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: 9796407
    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.
    Type: Grant
    Filed: February 1, 2016
    Date of Patent: October 24, 2017
    Assignee: NSK LTD.
    Inventors: Takayoshi Sugawara, Ryo Minaki, Hideki Sawada
  • Publication number: 20170297614
    Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus capable of smoothly switching the control systems without self-steer by gradually changing a control torque of the torque control and a command value of the position/speed control upon fade processing that switches the control systems.
    Type: Application
    Filed: November 30, 2015
    Publication date: October 19, 2017
    Applicant: NSK LTD.
    Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA
  • Publication number: 20170274928
    Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus capable of smoothly switching the control systems without self-steer by gradually changing a control torque of the torque control and a command value of the position/speed control upon the fade processing [Means for solving the problem] The present invention is the 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, comprising: 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, wherein a fade processing which switches from the torque control system to the position/speed control system or vice versa.
    Type: Application
    Filed: November 30, 2015
    Publication date: September 28, 2017
    Applicant: NSK LTD.
    Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA
  • Publication number: 20170166243
    Abstract: An electric power steering apparatus that improves an on-center feeling while improving vehicle response by increasing a steering assist current in a torque range where a steering torque is equal to or less than a static friction torque of a reduction mechanism mainly so as to reduce a static friction uncomfortable feeling in the vicinity of on-center. The apparatus drive-controls a motor for providing a steering mechanism with a steering assist force using a current command value calculated based on at least a steering torque. The apparatus includes: a static friction compensating section that calculates a static friction compensation command value for compensating static friction of the steering mechanism based on the steering torque and a vehicle speed, wherein the current command value is corrected with the static friction compensation command value.
    Type: Application
    Filed: August 3, 2015
    Publication date: June 15, 2017
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Masahiro MAEDA
  • Patent number: 9667179
    Abstract: A multi-phase motor control apparatus that reduces the occurrence of the vibrations and the noises by setting the shift amount per time more finely after realizing a reduction in processing ability of a CPU by using a one-shunt type current detection circuit and an electric power steering apparatus using the same. The apparatus includes a PWM-signal generating section that generates plural second each-phase PWM-signals within two control periods based on the current estimation value and the carrier signal, and in a case that a phase shift amount of a predetermined phase in a just before control period is zero and a phase shift amount of a predetermined phase in a present control period is not zero, the phase shift control section gradually increases the phase shift amount from zero in the present control period and a next control period, and uses the second each-phase PWM-signals in the next control period.
    Type: Grant
    Filed: May 4, 2016
    Date of Patent: May 30, 2017
    Assignee: NSK LTD.
    Inventors: Takayoshi Sugawara, Yousuke Imamura, Hiroyasu Kumagai
  • Patent number: 9586616
    Abstract: An electric power steering device includes a torque detector including an input shaft rotational angle detector and an output shaft rotational angle detector configured to respectively detect rotational angles of an input shaft and an output shaft coupled by a torsion bar arranged in a steering system of a vehicle; an electric motor configured to be controlled based on a torque detection value detected by the torque detector, and to generate a steering assistance force to be exerted on the output shaft; a motor rotational angle detector configured to detect a motor rotational angle of the electric motor; and a noise suppression unit configured to reduce a noise in a signal of the rotational angle of the output shaft detected by the output shaft rotational angle detector, by using the motor rotational angle detected by the motor rotational angle detector.
    Type: Grant
    Filed: February 23, 2015
    Date of Patent: March 7, 2017
    Assignee: NSK Ltd.
    Inventors: Takayoshi Sugawara, Yousuke Imamura, Masahiro Maeda
  • Publication number: 20160362128
    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.
    Type: Application
    Filed: February 1, 2016
    Publication date: December 15, 2016
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Ryo MINAKI, Hideki SAWADA
  • Publication number: 20160304119
    Abstract: An electric power steering device includes a torque detector including an input shaft rotational angle detector and an output shaft rotational angle detector configured to respectively detect rotational angles of an input shaft and an output shaft coupled by a torsion bar arranged in a steering system of a vehicle; an electric motor configured to be controlled based on a torque detection value detected by the torque detector, and to generate a steering assistance force to be exerted on the output shaft; a motor rotational angle detector configured to detect a motor rotational angle of the electric motor; and a noise suppression unit configured to reduce a noise in a signal of the rotational angle of the output shaft detected by the output shaft rotational angle detector, by using the motor rotational angle detected by the motor rotational angle detector.
