Patents by Inventor Ryoso Masaki

Ryoso Masaki 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).

  • Publication number: 20020088653
    Abstract: An electric vehicle is provided. The electric vehicle can minimize required energy based on position control for keeping the electric vehicle not being moved downward on a sloping road when a driver steps on the brake pedal even if the brake force is weak.
    Type: Application
    Filed: March 7, 2002
    Publication date: July 11, 2002
    Applicant: Hitachi Ltd.
    Inventors: Yuusuke Takamoto, Ryoso Masaki
  • Patent number: 6404152
    Abstract: In order to reduce undesired sound caused by circular ring oscillation in the diametric direction of the stator by an electromagnetic force, electromagnetic force drift memory stores a drift information of the electromagnetic force causing the circular ring oscillation of the stator. This electromagnetic force drift information is read out according to the position information &thgr; and is supplied to a correction coefficient generating circuitry. Correction coefficient generating circuitry corrects the amplitude component of the activation current wave from by forming correction coefficient &bgr; (t) of the activation current so as to cancel the electromagnetic force harmonic component in the diametric direction which component is the component of the circular ring oscillation of the stator.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: June 11, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Kobayashi, Fumio Tajima, Shoichi Kawamata, Yutaka Matsunobu, Ryoso Masaki, Suetaro Shibukawa, Osamu Koizumi
  • Publication number: 20020065162
    Abstract: A vehicle provided with an engine 1 which generates a driving energy for the vehicle, planetary gears 4 and 6 comprising sun gears, planet gears and ring gears, motors 8 and 9 for respectively controlling the sun gears, and a clutch 14, the planet gears being connected to an input shaft driven by the engine and the ring gears connected to an output shaft for driving wheels, wherein gear ratios from the input shafts to the output shafts in the planetary gears 4 and 6 are set at a value different to each other. A stepless speed changing function which permits vehicular operation in a high engine efficiency region while minimizing an electrical energy loss is realized by a small-sized transmission using small-sized motors. The vehicle, which uses the transmission, can be operated in a high engine efficiency region while keeping an electrical energy loss to a minimum.
    Type: Application
    Filed: January 18, 2002
    Publication date: May 30, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Satoru Kaneko, Yutaka Matsunobu, Ryoso Masaki
  • Publication number: 20020043953
    Abstract: A synchronous motor control system includes a synchronous motor 1, an inverter 3 and a controller 4 wherein a current differential detecting unit 13 detects a variation of a motor current when the three phases of the motor 1 is short circuited by the inverter 3, namely at the moment when a carrier wave in a PWM signal generator 9 assumes maximum or minimum value, in a calculating unit 14 a phase &ggr; from &agr; axis of a stationary coordinate system to a three phase short circuited current differential vector is calculated, a phase &dgr; is estimated from d axis to the three phase short circuited current differential vector by making use of d axis current id and q axis current iq on d-q axes coordinate system in the controller 4, thereafter the magnetic pole position &thgr; with respect to &agr; axis is calculated from the phases &ggr; and &dgr;, based on thus calculated magnetic pole position &thgr;, d-q axes control units 11, 7 and 8 are constituted to control the synchronous motor, thereby a highly reliab
    Type: Application
    Filed: May 29, 2001
    Publication date: April 18, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Ryoso Masaki, Satoru Kaneko
  • Publication number: 20020036106
    Abstract: In a driving system comprising an engine, a plurality of motor-generators and a plurality of coaxial differential mechanisms, rotating output axes of the plurality of motor-generators are disposed parallel to and opposite to a rotating output axis of the engine. The coaxial differential mechanisms are arranged between the engine and the motors. The coaxial differential mechanisms are disposed so that straight lines passing through rotating axes of at least two of the coaxial differential mechanisms are parallel to each other, and the output power of the engine is transmitted to the coaxial differential mechanisms through gears. It is possible to provide a small sized and high productive driving system.
    Type: Application
    Filed: December 6, 2001
    Publication date: March 28, 2002
    Inventors: Tomoyuki Hanyu, Ryoso Masaki, Masahiko Amano, Taizo Miyazaki, Yasuo Morooka
  • Patent number: 6360625
    Abstract: The invention provides a power transmission apparatus having a reduced power transmission loss. In the power transmission apparatus, an input shaft side variable pitch circle gear, an output shaft side variable pitch circle gear and a cycloid sliding gear which have a shape accumulated by a cycloid gear in which a pitch circle continuously changes are meshed with each other. The cycloid sliding gear slides and an engagement position thereof changes, thereby changing a radius of an engagement pitch circle of the gear so as to change a shift ratio.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: March 26, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Taizo Miyazaki, Toshimichi Minowa, Tomoyuki Hanyu, Ryoso Masaki, Yasuo Morooka
  • Publication number: 20010052760
    Abstract: In an automobile power supply where plural voltages can be supplied, a plurality of batteries and a DC/DC converter are assumed to be unnecessary, and it is possible to operate even when the controller breaks down.
