Patents by Inventor Isao NAMIKAWA

Isao NAMIKAWA 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).

  • Publication number: 20200361517
    Abstract: A control device is configured to control a reaction motor based on a command value that is computed depending on a steering state. The control device includes a first computation circuit configured to compute a first shaft force, a second computation circuit configured to compute a second shaft force, and a third computation circuit configured to set a limit value that limits a variation range of the first shaft. The third computation circuit is configured to compute a final shaft force using the set limit value, through execution of a limiting process by which the first shaft force is limited, the final shaft force being reflected in the command value.
    Type: Application
    Filed: April 28, 2020
    Publication date: November 19, 2020
    Applicant: JTEKT CORPORATION
    Inventors: Isao NAMIKAWA, Koji ANRAKU
  • Publication number: 20200307686
    Abstract: A steering apparatus includes: a mechanism that turns a turning wheel; a first motor that generates a driving force that is given to the mechanism; and a control device. The control device includes: a first computation circuit that computes a first limiting value to which an electric current to be supplied to the first motor is limited in a particular situation; a determination circuit that determines whether the turning wheel is in touch with an obstacle; a second computation circuit that computes a second limiting value to which the electric current to be supplied to the first motor is limited when the determination circuit determines that the turning wheel is in touch with the obstacle; and a third computation circuit that computes the threshold to be used by the determination circuit, based on a smaller limiting value of the first limiting value and the second limiting value.
    Type: Application
    Filed: March 20, 2020
    Publication date: October 1, 2020
    Applicant: JTEKT CORPORATION
    Inventors: Isao NAMIKAWA, Koji ANRAKU, Yusuke KAKIMOTO
  • Publication number: 20200307681
    Abstract: A steering control device includes a processor. The processor is configured to calculate an axial force component corresponding to an axial force acting on a steered shaft that operates so as to steer a steered wheel. The processor is also configured to calculate a restriction reaction force, when a vehicle comes into a condition in which steering of the steered wheel in one direction is restricted. The processor is also configured to calculate target reaction torque based on a reaction force component obtained by adding the axial force component and the restriction reaction force. The processor is also configured to perform, in the calculation of the axial force component, a guard process that restrains the reaction force component from becoming too large.
    Type: Application
    Filed: March 26, 2020
    Publication date: October 1, 2020
    Applicant: JTEKT CORPORATION
    Inventors: Yusuke KAKIMOTO, Isao NAMIKAWA, Koji ANRAKU
  • Publication number: 20200307680
    Abstract: A steering control device includes a processor. The processor is configured to calculate an axial force component and a restriction reaction force. The processor is also configured to calculate target reaction torque based on a reaction force component obtained by adding the axial force component and the restriction reaction force. The processor is also configured to limit an absolute value of the reaction force component to a limit value or less, the limit value being such a value that the reaction force component does not become too large.
    Type: Application
    Filed: March 26, 2020
    Publication date: October 1, 2020
    Applicant: JTEKT CORPORATION
    Inventors: Yusuke KAKIMOTO, Isao NAMIKAWA, Koji ANRAKU
  • Publication number: 20200298901
    Abstract: In a controller for a steering device, the steering device includes a structure where motive power transmission between a steering unit and a turning unit is separated. The controller includes a control circuit configured to control operation of a steering-side motor that is provided in the steering unit to give steering reaction force that is force against the steering input into the steering unit. In a case where turning of the turning wheels to one direction is restricted, the control circuit is configured to calculate restriction reaction force for restricting steering that is to turn the turning wheels to the one direction. The control circuit is configured to calculate the restriction reaction force based on information on the steering unit.
