Patents by Inventor Yuzuru Hoshi
Yuzuru Hoshi 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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Publication number: 20200382042Abstract: A current detection device (120) including: a current detection unit (200) configured to, on a basis of respective voltage drops of resistance elements (RS1 to RS3) connected in series to lower arm elements of respective phases of a PWM-controlled multiphase inverter (104), detect respective current values of the respective phases; a sum calculation unit (201) configured to calculate an all phase sum of current detection values detected by the current detection unit; a maximum duty phase determination unit (203) configured to determine a phase whose upper arm element is driven at a maximum duty ratio; an output switching unit (204) configured to, when the all phase sum of the current detection values has been determined to be equal to or more than a threshold value, switch a value to be output as a current detection value of a lower arm of the phase whose upper arm element is driven at the maximum duty ratio to a value obtained by inverting a sign of a sum of the current detection values detected in remainingType: ApplicationFiled: March 26, 2019Publication date: December 3, 2020Applicant: NSK LTD.Inventors: Sachio NAKAYAMA, Yuzuru HOSHI
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Patent number: 10343711Abstract: A tuning device of an electric power steering apparatus assisting steering based on the correspondence relationship between a steering torque and a steering auxiliary command value according to the steering torque. The tuning device receives a plurality of candidate points represented by a steering torque and a candidate value of the steering auxiliary command value according to the steering torque, calculates a high order polynomial approximating the plurality of candidate points, calculates a plurality of adjustment points, the number of which is larger than the plurality of candidate points and which are represented by the steering torque and the steering auxiliary command value according to the steering torque, based on the high order polynomial, calculates a plurality of linear functions connecting two adjacent points in the plurality of adjustment points, and outputs information on the plurality of linear functions in order to adjust the correspondence relationship.Type: GrantFiled: March 8, 2017Date of Patent: July 9, 2019Assignee: NSK LTD.Inventors: Takahiro Tsubaki, Yuzuru Hoshi
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Publication number: 20180370561Abstract: A tuning device of an electric power steering apparatus assisting steering based on the correspondence relationship between a steering torque and a steering auxiliary command value according to the steering torque. The tuning device receives a plurality of candidate points represented by a steering torque and a candidate value of the steering auxiliary command value according to the steering torque, calculates a high order polynomial approximating the plurality of candidate points, calculates a plurality of adjustment points, the number of which is larger than the plurality of candidate points and which are represented by the steering torque and the steering auxiliary command value according to the steering torque, based on the high order polynomial, calculates a plurality of linear functions connecting two adjacent points in the plurality of adjustment points, and outputs information on the plurality of linear functions in order to adjust the correspondence relationship.Type: ApplicationFiled: March 8, 2017Publication date: December 27, 2018Applicant: NSK LTD.Inventors: Takahiro TSUBAKI, Yuzuru HOSHI
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Patent number: 9604666Abstract: An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.Type: GrantFiled: March 18, 2013Date of Patent: March 28, 2017Assignee: NSK LTD.Inventors: Sachio Nakayama, Toru Sakaguchi, Yuzuru Hoshi, Shinichi Tanaka, Masanori Shingou
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Publication number: 20160052541Abstract: An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.Type: ApplicationFiled: March 18, 2013Publication date: February 25, 2016Applicant: NSK LTD.Inventors: Sachio NAKAYAMA, Toru SAKAGUCHI, Yuzuru HOSHI, Shinichi TANAKA, Masanori SHINGOU
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Patent number: 9143064Abstract: [Problem] An object of the present invention is to provide a control apparatus for an electric power steering apparatus that improves ripple accuracy of a torque, a velocity and so on, does not generate abnormal noises and does not generate an uncomfortable feeling with respect to a steering by compensating each-phase characteristics of a motor and the control apparatus and converting into a desired characteristic, and at the same time conforming each-phase characteristics.Type: GrantFiled: October 11, 2011Date of Patent: September 22, 2015Assignee: NSK LTD.Inventors: Yuzuru Hoshi, Fumitoshi Nakamura
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Patent number: 8831832Abstract: A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.Type: GrantFiled: March 28, 2013Date of Patent: September 9, 2014Assignee: NSK Ltd.Inventors: Yuzuru Hoshi, Toru Sakaguchi, Sachio Nakayama, Masahiro Maeda, Kenji Mori, Yousuke Imamura
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Publication number: 20140156144Abstract: A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.Type: ApplicationFiled: March 28, 2013Publication date: June 5, 2014Applicant: NSK LTD.Inventors: Yuzuru Hoshi, Toru Sakaguchi, Sachio Nakayama, Masahiro Maeda, Kenji Mori, Yousuke Imamura
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Publication number: 20130314015Abstract: [Problem] An object of the present invention is to provide a control apparatus for an electric power steering apparatus that improves ripple accuracy of a torque, a velocity and so on, does not generate abnormal noises and does not generate an uncomfortable feeling with respect to a steering by compensating each-phase characteristics of a motor and the control apparatus and converting into a desired characteristic, and at the same time conforming each-phase characteristics.Type: ApplicationFiled: October 11, 2011Publication date: November 28, 2013Applicant: NSK LTD.Inventors: Yuzuru Hoshi, Fumitoshi Nakamura