MOTOR CONTROL DEVICE, MOTOR CONTROL METHOD, AND ELECTRIC POWER STEERING DEVICE

    公开(公告)号:US20200255055A1

    公开(公告)日:2020-08-13

    申请号:US16499709

    申请日:2018-10-26

    Applicant: NSK Ltd.

    Abstract: A motor control device for performing PWM control of an inverter for driving a three-phase brushless motor on the basis of a current command value, wherein the motor control device is provided with: a voltage command value computation unit for calculating a voltage command value using the current command value, and a motor rotation speed and a motor electric angle acquired for each control cycle from the three-phase brushless motor; an electric angle interpolation unit for estimating an interpolated electric angle from the motor electric angle at division intervals obtained by dividing the control cycle; a conversion unit for calculating a three-phase Duty command value from the voltage command value and the motor electric angle, and calculating a three-phase interpolated Duty command value from the voltage command value and the interpolated electric angle; and an output setting unit for switching between, and outputting, the three-phase Duty command value and the three-phase interpolated Duty command value so as to match the division intervals.

    ELECTRIC POWER STEERING APPARATUS
    2.
    发明申请

    公开(公告)号:US20190168801A1

    公开(公告)日:2019-06-06

    申请号:US16320664

    申请日:2017-08-16

    Applicant: NSK Ltd.

    Abstract: An electric power steering apparatus of vector control system that calculates steering assist command values of dq axes based on at least a steering torque, calculates dq-axes current command values from the steering assist command values, converts the dq-axes current command values into 3-phase duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle, wherein the electric power steering apparatus has plural dead time compensating functions of which efficiencies to respectively perform a dead time compensation of the inverter are different each other, and performs the dead time compensation by gradually shifting from one of the plural dead time compensating functions to an another dead time compensating function while mixing the plural dead time compensating functions.

    ELECTRIC POWER STEERING APPARATUS
    3.
    发明申请

    公开(公告)号:US20180229764A1

    公开(公告)日:2018-08-16

    申请号:US15751315

    申请日:2016-09-15

    Applicant: NSK LTD.

    Abstract: [Problem]An object of the present invention is to provide an electric power steering apparatus that can perform an angle estimating by using a motor regenerative current so as to accurately perform an angle estimating even in a low speed steering.[Means for Solving the Problem]The present invention is the electric power steering apparatus that calculates a current command value based on at least a steering torque, driving-controls a motor, which applies an assist torque to a steering system based on the current command value, by an inverter with respective phase duties of a PWM, and detects an angle of the steering system or the motor, comprising: an angle estimating section to estimate the angle when a detecting system of the angle is failed, wherein the electric power steering apparatus performs an assist-control based on an estimating angle that is estimated at the angle estimating section. The present invention can be also adapted to the control of the motor having multi-system windings.

    MOTOR CONTROL UNIT AND ELECTRIC POWER STEERING APPARATUS EQUIPPED WITH THE SAME

    公开(公告)号:US20200180682A1

    公开(公告)日:2020-06-11

    申请号:US16613831

    申请日:2018-06-12

    Applicant: NSK Ltd.

    Abstract: A vector-control type motor control unit that calculates dq-axes control assist command values, calculates dq-axes current command values from the dq-axes control assist command values, converts the dq-axes current command values into 3-phase duty command values, and drives and controls a 3-phase brushless motor by an inverter of a PWM control, wherein a dead time compensation of the inverter is performed by calculating 3-phase dead time reference compensation values based on a motor rotational angle which is phase-corrected by using the dq-axes current command values, calculating dead time compensation values by processing the 3-phase dead time reference compensation values by a gain and a sign, and adding the dead time compensation values to dq-axes voltage command values or 3-phase voltage command values.

    ELECTRIC POWER STEERING APPARATUS
    5.
    发明申请

    公开(公告)号:US20190329817A1

    公开(公告)日:2019-10-31

    申请号:US16311469

    申请日:2017-07-20

    Applicant: NSK LTD.

    Abstract: An electric power steering apparatus that ideally compensates dead time of the inverter without the tuning operation, improves distortion of the current waveform and the responsibility of the current control, and suppresses sound, vibration, the ripple that the low speed steering maneuver is effective. The apparatus converts dq-axes current command values calculated based on at least a steering torque into 3-phase duty command values, controls a 3-phase brushless motor by an inverter of a PWM-control, and applies an assist torque to a steering system of a vehicle, wherein 3-phase detection voltages are estimated based on 3-phase motor terminal voltages, loss voltages due to a dead time of the inverter are estimated from differences between 3-phase correction command voltages calculated from the 3-phase duty command values and the 3-phase detection voltages, and a dead time compensation of the inverter is performed by feeding back dead time compensation values obtained by compensating the loss voltages to the dq-axes current command values.

    ELECTRIC POWER STEERING APPARATUS
    6.
    发明申请

    公开(公告)号:US20190322309A1

    公开(公告)日:2019-10-24

    申请号:US16312695

    申请日:2017-07-14

    Applicant: NSK LTD.

