Patents by Inventor Atsushi Yokoyama

Atsushi Yokoyama 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: 8744689
    Abstract: To provide a vehicle motion control system capable of defining clear guidelines on more specific control timing associated with accelerating, steering, and braking operations, and conducting motion control based on the defined guidelines. An ideal motion control unit 42 within a central controller 40 uses longitudinal jerk information of a vehicle to control the steering of the vehicle. Information for determining the initiation timing of steering is presented from a human-vehicle interface (HVI) 55 to a driver. In accordance with the information presented from the HVI 55, the driver controls the initiation timing of steering.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: June 3, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Yamakado, Atsushi Yokoyama, Masato Abe
  • Publication number: 20140129090
    Abstract: A vehicle motion control system is capable of defining clear guidelines on more specific control timing associated with accelerating, steering, and braking operations, and conducting motion control based on the defined guidelines. An ideal motion control unit within a central controller uses longitudinal jerk information of a vehicle to control the steering of the vehicle. Information for determining the initiation timing of steering is presented from a human-vehicle interface (HVI) to a driver. In accordance with the information presented from the HVI, the driver controls the initiation timing of steering.
    Type: Application
    Filed: January 15, 2014
    Publication date: May 8, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Makoto YAMAKADO, Atsushi YOKOYAMA, Masato ABE
  • Patent number: 8708071
    Abstract: A cooling system for an electric vehicle includes: a cooling unit that cools an electric drive unit; and a control unit that controls cooling of the electric drive unit by controlling the cooling unit. The control unit controls the cooling unit in a first cooling mode that provides a first cooling capacity when a force for driving the electric vehicle due to the electric drive unit is in a first operational region, and controls the cooling unit in a second cooling mode that provides a second cooling capacity that is higher than the first cooling capacity when the force due to the electric drive unit is in a second operational region that is higher than the first operational region; and in the second cooling mode, the control unit controls the cooling unit so that the second cooling capacity becomes higher as a rotational speed of the electric drive unit decreases.
    Type: Grant
    Filed: August 25, 2010
    Date of Patent: April 29, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Masatsugu Arai, Shingo Nasu
  • Patent number: 8600657
    Abstract: According to conventional art, if there is an obstacle on the left of a vehicle, a control threshold value is set so as to avoid the obstacle. If the control threshold value is exceeded, the vehicle is controlled in accordance with a deviation quantity so as to return to a position where the control threshold avoids being exceeded. However, even if a risky oncoming vehicle is approaching the vehicle on the right, the vehicle is controllably moved toward the oncoming vehicle. Thus, disadvantageously, a driver has a sense of fear or discomfort.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: December 3, 2013
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Shinjiro Saito, Atsushi Yokoyama, Toshiharu Sugawara, Tatsuya Yoshida, Akira Takahashi
  • Publication number: 20130294888
    Abstract: A motor is provided which can detect a rotor temperature with high precision with a simple configuration not taking an influence on a temperature caused by circulation of a cooling oil into account. In a motor including a rotor, a stator arranged around the rotor, and a temperature sensor, the rotor includes an oil reservoir unit that reserves an oil on a rotating shaft line in an interior thereof, and the temperature sensor detects a temperature of the oil reserved in the oil reservoir unit.
    Type: Application
    Filed: February 21, 2011
    Publication date: November 7, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Itsuro Sawada
  • Publication number: 20130285486
    Abstract: A cooling system includes a cooling circuit that has a circulation pump circulating a coolant containing antifreeze solution and cools down, by means of the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine; a control signal calculation unit that calculates heat quantity generated by the power element; a power element temperature sensor that detects the temperature of the power element; and a coolant temperature sensor that detects the temperature of the coolant. The control signal calculation unit calculates, on the basis of the heat quantity, the temperature of the power element, and the coolant temperature, power element cooling performance that is the amount of heat transferred from the power element to the coolant per unit temperature difference, and lowers the driving power of the circulation pump when the calculated power element cooling performance is greater than a predetermined criterion.
    Type: Application
    Filed: January 12, 2012
    Publication date: October 31, 2013
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Yuto Imanishi, Atsushi Yokoyama, Hiroyuki Yamada
  • Patent number: 8536809
    Abstract: A controller for vector-controlled motor of vehicle judges whether a battery needs to be warmed up in accordance with an output of a battery temperature sensor, and when the battery needs to be warmed up, in situation (i) where the vehicle is stopped, sets a q-axis current value of the motor at zero, or when a brake is released from the situation (i), sets a q-axis current at a value corresponding to a drive torque for a vehicle creep operation, and sets a d-axis current at a value for battery warm-up. When the battery needs to be warmed up in situation (ii) where the vehicle is running, the controller sets a q-axis current at a value corresponding to a drive torque of vehicle running and sets a d-axis current at a value for the battery warm-up in relation to the q-axis current value.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: September 17, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Takao Kojima, Atsushi Yokoyama
  • Publication number: 20130118820
    Abstract: An electric drive system for a vehicle includes: an electric drive unit that electrically drives the vehicle; and a cooling unit that cools the electric drive unit, wherein: the electric drive unit and the cooling unit are mounted at a body frame of the vehicle via an elastic support member, the electric drive unit and the cooling unit being configured as an integrated unit.
