Signal amplifier, phase detector, and motor drive controller

Patent metadata

Field	Value
Publication number	US-9647586-B2
Application number	US-201514682352-A
Country	US
Kind code	B2
Filing date	Apr 9, 2015
Priority date	Apr 21, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A signal amplifier for a phase detector, based on plural sensor signals having amplitude levels in accordance with a rotational position of a rotor of a motor to detect the rotational position thereof includes a first phase detector; a phase counter; a signal amplification factor operation circuit; a signal amplification factor controller; and a signal amplification unit.

First claim

What is claimed is:

1. A signal amplifier for a phase detector generating a phase information signal, based on plural sensor signals having amplitude levels in accordance with a rotational position of a rotor of a motor having a plural-phase coil to detect the rotational position thereof, comprising:
an amplitude detector configured to detect or estimate, for each sensor signal amongst the plural sensor signals, a peak level of the sensor signal, for each signal amplification section amongst plural signal amplification sections into which a phase of the sensor signal is divided by a predetermined number in accordance with a number of poles of the motor, based on a signal level of the sensor signal, to produce a result signal; and
a signal amplification unit configured to adjust an amplitude level of each of the sensor signals, for said each signal amplification section amongst the signal amplification sections, such that the detected or estimated peak level of the sensor signal for said each signal amplification section amongst the signal amplification sections has a specified amplitude level corresponding to the signal amplification section.

2. The signal amplifier of claim 1 , further comprising:
a signal amplification factor operation circuit configured to operate a signal amplification factor of each of the sensor signals for said each signal amplification section such that the detected or estimated peak level of the sensor signal represented by the result signal from the amplitude detector has a specified amplitude level,
a signal amplification factor controller configured to store and produce the signal amplification factor,
wherein the signal amplifier amplifies the amplitude level of the sensor signal, based on the signal amplification factor.

3. The signal amplifier of claim 1 , further comprising:
a phase counter configured to count the number of the phases to determine the signal amplification section, based on the signal levels of the plural sensor signals,
wherein the signal amplifier distinguishes said each signal amplification section of the sensor signal that divide the phase of the sensor signal by the predetermined number in accordance with the number of poles of the motor, using the number of phases counted by the phase counter.

4. A position detector, comprising:
the signal amplifier according to claim 1 ;
a signal selector configured to select and produce one selection signal from the plural sensor signals for each phase section determined by comparing the plural sensor signals with each other, amplified by the signal amplification unit; and
a second phase detector configured to compare the selection signal with plural threshold levels to produce a second phase information signal representing a rotational angle smaller than a rotational angle of the rotor.

5. A motor drive controller, comprising the signal amplifier according to claim 1 .

6. The signal amplifier of claim 2 , wherein the signal amplification factor controller determines the signal amplification section, based on pole number information representing the number of poles of the motor.

7. The signal amplifier of claim 3 , further comprising:
a first phase detector configured to compare the signal level of the sensor signal with a specified threshold level to detect a phase and produce a first phase information signal,
wherein the phase counter counts the number of the phases, based on the first information signal.

8. The position detector of claim 4 , wherein the sensor signal or the relevant signal selected by the signal selector is a continuous signal at a border of the divided phase section having an interval of electric angle of 30° or 60° of the motor.

9. The position detector of claim 4 , further comprising a synthesizer configured to synthesize the phase information signal to produce a one-phase digital signal used as a motor drive control signal.

10. A motor drive controller, comprising the position detector according to claim 4 .

11. The signal amplifier of claim 6 , wherein the pole number information is previously stored in the signal amplification factor controller, input from the outside of the signal amplifier or detected on the basis of periodicity of each of the sensor signals.

12. The signal amplifier of claim 11 , wherein the pole number information is determined from a total of a maximum value and a minimum value of each of the sensor signals in one cycle, based on periodicity of each of the sensor signals.

13. A method of detecting a rotational position of a rotor of a motor with a signal amplifier, based on plural sensor signals having amplitude levels in accordance with the rotational position thereof, comprising:
detecting or estimating, for each sensor signal amongst the plural sensor signals and with an amplitude detector, a peak level of the sensor signal, for each signal amplification section amongst plural signal amplification sections into which a phase of the sensor signal is divided by a predetermined number in accordance with a number of poles of the motor, based on a signal level of the sensor signal to produce a result signal; and
adjusting, with a signal amplification unit, an amplitude level of each of the sensor signals, for said each signal amplification section amongst the signal amplification sections, such that the detected or estimated peak level of the sensor signal for said each signal amplification section amongst the signal amplification sections has a specified amplitude level corresponding to the signal amplification section.

Assignees

• Tatebe Tetsuroh
• Ricoh Co Ltd

Inventors

• Tatebe Tetsuroh

Classifications

• H02P6/16 Primary

  Circuit arrangements for detecting position · CPC title