    Type: Application
    Filed: February 23, 2015
    Publication date: October 20, 2016
    Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
  • Publication number: 20160248351
    Abstract: A multi-phase motor control apparatus that reduces the occurrence of the vibrations and the noises by setting the shift amount per time more finely after realizing a reduction in processing ability of a CPU by using a one-shunt type current detection circuit and an electric power steering apparatus using the same. The apparatus includes a PWM-signal generating section that generates plural second each-phase PWM-signals within two control periods based on the current estimation value and the carrier signal, and in a case that a phase shift amount of a predetermined phase in a just before control period is zero and a phase shift amount of a predetermined phase in a present control period is not zero, the phase shift control section gradually increases the phase shift amount from zero in the present control period and a next control period, and uses the second each-phase PWM-signals in the next control period.
    Type: Application
    Filed: May 4, 2016
    Publication date: August 25, 2016
    Applicant: NSK LTD.
    Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Hiroyasu KUMAGAI
  • Patent number: 9362860
    Abstract: A control device for a multiple motor comprises: a drive unit constituted by a pair of upper and lower arm switching elements for driving the multiphase motor; a single current detection circuit for detecting a current value; a PWM signal generation unit for generating a plurality of first phase PWM signals within two control cycles on the basis of the current value and a carrier signal; a phase shift control unit for shifting a first PWM signal with a prescribed phase generated by the PWM signal generation unit by gradually changing the amount of phase shift within the two control cycles, and outputting the shifted first PWM signal to the drive unit; and a current detection observer for estimating a current value for the multiphase motor on the basis of the current value. The PWM signal generation unit generates a plurality of second phase PWM signals within two control cycles on the basis of the estimated current value and carrier signal.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: June 7, 2016
    Assignee: NSK LTD
    Inventors: Takayoshi Sugawara, Yousuke Imamura, Hiroyasu Kumagai
  • Publication number: 20160072421
    Abstract: A multi-phase motor control apparatus that reduces the occurrence of the vibrations and the noises by setting the shift amount per time more finely after realizing a reduction in processing ability of a CPU by using a one-shunt type current detection circuit and an electric power steering apparatus using the same. The apparatus includes a PWM-signal generating section that generates plural second each-phase PWM-signals within two control periods based on the current estimation value and the carrier signal, and in a case that a phase shift amount of a predetermined phase in a just before control period is zero and a phase shift amount of a predetermined phase in a present control period is not zero, the phase shift control section gradually increases the phase shift amount from zero in the present control period and a next control period, and uses the second each-phase PWM-signals in the next control period.
    Type: Application
    Filed: October 11, 2013
    Publication date: March 10, 2016
    Applicant: NSK LTD.
    Inventor: Takayoshi SUGAWARA
  • Patent number: 9254863
    Abstract: There is provided a torque detecting device for providing a highly accurate torque signal, and an electric power steering device using the torque detecting device. A torque sensor is provided with a first coil pair and a second coil pair, which detect a relative displacement between an input shaft and an output shaft by corresponding the relative displacement to a change in impedance. Magnetization signal generating units supply exciting currents with different magnetization frequencies to the first coil pair and a second coil pair, respectively. The magnetization frequency difference is set to 3.5 kHz or higher. Moreover, low-pass filters for intercepting passage of a frequency equivalent to the magnetization frequency difference are deployed in signal processing circuits respectively.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 9, 2016
    Assignee: NSK Ltd.
    Inventors: Masaki Kuwahara, Takayuki Kobayashi, Kazuhiro Yoshida, Toshiyuki Onizuka, Takayoshi Sugawara, Nobuhiko Andou
  • Patent number: 9248853
    Abstract: An abnormality diagnosing method is provided for a torque detecting device and an electric power steering device is provided using the torque detecting device. Immediately after the power supply is turned on and before steering auxiliary control is started, initial diagnosis is performed to determine that each monitoring block for monitoring an abnormality of a signal processing circuit constituting a torque detecting device operates normally. The initial diagnosis determines that a monitoring block is operating normally, by inputting a normal signal and an abnormal signal to the monitoring block alternately, and finding that the monitoring block carries out normal diagnosis when it receives the normal signal and that it carries out abnormal diagnosis when it receives the abnormal signal. Once all of the monitoring blocks are determined as normal, the steering auxiliary control based on a steering torque detected by the torque detecting device is started.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 2, 2016
    Assignee: NSK, Ltd.
    Inventors: Masaki Kuwahara, Takayuki Kobayashi, Kazuhiro Yoshida, Toshiyuki Onizuka, Takayoshi Sugawara, Nobuhiko Andou
  • Patent number: 9056626
    Abstract: An electric power steering apparatus that is capable of efficiently suppressing vibrations and simultaneously minimizing steering performance degradation such as an increase in a steering wheel's viscous feeling by extracting a vibration component having an arbitrary amplitude and an arbitrary frequency range depending on an electric power steering state parameter and feeding back a vibration suppression compensation value determined depending on the extracted vibration component to a current command value.
