Denso Corporation

Takafumi Satou

Nobuhiko Uryu

Takashi Suzuki

Yasuhiko Mukai

Nobuyori Nakajima

Haruo Suzuki

Shuhei Miyachi

Jiro Hayashi

Hiroyasu Ootake

Yuuta Kadoike

A rotation angle detector has a rotation angle sensor and a microcomputer, where the sensor detects a change of a magnetic field of a magnet that rotates with a shaft. The microcomputer has a first corrector for correcting a pre-correction mechanical angle, based on a first correction value that corrects an error due to an assembly process for assembling the magnet and the sensor, and a second corrector for correcting the pre-correction mechanical angle based on a second correction value that corrects an error due to a spill magnetic flux that is generated by a supply of an electric current to a winding wire. In such configuration, the rotation angle detector may correct the error due to the spill magnetic flux, thereby enabling an accurate detection of a mechanical angle.

Rotation angle detector

A motor control apparatus operates a power conversion circuit connected between a direct current power source and a motor, which performs mutual conversion between power at the direct current power source and power at the motor in response to a powering operation and a regenerative operation carried out by the motor. The motor control apparatus includes: a voltage command calculator that calculates a voltage command to the power conversion circuit; a suppression gain calculator that calculates a suppression gain such that an absolute value of an estimation value of a power source current or an absolute value of a detection value of the power source current is not more than a target value; and a voltage command suppressor that suppresses a voltage command by multiplying the suppression gain to the voltage command calculated by the voltage command calculator. Additionally, the suppression gain is within a range of 0 to 1.

Motor control apparatus

A rotary electric machine control apparatus controlling drive of a rotary electric machine includes a pre-limit d-axis voltage arithmetic portion calculating a pre-limit d-axis voltage command value; a pre-limit q-axis voltage arithmetic portion calculating a pre-limit q-axis voltage command value; a d-axis limit portion calculating a d-axis voltage command value; and a q-axis limit portion calculating a q-axis voltage command value. When an absolute value of the pre-limit q-axis voltage command value is greater than an absolute value of a second limit value, and an absolute value of a previous q-axis voltage command value is equal to or greater than the absolute value of the second limit value and is equal to or less than an absolute value of a first limit value, the q-axis limit portion determines a previous q-axis voltage command value as the q-axis voltage command value.

Rotary electric machine control apparatus

A power converter is for a rotating electrical machine including first and second winding sets, each of which has coils corresponding to phases of the rotating electrical machine. In the power converter, a first inverter energizes the first winding set, a second inverter energizes the second winding set, a current sensor detects a phase current flowing through each coil, and a control section drives the first and second inverters respectively based on first and second voltage command signals. The first inverter and the first winding set form a first system. The second inverter and the second winding set form a second system. The control section calculates the first and second voltage command signals so that average voltages applied to the first and second winding sets can be different from each other. The failure detector detects whether a short-circuit occurs between the first and second systems based on each phase current.

Power converter

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

A multi-phase rotary machine control apparatus executes calculation processing of an angle error caused by position error in attaching a rotation angle sensor to a motor. The control apparatus sets d-axis and q-axis current command values to zero. A rotary shaft of the rotary machine is rotated externally. The control apparatus detects phase currents caused by a counter-electromotive force, converts phases and outputs voltage command values so that the current detection values become zero. The control apparatus calculates an angle error based on the voltage command values, and stores the angle error as an angle correction value. The control apparatus corrects a detection value of a rotation angle sensor by the stored angle correction value.

Multi-phase rotary machine control apparatus and electric power steering system using the same

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

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 power transducer failure detection device detects a failure on a power transducer, making a power transducer control device stop driving the power transducer. A first switching control device turns off a first power supply relay of a power supply source switching device and turns on a second power supply relay of the power supply source switching device. While the power transducer stops driving, a motor may rotate due to an external force to generate a regenerative voltage. The regenerative voltage is then regenerated in a battery through a route from the power transducer via the second power supply relay being turned on and a parasitic diode of the first power supply relay. This can protect elements such as switching elements and a smoothing capacitor of the power transducer against a regenerative voltage and prevent the elements from being destroyed or reducing the useful life due to overvoltage.

Growing community of inventors

Okazaki, Japan

Takafumi Satou