    Abstract: An electric power steering apparatus of a vector control system that compensates a dead time of an inverter without tuning operation, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a sound, a vibration and a ripple. The apparatus of the vector control system that calculates dq-axes steering-assist command values based on at least a steering torque, calculates dq-axes current command values from the dq-axes steering-assist command values, converts the dq-axes current command values into 3-phase duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle, wherein dead time reference compensation values are calculated based on a motor rotational angle, wherein dead time compensation of the inverter is performed by adding dead time compensation values in which the dead time reference compensation values are processed by using a gain, a sign and the like, to dq-axes voltage command values or to 3-phase voltage command values.

    STEERING ANGLE DETECTING APPARATUS FOR VEHICLES AND ELECTRIC POWER STEERING APPARATUS EQUIPPED THEREWITH
    7.
    发明申请
    STEERING ANGLE DETECTING APPARATUS FOR VEHICLES AND ELECTRIC POWER STEERING APPARATUS EQUIPPED THEREWITH 有权
    用于车辆的转向角检测装置及其配备的电动转向装置

    公开(公告)号:US20160362128A1

    公开(公告)日:2016-12-15

    申请号:US15109566

    申请日:2016-02-01

    Applicant: NSK LTD.

    Abstract: A steering angle detecting apparatus for vehicles includes a vernier calculating section that performs vernier calculation based on a steering shaft angle and a motor angle, a neutral period specifying section that specifies a neutral period including a neutral point based on a reference angle calculated by the vernier calculation in the vernier calculating section, and a neutral point specifying section that specifies the neutral point from the neutral period and a stored neutral point value, and outputs a steering angle the neutral point of which is specified.

    Abstract translation: 一种用于车辆的转向角检测装置,包括:游标计算部,其根据转向轴角度和电动机角度进行游标运算;空档期间指定部,根据所述游标计算出的基准角, 游标计算部分中的计算,以及从中立期间指定中立点和存储的中性点值的中性点确定部,并输出其中性点被指定的转向角。

    ELECTRIC POWER STEERING APPARATUS
    8.
    发明申请

    公开(公告)号:US20190375449A1

    公开(公告)日:2019-12-12

    申请号:US16479254

    申请日:2018-02-13

    Applicant: NSK LTD.

    Abstract: An electric power steering apparatus of a vector control system that drives and controls a motor by an inverter and applies an assist torque to a steering system of a vehicle, including the first compensation function to perform a dead time (DT) compensation based on respective phase motor terminal voltages and respective phase duty command values, the second compensation function to perform a DT compensation based on steering assist command values, the third compensation function to perform the DT compensation based on dq-axis current command values, and a temperature detecting section to detect temperature of ECU, wherein the correction of the DT compensation is performed based on the temperature, wherein switches of the compensation functions are performed by using a conditional branch due to software and a gradual-changing switch, wherein the dq-axis DT compensation values after the conditional branch and the gradual-changing switch are performed are calculated, and wherein the dq-axis voltage command values are compensated by the dq-axis DT compensation values.

    ELECTRIC POWER STEERING APPARATUS
    9.
    发明申请

    公开(公告)号:US20190241208A1

    公开(公告)日:2019-08-08

    申请号:US16312443

    申请日:2017-07-20

    Applicant: NSK LTD.

    Abstract: An electric power steering apparatus of a vector control system that compensates a dead time of an inverter without tuning operation, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a steering sound, a vibration and a ripple. The apparatus converts dq-axes current command values calculated based on at least a steering torque into 3-phase voltage command values, converts the 3-phase voltage command values into duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle, wherein 3-phase detection voltages are estimated based on 3-phase motor terminal voltages, wherein loss voltages due to a dead time of the inverter are estimated from differences between 3-phase command voltages calculated from the duty command values and the 3-phase detection voltages, and wherein a dead time compensation of the inverter is performed by feeding-back dead time compensation values obtained by compensating the loss voltages to the 3-phase voltage command values.

    ELECTRIC POWER STEERING APPARATUS
    10.
    发明申请

    公开(公告)号:US20180178832A1

    公开(公告)日:2018-06-28

    申请号:US15738964

    申请日:2016-07-07

    Applicant: NSK LTD.

    Abstract: [Problem]An object of the present invention is to provide an electric power steering apparatus with high quality and reasonable price that estimates a motor shaft angle and a steering shaft angle with high accuracy by learning nonlinear elements of a mechanism system and a steering system, and can back up the both angle sensors by utilizing the estimating angles of the angle sensors.[Means for solving the problem]The present invention is the electric power steering apparatus that a motor to assist-control a steering system of a vehicle is connected to a steering shaft via a reduction mechanism, and comprises a first angle sensor to detect a steering shaft angle of the steering shaft and a second angle sensor to detect a motor shaft angle of the motor, comprising: a function that obtains compensation value maps by iteratively learning characteristics of nonlinear elements including the reduction mechanism based on an actual measuring angle of the first angle sensor, an actual measuring angle of the second angle sensor, a motor torque and a motor angular speed, and estimates the steering shaft angle and the motor shaft angle by using the compensation value maps.

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