Patents by Inventor Takayoshi Sugawara

Takayoshi Sugawara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11101756
    Abstract: A motor control unit that vector-controls a 3-phase brushless motor based on a d-axis voltage command value and a q-axis voltage command value via an inverter with feedback-controlling, comprises: a central processing unit which comprises: a dq-axes dead time compensating section to calculate dq-axes dead time compensation values of the inverter and perform a dead time compensation; and a dq-axes disturbance estimating observer to input a d-axis current command value, a q-axis current command value, a motor rotational number, a motor angular velocity, a d-axis feedback current, a q-axis feedback current, the d-axis voltage command value and the q-axis voltage command value and calculate a d-axis disturbance compensation value and a q-axis disturbance compensation value, which cannot be compensated by the dead time compensation, by respectively adding the d-axis disturbance compensation value and the q-axis disturbance compensation value to the d-axis voltage command value and the q-axis voltage command value.
    Type: Grant
    Filed: January 29, 2019
    Date of Patent: August 24, 2021
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Takayoshi Sugawara
  • Patent number: 11097770
    Abstract: An electric power steering apparatus including a torque sensor to detect a steering torque and a motor control unit to control a motor that applies an assist torque to a steering system of a vehicle, including: a function to switch a control system of the motor between a torque control system to control a motor output torque and a position/speed control system to control a steering angle of a steering in accordance with a predetermined switching trigger. The fade processing time from the torque control system to the position/speed control system and the fade processing time from the position/speed control system to the torque control system are individually set.
    Type: Grant
    Filed: September 24, 2018
    Date of Patent: August 24, 2021
    Assignee: NSK LTD.
    Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
  • Patent number: 11097772
    Abstract: [Problem] An object of the present invention is to provide a vector control type motor control unit that compensates a dead time of an inverter without a tuning operation, improves a distortion of a current waveform and responsibility of the current control, and suppresses sound, vibration and a torque ripple.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: August 24, 2021
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
  • Patent number: 11084528
    Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compens
    Type: Grant
    Filed: February 10, 2020
    Date of Patent: August 10, 2021
    Assignee: NSK LTD.
    Inventors: Takayoshi Sugawara, Yousuke Imamura, Masahiro Maeda
  • Patent number: 11001295
    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 s
    Type: Grant
    Filed: October 26, 2018
    Date of Patent: May 11, 2021
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Takayoshi Sugawara, Kouichi Nampei
  • Patent number: 10882550
    Abstract: An electric power steering apparatus includes a function to switch a control system of the motor between a torque control system of a torque system to control a motor output torque and a position and speed control system of a steering angle system to control a steering angle of a steering in accordance with an ON/OFF of a post-diagnosis automatic steering command being a judgment result of an automatic steering execution judging section; and a characteristic calculating section to calculate a fade gain signal F1 that applies a first fade characteristic of the torque system, a fade gain signal F2 that applies a second fade characteristic of the steering angle system, and a fade gain signal F3 that applies a third fade characteristic of the steering angle speed, sensitive to the steering torque.
    Type: Grant
    Filed: October 5, 2018
    Date of Patent: January 5, 2021
    Assignee: NSK LTD.
    Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
  • Patent number: 10873284
    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.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: December 22, 2020
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
  • Publication number: 20200395882
    Abstract: A vector-control type electric power steering apparatus that applies an assist torque to a steering mechanism of a vehicle, including: a temperature coefficient calculating section to calculate a temperature coefficient depending on a temperature of a control section including the inverter, wherein a dead time compensation of the inverter is performed by estimating compensation signs of 3-phase current model command values in which the dq-phase current command values are converted into a 3-phase current command value model, calculating a first dead time compensation amount based on an inverter applying voltage, calculating a second dead time compensation amount by multiplying the first dead time compensation amount by the temperature coefficient, and adding 2-phase dead time compensation values in which values multiplied the second dead time compensation amount by the compensation signs are converted into 2-phase values, to dq-phase voltage command values.
    Type: Application
    Filed: January 16, 2019
    Publication date: December 17, 2020
    Applicant: NSK LTD.
    Inventors: Hiroaki TAKASE, Ryo MINAKI, Hideki SAWADA, Takayoshi SUGAWARA
  • Patent number: 10864941
    Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compens
    Type: Grant
    Filed: February 10, 2020
    Date of Patent: December 15, 2020
    Assignee: NSK LTD.
