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).
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Patent number: 10286949Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that can perform an angle estimating by using a motor regenerative current so as to accurately perform an angle estimating even in a low speed steering. [Means for Solving the Problem] The present invention is the electric power steering apparatus that calculates a current command value based on at least a steering torque, driving-controls a motor, which applies an assist torque to a steering system based on the current command value, by an inverter with respective phase duties of a PWM, and detects an angle of the steering system or the motor, comprising: an angle estimating section to estimate the angle when a detecting system of the angle is failed, wherein the electric power steering apparatus performs an assist-control based on an estimating angle that is estimated at the angle estimating section. The present invention can be also adapted to the control of the motor having multi-system windings.Type: GrantFiled: September 15, 2016Date of Patent: May 14, 2019Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Hideki Sawada, Ryo Minaki
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Patent number: 10279837Abstract: A vehicle steering angle detecting apparatus and an electric power steering apparatus equipped therewith. The apparatus connects a motor, which assist-controls a steering system of a vehicle, to the steering shaft via a reduction mechanism, and includes a first angle sensor which detects the steering shaft angle of the steering shaft and the second angle sensor which detects the motor shaft angle of the motor, including: a function that updates a static characteristic map and a dynamic characteristic map by iteratively learning a static characteristic and a dynamic characteristic of the nonlinear elements including the reduction mechanism, and mutually estimates the steering shaft angle and the motor shaft angle by using the static characteristic map and the dynamic characteristic map.Type: GrantFiled: September 16, 2016Date of Patent: May 7, 2019Assignee: NSK LTD.Inventors: Ryo Minaki, Hideki Sawada, Takayoshi Sugawara
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Publication number: 20190039642Abstract: An electric power steering apparatus includes a function to switch a control system of the motor between a torque control system of a torque system to control a motor output torque and a position and speed control system of a steering angle system to control a steering angle of a steering in accordance with an ON/OFF of a post-diagnosis automatic steering command being a judgment result of an automatic steering execution judging section; and a characteristic calculating section to calculate a fade gain signal F1 that applies a first fade characteristic of the torque system, a fade gain signal F2 that applies a second fade characteristic of the steering angle system, and a fade gain signal F3 that applies a third fade characteristic of the steering angle speed, sensitive to the steering torque.Type: ApplicationFiled: October 5, 2018Publication date: February 7, 2019Applicant: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Publication number: 20190023312Abstract: An 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, including: 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. The fade processing time from the torque control system to the position/speed control system and the fade processing time from the position/speed control system to the torque control system are individually set.Type: ApplicationFiled: September 24, 2018Publication date: January 24, 2019Applicant: NSK LTD.Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA
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Patent number: 10179603Abstract: An 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, including 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, such that a fade processing switches from the torque control system to the position/speed control system or vice versa.Type: GrantFiled: February 15, 2018Date of Patent: January 15, 2019Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Publication number: 20180354550Abstract: [Problem] An object of the present invention is to provide a control method and a control unit of an electric power steering apparatus that simplifies a calculation of a transformation from a two-phase command value to a three-phase command value performed in the case of driving and controlling a motor mounted on the electric power steering apparatus, reduces a load of the calculation, and enables installation to a microcomputer.Type: ApplicationFiled: November 4, 2016Publication date: December 13, 2018Applicant: NSK LTD.Inventors: Hideki SAWADA, Takayoshi SUGAWARA, Ryo MINAKI
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Patent number: 10144448Abstract: An 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, including: 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. The fade processing time from the torque control system to the position/speed control system and the fade processing time from the position/speed control system to the torque control system are individually set.Type: GrantFiled: November 30, 2015Date of Patent: December 4, 2018Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Patent number: 10131377Abstract: An 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 may include a function to switch a control system of the motor between a torque control system of a torque system to control a motor output torque and a position or speed control system of a steering angle system to control a steering angle of a steering in accordance with a predetermined switching trigger. Each of a steering angle command value and a steering angle speed of the position or speed control system and an assist torque level of the torque control system gradually change sensitive to the steering torque, when shifting from the torque control system to the position or speed control system.Type: GrantFiled: November 30, 2015Date of Patent: November 20, 2018Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Patent number: 10086866Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus with high quality and reasonable price that estimates a motor shaft angle and a steering shaft angle with high accuracy by learning nonlinear elements of a mechanism system and a steering system, and can back up the both angle sensors by utilizing the estimating angles of the angle sensors.Type: GrantFiled: July 7, 2016Date of Patent: October 2, 2018Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Publication number: 20180257704Abstract: A vehicle steering angle detecting apparatus that connects a motor, which assist-controls a steering system of a vehicle, to the steering shaft via a reduction mechanism, and includes the first angle sensor which detects the steering shaft angle of the steering shaft and the second angle sensor which detects the motor shaft angle of the motor, including: a function that updates a static characteristic map and a dynamic characteristic map by iteratively learning a static characteristic and a dynamic characteristic of the nonlinear elements including the reduction mechanism, and mutually estimates the steering shaft angle and the motor shaft angle by using the static characteristic map and the dynamic characteristic map. The present invention is also the electric power steering apparatus equipped with the vehicle steering angle detecting apparatus.Type: ApplicationFiled: September 16, 2016Publication date: September 13, 2018Applicant: NSK LTD.Inventors: Ryo MINAKI, Hideki SAWADA, Takayoshi SUGAWARA