    Type: Application
    Filed: March 17, 2020
    Publication date: September 24, 2020
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO, Tetsuya MORINO
  • Publication number: 20200298908
    Abstract: A steering device includes: a mechanism configured to turn turning wheels of a vehicle; a motor configured to generate drive force that is applied to the mechanism; and a controller configured to control the motor in accordance with a steering state. The controller includes a determination circuit configured to determine whether or not one of the turning wheels is in contact with an obstacle based on at least a value of electric current that is supplied to the motor and a vehicle speed. The controller is configured to, when one of the turning wheels is in contact with the obstacle, notify a driver that one of the turning wheels is in contact with the obstacle.
    Type: Application
    Filed: March 17, 2020
    Publication date: September 24, 2020
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Isao NAMIKAWA, Koji ANRAKU, Yusuke KAKIMOTO, Yoshio KUDO
  • Publication number: 20200283059
    Abstract: A steering control device for a steering system includes an electronic control unit configured to: calculate target torque that is a target value of the motor torque; control operation of the motor; calculate a vehicle speed basic axial force based on a detected vehicle speed; calculate another state quantity basic axial force based on a state quantity other than the detected vehicle speed; calculate a distributed axial force by adding the vehicle speed basic axial force and the other state quantity basic axial force at individually set distribution ratios; calculate the target torque based on the distributed axial force; and reduce the distribution ratio of the vehicle speed basic axial force when the detected vehicle speed is abnormal as compared to when the detected vehicle speed is normal.
    Type: Application
    Filed: February 26, 2020
    Publication date: September 10, 2020
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takashi KODERA, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO
  • Publication number: 20200269903
    Abstract: A steering control device includes an electronic control unit. The electronic control unit controls operation of a steering-side motor so as to apply a steering reaction force that resists a steering operation input to the steering wheel. The electronic control unit computes an obstruction strike reaction force for regulating a steering operation that steers a steered wheel toward an obstruction. The electronic control unit generates determination information indicating that the steered wheel is struck by an obstruction. The determination information includes first determination information indicating that the left side of the steered wheel is struck by an obstruction, and second determination information indicating that the right side of the steered wheel is struck by an obstruction. The electronic control unit sets a direction in which the obstruction strike reaction force is applied based on the generated determination information.
    Type: Application
    Filed: February 13, 2020
    Publication date: August 27, 2020
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO
  • Publication number: 20200269907
    Abstract: A steering system includes a mechanism configured to turn a steer wheel of a vehicle, a motor configured to generate driving force that is applied to the mechanism, and a controller configured to control the motor according to a steering status. The controller includes a limiting control circuit configured to limit a current that is supplied to the motor to a limiting value, a determining circuit configured to determine whether the steer wheel is in contact with an obstacle by using at least a comparison between a value of the current that is supplied to the motor and a threshold, and a threshold computing circuit configured to compute the threshold that is used by the determining circuit, the threshold computing circuit being configured to compute a value less than the limiting value according to the limiting value as the threshold.
    Type: Application
    Filed: February 19, 2020
    Publication date: August 27, 2020
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Isao NAMIKAWA, Koji ANRAKU, Yusuke KAKIMOTO, Yoshio KUDO
  • Patent number: 10562568
    Abstract: A vehicle control device includes a control unit configured to execute one of a plurality of assist controls based on an input of an execution command signal that is externally given. The control unit includes a control state switching unit that executes, based on an input state of the execution command signal, switching of a control state to execute the assist control. The control state includes a first control state and a second control state, the control state being switched from one of the first and second control states to the other of the first and second control states based on the input state of the execution command signal. When one control state of the first and second control states is being executed and when execution of the other control state is commanded, the control state switching unit switches the control state such that the other control state is executed.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: February 18, 2020
    Assignees: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Isao Namikawa, Takahiro Toko, Hiromasa Tamaki, Yuji Okuda
  • Publication number: 20190367078
    Abstract: A control apparatus controls a steering reaction motor. The control apparatus includes an ideal axial force calculation circuit, an estimated axial force calculation circuit, an imaginary rack end axial force calculation circuit, an axial force allocation calculation circuit and a maximum value selection circuit. The calculation circuits calculate an ideal axial force based on a target pinion angle, an estimated axial force based on a current value of a steering operation motor, an imaginary rack end axial force for imaginarily limiting an operation range of a steering wheel, a mixed axial force obtained by allocating the ideal axial force and the estimated axial force at predetermined allocation ratios. The maximum value selection circuit selects the mixed axial force or the imaginary rack end axial force having a larger absolute value as an axial force to be reflected in the command value.
