Nsk Corporation

Toshiba Electronic Devices & Storage Corporation

Kyosho Uryu

Shin Kumagai

Nobuhiko Ando

Takayuki Kobayashi

Takahiro Yamazaki

Shigeru Fukinuki

A current detection device includes a current detection unit configured to detect current flowing through a switching element of a lower-side arm; a correction value calculation unit configured to calculate an offset correction value, based on a detection value of the current detected by the current detection unit in a period during which the switching element off during PWM control, and to hold and update the calculated offset correction value; and a correction unit configured to correct, by the offset correction value held by the correction value calculation unit, the detection value of the current detected by the current detection unit in a period during which the switching element is on. The correction value calculation unit is configured to not update the offset correction value in a case where a duty ratio of the PWM control is equal to or less than a duty ratio lower limit value.

Current detection device, motor control device, and electric power steering device

An electronic control unit diagnoses a short failure of an inverter FETs and diagnoses whether the failure of the FET-short detecting section has occurred. The unit controls a motor through an inverter including a bridge having an upper-stage FETs and a lower-stage FETs via an MCU, having: an FET-short detecting section to detect a short failure of the upper-stage FETs and the lower-stage FETs based on respective connection point voltages of the upper-stage FETs and the lower-stage FETs; and a diagnostic function to detect a failure of the FET-short detecting section. The diagnostic function diagnoses the failure of the FET-short detecting section at start up and turns-OFF the upper-stage FETs and the lower-stage FETs when the failure is detected. The FET-short detecting section diagnoses the short failure of the upper-stage FETs and the lower-stage FETs when the failure of the FET-short detecting section is not detected.

Electronic control unit and electric power steering apparatus equipped with the same

[Problem] An object of the present invention is to provide a motor control unit that driving-controls a motor having the dual-system windings, even in a case that one driving control system is an abnormality (including a failure), turns-ON of one common reverse-connection protection-FET by a driving signal of the other normal driving control system, and achieves a miniaturization and a reduction in costs, an electric power steering apparatus that is equipped with the motor control unit, and a vehicle. [Means for Solving the Problem] The present invention is the motor control unit, comprising: an MCU to control the motor having dual-system motor windings, dual-system inverters to drive the respective dual-system motor windings via dual-system driving sections, and one reverse-connection protection-FET that is connected between the dual-system inverters and a power supply, wherein the reverse-connection protection-FET is turned-ON or turned-OFF by a logical sum of gate driving signals from the dual-system gate driving sections.

Motor control unit, electric power steering apparatus equipped with the same, and vehicle

An electronic control unit where an external watch dog timer (WDT) can always normally detect an abnormality (a failure) to a micro controller unit (MCU) related to a built-in self-test (BIST) function and which can maintain safety of a system. The control unit includes an external WDT to detect an abnormality of the MCU, a reset circuit to reset the MCU when the external WDT detects the abnormality of the MCU, and an ON/OFF control section to turn a gate of the semiconductor switching device on or off in accordance with the external WDT. The inverter is stopped by turning the gate off via the ON/OFF control section when the external WDT is a disable state. When the abnormality of the MCU is not detected in an enable state, the inverter is driven by turning the gate on via the ON/OFF control section. When the abnormality of the MCU is detected, the inverter is stopped by turning the gate off via the ON/OFF control section and the MCU is reset by the reset circuit.

A motor control unit which drives a motor through an inverter based on a calculated command value of a control section to which a power supply voltage is supplied, including: a charging/discharging mechanism for charging and discharging electric charges of an inverter voltage supplied to the inverter; and a separation means for separating the charging/discharging mechanism from the power supply voltage, wherein when a warning signal informing of a drop in the power supply voltage is inputted, the charging/discharging mechanism is separated from the power supply voltage by the separation means as well as a voltage is applied to the control section from the charging/discharging mechanism to avoid power supply reset of the control section. The motor may be a motor with multi-system windings.

Motor control unit and electric power steering apparatus using the same and vehicle

A power-source voltage diagnostic device of an electric power steering apparatus that improves the performance for the anomalous detection of the motor power-source voltage VR-detecting circuit and is capable of continuing the assist control even if the extraordinary state is detected. When the failure (extraordinary state) detection of the VR-detecting circuit is performed by using the correlation between Vbat-voltage obtained by the detecting section (Vbat-detecting circuit) to detect the control voltage from the control power-source circuit and VR-voltage obtained by the detecting circuit (VR-detecting circuit) to detect the motor power-source voltage from the power source circuit, multiplexing is performed by providing VR-detecting circuits (VR-detecting circuit, VR-detecting circuit) of two systems and mutually comparing them so as to accurately perform the failure diagnosis of the VR-detecting circuits.

Power-source voltage diagnostic device of electric power steering apparatus

An electric power steering apparatus that calculates a current command value based on at least a steering torque, performs a PWM-control of a brushless motor by an inverter based on the current command value, performs a current control by detecting a rotational angle of the brushless motor, and performs an assist-control of a steering system. The apparatus includes three rotational angle detecting systems to detect three rotational angles of the brushless motor; and an angle diagnosing section that compares absolute values of differences on respective angles outputted from the three rotational angle detecting systems with a threshold, and performs a process by diagnosing whether the rotational angle detecting systems are normal or abnormal; wherein the assist control is continuously performed by using output angles outputted from systems diagnosed as being normal.

Electric power steering apparatus

[Problem] An object of the present invention is to provide an electric power steering apparatus that has a 3-shunt control function to perform a 3-shunt PWM-control for raising a reliability of the apparatus and for improving a stability, and a 1-shunt control function to perform a 1-shunt PWM-control so as to continue an assist control when the 3-shunt control function is damaged. [Means for solving the problem] The electric power steering apparatus according to the present invention, having: a 3-shunt control function to perform a 3-shunt PWM-control with a first 3-phase detected current values based on down-stream 3-shunt; a 1-shunt control function to perform a 1-shunt PWM-control with a second 3-phase detected current values based on down-stream 1-shunt; and a switching function to switch from the 3-shunt control function to the 1-shunt function when a failure of current detection circuit system in relation to the first 3-phase detected current values is detected.

Growing community of inventors

Tokyo, Japan

Kyosho Uryu