    Type: Application
    Filed: June 19, 2001
    Publication date: December 20, 2001
    Applicant: Hitachi, Ltd.
    Inventors: Masahiko Amano, Ryoso Masaki, Yasuo Morooka
  • Patent number: 6328670
    Abstract: Disclosed is a power transmission apparatus for an automobile comprising an engine 1, a generator 15 driven by an output of the engine 1, and a motor 29 driven by a generation output of the generator 15 and a discharge output of a battery 47, wherein a clutch mechanism 23 is provided between an output shaft of the engine 1 and an output shaft of the generator 15. In a hybrid vehicle, a loss caused by an inertia torque of the generator can be avoided.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: December 11, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshimichi Minowa, Ryoso Masaki, Toshiyuki Innami, Yuzo Kadomukai
  • Patent number: 6320349
    Abstract: A power corresponding to an A/C voltage command id1* is applied in the d-axis direction of rotational coordinates of a stopped synchronous motor via a current control unit, a three-phase converting unit, and a power converter. Further, by using “an amplitude value of a current iq′ in the q-axis direction of the rotational coordinates generated in response to the A/C voltage command id1*” which is fed back and detected via a current detector and a dq converting unit, a field pole position estimation value &thgr;{circumflex over ( )} is converged. The field pole position is estimated by using the converged field pole position estimation value &thgr;{circumflex over ( )} as a true value of the field pole position &thgr; of the synchronous motor.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: November 20, 2001
    Inventors: Satoru Kaneko, Ryoso Masaki, Yuusuke Takamoto, Taizou Miyazaki, Sanshiro Obara
  • Patent number: 6318486
    Abstract: In a series-parallel hybrid vehicle, a check is made to see if there is any trouble of a clutch such as slip or overheating in an engaged state of the clutch, and upon detection of a clutch trouble, the vehicle is driven in accordance with a series hybrid type to prevent driving characteristics from being deteriorated by the clutch trouble.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: November 20, 2001
    Assignee: Hitachi, Ltd.
    Inventor: Ryoso Masaki
  • Publication number: 20010019224
    Abstract: A power controller for a vehicle can operate electrical load upon stopping of engine or turning OFF of a key switch, and lowering of remaining capacity of a main battery can be prevented. The control system has a control portion controlling operation of a power generator and an electrical load mounted on an automotive vehicle. The control system also includes remaining capacity measuring means for measuring a remaining capacity of a battery. The control portion drives a predetermined power load when an engine is stopped or a key switch is held OFF, and operation of the power load is stopped when a remaining capacity of the battery measured by the remaining capacity measuring means becomes smaller than a predetermined value.
    Type: Application
    Filed: February 27, 2001
    Publication date: September 6, 2001
    Applicant: Hitachi, Ltd.
    Inventors: Masahiko Amano, Ryoso Masaki, Yasuo Morooka
  • Publication number: 20010017227
    Abstract: A hybrid vehicle is disclosed, in which the drive torque is controlled according to a target, and the engine operating point and the battery charging rate are controlled thereby as targeted to improve the fuel consumption rate of the hybrid vehicle as a whole An engine torque estimating unit estimates the engine torque based on the motor current, and an engine output correction unit.
    Type: Application
    Filed: May 8, 2001
    Publication date: August 30, 2001
    Inventors: Masahiko Amano, Ryoso Masaki, Taizo Miyazaki, Tomoyuki Hanyu
  • Patent number: 6281656
    Abstract: A synchronous motor control system includes a synchronous motor 1, an inverter 3 and a controller 4 wherein a current differential detecting unit 13 detects a variation of a motor current when the three phases of the motor 1 is short circuited by the inverter 3, namely at the moment when a carrier wave in a PWM signal generator 9 assumes maximum or minimum value, in a calculating unit 14 a phase &ggr; from &agr; axis of a stationary coordinate system to a three phase short circuited current differential vector is calculated, a phase &dgr; is estimated from d axis to the three phase short circuited current differential vector by making use of d axis current id and q axis current iq on d-q axes coordinate system in the controller 4, thereafter the magnetic pole position &thgr; with respect to &agr; axis is calculated from the phases &ggr; and &dgr;, based on thus calculated magnetic pole position &thgr;, d-q axes control units 11, 7 and 8 are constituted to control the synchronous motor, thereby a highly reliab
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: August 28, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Ryoso Masaki, Satoru Kaneko
  • Publication number: 20010016536
    Abstract: Disclosed is a power transmission apparatus for an automobile comprising an engine 1, a generator 15 driven by an output of the engine 1, and a motor 29 driven by a generation output of the generator 15 and a discharge output of a battery 47, wherein a clutch mechanism 23 is provided between an output shaft of the engine 1 and an output shaft of the generator 15. In a hybrid vehicle, a loss caused by an inertia torque of the generator can be avoided.
