Patents by Inventor Masatoshi Nakatsu

Masatoshi Nakatsu 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).

  • Patent number: 10046643
    Abstract: In order to enable satisfactory vehicle motion control to be carried out while wheels (10) are being braked, on a vehicle in which each of the wheels (10) is braked by a regenerative braking force by a motor (30) and a friction braking force by a friction brake mechanism (40), a brake ECU (53) acquires at least one parameter out of a steering angle, a steering velocity, a lateral acceleration of a vehicle body, a yaw rate of the vehicle body, a sprung vertical acceleration, and an unsprung vertical acceleration, and when a magnitude of the parameter is more than a threshold, decreases a ratio of the regenerative braking force out of a driver-requested braking force, and increases a ratio of the friction braking force.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: August 14, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Publication number: 20170106755
    Abstract: A vehicle control apparatus includes a controller configured to change a ratio between a regenerative braking force and a frictional braking force, in a specific wheel among wheels, such that the ratio in the specific wheel differs from the ratio between the regenerative braking force and the frictional braking force in each of the other wheels, when a command to generate the require braking force is issued and a vehicle motion control is executed.
    Type: Application
    Filed: October 14, 2016
    Publication date: April 20, 2017
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi NAKATSU
  • Patent number: 9475404
    Abstract: A wheel control device configured to control a plurality of wheels (11-14) mounted on a vehicle (10) includes a controller (110) configured to perform feedback control of a motor (21-24), which is mounted to each of the plurality of wheels (11-14) in order to drive the each of the plurality of wheels, so that a driving torque of the motor follows a target torque. The controller (110) reduces, for a motor driving a subject wheel that has received a predetermined road surface input among the plurality of wheels (11-14), a feedback amount relating to the feedback control to be less than a feedback amount before the subject wheel receives the road surface input.
    Type: Grant
    Filed: October 10, 2012
    Date of Patent: October 25, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Publication number: 20160159225
    Abstract: In order to enable satisfactory vehicle motion control to be carried out while wheels (10) are being braked, on a vehicle in which each of the wheels (10) is braked by a regenerative braking force by a motor (30) and a friction braking force by a friction brake mechanism (40), a brake ECU (53) acquires at least one parameter out of a steering angle, a steering velocity, a lateral acceleration of a vehicle body, a yaw rate of the vehicle body, a sprung vertical acceleration, and an unsprung vertical acceleration, and when a magnitude of the parameter is more than a threshold, decreases a ratio of the regenerative braking force out of a driver-requested braking force, and increases a ratio of the friction braking force.
    Type: Application
    Filed: November 30, 2015
    Publication date: June 9, 2016
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi NAKATSU
  • Patent number: 9283936
    Abstract: An electronic control unit of a braking force control apparatus for a vehicle activates, as a first state, in-wheel motors in a regeneration state, thereby generating motor braking torques, and causes friction brake mechanisms to generate friction braking forces. Moreover, the unit activates, as a second state, the motors in a power running state, thereby generating motor driving torques, and causes the mechanisms to generate friction braking forces. Then, when the state is caused to transition between the first state and the second state, the unit changes magnitudes of the braking torques or the driving torques generated by the motors to one of increase and decrease, and changes magnitudes of the friction braking forces generated by the mechanisms to one of increase and decrease.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: March 15, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Daisuke Akaho, Masatoshi Nakatsu
  • Patent number: 9283959
    Abstract: In order to control a behavior generated on a body as a result of a travel of a vehicle, an electronic control unit controls rotation of each of in-wheel motors, thereby generating a predetermined braking force or driving force approximately the same in magnitude on each wheel. Meanwhile, the electronic control unit uses respective pipelines and a direction control circuit depending on the behavior generated on the body to connect fluid pressure cylinders on a fluid pressure supplying side and fluid pressure cylinders on a fluid pressure supplied side to each other for communication. As a result, the fluid pressure cylinders convert vertical forces of the body acting as component forces of a predetermined braking/driving force into hydraulic pressures and supply the fluid pressure cylinders with the hydraulic pressures, and the fluid pressure cylinders convert the supplied hydraulic pressures into vertical forces, thereby exerting the vertical forces on the body.
    Type: Grant
    Filed: February 24, 2012
    Date of Patent: March 15, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Patent number: 9233689
    Abstract: When an ECU carries out vehicle yaw motion control on such a vehicle that a conversion rate of converting the braking/driving force into a vertical force is larger on rear wheels than on front wheels, a driver-requested braking/driving force is distributed to the four wheels so that a distribution ratio is larger for the rear wheels than for the front wheels. Thus, when roll control necessary as a result of the vehicle yaw motion control is carried out, a target braking/driving force of a turning outer wheel for which the largest control driving force is required becomes hard to reach a driving limit. From the foregoing, when vehicle motion control is carried out with use of a braking/driving force of each wheel, each wheel is prevented from reaching a driving force limit as much as possible.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: January 12, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Patent number: 9227637
    Abstract: When a braking/driving force on each wheel is used for vehicle motion control, in order to reduce a noise generated by a zero cross of a motor torque, provided is a distribution setting part, which is to be applied to a vehicle configured so that a conversion rate of converting a braking/driving force on the wheel into a force in a vertical direction of a body by a suspension is different between a front wheel side and a rear wheel side. The distribution setting part sets distributions of a driver-requested driving force to front/rear wheels so as to be larger to the wheels coupled to the suspensions smaller in conversion rate than to the wheels coupled to the suspensions larger in conversion rate. As a result, a zero cross of a motor torque is restrained, resulting in a reduction in generation of a noise caused by a backlash of speed reduction gears.
