Denso Corporation

Nippondenso Co., Ltd.

Asmo Co., Ltd.

Nobuhiko Uryu

Yasuhiko Mukai

Takafumi Satou

Tsutomu Shiga

Takashi Suzuki

Nobuyuki Hayashi

Yasuhiro Nagao

Naoki Matsuda

Yuuji Hashiba

Masami Niimi

Masanori Ohmi

Masashi Yamasaki

Masashi Hori

Kouichi Nakamura

Hideyuki Hayakawa

Kenji Morikawa

Yoshihide Kuroda

Toshitaka Tanahashi

Yoshikazu Fujii

Masanori Oomi

Norihisa Ito

Yasuhiko Sugihara

Shozou Ikezima

A motor drive device for driving a motor, which has a plurality of winding pairs, includes a plurality of inverter units for the plurality of winding pairs. The inverter units are coupled in parallel to a power source. A plurality of capacitors provided for the plurality of inverter units, and a plurality of power relays are disposed between the power supply and the inverter units. In particular, a power relay is provided for each of the inverter units. A control unit detects a short failure of the power relay, and simultaneously turns ON the power relays that do not have a short failure. In such manner, damage to the power relays as well as damage to other electronic components of the motor driver device due to a large electric current is prevented.

Motor drive device

A rotating electric machine for driving a drive object is provided. The rotating electric machine includes a motor case, a stator, a winding, a rotor, a shaft, a base cap, an end cap, an output rod, base cap holes, end cap holes, and through bolts. The base cap has base cap flanges formed on a circumferential edge and extending radially-outward beyond an outer wall of the motor case. The end cap has end cap flanges formed on a circumferential edge and extending radially-outward beyond the outer wall of the motor case. Base cap holes are formed on the base cap flanges and end cap holes in axial alignment with the base cap holes are formed on the end cap flanges. Through bolts fasten the base cap flanges to the end cap flanges.

Rotating electric machine and electric power steering device

An electric motor drive apparatus includes multiple inverter sections arranged corresponding to winding sets of a motor, multiple relays that controls power supplies to the inverter sections, and a control unit. Each inverter section and corresponding winding set are referred to as a system. The control unit includes an obtaining section that obtains a winding current, a determination section that determines a fault occurrence, a specifying section that specifies a faulty system in which the fault occurs, an interrupting section that controls the relay corresponding to the faulty system to interrupt the power supply to the faulty system, and a vibrating section that controls the inverter section of a properly-operating system to add a vibration to an output torque from the electric motor. The vibrating section gradually increases a vibration component of the vibration added to the output torque from the electric motor.

Electric motor drive apparatus and electric power steering apparatus having the same

A rotation angle detection device uses a control unit to acquire output signals Vx, Vx, Vy, Vythat are from four half-bridges, from the four half-bridges. The control unit calculates a rotation angle &#x3b8; of a detection target based on the acquired output signals Vx, Vx, Vy, Vy. The control unit checks whether a mean value fixation abnormality is caused to any one of the four output signals Vx, Vx, Vy, Vy, based on calculation values Cor Cthat are derived/yielded from the four output signals Vx, Vx, Vy, Vy. The mean value fixation abnormality caused to the output signals Vx, Vx, Vy, Vythat yielded the calculation values Cand Cis appropriately determined.

Rotation angle detection device and electric power steering apparatus using same

In a motor driving device, a first relay portion is connected between a power source and an inverter portion, a second relay portion is connected between the first relay portion and the inverter portion, and a motor relay portion is connected between the inverter portion and a winding group of a motor. Inverter pre-driver circuits respectively drive switching elements of the inverter portion. A first pre-driver circuit drives the first relay portion. A second pre-driver circuit drives the second relay portion and the motor relay portion. A controller controls driving of the inverter portion, the first relay portion, the second relay portion, and the motor relay portion, and detects a failure of the first relay portion, the second relay portion, and the motor relay portion.

Motor driving device and electric power steering apparatus including motor driving device

The electric power steering apparatus has a plurality of power systems each including an inverter apparatus provided corresponding to a plurality of wiring sets of a motor thereof. The control section calculates the assist current to be supplied to the motor using a one power system failure-state map when the inverter apparatus or its corresponding wiring set of one of the power systems fails, or using a vehicle speed detection failure-state map when there is a failure in detecting the vehicle speed. The assist current limit value in the one power system failure-state map and the assist current limit value in the vehicle speed detection failure-state map are set to the same value.

