and fourth phase signals having phases different from each other by roughly 180°

.

11. The method for controlling a motor according to claim 9, further comprising the steps of:

generating a correction signal for cancelling out a ripple component caused by the carrier signal of the resolver; and

superposing the correction signal on the phase-modulated signal.