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: January 5, 2016
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Publication number: 20150298575
    Abstract: A wheel control device configured to control a plurality of wheels (11-14) mounted on a vehicle (10) includes a controller (110) configured to perform feedback control of a motor (21-24), which is mounted to each of the plurality of wheels (11-14) in order to drive the each of the plurality of wheels, so that a driving torque of the motor follows a target torque. The controller (110) reduces, for a motor driving a subject wheel that has received a predetermined road surface input among the plurality of wheels (11-14), a feedback amount relating to the feedback control to be less than a feedback amount before the subject wheel receives the road surface input.
    Type: Application
    Filed: October 10, 2012
    Publication date: October 22, 2015
    Inventor: Masatoshi NAKATSU
  • Publication number: 20150158493
    Abstract: When a braking/driving force on each wheel is used for vehicle motion control, in order to reduce a noise generated by a zero cross of a motor torque, provided is a distribution setting part, which is to be applied to a vehicle configured so that a conversion rate of converting a braking/driving force on the wheel into a force in a vertical direction of a body by a suspension is different between a front wheel side and a rear wheel side. The distribution setting part sets distributions of a driver-requested driving force to front/rear wheels so as to be larger to the wheels coupled to the suspensions smaller in conversion rate than to the wheels coupled to the suspensions larger in conversion rate. As a result, a zero cross of a motor torque is restrained, resulting in a reduction in generation of a noise caused by a backlash of speed reduction gears.
    Type: Application
    Filed: October 15, 2014
    Publication date: June 11, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi NAKATSU
  • Publication number: 20150105978
    Abstract: When an ECU carries out vehicle yaw motion control on such a vehicle that a conversion rate of converting the braking/driving force into a vertical force is larger on rear wheels than on front wheels, a driver-requested braking/driving force is distributed to the four wheels so that a distribution ratio is larger for the rear wheels than for the front wheels. Thus, when roll control necessary as a result of the vehicle yaw motion control is carried out, a target braking/driving force of a turning outer wheel for which the largest control driving force is required becomes hard to reach a driving limit. From the foregoing, when vehicle motion control is carried out with use of a braking/driving force of each wheel, each wheel is prevented from reaching a driving force limit as much as possible.
    Type: Application
    Filed: October 15, 2014
    Publication date: April 16, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi NAKATSU
  • Patent number: 8954249
    Abstract: A braking force control apparatus for a vehicle estimates the friction coefficient ? of a road surface as the state of the road surface on which the vehicle travels, and determines an ideal braking force ?W by making use of the estimated road surface friction coefficient ?. When ? is equal to or greater than a predetermined friction coefficient ?0, the braking force control apparatus operates an in-wheel motor in a regeneration state to generate a motor braking torque Tmr, and causes a friction brake mechanism to generate a frictional braking force Bf computed by subtracting Tmr from ?W. When ? is less than ?0, the braking force control apparatus operates the in-wheel motor in a power running state to generate a motor driving torque Tmc, and causes the friction brake mechanism to generate a Bf computed by adding Tmc to ?W.
    Type: Grant
    Filed: August 30, 2010
    Date of Patent: February 10, 2015
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masatoshi Nakatsu, Fumito Kurata
  • Patent number: 8948971
    Abstract: Disclosed is a steering control device capable of adjusting reference points of a plurality of motions, which are used for a steering operation in a steering operating unit, with high precision. In the steering control device, a control unit performs N-point learning under the condition that the absolute value of an operating amount in operation systems other than a target is smaller than a predetermined value (or substantially 0). This makes it possible to suppress the influence of operation systems other than the target on the steering of a vehicle M during N-point learning, making it possible to learn the N point in the operation system of the target with high precision. With this N-point learning for each target, even in an operation system which can be steered through a plurality of motions, it is possible to learn the N point of each motion with high precision.
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: February 3, 2015
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masatoshi Nakatsu
  • Publication number: 20150032333
    Abstract: In order to control a behavior generated on a body as a result of a travel of a vehicle, an electronic control unit controls rotation of each of in-wheel motors, thereby generating a predetermined braking force or driving force approximately the same in magnitude on each wheel. Meanwhile, the electronic control unit uses respective pipelines and a direction control circuit depending on the behavior generated on the body to connect fluid pressure cylinders on a fluid pressure supplying side and fluid pressure cylinders on a fluid pressure supplied side to each other for communication. As a result, the fluid pressure cylinders convert vertical forces of the body acting as component forces of a predetermined braking/driving force into hydraulic pressures and supply the fluid pressure cylinders with the hydraulic pressures, and the fluid pressure cylinders convert the supplied hydraulic pressures into vertical forces, thereby exerting the vertical forces on the body.
