Patents by Inventor Tetsuya Kitazume
Tetsuya Kitazume 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: 12103607Abstract: In a detection method for detecting an end position of a mechanism portion of a turning device, detection of a limit position of a steering angle in a direction of a torque value is started when the torque value of the mechanism portion loaded by at least one of a drive force from an actuator and steering torque to the mechanism portion exceeds a first threshold. The limit position continues to be detected by storing a peak value of the steering angle in the mechanism portion as the limit position while the torque value of the mechanism portion is between the first threshold and a second threshold. The stored limit position is regarded as the end position indicated by the torque value when the torque value of the mechanism portion exceeds the second threshold.Type: GrantFiled: October 29, 2021Date of Patent: October 1, 2024Assignee: NSK LTD.Inventors: Shoya Maruyama, Tetsuya Kitazume
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Patent number: 12012165Abstract: Provided is a control device for an electric power steering device including a first control portion that derives a first command value based on a steering torque and a second control portion that derives a second command value based on a target command value for a driving support function, where the first control portion generates the first command value by extracting a command value corresponding to a vibration suppression component from a command value including the vibration suppression component derived from the steering torque, adjusting the derived command value according to an operating state of a function of the second control portion, and adding the extracted command value to the adjusted command value.Type: GrantFiled: October 29, 2021Date of Patent: June 18, 2024Assignee: NSK LTD.Inventor: Tetsuya Kitazume
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Publication number: 20240140525Abstract: In a detection method for detecting an end position of a mechanism portion of a turning device, detection of a limit position of a steering angle in a direction of a torque value is started when the torque value of the mechanism portion loaded by at least one of a drive force from an actuator and steering torque to the mechanism portion exceeds a first threshold. The limit position continues to be detected by storing a peak value of the steering angle in the mechanism portion as the limit position while the torque value of the mechanism portion is between the first threshold and a second threshold. The stored limit position is regarded as the end position indicated by the torque value when the torque value of the mechanism portion exceeds the second threshold.Type: ApplicationFiled: October 29, 2021Publication date: May 2, 2024Applicant: NSK LTD.Inventors: Shoya MARUYAMA, Tetsuya KITAZUME
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Publication number: 20240116567Abstract: Provided is a control device for an electric power steering device including a first control portion that derives a first command value based on a steering torque and a second control portion that derives a second command value based on a target command value for a driving support function, where the first control portion generates the first command value by extracting a command value corresponding to a vibration suppression component from a command value including the vibration suppression component derived from the steering torque, adjusting the derived command value according to an operating state of a function of the second control portion, and adding the extracted command value to the adjusted command value.Type: ApplicationFiled: October 29, 2021Publication date: April 11, 2024Applicant: NSK LTD.Inventor: Tetsuya KITAZUME
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Patent number: 11780489Abstract: A turning angle detecting device includes: a first storage unit configured to store a turning angle neutral point correction value being a difference between a median of the turning angles at respective limits in right and left steering and the turning angle in a straight traveling state; a second storage unit configured to store an initial position of a movable portion of an actuator of a wheel turning mechanism in the straight traveling state; a first turning angle calculating unit configured to calculate a first turning angle with respect to the median of the turning angles at the respective limits based on a detection value of a position of the movable portion; and a second turning angle calculating unit configured to calculate a second turning angle based on the detection value, the turning angle neutral point correction value, the initial position and the first turning angle.Type: GrantFiled: February 4, 2022Date of Patent: October 10, 2023Assignee: NSK LTD.Inventors: Shoya Maruyama, Tetsuya Kitazume
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Patent number: 11753068Abstract: A turning control device includes a terminal position learning unit configured to learn a terminal position of the turning mechanism, based on a steered position of the turning mechanism detected by a position detection unit, a command value correction unit configured to, when a steered position detected by the position detecting unit is in a vicinity of a learned terminal position, correct a current command value for an actuator providing a turning mechanism with steering assist force, and a correction amount limiting unit configured to limit a correction amount of the current command value by the command value correction unit, based on a comparison result between the learned terminal position and a predetermined position and a comparison result between stroke length of the turning mechanism calculated from the learned terminal positions and a predetermined length.Type: GrantFiled: February 14, 2022Date of Patent: September 12, 2023Assignee: NSK LTD.Inventor: Tetsuya Kitazume
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Patent number: 11753069Abstract: A control device includes a current command value calculation unit configured to calculate a first current command value causing an actuator to generate steering assist torque, a correction value calculation unit configured to, when an absolute value of steering angle is greater than or equal to a threshold value, calculate a correction value for suppressing increase in an absolute value of the steering angle by correcting the steering assist torque, a correction unit configured to calculate a second current command value obtained by correcting the first current command value by the correction value, and a driving unit configured to drive the actuator, based on the second current command value. The correction value calculation unit calculates the correction value, based on first torque, the first torque changing nonlinearly with respect to steering angular velocity.Type: GrantFiled: October 4, 2021Date of Patent: September 12, 2023Assignee: NSK LTD.Inventors: Tetsuya Kitazume, Shoya Maruyama
