US 8,917,041 B2 · Phase-shift detection device, motor drive device, brushless motor, and phase-shift detection method

Abstract

A phase-shift detection circuit detects a phase shift in motor driving, using pulse-shaped position detection signal Rd and measurement signal Ms. The position detection signal is based on sensor signal Hs from a position sensor disposed in a motor. The measurement signal is based on the induced voltage from windings. The phase-shift detection circuit includes a level difference calculator and a phase-shift calculator. The level difference calculator calculates a level difference between the level of measurement signal Ms at a rising timing of position detection signal Rd and the level of measurement signal Ms at a falling timing thereof. The phase-shift calculator calculates the amount of phase shifts based on the level difference.

Claims23

Dependent claims

A phase-shift detection device for detecting a phase shift caused by misalignment in rotational position detection of a motor that comprises:

a rotor and multi-phase drive coils;
and
magnetic pole position sensors, corresponding in number to the multi-phase drive coils, configured to detect positions of rotating magnetic poles of the rotor,
the phase-shift detection device comprising:
a measurement signal generator configured to output a sinusoidal measurement signal induced in one of the multi-phase drive coils during rotation of the rotor in a non-driving state;
a level difference calculator configured to receive a pulse-shaped position detection signal formed based on a sensor signal from one of the magnetic pole position sensors and calculate a level difference between a level of the sinusoidal measurement signal measured at a rising timing of the pulse-shaped position detection signal and a level of the sinusoidal measurement signal measured at a falling timing thereof;
and
a phase-shift calculator configured to calculate a degree of the phase shift, based on the level difference from the level difference calculator.

5 more elements

A phase-shift detection method for detecting a phase shift caused by misalignment in rotational position detection in motor driving of a motor that comprises:

a rotor and multi-phase drive coils;
and
magnetic pole position sensors, corresponding in number to the multi-phase drive coils, configured to detect positions of rotating magnetic poles of the rotor, the method comprising:
measuring a sinusoidal measurement signal induced in one of the multi-phase coils in a non-driving state;
calculating a level difference between a level of the sinusoidal measurement signal measured at a rising timing of a pulse-shaped position detection signal formed based on a sensor signal from one of the magnetic pole position sensors and a level of the measurement signal measured at a falling timing thereof;
and
calculating a degree of phase shift based on the level difference from the level difference calculator.

4 more elements

Dependencies are inferred from the claim text.

Phase-shift detection device, motor drive device, brushless motor, and phase-shift detection method

Life of this patent

Phase-shift detection device, motor drive device, brushless motor, and phase-shift detection method

Life of this patent

Abstract

Claims23