    Type: Application
    Filed: May 24, 2019
    Publication date: December 5, 2019
    Applicant: JTEKT CORPORATION
    Inventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO
  • Publication number: 20190367083
    Abstract: A steering control apparatus includes an electronic control unit. The electronic control unit computes a first component of a command value. The electronic control unit computes a target rotation angle of a rotatable element based on an input torque. The rotatable element rotates with an operation of the steering wheel. The electronic control unit computes a second component of the command value through feedback control. The electronic control unit computes an ideal axial force based on the target rotation angle. The electronic control unit shifts the ideal axial force as a function of a cross slope, which is a slope in a direction that intersects at right angles with a road, in a specified direction with reference to a neutral value of the ideal axial force, associated with a state where the vehicle travels straight ahead.
    Type: Application
    Filed: May 23, 2019
    Publication date: December 5, 2019
    Applicant: JTEKT CORPORATION
    Inventors: Takashi KODERA, Terutaka TAMAIZUMI, Masayuki KITA, Isao NAMIKAWA
  • Publication number: 20190351936
    Abstract: Provided is a steering control unit for supplying an appropriate steering reaction force in accordance with situations. A reaction force component calculation circuit includes a base reaction force calculation circuit that calculates a base reaction force, an end reaction force calculation circuit that calculates an end reaction force, an obstruction-hit reaction force calculation circuit that calculates an obstruction-hit reaction force, and a steered-side limit reaction force calculation circuit that calculates a steered-side limit reaction force. A reaction force selector circuit selects, as a selected reaction force, one of the end reaction force, the obstruction-hit reaction force, and the steered-side limit reaction force. The reaction force component calculation circuit calculates and outputs a reaction force component by adding the selected reaction force to the base reaction force.
    Type: Application
    Filed: May 10, 2019
    Publication date: November 21, 2019
    Applicant: JTEKT CORPORATION
    Inventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO
  • Publication number: 20190233001
    Abstract: A steering control device with reduced power consumption is provided. In the case where an IG signal is turned on, a CPU disengages a clutch, and operates torque of a steered-side motor in order to control the steered angle of steered wheels to a target steered angle that matches an operation on the steering wheel through feedback control. The CPU decreases a current that flows through the steered-side motor with respect to a request by feedback control in the case where the logical product of a statement that a vehicle speed is equal to or less than a prescribed speed, a statement that the absolute value of steering torque which is input torque input to the steering wheel is equal to or less than a prescribed value, and a statement that the absolute value of a steering speed is equal to or less than a predetermined speed.
    Type: Application
    Filed: January 18, 2019
    Publication date: August 1, 2019
    Applicant: JTEKT CORPORATION
    Inventors: Isao NAMIKAWA, Koji ANRAKU, Yuusuke KAKIMOTO, Satoshi MATSUDA
  • Publication number: 20190233000
    Abstract: A steering control device which can suppress a degradation in the steering feel caused when a steering wheel is moved back from a steering limit is provided. A steering control device controls a steer-by-wire steering system that includes a steering-side motor that generates a steering reaction force to be applied to a steering wheel to control operation of the steering-side motor. The steering control device includes an angular speed control circuit that performs feedback control on the steering-side motor in the case where a steering angle of the steering wheel reaches a virtual rack end and the steering wheel is steered back toward the steering neutral. The feedback control is performed such that a steering speed computed on the basis of the steering angle coincides with a target steering speed that is the target value for the steering speed and that is set in accordance with the steering angle.