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Patent number: 11731687Abstract: A terminal position learning unit includes a first storage unit configured to store a steered position positioned farthest from a neutral position of a turning mechanism within a range of a steered position detected by a position detection unit when rotational force applied to the turning mechanism is less than or equal to a first predetermined value, a second storage unit configured to store a steered position positioned farthest from the neutral position within a range of a position to which a steered position detected by the position detection unit is shifted in a direction toward the neutral position by a second predetermined value, and a third storage unit configured to store, as a terminal position stored by the terminal position learning unit, one of the steered positions stored in the first storage unit and the second storage unit positioned farther from the neutral position than the other.Type: GrantFiled: February 14, 2022Date of Patent: August 22, 2023Assignee: NSK LTD.Inventors: Tetsuya Kitazume, Shoya Maruyama
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Publication number: 20230192178Abstract: A turning angle detecting device includes: a first storage unit configured to store a turning angle neutral point correction value being a difference between a median of the turning angles at respective limits in right and left steering and the turning angle in a straight traveling state; a second storage unit configured to store an initial position of a movable portion of an actuator of a wheel turning mechanism in the straight traveling state; a first turning angle calculating unit configured to calculate a first turning angle with respect to the median of the turning angles at the respective limits based on a detection value of a position of the movable portion; and a second turning angle calculating unit configured to calculate a second turning angle based on the detection value, the turning angle neutral point correction value, the initial position and the first turning angle.Type: ApplicationFiled: February 4, 2022Publication date: June 22, 2023Applicant: NSK LTDInventors: Shoya MARUYAMA, Tetsuya KITAZUME
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Publication number: 20230120193Abstract: A terminal position learning unit includes a first storage unit configured to store a steered position positioned farthest from a neutral position of a turning mechanism within a range of a steered position detected by a position detection unit when rotational force applied to the turning mechanism is less than or equal to a first predetermined value, a second storage unit configured to store a steered position positioned farthest from the neutral position within a range of a position to which a steered position detected by the position detection unit is shifted in a direction toward the neutral position by a second predetermined value, and a third storage unit configured to store, as a terminal position stored by the terminal position learning unit, one of the steered positions stored in the first storage unit and the second storage unit positioned farther from the neutral position than the other.Type: ApplicationFiled: February 14, 2022Publication date: April 20, 2023Applicant: NSK LTD.Inventors: Tetsuya KITAZUME, Shoya MARUYAMA
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Publication number: 20230117916Abstract: A turning control device includes a terminal position learning unit configured to learn a terminal position of the turning mechanism, based on a steered position of the turning mechanism detected by a position detection unit, a command value correction unit configured to, when a steered position detected by the position detecting unit is in a vicinity of a learned terminal position, correct a current command value for an actuator providing a turning mechanism with steering assist force, and a correction amount limiting unit configured to limit a correction amount of the current command value by the command value correction unit, based on a comparison result between the learned terminal position and a predetermined position and a comparison result between stroke length of the turning mechanism calculated from the learned terminal positions and a predetermined length.Type: ApplicationFiled: February 14, 2022Publication date: April 20, 2023Applicant: NSK LTD.Inventor: Tetsuya KITAZUME
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Publication number: 20230016560Abstract: A control device includes a current command value calculation unit configured to calculate a first current command value causing an actuator to generate steering assist torque, a correction value calculation unit configured to, when an absolute value of steering angle is greater than or equal to a threshold value, calculate a correction value for suppressing increase in an absolute value of the steering angle by correcting the steering assist torque, a correction unit configured to calculate a second current command value obtained by correcting the first current command value by the correction value, and a driving unit configured to drive the actuator, based on the second current command value. The correction value calculation unit calculates the correction value, based on first torque, the first torque changing nonlinearly with respect to steering angular velocity.Type: ApplicationFiled: October 4, 2021Publication date: January 19, 2023Applicant: NSK LTD.Inventors: Tetsuya KITAZUME, Shoya MARUYAMA
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Patent number: 11472479Abstract: A hands-off detection device includes: a first steering angle acquisition unit configured to acquire a first steering angle of a steering wheel; a second steering angle acquisition unit configured to acquire a second steering angle of a steering mechanism connected to the steering wheel via a torsion bar; a steering angle estimation unit configured to obtain an estimation angle of the first steering angle in a state where the steering wheel is not being grasped on a basis of the second steering angle; and a grasping state determination unit configured to determine a grasping state of the steering wheel on a basis of the frequency component of a angle difference between the first steering angle and the estimation angle and a reference frequency component being the frequency component of the angle difference in the state where the steering wheel is not being grasped.Type: GrantFiled: March 15, 2021Date of Patent: October 18, 2022Assignee: NSK LTD.Inventor: Tetsuya Kitazume
