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).
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Publication number: 20200307681Abstract: 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: ApplicationFiled: March 26, 2020Publication date: October 1, 2020Applicant: JTEKT CORPORATIONInventors: Yusuke KAKIMOTO, Isao NAMIKAWA, Koji ANRAKU
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Publication number: 20200307680Abstract: 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: ApplicationFiled: March 26, 2020Publication date: October 1, 2020Applicant: JTEKT CORPORATIONInventors: Yusuke KAKIMOTO, Isao NAMIKAWA, Koji ANRAKU
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Publication number: 20200298908Abstract: 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: ApplicationFiled: March 17, 2020Publication date: September 24, 2020Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Isao NAMIKAWA, Koji ANRAKU, Yusuke KAKIMOTO, Yoshio KUDO
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Publication number: 20200298901Abstract: 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: ApplicationFiled: March 17, 2020Publication date: September 24, 2020Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO, Tetsuya MORINO
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Publication number: 20200283059Abstract: 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: ApplicationFiled: February 26, 2020Publication date: September 10, 2020Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takashi KODERA, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO
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Publication number: 20200269903Abstract: 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: ApplicationFiled: February 13, 2020Publication date: August 27, 2020Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO, Yoshio KUDO
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Publication number: 20200269907Abstract: 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: ApplicationFiled: February 19, 2020Publication date: August 27, 2020Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Isao NAMIKAWA, Koji ANRAKU, Yusuke KAKIMOTO, Yoshio KUDO
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Patent number: 10562568Abstract: 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: GrantFiled: December 11, 2017Date of Patent: February 18, 2020Assignees: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Isao Namikawa, Takahiro Toko, Hiromasa Tamaki, Yuji Okuda
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Publication number: 20190367083Abstract: 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: ApplicationFiled: May 23, 2019Publication date: December 5, 2019Applicant: JTEKT CORPORATIONInventors: Takashi KODERA, Terutaka TAMAIZUMI, Masayuki KITA, Isao NAMIKAWA
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Publication number: 20190367078Abstract: 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: ApplicationFiled: May 24, 2019Publication date: December 5, 2019Applicant: JTEKT CORPORATIONInventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO
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Publication number: 20190351936Abstract: 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: ApplicationFiled: May 10, 2019Publication date: November 21, 2019Applicant: JTEKT CORPORATIONInventors: Koji ANRAKU, Isao NAMIKAWA, Yusuke KAKIMOTO
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Publication number: 20190233000Abstract: 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: ApplicationFiled: January 18, 2019Publication date: August 1, 2019Applicant: JTEKT CORPORATIONInventors: Satoshi MATSUDA, Isao NAMIKAWA, Yuusuke KAKIMOTO, Koji ANRAKU
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Publication number: 20190233001Abstract: 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: ApplicationFiled: January 18, 2019Publication date: August 1, 2019Applicant: JTEKT CORPORATIONInventors: Isao NAMIKAWA, Koji ANRAKU, Yuusuke KAKIMOTO, Satoshi MATSUDA
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Publication number: 20180312194Abstract: 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: ApplicationFiled: April 19, 2018Publication date: November 1, 2018Applicant: JTEKT CORPORATIONInventors: Isao NAMIKAWA, Naoki YAMANO
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Publication number: 20180162445Abstract: 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: ApplicationFiled: December 11, 2017Publication date: June 14, 2018Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Isao NAMIKAWA, Takahiro TOKO, Hiromasa TAMAKI, Yuji OKUDA
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Patent number: 9889879Abstract: 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: GrantFiled: February 16, 2017Date of Patent: February 13, 2018Assignee: JTEKT CORPORATIONInventors: Isao Namikawa, Terutaka Tamaizumi
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Publication number: 20170247048Abstract: 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: ApplicationFiled: February 16, 2017Publication date: August 31, 2017Applicant: JTEKT CORPORATIONInventors: Isao NAMIKAWA, Terutaka TAMAIZUMI
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Patent number: 9718492Abstract: 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: GrantFiled: February 10, 2014Date of Patent: August 1, 2017Assignee: JTEKT CORPORATIONInventors: Terutaka Tamaizumi, Hirozumi Eki, Masayuki Kita, Isao Namikawa
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Patent number: 9573616Abstract: A control device in an electric power steering device calculates a first assist component based on steering torque and a vehicle speed. The control device also calculates a compensation component associated with an reverse input and calculates a steered angle command value based on an addition value of the compensation component and basic drive torque that is an addition value of the steering torque and the first assist component, produces a second assist component by performing steered angle feedback control that causes the steered angle of a vehicle to follow the steered angle command value. The control device controls drive of a motor based on an assist command value that is an addition value of the first assist component and the second assist component.Type: GrantFiled: February 27, 2015Date of Patent: February 21, 2017Assignee: JTEKT CORPORATIONInventors: Terutaka Tamaizumi, Hirozumi Eki, Masayuki Kita, Isao Namikawa, Akihiko Nishimura, Jun Hasegawa
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Patent number: 9327760Abstract: There is provided an electric power steering system that makes it possible to improve the driver's steering feel, and that includes a controller that controls driving of a motor. The controller computes a first assist component based on a steering torque. The controller computes a torque command value based on a basic drive torque that is the sum of the steering torque and the first assist component, and computes an assist compensation component through feedback control based on the torque command value. The controller computes a steered angle command value based on a value obtained by adding the assist compensation component to the basic drive torque, and computes a second assist component through feedback control based on the steered angle command value. The controller controls driving of the motor based on an assist command value that is the sum of the first assist component and the second assist component.Type: GrantFiled: May 7, 2014Date of Patent: May 3, 2016Assignee: JTEKT CORPORATIONInventors: Terutaka Tamaizumi, Hirozumi Eki, Masayuki Kita, Isao Namikawa, Jun Hasegawa, Akihiko Nishimura