Patents by Inventor Takahiro Yokota
Takahiro Yokota 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: 10239557Abstract: A vehicle travel control device includes: an EPS device turning a wheel of a vehicle; and a control device performing autonomous driving control that controls autonomous driving of the vehicle. The autonomous driving control includes: calculating a target steering angle of the wheel; and actuating the EPS device to turn the wheel such that a steering angle of the wheel becomes the target steering angle. Calculating the target steering angle includes: calculating an autonomous driving steering angle and a target state quantity required for automatic steering in the autonomous driving; calculating a counter steering angle required for vehicle stabilization control, based on the target state quantity without using a steering wheel angle; and calculating a sum of the autonomous driving steering angle and the counter steering angle as the target steering angle.Type: GrantFiled: October 26, 2017Date of Patent: March 26, 2019Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Go Inoue, Mitsutaka Tanimoto, Takahiro Yokota, Yoshio Kudo, Yutaka Aoki
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Publication number: 20180339693Abstract: A SS control device is configured to: be allowed to stop an internal combustion engine when a required voltage is smaller than or equal to a first voltage value under a state where a stopping condition is satisfied, and be prohibited from stopping the internal combustion engine when the required voltage is larger than the first voltage value under a state where the stopping condition is satisfied; and be allowed to restart the internal combustion engine when the required voltage is smaller than or equal to a second voltage value smaller than the first voltage value under a state where the restart condition is satisfied, and be prohibited from restarting the internal combustion engine when the required voltage is larger than the second voltage value under a state where the restart condition is satisfied.Type: ApplicationFiled: February 21, 2018Publication date: November 29, 2018Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yoji KUNIHIRO, Hiroki ASADA, Yoshio KUDO, Takahiro YOKOTA, Masateru AMANO
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Publication number: 20180304890Abstract: An autonomous driving system mounted on a vehicle determines a target path based on necessary information and performs vehicle travel control such that the vehicle follows the target path. A first coordinate system is a vehicle coordinate system at a first timing when the necessary information is acquired. A second coordinate system is a vehicle coordinate system at a second timing later than the first timing. The autonomous driving system calculates, based on the necessary information acquired at the first timing, a first target path defined in the first coordinate system. Then, the autonomous driving system corrects the first target path to a second target path defined in the second coordinate system by performing coordinate transformation from the first coordinate system to the second coordinate system. The autonomous driving system uses the second target path as the target path to perform the vehicle travel control.Type: ApplicationFiled: February 20, 2018Publication date: October 25, 2018Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Atsushi SONE, Yoji KUNIHIRO, Takahiro YOKOTA, Ryo IRIE, Yoshinori WATANABE, Masateru AMANO
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Publication number: 20180178838Abstract: A vehicle travel control device includes: an EPS device turning a wheel of a vehicle; and a control device performing autonomous driving control that controls autonomous driving of the vehicle. The autonomous driving control includes: calculating a target steering angle of the wheel; and actuating the EPS device to turn the wheel such that a steering angle of the wheel becomes the target steering angle. Calculating the target steering angle includes: calculating an autonomous driving steering angle and a target state quantity required for automatic steering in the autonomous driving; calculating a counter steering angle required for vehicle stabilization control, based on the target state quantity without using a steering wheel angle; and calculating a sum of the autonomous driving steering angle and the counter steering angle as the target steering angle.Type: ApplicationFiled: October 26, 2017Publication date: June 28, 2018Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Go INOUE, Mitsutaka TANIMOTO, Takahiro YOKOTA, Yoshio KUDO, Yutaka AOKI
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Publication number: 20180181130Abstract: A vehicle travel control device includes: an EPS device turning a wheel of a vehicle; a VCRS device capable of changing a ratio of a steering wheel angle and a steering angle of the wheel; and a control device performing autonomous driving control that controls autonomous driving of the vehicle. The autonomous driving control includes: target steering angle calculation processing that calculates a target steering angle of the wheel; turning control that actuates the EPS device to turn the wheel such that the steering angle of the wheel becomes the target steering angle; and steering wheel angle control that actuates, based on the target steering angle, the VGRS device in a direction to suppress a change in the steering wheel angle caused by the turning control.Type: ApplicationFiled: October 27, 2017Publication date: June 28, 2018Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Go INOUE, Mitsutaka TANIMOTO, Takahiro YOKOTA, Yoshio KUDO, Yutaka AOKI
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Patent number: 9604636Abstract: A turning-characteristic estimating unit of an ECU estimates a stability factor and a steering-response time constant coefficient that are parameter values related to turning characteristics of a vehicle. A standard yaw rate of the vehicle is calculated using the estimation values of the stability factor and the steering-response time constant coefficient estimated by the turning-characteristic estimating unit. A validity determining unit of the ECU determines the validity of the estimation values based on the standard yaw rate and an actual yaw rate of the vehicle. This allows improving the estimation accuracy of the stability factor and the steering-response time constant coefficient.Type: GrantFiled: February 24, 2012Date of Patent: March 28, 2017Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota
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Publication number: 20160016581Abstract: A reference yaw rate of a vehicle in a relationship of a first-order lag with respect to a normative yaw rate is calculated by using a time constant of a first-order lag set in advance (S320), and when a magnitude of a deviation between an actual yaw rate and the reference yaw rate of the vehicle exceeds a threshold, vehicle motion control by controlling braking/driving force of each wheel is carried out so as to decrease the magnitude of the deviation (S420 to S500). A correction value (??cs) is acquired for preventing unnecessary execution of the vehicle motion control caused by the time constant different from an actual value resulting from a change in an overall weight of the vehicle or a change in a vehicle longitudinal direction position of a vehicle center of gravity (S330 to S390), and the threshold is corrected by using the correction value (S420).Type: ApplicationFiled: March 4, 2013Publication date: January 21, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro YOKOTA
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Publication number: 20160016591Abstract: Provided is a method of calculating a reference yaw rate as a reference motion state amount of a vehicle in a relationship of a first-order lag with respect to a normative yaw rate as a normative motion state amount of the vehicle. An overall weight (W) of the vehicle and a stability factor (Kh) of the vehicle are estimated (S20 and S30), cornering powers (Kf and Kr) of front and rear wheels and a yaw moment of inertia (Iz) of the vehicle are calculated based on the overall weight and the stability factor (S60 to S110). Then, a steering response time constant coefficient (Tp) for determining a time constant of the first-order lag is calculated based on the cornering powers (Kf and Kr) and the yaw moment of inertia (Iz) (S120), and the reference yaw rate is calculated by using the coefficient (S130).Type: ApplicationFiled: March 4, 2013Publication date: January 21, 2016Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro YOKOTA
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Publication number: 20150291156Abstract: A turning-characteristic estimating unit of an ECU estimates a stability factor and a steering-response time constant coefficient that are parameter values related to turning characteristics of a vehicle. A standard yaw rate of the vehicle is calculated using the estimation values of the stability factor and the steering-response time constant coefficient estimated by the turning-characteristic estimating unit. A validity determining unit of the ECU determines the validity of the estimation values based on the standard yaw rate and an actual yaw rate of the vehicle. This allows improving the estimation accuracy of the stability factor and the steering-response time constant coefficient.Type: ApplicationFiled: February 24, 2012Publication date: October 15, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota
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Patent number: 9096232Abstract: There is provided a vehicle condition estimating device which enables the estimations of the longitudinal position of a vehicle centroid, loads exerted on front and rear wheel axles and cornering powers even during the running of a vehicle without detecting directly the loads exerted on front and rear wheel axles. The inventive device is characterized by estimating a centroid position in the longitudinal direction of a vehicle based on a vehicle weight value, a stability factor value, a relation between a front wheel axle load and a front wheel cornering power and a relation between a rear wheel axle load and a rear wheel cornering power.Type: GrantFiled: January 13, 2009Date of Patent: August 4, 2015Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota
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Patent number: 9031746Abstract: A vehicle control device includes: a weight calculating unit configured to estimate a weight of the vehicle; a traveling state calculating unit configured to estimate a turning characteristic of the vehicle; a guard setting unit configured to change and set at least one of an upper limit value and a lower limit value of the turning characteristic based on the weight of the vehicle estimated by the weight calculating unit; an upper and lower limit processing unit configured to perform a process of putting the turning characteristic into a range of the upper and lower limit values; and a behavior control unit configured to perform behavior control of the vehicle based on the turning characteristic after the process of putting the turning characteristic into the range of the upper and lower limit values.Type: GrantFiled: January 9, 2013Date of Patent: May 12, 2015Assignee: Toyota Jidosha Kabushiki KaishaInventors: Tomoyuki Kozuka, Takahiro Yokota
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Publication number: 20150006034Abstract: A vehicle control device includes: a weight calculating unit configured to estimate a weight of the vehicle; a traveling state calculating unit configured to estimate a turning characteristic of the vehicle; a guard setting unit configured to change and set at least one of an upper limit value and a lower limit value of the turning characteristic based on the weight of the vehicle estimated by the weight calculating unit; an upper and lower limit processing unit configured to perform a process of putting the turning characteristic into a range of the upper and lower limit values; and a behavior control unit configured to perform behavior control of the vehicle based on the turning characteristic after the process of putting the turning characteristic into the range of the upper and lower limit values.Type: ApplicationFiled: January 9, 2013Publication date: January 1, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Tomoyuki Kozuka, Takahiro Yokota
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Patent number: 8744686Abstract: The device calculates a transient yaw rate of the vehicle on the basis of a standard yaw rate of the vehicle using an estimated value of a time constant coefficient of steering response, and adjusts the estimated value of a time constant coefficient of steering response on the basis of the relationship between a transient yaw rate of the vehicle and an actual yaw rate of the vehicle so that a transient yaw rate of the vehicle approaches an actual yaw rate of the vehicle.Type: GrantFiled: September 24, 2009Date of Patent: June 3, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventor: Takahiro Yokota