    Type: Application
    Filed: August 25, 2010
    Publication date: May 16, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Masatsugu Arai, Tadashi Osaka, Itsuro Sawada
  • Patent number: 8430213
    Abstract: Provided is an electric brake capable of accurately estimating the brake pad temperature and securing a sufficient braking force and response. An electric brake has a disc rotor rotating with a wheel, an actuator for rectilinearly actuating a piston in the axial direction of the disc rotor by using an electric motor, a drive controller for controlling the drive of the actuator, a brake pad pressed by the piston to give a frictional resistance to the disc rotor in the direction of rotation, and a braking start position detector for detecting a braking start position of the piston where the disc rotor is brought into contact with the brake pad. The drive controller stores the braking start position detected by the braking start position detector as the maximum braking start position. When the braking start position shifts in the pressing force-increasing direction, the drive controller updates the value stored as the maximum braking-start position.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: April 30, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Yoshinari Kawahara, Satoru Kuragaki
  • Patent number: 8388071
    Abstract: A braking controller is equipped to provide braking force distribution of the required total braking force, to distribute the required total braking force by regeneration distribution. The regeneration distribution is required to be within a rear-wheel dominant range, in which the distribution ratio is inclined toward the rear-wheels when compared with an ideal distribution line that provides distribution enabling the front and rear wheels to simultaneously lock, as well as within a range that is not greater than a rear-wheel locking limit enabling the rear wheels to lock in relation to a road-surface friction coefficient upon braking. A rear-wheel braking force change ratio, which is a change ratio of the rear-wheel braking force with regard to a change of the front-wheel braking force associated with the change of the required total braking force, is required to always be positive.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: March 5, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Hidekazu Moriki, Masaru Ito
  • Patent number: 8382223
    Abstract: An image forming apparatus includes a computing unit to compute an amount of ink to be used to record raster data if a remaining amount of ink reaches a predetermined amount, and a recording control part to enable the recording if the remaining amount of ink is greater than the amount of ink computed by the computing unit. The recording control part disables the recording if the remaining amount of ink is less than or equal to the amount of ink computed by the computing unit.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: February 26, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Yokoyama, Kohichi Sadano, Satoshi Miyazaki, Masaharu Ohtani, Yoshiaki Satoh
  • Publication number: 20130031393
    Abstract: An information processing apparatus includes a control unit to control the apparatus, a power supplying control unit to control power supply and a stop of the power supply to the control unit, a receiving unit to receive data from outside, and a response unit to generate and send first response data with respect to first received data received by the receiving unit while the power supply to the control unit is stopped, when the response unit verifies the first received data are predetermined data capable of being responded to by the response unit. The control unit includes a unit to send an instruction to make the power supplying control unit stop the power supply to the control unit, in a predetermined condition while the power is supplied to the control unit.
    Type: Application
    Filed: July 2, 2012
    Publication date: January 31, 2013
    Inventor: Atsushi YOKOYAMA
  • Patent number: 8346436
    Abstract: A driving support system includes a lane detecting unit for detecting lanes around a vehicle, a route correcting unit for correcting a route along which the vehicle is expected to travel taking into consideration an obstacle on the route after the route has been recognized by lanes detected by the lane detecting unit, and a control unit for controlling the vehicle on the basis of the positional relation between the corrected route determined by the route correcting unit and the vehicle.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: January 1, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Yokoyama, Shinjiro Saito, Masatsugu Arai, Tatsuya Yoshida
  • Patent number: 8247762
    Abstract: Molecules of a specific species can be selectively excited among molecules of a plurality of species that show only a slight difference of mass. Energy levels can be displayed on a graph where the horizontal axis indicates excitation energy. Assume an instance where an electromagnetic wave showing a comb-shaped spectrum having a plurality of narrow bands as indicated by P1 through P14 and tuning with excitation energies corresponding to the rotational levels of molecule X is irradiated onto the molecule X. The molecule X can sequentially make transitions to higher energy levels by using an electromagnetic wave showing such a comb-shaped spectrum. The energy levels of molecule Y are not synchronized with the comb-shaped spectrum. The two ranges of Y4 through Y7 and Y12 through Y15 operate as gates and the molecule Y cannot make transition from a rotational level to another when a gate is found between them.
