Patents by Inventor Isao Kezobo

Isao Kezobo 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: 8326493
    Abstract: A motor-driven power steering control apparatus is achieved, which uses a small-amplitude pass filter, the filter filtering out a component having a small amplitude, to remove a steering component from dynamic state quantity such as a rotational speed signal, and to accurately extract only a vibration component having a small amplitude compared with the steering component, and controls the vibration component to be reduced.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: December 4, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiko Kurishige, Masaya Endo, Takayuki Kifuku, Seiji Sawada, Masaki Matsushita
  • Patent number: 8232752
    Abstract: An electric motor control apparatus that can quickly and accurately locate a short-circuit fault point. The electric motor control apparatus includes: a current controller determining respective phase voltage commands according to currents flowing in respective phases of an electric motor and a torque current command; a switching element drive circuit instructing, based on the respective phase voltage commands, an inverter to perform a switching operation; the inverter receiving a switching operation signal to drive the electric motor; current detectors disposed in series with the switching elements in the respective phases of the inverter; and a short-circuit point locating mechanism storing a test pattern indicative of a predetermined combination for turning on the switching elements of the inverter, and locating a short-circuit fault point based on the test pattern and current detection values in the respective phases detected by the current detectors in response to the test pattern.
    Type: Grant
    Filed: April 16, 2007
    Date of Patent: July 31, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiro Kimata, Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto, Noriyuki Inoue
  • Publication number: 20120185132
    Abstract: An electric power steering control device includes: a vibration extracting filter for performing filter processing on a rotation speed of a motor to reduce a gain on a low frequency side so as to output a vibration-component signal; a current variable gain map for detecting a current flowing through the motor as a first state quantity so as to calculate a current variable gain based on the current; a rotation-speed variable gain map for detecting the rotation speed of the motor as a second state quantity so as to calculate a rotation-speed variable gain based on the rotation speed; a correction mechanism calculating a vibration suppression current; and current controller calculating a target current so as to control the current flowing through the motor.
    Type: Application
    Filed: October 21, 2010
    Publication date: July 19, 2012
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Masahiko Kurishige, Masaya Endo, Takayuki Kifuku
  • Patent number: 8050825
    Abstract: A steering-torque detecting unit detects a steering torque applied by a driver as a steering torque signal. A phase-lag compensation unit performs an operation having a frequency response characteristic of multiplying a phase-lag compensation by a constant for the steering torque signal based on a signal obtained by applying an amplification by a first gain and a low pass filter on the steering torque signal and a signal obtained by applying an amplification by a second gain on the steering torque signal. A current control unit controls a current applied to a motor to follow a current command that is obtained based on an output of the phase-lag compensation unit.
    Type: Grant
    Filed: May 4, 2009
    Date of Patent: November 1, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hidetoshi Ikeda, Masaya Endo, Isao Kezobo
  • Patent number: 7990093
    Abstract: A control apparatus for a multiphase AC electric motor having an inverter includes a current control including an abnormal-state current controller; an abnormal-state detector that detects an abnormal state of any of a wire of an electric motor, a wire of an inverter, and a wire connecting the electric motor to the inverter as an abnormal phase; and an abnormal phase disconnect. The abnormal phase disconnect disconnects one or more of phases detected to be in an abnormal-state and the abnormal-state current controller generates an abnormal state voltage command in accordance with detection of an abnormal state, and uses phases other than the disconnected phases of the inverter to control individual currents of the phases, with the abnormal-state voltage command used as a multiphase voltage command.
    Type: Grant
    Filed: April 20, 2006
    Date of Patent: August 2, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiro Kimata, Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto, Noriyuki Inoue
  • Publication number: 20110153162
    Abstract: A motor-driven power steering control apparatus is achieved, which uses a small-amplitude pass filter, the filter filtering out a component having a small amplitude, to remove a steering component from dynamic state quantity such as a rotational speed signal, and to accurately extract only a vibration component having a small amplitude compared with the steering component, and controls the vibration component to be reduced.
    Type: Application
    Filed: December 14, 2007
    Publication date: June 23, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Masahiko Kurishige, Masaya Endo, Takayuki Kifuku, Seiji Sawada, Masaki Matsushita
  • Publication number: 20100286870
    Abstract: To accurately extract a pulsating component generated due to a cogging torque or a torque ripple to reduce a pulsation, the pulsating component is extracted using a bandpass filter having a variable time constant, and the time constant is set according to a frequency of cogging torque or torque ripple to be extracted. Further, a reference angle for a rotation angle of a motor is preset according to a generation harmonic order of the cogging torque or torque ripple, and the time constant of the bandpass filter is set from a time period required for the motor to rotate by the reference angle.