    Inventors: Takayoshi Sugawara, Yousuke Imamura, Masahiro Maeda
  • Publication number: 20200382032
    Abstract: A motor control unit that vector-controls a 3-phase brushless motor based on dq-axes current command values, converts 3-phase current detection values of the 3-phase brushless motor into dq-axes feedback currents, performs feedbacks of the dq-axes feedback currents to the dq-axes current command values, converts dq-axes deviation voltages of the feedbacks into 2-phase duty command values, converts the 2-phase duty command values into 3-phase duty command values, and vector-controls the 3-phase brushless motor via an inverter, comprising a dq-axes dead time compensating section to calculate dq-axes dead time compensation values of the inverter and perform a dead time compensation, and a dq-axes disturbance estimating observer to input the dq-axes current command values, a motor rotational number, the dq-axes feedback currents and the deviation voltage, and calculate and output dq-axes disturbance compensation values, wherein the motor control unit estimates a disturbance, which cannot be compensated by said de
    Type: Application
    Filed: January 29, 2019
    Publication date: December 3, 2020
    Inventors: Hiroaki TAKASE, Ryo MINAKI, Takayoshi SUGAWARA
  • Patent number: 10850765
    Abstract: An electric power steering system is provided that is capable of performing assist control in which a change in a steering feel is reduced. The electric power steering system includes a current command value calculating unit configured to output a current command value Iref1 in accordance with steering torque and a vehicle speed on the basis of an assist map. The current command value calculating unit includes a vibration component reducing section configured to reduce a vibration component resulting from vibrations for warning that have been transmitted to a steering wheel and included in the steering torque.
    Type: Grant
    Filed: June 7, 2019
    Date of Patent: December 1, 2020
    Assignee: NSK LTD.
    Inventors: Takayoshi Sugawara, Takuya Masuko, Tomoki Fukuda, Hideki Sawada
  • Patent number: 10807635
    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 val
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: October 20, 2020
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
  • Patent number: 10807636
    Abstract: An electric power steering apparatus that drives and controls a motor which applies an assist torque to a steering system of a vehicle and has a function switching between an assist mode and an automatic mode, including a torsion bar torsional angle calculating section to calculate a torsion bar torsional angle based on a torque information, an output-side column shaft relative angle generating section to output an output-side relative angle from an electrical angle signal of the motor, an actual handle angle calculating section to calculate an actual handle angle based on the torsion bar torsional angle and the output-side relative angle, a resonance filter to obtain an estimated handle angle in a hands-off state from the output-side relative angle, and a hands-on/off judging section to judge a hands-on state when a time that a deviation angle between the actual handle angle and the estimated handle angle is equal to or more than a predetermined angle is continued for the predetermined time or more.
    Type: Grant
    Filed: February 19, 2018
    Date of Patent: October 20, 2020
    Assignee: NSK LTD.
    Inventors: Hideki Sawada, Yukie Fujiwara, Ryo Minaki, Takayoshi Sugawara
  • Publication number: 20200269905
    Abstract: An electric power steering system is provided that is capable of performing assist control in which a change in a steering feel is reduced. The electric power steering system includes a current command value calculating unit configured to output a current command value Iref1 in accordance with steering torque and a vehicle speed on the basis of an assist map. The current command value calculating unit includes a vibration component reducing section configured to reduce a vibration component resulting from vibrations for warning that have been transmitted to a steering wheel and included in the steering torque.
    Type: Application
    Filed: June 7, 2019
    Publication date: August 27, 2020
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Takuya MASUKO, Tomoki FUKUDA, Hideki SAWADA
  • Publication number: 20200255055
    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 s
    Type: Application
    Filed: October 26, 2018
    Publication date: August 13, 2020
    Applicant: NSK Ltd.
    Inventors: Hiroaki TAKASE, Ryo MINAKI, Takayoshi SUGAWARA, Kouichi NAMPEI
  • Publication number: 20200189654
    Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compens
    Type: Application
    Filed: February 10, 2020
    Publication date: June 18, 2020
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
  • Publication number: 20200180682
    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.
    Type: Application
    Filed: June 12, 2018
    Publication date: June 11, 2020
    Applicant: NSK Ltd.
    Inventors: Hiroaki TAKASE, Ryo MINAKI, Hideki SAWADA, Takayoshi SUGAWARA
  • Patent number: 10676127
    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.
    Type: Grant
    Filed: July 20, 2017
    Date of Patent: June 9, 2020
    Assignee: NSK LTD.
    Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
  • Publication number: 20200172162
    Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compens
    Type: Application
    Filed: February 10, 2020
    Publication date: June 4, 2020
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
  • Publication number: 20200172161
    Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compens
    Type: Application
    Filed: February 10, 2020
    Publication date: June 4, 2020
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Yousuke Imamura, Masahiro Maeda