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Patent number: 11377141Abstract: An electric power steering device including: a control rotational displacement calculation unit configured to calculate a control rotational displacement when a steering angle of the steering system is in an angular range from a maximum allowable steering angle for the steering system to a predetermined threshold steering angle; a control steering angle shifting unit configured to calculate the control rotational displacement corrected by a correction amount based on one of the steering torque and rack axial force and a sign of one of the control rotational displacement and the steering angle as a shift control steering angle; and a feedforward control unit configured to output a second current command value based on the shift control steering angle and steering velocity. An assist control is controlled with a third current command value calculated by adding the second current command value to the first current command value.Type: GrantFiled: December 12, 2019Date of Patent: July 5, 2022Assignee: NSK LTD.Inventors: Tetsuya Kitazume, Shoya Maruyama
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Patent number: 11352053Abstract: A turning control device includes: a target steering angle calculation unit configured to calculate a target steering angle of a turning mechanism, based on a second steering angle of a steering mechanism; a steering angular displacement calculation unit configured to, when a third steering angle, the third steering angle being either a first steering angle of the turning mechanism or the second steering angle, is in a range from a maximum steering angle that the third steering angle can take to a first threshold steering angle, calculate a steering angular displacement of the third steering angle with the first threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; and a corrected target steering angle calculation unit configured to correct the target steering angle with the steering angle correction value.Type: GrantFiled: October 21, 2020Date of Patent: June 7, 2022Assignee: NSK LTD.Inventors: Toru Sakaguchi, Tetsuya Kitazume, Shoya Maruyama
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Publication number: 20220126913Abstract: A hands-off detection device includes: a first steering angle acquisition unit configured to acquire a first steering angle of a steering wheel; a second steering angle acquisition unit configured to acquire a second steering angle of a steering mechanism connected to the steering wheel via a torsion bar; a steering angle estimation unit configured to obtain an estimation angle of the first steering angle in a state where the steering wheel is not being grasped on a basis of the second steering angle; and a grasping state determination unit configured to determine a grasping state of the steering wheel on a basis of the frequency component of a angle difference between the first steering angle and the estimation angle and a reference frequency component being the frequency component of the angle difference in the state where the steering wheel is not being grasped.Type: ApplicationFiled: March 15, 2021Publication date: April 28, 2022Applicant: NSK LTD.Inventor: Tetsuya KITAZUME
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Patent number: 11260902Abstract: A turning control device includes: a steering angular displacement calculation unit configured to, when a third steering angle that is either a first steering angle of a turning mechanism or a second steering angle of a steering mechanism, is in an angular range from a maximum angle to a threshold steering angle, calculate a steering angular displacement of the third steering angle with the threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; a steering angle correction value limiting unit configured to limit the steering angle correction value according to at least a steering state, the third steering angle, and angular velocity thereof; a corrected target steering angle calculation unit configured to correct the target steering angle of the turning mechanism with a limited steering angle correction value.Type: GrantFiled: October 21, 2020Date of Patent: March 1, 2022Assignee: NSK LTD.Inventors: Toru Sakaguchi, Tetsuya Kitazume, Shoya Maruyama
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Publication number: 20220041210Abstract: A turning control device includes: a target steering angle calculation unit configured to calculate a target steering angle of a turning mechanism, based on a second steering angle of a steering mechanism; a steering angular displacement calculation unit configured to, when a third steering angle, the third steering angle being either a first steering angle of the turning mechanism or the second steering angle, is in a range from a maximum steering angle that the third steering angle can take to a first threshold steering angle, calculate a steering angular displacement of the third steering angle with the first threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; and a corrected target steering angle calculation unit configured to correct the target steering angle with the steering angle correction value.Type: ApplicationFiled: October 21, 2020Publication date: February 10, 2022Applicant: NSK LTD.Inventors: Toru SAKAGUCHI, Tetsuya KITAZUME, Shoya MARUYAMA
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Patent number: 11214298Abstract: The present invention is the electric power steering apparatus that drives a motor based on the current command value and assist-controls a steering system by a driving-control of the motor, comprising: a handle-returning control section to calculate the target steering angle velocity for handle-returning based on the steering torque, the current command value, a vehicle speed, a steering angle, calculate the handle-returning control current based on a deviation between the steering angle velocity and the target steering angle velocity, and interpose a filter, which motion characteristic, in a calculation path of the target steering angle velocity, wherein the motor is driven by the corrected current command value by using the handle-returning control current.Type: GrantFiled: January 15, 2018Date of Patent: January 4, 2022Assignee: NSK LTD.Inventors: Tetsuya Kitazume, Satoshi Shimokawabe
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Publication number: 20210387669Abstract: A turning control device includes: a steering angular displacement calculation unit configured to, when a third steering angle that is either a first steering angle of a turning mechanism or a second steering angle of a steering mechanism, is in an angular range from a maximum angle to a threshold steering angle, calculate a steering angular displacement of the third steering angle with the threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; a steering angle correction value limiting unit configured to limit the steering angle correction value according to at least a steering state, the third steering angle, and angular velocity thereof; a corrected target steering angle calculation unit configured to correct the target steering angle of the turning mechanism with a limited steering angle correction value.Type: ApplicationFiled: October 21, 2020Publication date: December 16, 2021Applicant: NSK LTD.Inventors: Toru SAKAGUCHI, Tetsuya KITAZUME, Shoya MARUYAMA