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).
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Patent number: 11097770Abstract: 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: GrantFiled: September 24, 2018Date of Patent: August 24, 2021Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Patent number: 11097772Abstract: [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: GrantFiled: June 12, 2018Date of Patent: August 24, 2021Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
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Patent number: 11101756Abstract: 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: GrantFiled: January 29, 2019Date of Patent: August 24, 2021Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Takayoshi Sugawara
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Patent number: 11084528Abstract: 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 compensType: GrantFiled: February 10, 2020Date of Patent: August 10, 2021Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Yousuke Imamura, Masahiro Maeda
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Patent number: 11001295Abstract: 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 sType: GrantFiled: October 26, 2018Date of Patent: May 11, 2021Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Takayoshi Sugawara, Kouichi Nampei
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Patent number: 10882550Abstract: 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: GrantFiled: October 5, 2018Date of Patent: January 5, 2021Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Patent number: 10873284Abstract: 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: GrantFiled: June 12, 2018Date of Patent: December 22, 2020Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
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Publication number: 20200395882Abstract: 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: ApplicationFiled: January 16, 2019Publication date: December 17, 2020Applicant: NSK LTD.Inventors: Hiroaki TAKASE, Ryo MINAKI, Hideki SAWADA, Takayoshi SUGAWARA
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Patent number: 10864941Abstract: 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 compensType: GrantFiled: February 10, 2020Date of Patent: December 15, 2020Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Yousuke Imamura, Masahiro Maeda
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Publication number: 20200382032Abstract: 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 deType: ApplicationFiled: January 29, 2019Publication date: December 3, 2020Inventors: Hiroaki TAKASE, Ryo MINAKI, Takayoshi SUGAWARA
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Patent number: 10850765Abstract: 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: GrantFiled: June 7, 2019Date of Patent: December 1, 2020Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Takuya Masuko, Tomoki Fukuda, Hideki Sawada
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Patent number: 10807636Abstract: 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: GrantFiled: February 19, 2018Date of Patent: October 20, 2020Assignee: NSK LTD.Inventors: Hideki Sawada, Yukie Fujiwara, Ryo Minaki, Takayoshi Sugawara
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Patent number: 10807635Abstract: 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 valType: GrantFiled: February 13, 2018Date of Patent: October 20, 2020Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
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Publication number: 20200269905Abstract: 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: ApplicationFiled: June 7, 2019Publication date: August 27, 2020Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Takuya MASUKO, Tomoki FUKUDA, Hideki SAWADA
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Publication number: 20200255055Abstract: 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 sType: ApplicationFiled: October 26, 2018Publication date: August 13, 2020Applicant: NSK Ltd.Inventors: Hiroaki TAKASE, Ryo MINAKI, Takayoshi SUGAWARA, Kouichi NAMPEI
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Publication number: 20200189654Abstract: 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 compensType: ApplicationFiled: February 10, 2020Publication date: June 18, 2020Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
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Publication number: 20200180682Abstract: 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: ApplicationFiled: June 12, 2018Publication date: June 11, 2020Applicant: NSK Ltd.Inventors: Hiroaki TAKASE, Ryo MINAKI, Hideki SAWADA, Takayoshi SUGAWARA
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Patent number: 10676127Abstract: 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: GrantFiled: July 20, 2017Date of Patent: June 9, 2020Assignee: NSK LTD.Inventors: Hiroaki Takase, Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
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Publication number: 20200172163Abstract: [Problem] 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 suppressiType: ApplicationFiled: February 10, 2020Publication date: June 4, 2020Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
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Publication number: 20200172162Abstract: 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 compensType: ApplicationFiled: February 10, 2020Publication date: June 4, 2020Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA