Patents by Inventor Akifumi Doura
Akifumi Doura 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: 9150204Abstract: A braking force control device can control braking forces of the respective wheels of a vehicle, suppresses an increase of the braking force of a first wheel that is a wheel having a relatively large slip amount in a pair of right/left wheels and increases the braking force of a second wheel that is a wheel having a relatively small slip amount. The braking force control device may suppress the increase of the braking force of the first wheel before the friction coefficient of a road surface to the first wheel reaches a peak and when the friction coefficient is in the vicinity of the peak. It is preferable to suppress the increase of the braking force of the first wheel by holding the braking force of the first wheel.Type: GrantFiled: November 2, 2011Date of Patent: October 6, 2015Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Satoshi Udaka, Noritaka Yamada, Hideyuki Aizawa, Akifumi Doura
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Publication number: 20140195133Abstract: A vehicle braking force control device includes a controller that controls braking force of a wheel by controlling friction braking force generated by a friction braking device and regenerative braking force generated by regenerative braking devices and that performs anti-skid control based on a requested amount of braking force reduction by controlling the friction braking force and reducing the regenerative braking force by an amount of regenerative braking force reduction. The controller sets a target change amount of the friction braking force based on the requested amount of braking force reduction and the amount of regenerative braking force reduction, and controls the friction braking force based on the target change amount when the controller reduces the regenerative braking force by the amount of regenerative braking force reduction.Type: ApplicationFiled: August 9, 2012Publication date: July 10, 2014Applicants: ADVICS CO., LTD., TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hidehisa Kato, Takayuki Goto, Atsushi Sone, Akifumi Doura
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Patent number: 8744714Abstract: A vehicle braking control system includes a wheel cylinder which applies a braking force in accordance with a fluid pressure to a vehicle wheel and a control device which controls the fluid pressure of the wheel cylinder based on the vehicle wheel acceleration. Then, the control device applies the predetermined fluid pressure to the wheel cylinder so as to acquire a return level of the vehicle wheel acceleration and calculates a control target value of the fluid pressure based on a behavior of the vehicle wheel acceleration after starting a sudden braking operation and before starting ABS control.Type: GrantFiled: November 11, 2011Date of Patent: June 3, 2014Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co., Ltd.Inventors: Satoshi Udaka, Noritaka Yamada, Hitoshi Terada, Akifumi Doura
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Patent number: 8600637Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.Type: GrantFiled: April 2, 2004Date of Patent: December 3, 2013Assignee: Advics Co., Ltd.Inventors: Chiaki Hamada, Akifumi Doura
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Publication number: 20130297171Abstract: A vehicle braking control system includes a wheel cylinder which applies a braking force in accordance with a fluid pressure to a vehicle wheel and a control device which controls the fluid pressure of the wheel cylinder based on the vehicle wheel acceleration. Then, the control device applies the predetermined fluid pressure to the wheel cylinder so as to acquire a return level of the vehicle wheel acceleration and calculates a control target value of the fluid pressure based on a behavior of the vehicle wheel acceleration after starting a sudden braking operation and before starting ABS control.Type: ApplicationFiled: November 11, 2011Publication date: November 7, 2013Applicants: Advics Co., Ltd., TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Satoshi Udaka, Noritaka Yamada, Hitoshi Terada, Akifumi Doura
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Publication number: 20130226429Abstract: A braking force control device can control braking forces of the respective wheels of a vehicle, suppresses an increase of the braking force of a first wheel that is a wheel having a relatively large slip amount in a pair of right/left wheels and increases the braking force of a second wheel that is a wheel having a relatively small slip amount. The braking force control device may suppress the increase of the braking force of the first wheel before the friction coefficient of a road surface to the first wheel reaches a peak and when the friction coefficient is in the vicinity of the peak. It is preferable to suppress the increase of the braking force of the first wheel by holding the braking force of the first wheel.Type: ApplicationFiled: November 2, 2011Publication date: August 29, 2013Applicants: ADVICS CO., LTD., TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Satoshi Udaka, Noritaka Yamada, Hideyuki Aizawa, Akifumi Doura
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Patent number: 7255407Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to the front wheels, taking into account auxiliary braking control such as braking assist control (BAS) executed when an abrupt or full braking action is performed by the driver. In BFD control a braking force on the rear wheels is held at a holding braking force and a braking force on the front wheels is incremented beyond a braking force requested by a braking action of the driver. After the starting of BFD control, further increase in the braking action is reflected in the braking force of the front wheels. When auxiliary braking control is executed, the holding braking force on the rear wheels and the increment of the braking force on the front wheels are determined based upon a demand of the auxiliary braking action as well as the braking action amount by the driver.Type: GrantFiled: April 2, 2004Date of Patent: August 14, 2007Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co., Ltd.Inventors: Chiaki Hamada, Akifumi Doura