    Type: Application
    Filed: January 30, 2008
    Publication date: November 11, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masaya Endo, Masahiko Kurishige, Isao Kezobo
  • Patent number: 7828112
    Abstract: An electric power steering apparatus in which, when an abnormality is generated in an electric power steering apparatus, an assist is reduced smaller than normal when a steering burden is estimated to be small; and the assist can be increased to normal and the steering burden can be sufficiently reduced when the steering burden is estimated to be large. When an abnormality is detected, an assist command is set smaller than at a normal time when there is no abnormality in a first range where the steering burden estimated by the steering burden estimation unit is small; the assist command is increased to that at a normal time in a second range where the steering burden estimated by the steering burden estimation unit is larger than the first range; and an assist torque of a motor is controlled in response to the assist command at the abnormal time.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: November 9, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Noriyuki Inoue, Chiaki Fujimoto, Takayuki Kifuku, Masahiro Kimata, Kazumichi Tsutsumi
  • Publication number: 20100060222
    Abstract: An electric motor control apparatus that can quickly and accurately locate a short-circuit fault point. The electric motor control apparatus includes: a current controller determining respective phase voltage commands according to currents flowing in respective phases of an electric motor and a torque current command; a switching element drive circuit instructing, based on the respective phase voltage commands, an inverter to perform a switching operation; the inverter receiving a switching operation signal to drive the electric motor; current detectors disposed in series with the switching elements in the respective phases of the inverter; and a short-circuit point locating mechanism storing a test pattern indicative of a predetermined combination for turning on the switching elements of the inverter, and locating a short-circuit fault point based on the test pattern and current detection values in the respective phases detected by the current detectors in response to the test pattern.
    Type: Application
    Filed: April 16, 2007
    Publication date: March 11, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Masahiro Kimata, Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto, Noriyuki Inoue
  • Publication number: 20100004824
    Abstract: A steering-torque detecting unit detects a steering torque applied by a driver as a steering torque signal. A phase-lag compensation unit performs an operation having a frequency response characteristic of multiplying a phase-lag compensation by a constant for the steering torque signal based on a signal obtained by applying an amplification by a first gain and a low pass filter on the steering torque signal and a signal obtained by applying an amplification by a second gain on the steering torque signal. A current control unit controls a current applied to a motor to follow a current command that is obtained based on an output of the phase-lag compensation unit.
    Type: Application
    Filed: May 4, 2009
    Publication date: January 7, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hidetoshi IKEDA, Masaya ENDO, Isao KEZOBO
  • Publication number: 20090084616
    Abstract: An electric power steering apparatus in which, when an abnormality is generated in an electric power steering apparatus, an assist is reduced smaller than normal when a steering burden is estimated to be small; and the assist can be increased to normal and the steering burden can be sufficiently reduced when the steering burden is estimated to be large. When an abnormality is detected, an assist command is set smaller than at a normal time when there is no abnormality in a first range where the steering burden estimated by the steering burden estimation unit is small; the assist command is increased to that at a normal time in a second range where the steering burden estimated by the steering burden estimation unit is larger than the first range; and an assist torque of a motor is controlled in response to the assist command at the abnormal time.
    Type: Application
    Filed: March 8, 2007
    Publication date: April 2, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Noriyuki Inoue, Chiaki Fujimoto, Takayuki Kifuku, Masahiro Kimata, Kazumichi Tsutsumi
  • Publication number: 20090021207
    Abstract: A control apparatus for a multiphase AC electric motor having an inverter includes a current control including an abnormal-state current controller; an abnormal-state detector that detects an abnormal state of any of a wire of an electric motor, a wire of an inverter, and a wire connecting the electric motor to the inverter as an abnormal phase; and an abnormal phase disconnect. The abnormal phase disconnect disconnects one or more of phases detected to be in an abnormal-state and the abnormal-state current controller generates an abnormal state voltage command in accordance with detection of an abnormal state, and uses phases other than the disconnected phases of the inverter to control individual currents of the phases, with the abnormal-state voltage command used as a multiphase voltage command.
    Type: Application
    Filed: April 20, 2006
    Publication date: January 22, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Masahiro Kimata, Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto, Noriyuki Inoue
  • Patent number: 7459879
    Abstract: A control apparatus for an electric motor, in which a current controller giving multiphase voltage commands to a drive circuit for an inverter includes a normal-mode current controller for use in a normal mode, an abnormal-mode current controller for use in an abnormal mode, and an abnormality decision device. In a case of an abnormality occurring to one phase of an electric motor or the inverter, the controller is altered, and the abnormal-mode multiphase voltage commands which are generated by the abnormal-mode current controller are set as the multiphase voltage commands for the inverter drive circuit.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: December 2, 2008
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiro Kimata, Kazumichi Tsutsumi, Chiaki Fujimoto, Kouji Fukusumi, Noriyuki Inoue
  • Publication number: 20070176577
    Abstract: A control apparatus for an electric motor, in which a current controller giving multiphase voltage commands to a drive circuit for an inverter includes a normal-mode current controller for use in a normal mode, an abnormal-mode current controller for use in an abnormal mode, and an abnormality decision device. In a case of an abnormality occurring to one phase of an electric motor or the inverter, the controller is altered, and the abnormal-mode multiphase voltage commands which are generated by the abnormal-mode current controller are set as the multiphase voltage commands for the inverter drive circuit.
    Type: Application
    Filed: March 16, 2005
    Publication date: August 2, 2007
    Inventors: Isao Kezobo, Masahiro Kimata, Kazumichi Tsutsumi, Chiaki Fujimoto, Kouji Fukusumi, Noriyuki Inoue