    Type: Application
    Filed: February 24, 2012
    Publication date: January 29, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Publication number: 20140207355
    Abstract: An electronic control unit of a braking force control apparatus for a vehicle activates, as a first state, in-wheel motors in a regeneration state, thereby generating motor braking torques, and causes friction brake mechanisms to generate friction braking forces. Moreover, the unit activates, as a second state, the motors in a power running state, thereby generating motor driving torques, and causes the mechanisms to generate friction braking forces. Then, when the state is caused to transition between the first state and the second state, the unit changes magnitudes of the braking torques or the driving torques generated by the motors to one of increase and decrease, and changes magnitudes of the friction braking forces generated by the mechanisms to one of increase and decrease.
    Type: Application
    Filed: August 29, 2011
    Publication date: July 24, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Daisuke Akaho, Masatoshi Nakatsu
  • Publication number: 20130173127
    Abstract: A braking force control apparatus for a vehicle estimates the friction coefficient ? of a road surface as the state of the road surface on which the vehicle travels, and determines an ideal braking force ?W by making use of the estimated road surface friction coefficient ?. When ? is equal to or greater than a predetermined friction coefficient ?0, the braking force control apparatus operates an in-wheel motor in a regeneration state to generate a motor braking torque Tmr, and causes a friction brake mechanism to generate a frictional braking force Bf computed by subtracting Tmr from ?W. When ? is less than ?0, the braking force control apparatus operates the in-wheel motor in a power running state to generate a motor driving torque Tmc, and causes the friction brake mechanism to generate a Bf computed by adding Tmc to ?W.
    Type: Application
    Filed: August 30, 2010
    Publication date: July 4, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masatoshi Nakatsu, Fumito Kurata
  • Publication number: 20130035826
    Abstract: Disclosed is a steering control device capable of adjusting reference points of a plurality of motions, which are used for a steering operation in a steering operating unit, with high precision. In the steering control device, a control unit performs N-point learning under the condition that the absolute value of an operating amount in operation systems other than a target is smaller than a predetermined value (or substantially 0). This makes it possible to suppress the influence of operation systems other than the target on the steering of a vehicle M during N-point learning, making it possible to learn the N point in the operation system of the target with high precision. With this N-point learning for each target, even in an operation system which can be steered through a plurality of motions, it is possible to learn the N point of each motion with high precision.
    Type: Application
    Filed: February 25, 2010
    Publication date: February 7, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masatoshi Nakatsu
  • Patent number: 8051944
    Abstract: In a steering apparatus, a differential lock mechanism has a lock holder in which a plurality of groove portions are formed on an outer periphery thereof, and selectively allows and prohibits to generate a difference of steering amount in the rotational direction between an input shaft and an output shaft by selectively engaging and disengaging an engaging portion with respect to the groove portions. A rotation sensor detects the position in the rotational direction of the lock holder during one rotation of the lock holder and repeatedly detects the same sensor pattern being output a plurality of times. A variable transfer ratio unit ECU detects which groove portion, from among the plurality of groove portions, the engaging portion is engaged with using the sensor pattern output by the rotation sensor when a side portion of one of the groove portions is pressing against a side portion of the engaging portion.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: November 8, 2011
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masatoshi Nakatsu
  • Patent number: 7974754
    Abstract: A vehicle steering control system includes a variable transmission ratio device that rotates an output shaft relative to an input shaft so as to change the transmission ratio, and a locking device that is switched between a lock-on state in which the transmission ratio between the input shaft and the output shaft is inhibited from being changed and a lock-off state in which the transmission ratio between the input shaft and the output shaft is allowed to be changed. The variable transmission ratio device includes an electric motor and a speed reduction mechanism. The locking device inhibits the input shaft and a rotor of the electric motor from rotating relative to each other when placed in the lock-on state, and allows the input shaft and the rotor to rotate relative to each other when placed in the lock-off state.
    Type: Grant
    Filed: April 9, 2008
    Date of Patent: July 5, 2011
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masatoshi Nakatsu
  • Patent number: 7789784
    Abstract: In a steering device (200), a first motor (34a) operates in accordance with a steering operation of a steering handle (12), a first steering shaft (52) steers one of the pair of wheels (58), and a first conversion unit converts a rotation of a first rotor (31 a) as a rotation element of the first motor (31a) into an axial-direction movement of the first steering shaft (52). A second motor (34b) operates in accordance with the steering operation of the steering handle (12), a second steering shaft (53) is separated from the first steering shaft (52) and steers the other of the pair of wheels (58), and a second conversion unit converts a rotation of a second rotor (31b) as a rotation element of the second motor (34b) into an axial-direction movement of the second steering shaft (53). A coupling unit (60) couples the first rotor (31a) and the second rotor (31b) together and cancels the coupling of the first rotor (31a) and the second rotor (31b).
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: September 7, 2010
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenji Hayashi, Masatoshi Nakatsu