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Patent number: 7168769Abstract: The brake system of the invention, during the ABS control mode, corrects the target slip rate in accordance with the turning of the vehicle, and determines whether the vehicle is running on a poor surface road. If the vehicle is running on a poor surface road, the system sets a target slip rate that provides a greater longitudinal force than the aforementioned target slip rate.Type: GrantFiled: December 15, 2003Date of Patent: January 30, 2007Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co., Ltd.Inventors: Toshihisa Nihei, Masahiro Hara, Masahiro Matsuura, Akifumi Doura
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Patent number: 7076357Abstract: A braking control device of a vehicle starts executing braking force distribution (BFD) biased to front wheels for avoiding the locking of rear wheels prior to the front wheel at appropriate time by reducing errors of a judgment of the starting of the control. Usually, the BFD control is started in response to the increase of a master cylinder pressure, assuming that the rear wheel braking pressure is equally increased. When a fast braking action occurs, the delay of the pressure variation of the rear wheel braking pressure relative to the master cylinder is conspicuous because the responsibility of a master cylinder pressure to the braking action is too fast.Type: GrantFiled: April 2, 2004Date of Patent: July 11, 2006Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co. LTDInventors: Chiaki Hamada, Akifumi Doura
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Patent number: 6928355Abstract: If a condition for starting a yaw control during an antiskid control is met while the antiskid control is being executed on one of right and left front wheels during braking on a uneven friction-coeffient road surface, the reference value for making the determination to start the antiskid control on the other one of the front wheels is reduced, and therefore the antiskid control is started at an earlier timing. If the antiskid control is executed on the wheel, the brake pressure of the wheel is controlled in a pre-set specific pattern.Type: GrantFiled: December 15, 2003Date of Patent: August 9, 2005Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co., Ltd.Inventors: Toshihisa Nihei, Satoshi Udaka, Yoshinori Suzuki, Akifumi Doura, Yasuhisa Kuwahata
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Publication number: 20040256912Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel, taking into account auxiliary braking control such as Braking assist control to be executed when an abrupt or full braking action is done by the driver. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. When the auxiliary braking control is executed, the holding braking force on the rear wheels and the increment of the braking force on the front wheels are determined based upon a demand of the auxiliary braking action as well as the braking action amount by the driver.Type: ApplicationFiled: April 2, 2004Publication date: December 23, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Chiaki Hamada, Akifumi Doura
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Publication number: 20040260447Abstract: A braking control device of a vehicle starts executing braking force distribution (BFD) biased to front wheels for avoiding the locking of rear wheels prior to the front wheel at appropriate time by reducing errors of a judgment of the starting of the control. Usually, the BFD control is started in response to the increase of a master cylinder pressure, assuming that the rear wheel braking pressure is equally increased. When a fast braking action occurs, the delay of the pressure variation of the rear wheel braking pressure relative to the master cylinder is conspicuous because the responsibility of a master cylinder pressure to the braking action is too fast.Type: ApplicationFiled: April 2, 2004Publication date: December 23, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Chiaki Hamada, Akifumi Doura
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Publication number: 20040260446Abstract: A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.Type: ApplicationFiled: April 2, 2004Publication date: December 23, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Chiaki Hamada, Akifumi Doura
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Publication number: 20040124701Abstract: The brake system of the invention, during the ABS control mode, corrects the target slip rate in accordance with the turning of the vehicle, and determines whether the vehicle is running on a poor surface road. If the vehicle is running on a poor surface road, the system sets a target slip rate that provides a greater longitudinal force than the aforementioned target slip rate.Type: ApplicationFiled: December 15, 2003Publication date: July 1, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Toshihisa Nihei, Masahiro Hara, Masahiro Matsuura, Akifumi Doura
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Publication number: 20040128052Abstract: If a condition for starting a yaw control during an antiskid control is met while the antiskid control is being executed on one of right and left front wheels during braking on a uneven friction-coeffient road surface, the reference value for making the determination to start the antiskid control on the other one of the front wheels is reduced, and therefore the antiskid control is started at an earlier timing. If the antiskid control is executed on the wheel, the brake pressure of the wheel is controlled in a pre-set specific pattern.Type: ApplicationFiled: December 15, 2003Publication date: July 1, 2004Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Toshihisa Nihei, Satoshi Udaka, Yoshinori Suzuki, Akifumi Doura, Yasuhisa Kuwahata