    Type: Application
    Filed: April 27, 2001
    Publication date: August 23, 2001
    Applicant: HITACHI, LTD.
    Inventors: Toshimichi Minowa, Ryoso Masaki, Toshiyuki Innami, Yuzo Kadomukai
  • Publication number: 20010009878
    Abstract: A vehicle provided with an engine 1 which generates a driving energy for the vehicle, planetary gears 4 and 6 comprising sun gears, planet gears and ring gears, motors 8 and 9 for respectively controlling the sun gears, and a clutch 14, the planet gears being connected to an input shaft driven by the engine and the ring gears connected to an output shaft for driving wheels, wherein gear ratios from the input shafts to the output shafts in the planetary gears 4 and 6 are set at a value different to each other. A stepless speed changing function which permits vehicular operation in a high engine efficiency region while minimizing an electrical energy loss is realized by a small-sized transmission using small-sized motors. The vehicle, which uses the transmission, can be operated in a high engine efficiency region while keeping an electrical energy loss to a minimum.
    Type: Application
    Filed: March 14, 2001
    Publication date: July 26, 2001
    Inventors: Satoru Kaneko, Yutaka Matsunobu, Ryoso Masaki
  • Publication number: 20010008859
    Abstract: Disclosed herein is a transmission comprising a mechanism for distributing energy of a drive source into a plurality of differential mechanisms; a plurality of motors connected to said plurality of differential mechanisms, respectively; and a mechanism for synthesizing energies outputted from said plurality of differential mechanisms.
    Type: Application
    Filed: March 9, 2001
    Publication date: July 19, 2001
    Applicant: Hitachi, Ltd.
    Inventor: Ryoso Masaki
  • Patent number: 6258006
    Abstract: Disclosed is a transmission comprising a first power transfer path for transferring an output of an engine to a vehicle driving shaft through a planetary gear connected to a motor, a second power transfer path for transferring the output of the engine to the vehicle driving shaft through gears and, and a power transfer switch which switches over the first and second power transfer paths from one to the other. In a hybrid vehicle wherein an engine, a motor and a generator are connected to a planetary gear, a follow-up loss caused by the generator is avoided in the case where the engine stops and the vehicle travels with the motor alone. In high-speed running, it is avoided that an electric energy for stopping the rotation of the generator is consumed. Further, torque assist by the generator is not restricted by constraints of the planetary gear.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: July 10, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Tomoyuki Hanyu, Hiroshi Sakamoto, Toshimichi Minowa, Taizo Miyazaki, Ryoso Masaki
  • Patent number: 6255798
    Abstract: A more compact and light-weight drive unit is required for an electric vehicle in order to improve its mileage per charge, acceleration performance and overall efficiency. A control apparatus which generates drive signals to drive power devices in the power converter includes: a current reference generator calculates from a torque reference value a d-axis exciting current reference value on the basis of which the ac motor generates a magnetic flux, and a q-axis torque current reference value, the d-axis and the q-axis being orthogonal to each other; a current control circuit generates ac voltage reference values Vu*, Vv* and Vw* from the d-axis exciting current reference value and the q-axis torque current reference value; and a drive signal generator generates drive signals to drive power devices from the ac voltage reference values. Both the current reference generator and the current control circuit are processed digitally by the same arithmetic unit.
    Type: Grant
    Filed: October 23, 1996
    Date of Patent: July 3, 2001
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Sanshiro Obara, Ryoso Masaki, Yuusuke Takamoto, Eiichi Ohtsu, Hiroyuki Yamada
  • Publication number: 20010004027
    Abstract: In a series-parallel hybrid vehicle, a check is made to see if there is any trouble of a clutch such as slip or overheating in an engaged state of the clutch, and upon detection of a clutch trouble, the vehicle is driven in accordance with a series hybrid type to prevent driving characteristics from being deteriorated by the clutch trouble.
    Type: Application
    Filed: February 8, 2001
    Publication date: June 21, 2001
    Applicant: Hitachi, Ltd.
    Inventor: Ryoso Masaki
  • Patent number: 6248036
    Abstract: Disclosed herein is a transmission comprising a mechanism for distributing energy of a drive source into a plurality of differential mechanisms; a plurality of motors connected to said plurality of differential mechanisms, respectively; and a mechanism for synthesizing energies outputted from said plurality of differential mechanisms.
    Type: Grant
    Filed: February 1, 2000
    Date of Patent: June 19, 2001
    Assignee: Hitachi, Ltd.
    Inventor: Ryoso Masaki