    Type: Application
    Filed: January 18, 2019
    Publication date: August 1, 2019
    Applicant: JTEKT CORPORATION
    Inventors: Satoshi MATSUDA, Isao NAMIKAWA, Yuusuke KAKIMOTO, Koji ANRAKU
  • Publication number: 20180312194
    Abstract: A steering control apparatus determines whether one of an upper variation angle and a lower variation angle is greater than a first threshold value. When one of the upper variation angle and the lower variation angle is greater than the first threshold value, the steering control apparatus determines the state of a clutch in accordance with the result of a comparison between a resulting angle difference variation and a second threshold value. The steering control apparatus updates a reference upper steering angle and a reference lower steering angle such that the reference upper steering angle and the reference lower steering angle respectively correspond to an upper steering angle and a lower steering angle obtained in a predetermined calculation period.
    Type: Application
    Filed: April 19, 2018
    Publication date: November 1, 2018
    Applicant: JTEKT CORPORATION
    Inventors: Isao NAMIKAWA, Naoki YAMANO
  • Publication number: 20180162445
    Abstract: A vehicle control device includes a control unit configured to execute one of a plurality of assist controls based on an input of an execution command signal that is externally given. The control unit includes a control state switching unit that executes, based on an input state of the execution command signal, switching of a control state to execute the assist control. The control state includes a first control state and a second control state, the control state being switched from one of the first and second control states to the other of the first and second control states based on the input state of the execution command signal. When one control state of the first and second control states is being executed and when execution of the other control state is commanded, the control state switching unit switches the control state such that the other control state is executed.
    Type: Application
    Filed: December 11, 2017
    Publication date: June 14, 2018
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Isao NAMIKAWA, Takahiro TOKO, Hiromasa TAMAKI, Yuji OKUDA
  • Patent number: 9889879
    Abstract: A steering control device capable of transmitting road surface state to a driver is provided. An ideal vehicle model computes first spring reaction force torque based on a target pinion angle and second spring reaction force torque based on at least lateral acceleration as components of a spring component of a steering assist force. The ideal vehicle model combines the first and second spring reaction force torques with specified proportions of use to compute the spring component. The ideal vehicle model decides the proportions of use of the first and second spring reaction force torques on the basis of a distribution gain set in accordance with the difference value between the first and second spring reaction force torques. The ideal vehicle model increases the proportion of use of the second spring reaction force torque as the difference value between the first and second spring reaction force torques is increased.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: February 13, 2018
    Assignee: JTEKT CORPORATION
    Inventors: Isao Namikawa, Terutaka Tamaizumi
  • Publication number: 20170247048
    Abstract: A steering control device capable of transmitting road surface state to a driver is provided. An ideal vehicle model computes first spring reaction force torque based on a target pinion angle and second spring reaction force torque based on at least lateral acceleration as components of a spring component of a steering assist force. The ideal vehicle model combines the first and second spring reaction force torques with specified proportions of use to compute the spring component. The ideal vehicle model decides the proportions of use of the first and second spring reaction force torques on the basis of a distribution gain set in accordance with the difference value between the first and second spring reaction force torques. The ideal vehicle model increases the proportion of use of the second spring reaction force torque as the difference value between the first and second spring reaction force torques is increased.
    Type: Application
    Filed: February 16, 2017
    Publication date: August 31, 2017
    Applicant: JTEKT CORPORATION
    Inventors: Isao NAMIKAWA, Terutaka TAMAIZUMI
  • Patent number: 9718492
    Abstract: An end determination unit determines that a steering apparatus is in an end touching state when an angle deviation, which is a difference between an actual turning angle and a target turning angle, exceeds a threshold. This angle deviation exceeds the threshold before a large axial force is generated in a steering shaft. Accordingly, is it possible to determine that the steering apparatus is in the end touching state more quickly.
    Type: Grant
    Filed: February 10, 2014
    Date of Patent: August 1, 2017
    Assignee: JTEKT CORPORATION
    Inventors: Terutaka Tamaizumi, Hirozumi Eki, Masayuki Kita, Isao Namikawa