Electric power steering apparatus

Bridge circuits have half bridges formed of sensor elements, which vary respective impedances in accordance with a rotating magnetic field generated by a rotary object. A control unit acquires output signals produced from intermediate points of the half bridges, and calculates a rotation angle of the rotary object based on the output signals. The control unit determines that the output signal is abnormal, if a calculation value of the output signal calculated based on at least four output signals is outside a predetermined range. The control unit thus determines which one of the output signals has become abnormal due to failure or the like.

Rotation angle detection device and electric power steering system

A bridge circuit includes a plurality of half-bridges formed of sensor elements, which change impedance in accordance with a rotation angle of a detection target. A control circuit acquires output signals of the half-bridges and calculates a phase correction value for correcting a phase deviation. A memory circuit stores the phase correction value. The control circuit corrects a pre-correction rotation angle by the phase correction value. Since the pre-correction rotation angle is corrected by the phase correction value, a rotation angle of the detection target is detected with high accuracy even if the sensor elements are assembled with some positional deviations.

Rotation angle detection device and electric power steering system using the same

A motor drive apparatus drives a motor by a first motor drive part and a second motor drive part. The first motor drive part includes a first inverter for supplying current to a first winding set. The second motor drive part includes a second inverter for supplying current to a second winding set. A control unit starts to supply currents to the first winding set and the second winding set at the same time after waiting for completion of all failure detection processing with respect to each of the first motor drive part and the second motor drive part.

Motor drive apparatus and electric power steering apparatus using the same

When failure of an inverter or a coil set of one system of a motor drive apparatus having two systems, is detected, a power supply relay of the failing system is interrupted. At the same time, a control circuit sets a same maximum current limitation value as set before detection of failure. When an IG switch is in an ON-state and a steering toque detection value exceeds a predetermined threshold value thereafter, a vibration component, which has a predetermined amplitude and frequency, is added to a current command value so that a steering wheel is vibrated in a direction of rotation so that a driver is cautioned to notice the failure surely.

Motor drive apparatus and method, and electric power steering system using the same

An electric power steering device includes: an electric power source for supplying first current; a controller for setting a current instruction value; multiple electric power converters for converting the first current to second current corresponding to the current instruction value; multiple pairs of windings for generating a driving force of a motor; and a failure detection element for detecting failure of the electric power converters and the windings. The controller reduces the current instruction value to be equal to or smaller than a predetermined instruction value of a normal operation when the failure detection element detects the failure. The controller controls the electric power converter in a normal state to supply the second current to a corresponding winding.

Electric power steering device

A motor drive apparatus has a plurality of motor drive parts and a control unit. The control unit performs first and second failure detection processing for the motor drive parts before starting to drive the motor. If the first motor drive part is determined to have failure by the first failure detection processing, a first power supply relay for the first motor drive part is turned off and the second failure detection processing for the first motor drive part is inhibited. If the second motor drive part is determined to have no failure by the first failure detection processing and then by the second failure detection processing, the motor is started to operate.

An electric power steering device includes a torque detector that includes a torque sensor and a control unit. When abnormality has not occurred in a torque signal, an output section in the torque sensor transmits a normal signal that is a value based on the torque signal and is between a second lower limit that is greater than a first lower limit and a second upper limit that is less than a first upper limit. When abnormality has occurred in the torque signal, the output section transmits a first fault notification signal that is a value between the first and second lower limits or a second fault notification signal that is a value between the first and second upper limits. The control unit identifies a fault and calculates an amount of assist for reducing steering torque based on a signal transmitted from the output section.

Torque sensor, torque detector, and electric power steering device

In a multi-system motor drive apparatus, a power supply relay is interrupted when a first power supply system fails at time t. A power control unit doubles a current supplied to an inverter of a second power supply system thereby to supplement the electric power, which has been supplied by an inverter of the first power supply system. The total output of inverters is thus maintained before and after the failure. After an elapse of a predetermined period, the electric power supplied by the second power supply system is reduced gradually so that the inverter of the second power supply system will not be operated to supply the doubled power for a long period.

Motor drive and electric power steering apparatus using the same

When an inverter or a coil set of one system in a motor drive apparatus having two systems fails, a power supply relay of a failing system interrupts power supply and a control circuit gradually reduces a current supply limitation value of a normal system to zero. Then when a steering torque becomes greater than a predetermined threshold value, the control circuit increases the current supply limitation value by a predetermined amount. By reducing the current supply limitation value to zero once and then gradually increasing the current supply limitation value to generate steering assist torque, a driver will be caused to sense changes in the steering torque and surely notice occurrence of failure.

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Kariya, Japan

Nobuhiko Uryu