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Publication number: 20180229764Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that can perform an angle estimating by using a motor regenerative current so as to accurately perform an angle estimating even in a low speed steering. [Means for Solving the Problem] The present invention is the electric power steering apparatus that calculates a current command value based on at least a steering torque, driving-controls a motor, which applies an assist torque to a steering system based on the current command value, by an inverter with respective phase duties of a PWM, and detects an angle of the steering system or the motor, comprising: an angle estimating section to estimate the angle when a detecting system of the angle is failed, wherein the electric power steering apparatus performs an assist-control based on an estimating angle that is estimated at the angle estimating section. The present invention can be also adapted to the control of the motor having multi-system windings.Type: ApplicationFiled: September 15, 2016Publication date: August 16, 2018Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Hideki SAWADA, Ryo MINAKI
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Publication number: 20180178832Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus with high quality and reasonable price that estimates a motor shaft angle and a steering shaft angle with high accuracy by learning nonlinear elements of a mechanism system and a steering system, and can back up the both angle sensors by utilizing the estimating angles of the angle sensors.Type: ApplicationFiled: July 7, 2016Publication date: June 28, 2018Applicant: NSK LTD.Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA
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Publication number: 20180170421Abstract: An 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, including 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, such that a fade processing switches from the torque control system to the position/speed control system or vice versa.Type: ApplicationFiled: February 15, 2018Publication date: June 21, 2018Applicant: NSK LTD.Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA
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Patent number: 9919733Abstract: An 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, including 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, such that a fade processing switches from the torque control system to the position/speed control system or vice versa.Type: GrantFiled: November 30, 2015Date of Patent: March 20, 2018Assignee: NSK LTD.Inventors: Ryo Minaki, Takayoshi Sugawara, Hideki Sawada
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Publication number: 20180009472Abstract: A steering holding judging apparatus for the vehicle including: at least two steering angle sensors to detect a steering angle; and a steering state judging section to calculate a hysteresis central value by using a hysteresis signal that sets a hysteresis width to the two steering angle sensor, judge a steering state using the hysteresis central value, and output provisional steering information, wherein a steering holding state is detected based on the provisional steering information, and the electric power steering apparatus equipped with the steering holding judging apparatus for the vehicle.Type: ApplicationFiled: February 2, 2016Publication date: January 11, 2018Applicant: NSK LTD.Inventors: Hideki SAWADA, Takayoshi SUGAWARA, Ryo MINAKI
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Patent number: 9866155Abstract: [Problem] An object of the present invention is to provide a motor control unit that the heat generation of FETs is not concentrated in one FET and the heat generation is distributed to the plural FETs by operating the duties of all three-phases in a case that the driving of the motor is stopped.Type: GrantFiled: February 2, 2016Date of Patent: January 9, 2018Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Ryo Minaki, Hideki Sawada
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Patent number: 9840272Abstract: 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: GrantFiled: August 3, 2015Date of Patent: December 12, 2017Assignee: NSK LTD.Inventors: Takayoshi Sugawara, Masahiro Maeda
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Publication number: 20170349208Abstract: An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compensType: ApplicationFiled: December 21, 2015Publication date: December 7, 2017Applicant: NSK LTD.Inventors: Takayoshi SUGAWARA, Yousuke IMAMURA, Masahiro MAEDA
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Publication number: 20170331398Abstract: [Problem] An object of the present invention is to provide a motor control unit that the heat generation of FETs is not concentrated in one FET and the heat generation is distributed to the plural FETs by operating the duties of all three-phases in a case that the driving of the motor is stopped.Type: ApplicationFiled: February 2, 2016Publication date: November 16, 2017Applicant: NSK Ltd.Inventors: Takayoshi SUGAWARA, Ryo MINAKI, Hideki SAWADA
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Publication number: 20170305459Abstract: An 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, including: 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. The fade processing time from the torque control system to the position/speed control system and the fade processing time from the position/speed control system to the torque control system are individually set.Type: ApplicationFiled: November 30, 2015Publication date: October 26, 2017Applicant: NSK LTD.Inventors: Ryo MINAKI, Takayoshi SUGAWARA, Hideki SAWADA