    Type: Grant
    Filed: April 24, 2013
    Date of Patent: June 16, 2015
    Assignee: NSK LTD.
    Inventors: Yousuke Imamura, Takayoshi Sugawara, Masahiro Maeda
  • Publication number: 20150088381
    Abstract: An electric power steering apparatus that is capable of efficiently suppressing vibrations and simultaneously minimizing steering performance degradation such as an increase in a steering wheel's viscous feeling by extracting a vibration component having an arbitrary amplitude and an arbitrary frequency range depending on an electric power steering state parameter and feeding back a vibration suppression compensation value determined depending on the extracted vibration component to a current command value.
    Type: Application
    Filed: April 24, 2013
    Publication date: March 26, 2015
    Applicant: NSK LTD.
    Inventors: Yousuke Imamura, Takayoshi Sugawara, Masahiro Maeda
  • Patent number: 8825301
    Abstract: An electric power steering apparatus that compensates both a static friction and a dynamic friction, performs the switching between a static friction compensation and a dynamic friction compensation smoothly and without unpleasant sensation in order to achieve a natural comfortable steering feeling. In an electric power steering apparatus wherein a current command value is calculated based on at least a steering torque, and a motor is controlled by a current control value calculated based on said current command value to provide a steering assist force to a steering mechanism, wherein: there is provided a friction compensator calculating a friction compensation value for compensating friction to said steering mechanism on the basis of said steering torque, and said current command value is corrected by said friction compensation value.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: September 2, 2014
    Assignee: NSK Ltd.
    Inventors: Takayoshi Sugawara, Masahiro Maeda, Yong Wei
  • Publication number: 20140195117
    Abstract: There is provided a torque detecting device for providing a highly accurate torque signal, and an electric power steering device using the torque detecting device. A torque sensor is provided with a first coil pair and a second coil pair, which detect a relative displacement between an input shaft and an output shaft by corresponding the relative displacement to a change in impedance. Magnetization signal generating units supply exciting currents with different magnetization frequencies to the first coil pair and a second coil pair, respectively. The magnetization frequency difference is set to 3.5 kHz or higher. Moreover, low-pass filters for intercepting passage of a frequency equivalent to the magnetization frequency difference are deployed in signal processing circuits respectively.
    Type: Application
    Filed: March 21, 2012
    Publication date: July 10, 2014
    Applicant: NSK Ltd.
    Inventors: Masaki Kuwahara, Takayuki Kobayashi, Kazuhiro Yoshida, Toshiyuki Onizuka, Takayoshi Sugawara, Nobuhiko Andou
  • Publication number: 20140102219
    Abstract: An abnormality diagnosing method is provided for a torque detecting device and an electric power steering device is provided using the torque detecting device. Immediately after the power supply is turned on and before steering auxiliary control is started, initial diagnosis is performed to determine that each monitoring block for monitoring an abnormality of a signal processing circuit constituting a torque detecting device operates normally. The initial diagnosis determines that a monitoring block is operating normally, by inputting a normal signal and an abnormal signal to the monitoring block alternately, and finding that the monitoring block carries out normal diagnosis when it receives the normal signal and that it carries out abnormal diagnosis when it receives the abnormal signal. Once all of the monitoring blocks are determined as normal, the steering auxiliary control based on a steering torque detected by the torque detecting device is started.
    Type: Application
    Filed: March 21, 2012
    Publication date: April 17, 2014
    Applicant: NSK Ltd.
    Inventors: Masaki Kuwahara, Takayuki Kobayashi, Kazuhiro Yoshida, Toshiyuki Onizuka, Takayoshi Sugawara, Nobuhiko Andou
  • Publication number: 20110276229
    Abstract: [Problem] An object is to provide an electric power steering apparatus that compensates both a static friction and a dynamic friction, performs the switching between a static friction compensation and a dynamic friction compensation smoothly and without unpleasant sensation in order to achieve a natural comfortable steering feeling. [Means for Solving] In an electric power steering apparatus wherein a current command value is calculated based on at least a steering torque, and a motor is controlled by a current control value calculated based on said current command value to provide a steering assist force to a steering mechanism, wherein: there is provided a friction compensator calculating a friction compensation value for compensating friction to said steering mechanism on the basis of said steering torque, and said current command value is corrected by said friction compensation value.
    Type: Application
    Filed: January 25, 2010
    Publication date: November 10, 2011
    Applicant: NSK LTD.
    Inventors: Takayoshi Sugawara, Masahiro Maeda, Yong Wei