Gm Global Technolgoy Operations, Inc.

Gilsu Choi

Scott M Reilly

Yo Chan Son

Anno Yoo

Song He

Dwarakanath V Simili

John P Miller

Caleb W Secrest

Aja Anjilivelil

In various embodiments, methods, systems, and vehicles are provided for masking a tonal noise of a motor. In certain embodiments, a vehicle includes a drive system and an active masking acoustic signal generator (AMAG). The drive system includes a motor generating a tonal noise. The AMAG is configured to at least facilitate masking the tonal noise, by introducing a complementary harmonic tone, injecting dithering into the motor, or both.

Active masking of tonal noise using motor-based acoustic generator to improve sound quality

A method in a motor controller for an electric motor is disclosed. The method includes receiving a motor current measurement, a motor reference voltage or measured voltage, and an estimated temperature from the electric motor, determining a reference flux linkage estimate (&#x3bb;pm,ref) from a lookup table based on the motor current measurement and the estimated temperature, determining a back-EMF (electromotive force) estimate based on the motor current measurement, the motor voltage and the estimated temperature, determining an observed flux linkage estimate (&#x3bb;pm,obs) from the back-EMF estimate, determining a magnetic strength as a ratio of the observed flux linkage estimate to the reference flux linkage estimate, and determining that a rotor magnet has been demagnetized to an unacceptable level when the magnetic strength is below a threshold level.

Apparatus and method for monitoring magnet flux degradation of a permanent magnet motor

Growing community of inventors

Shelby Township, MI, United States of America

Gilsu Choi