    Type: Grant
    Filed: September 22, 2010
    Date of Patent: August 21, 2012
    Assignee: Japan Atomic Energy Agency
    Inventors: Keiichi Yokoyama, Leo Matsuoka, Hiroshi Akagi, Tatsuya Kasajima, Masaaki Tsubouchi, Atsushi Yokoyama
  • Publication number: 20120209489
    Abstract: There is provided a vehicle motion control device that defines a pre-curve entry deceleration amount taking the deceleration amount that occurs while traveling a curve into consideration. A vehicle motion control device 6 comprises: a lateral motion-coordinated acceleration/deceleration calculation means 11 that calculates lateral motion-coordinated acceleration/deceleration Gx_dGy, which is the longitudinal acceleration/deceleration of a vehicle 0 that is coordinated with lateral motion, in accordance with lateral jerk Gy_max that acts on the vehicle 0 at curve entry; and a vehicle speed control device 12, which calculates pre-curve entry deceleration Gx_preC that is to be generated with respect to the vehicle 0 before entering the curve, taking lateral motion-coordinated acceleration/deceleration Gx_dGy calculated by the lateral motion-coordinated acceleration/deceleration calculation device 11 into consideration.
    Type: Application
    Filed: August 10, 2010
    Publication date: August 16, 2012
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Shinjiro Saito, Junya Takahashi, Atsushi Yokoyama, Makoto Yamakado
  • Publication number: 20120200241
    Abstract: A controller for vector-controlled motor of vehicle judges whether a battery needs to be warmed up in accordance with an output of a battery temperature sensor, and when the battery needs to be warmed up, in situation (i) where the vehicle is stopped, sets a q-axis current value of the motor at zero, or when a brake is released from the situation (i), sets a q-axis current at a value corresponding to a drive torque for a vehicle creep operation, and sets a d-axis current at a value for battery warm-up. When the battery needs to be warmed up in situation (ii) where the vehicle is running, the controller sets a q-axis current at a value corresponding to a drive torque of vehicle running and sets a d-axis current at a value for the battery warm-up in relation to the q-axis current value.
    Type: Application
    Filed: February 2, 2012
    Publication date: August 9, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Takao KOJIMA, Atsushi YOKOYAMA
  • Publication number: 20120179349
    Abstract: There is provided a vehicle drive control system that feels less unnatural and that enables an improvement in safety performance. A vehicle motion control system capable of independently controlling a driving force and a braking force of four wheels comprises: a first mode (G-Vectoring control) in which substantially the same driving force and braking force are generated with respect to left and right wheels among the four wheels based on a longitudinal acceleration/deceleration control command that is coordinated with the vehicle's lateral motion; and a second mode (sideslip prevention control) in which different driving forces and braking forces are generated with respect to the left and right wheels among the four wheels based on a target yaw moment derived from the vehicle's sideslip information, wherein the first mode is selected when the target yaw moment is equal to or less than a pre-defined threshold, and the second mode is selected when the target yaw moment is greater than the threshold (FIG. 11).
    Type: Application
    Filed: August 2, 2010
    Publication date: July 12, 2012
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Makoto Yamakado, Shinjiro Saito, Atsushi Yokoyama, Junya Takahashi, Tatsuya Yoshida
  • Publication number: 20120123624
    Abstract: A running control device for an electric vehicle includes: a first calculation unit that calculates a predetermined reference torque required for braking/driving the motor that provides a beneficial effect with regard to power consumption of the electric vehicle; a second calculation unit that calculates interval allocation between a first interval in which the electric vehicle is propelled by braking/driving the motor at the predetermined reference torque and a second interval in which the electric vehicle is coasted without the motor being braked or driven; a third calculation unit that calculates a control requested torque for braking/driving the motor intermittently, so as alternatingly to repeat running of the electric vehicle in the first intervals and coasting of the electric vehicle in the second intervals; and a running control unit that performs running control of the electric vehicle by braking/driving the motor intermittently according to the control requested torque.
    Type: Application
    Filed: November 15, 2011
    Publication date: May 17, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Shinya SATO, Naoyuki Tashiro, Kentaro Maki, Atsushi Yokoyama
  • Patent number: 8165776
    Abstract: A drive assist system includes an assist starting part starting assist, a detection part detecting relative distances and speeds between a vehicles, a calculation part calculating collision risks when changing a lane by the basis of the relative distances and speeds, a first judgment part judging whether the lane can be changed by the relative distances, speeds and the collision risks, a decision part deciding a target space for lane change by the relative distances and speeds when the lane cannot be changed, a second judgment part judging whether a lane changeable space is in the target space, a setting part setting a target speed for the vehicle go to a lane change waiting position when no space and to setting a target speed the vehicle enters a lane changeable position when there is the space, and a control part controlling a speed of the vehicle reaches the target speed.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: April 24, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Toshiharu Sugawara, Atsushi Yokoyama, Takaomi Nishigaito, Masatoshi Hoshino, Tatsuya Yoshida, Jun Kubo, Shinjiro Saito
  • Publication number: 20120049664
    Abstract: A drive unit for an electric vehicle comprises a device that electrically drives a vehicle, a heat transport system for transporting heat absorbed from the device into the vehicle interior air, and a heat-radiation adjusting system for adjusting heat radiating from the device into the ambient air.
    Type: Application
    Filed: August 19, 2011
    Publication date: March 1, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Atsushi YOKOYAMA, Tadashi Osaka, Yuto Imanishi, Sachio Sekiya