Omron Automotive Electronics Co., Ltd.

Yoji Mori

Satoshi Doba

Tomoya Yamanaka

Taku Ogasawara

In a magnetic pole direction detection device, a detecting target magnet is attached to a tip of a rotating shaft of the rotor. A magnetic detection unit outputs a detection signal which changes according to a change in a magnetic field. A magnetic pole direction calculation unit calculates a magnetic pole direction of a rotor based on the detection signal. A current detection unit detects a current flowing through each multiphase coil. A rotating magnetic field vector calculation unit calculates a vector of a rotating magnetic field based on magnitude of the detected current. A direction correction amount calculation unit calculates a direction correction amount based on a direction and magnitude of the rotating magnetic field calculated by the rotating magnetic field vector calculation unit. A magnetic pole direction correction unit corrects the calculated magnetic pole direction by using the calculated direction correction amount calculated.

Magnetic pole direction detection device

A polyphase electric motor control device stores a first threshold as a duty cycle at which noise caused by a high potential-side switching element starts to overlap a first measurement period, and a second threshold as a duty cycle at which time when a low potential-side switching element is switched from on to off is after an end of a second measurement period, makes a first judgment for comparing a maximum target duty cycle with the first threshold, and a second judgment for comparing a second greatest target duty cycle with the second threshold, measures a current in the first measurement period when the maximum target duty cycle is smaller than the first threshold, and measures a current in the second measurement period when the maximum target duty cycle is greater than the first threshold and the second greatest target duty cycle is smaller than the second threshold.

Polyphase electric motor control device

A multiphase electric motor control device includes: a bridge circuit including phase circuits each including a high potential side switching element, a low potential side switching element, and a current detector, a PWM control unit that outputs PWM signals to the switching elements; a control unit that acquires phase current values at a timing synchronized with a triangle wave; and a current value estimation unit that estimates a phase current value of one phase based on phase current values of other phases. In a case where an ON time of the PWM signal output to the low potential side switching element of the one phase from the PWM control unit is shorter than a predetermined time, the control unit acquires the phase current values which are detected by shifting the timing by using the current detectors of at least the other phases.

Growing community of inventors

Aichi, Japan

Yoji Mori