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Patent number: 8694208Abstract: A vehicle behavior control apparatus including a deceleration control mechanism decelerating the vehicle to reduce a deviation between a target turning index value, which is determined based on a steering angle of the vehicle, and an actual turning index value. The deceleration control mechanism reduces the decrease gradient of the deceleration when a roll motion index value of the vehicle exceeds a threshold roll motion index value.Type: GrantFiled: August 25, 2008Date of Patent: April 8, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventor: Takahiro Yokota
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Patent number: 8515591Abstract: A device for estimating a turning characteristic of a vehicle estimates a stability factor indicating the turning characteristic of a vehicle. The device for estimating the turning characteristic calculates the transient yaw rate of a vehicle involved in the relationship of a primary delay relative to the steady-state standard yaw rate of a vehicle, and calculates the deviation between the transient yaw rate of the vehicle and the actual yaw rate of the vehicle. The device for estimating the turning characteristic corrects the estimated value of the stability factor so as to approach the true stability factor by correcting the initial value of the stability factor supplied to the calculation of the standard yaw rate of the vehicle on the basis of the relationship between the deviation of the yaw rate and the lateral acceleration of the vehicle so that the transient yaw rate of the vehicle approaches the true yaw rate.Type: GrantFiled: September 24, 2009Date of Patent: August 20, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventor: Takahiro Yokota
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Publication number: 20130211620Abstract: A vehicle motion control system 1 includes a vehicle state amount obtaining unit configured to obtain a reference yaw rate and an actual yaw rate of a vehicle, a vehicle state estimating unit configured to determine OS/US determinations based on the reference yaw rate and the actual yaw rate, and a vehicle motion control unit configured to execute a vehicle motion control based on a result of the OS/US determinations. In the vehicle motion control system, a high-pass filter unit of a control unit executes a high-pass filter process for removing a component equal to or less than a predetermined cut-off frequency from the reference yaw rate and the actual yaw rate. Then, an OS/US determining unit executes the OS/US determinations based on a deviation between the reference yaw rate after the high-pass filter process and the actual yaw rate after the high-pass filter process.Type: ApplicationFiled: October 8, 2010Publication date: August 15, 2013Applicant: Toyota Jidosha Kabushiki KaishaInventor: Takahiro Yokota
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Publication number: 20120173039Abstract: The device calculates a transient yaw rate of the vehicle on the basis of a standard yaw rate of the vehicle using an estimated value of a time constant coefficient of steering response, and adjusts the estimated value of a time constant coefficient of steering response on the basis of the relationship between a transient yaw rate of the vehicle and an actual yaw rate of the vehicle so that a transient yaw rate of the vehicle approaches an actual yaw rate of the vehicle.Type: ApplicationFiled: September 24, 2009Publication date: July 5, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota
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Publication number: 20120173040Abstract: A device for estimating turning characteristic of a vehicle estimates a stability factor indicating the turning characteristic of a vehicle. The device for estimating the turning characteristic calculates the transient yaw rate of a vehicle involved in the relationship of a primary delay relative to the steady-state standard yaw rate of a vehicle, and calculates the deviation between the transient yaw rate of the vehicle and the actual yaw rate of the vehicle. The device for estimating the turning characteristic corrects the estimated value of the stability factor so as to approach the true stability factor by correcting the initial value of the stability factor supplied to the calculation of the standard yaw rate of the vehicle on the basis of the relationship between the deviation of the yaw rate and the lateral acceleration of the vehicle so that the transient yaw rate of the vehicle approaches the true yaw rate.Type: ApplicationFiled: September 24, 2009Publication date: July 5, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota
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Publication number: 20120046806Abstract: Disclosed is a specification information estimating device which estimates the steering gear ratio n of a vehicle. A specification information estimating device includes a steering angle sensor 26 and a yaw rate sensor 51 which acquire the wheel steering angle St and the yaw rate Yr of the vehicle during traveling, and an ECU 4 which estimates a steering gear ratio n on the basis of the wheel steering angle St and the yaw rate Yr acquired by the steering angle sensor 26 and the yaw rate sensor 51. Therefore, it is possible to estimate the steering gear ratio n of each vehicle without using a stability factor KH.Type: ApplicationFiled: May 13, 2009Publication date: February 23, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiro Yokota, Yutaka Obuchi, Yuuichi Toyoda, Hiroaki Endo
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Publication number: 20110257876Abstract: There is provided a vehicle condition estimating device which enables the estimations of the longitudinal position of a vehicle centroid, loads exerted on front and rear wheel axles and cornering powers even during the running of a vehicle without detecting directly the loads exerted on front and rear wheel axles. The inventive device is characterized by estimating a centroid position in the longitudinal direction of a vehicle based on a vehicle weight value, a stability factor value, a relation between a front wheel axle load and a front wheel cornering power and a relation between a rear wheel axle load and a rear wheel cornering power.Type: ApplicationFiled: January 13, 2009Publication date: October 20, 2011Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Yokota