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).

  • Publication number: 20160373050
    Abstract: A control apparatus for an AC rotary machine includes voltage application units 3, 4 for applying voltages respectively to two sets of three-phase windings of AC rotary machine 1, control unit 5 that controls the voltage application units 3, 4, and fault detection units 6, 7 that output fault detection signals to control unit 5 varying in accordance with the ground short fault and the power short fault. When detecting, control unit 5 outputs a voltage command to faulty voltage application unit 3, 4 to set voltages of respective phases of the three-phase windings at a negative electrode side potential V? of DC power supply 2, and when detecting a power short fault, control unit 5 outputs a voltage command to set the voltages of the respective phases of the three-phase windings at a positive electrode side potential V+ of DC power supply 2.
    Type: Application
    Filed: April 23, 2014
    Publication date: December 22, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Isao KEZOBO, Yoshihiko KIMPARA, Masaya SAKAI, Akira FURUKAWA, Yu KAWANO, Rei ARAKI
  • Publication number: 20160329850
    Abstract: This invention is concerning a control apparatus for an AC rotary machine including: an AC rotary machine that includes a first winding and a second winding which have a phase difference; a first current detection unit that detects a current of the first winding; a second current detection unit that detects a current of the second winding; a control unit that calculates a first voltage command and a second voltage command on the basis of a detected current value; and a first detectability determination unit that determines a detectability of the current of the first winding, detected by the first current detection unit, on the basis of at least one of the first voltage command and the second voltage command, wherein the control unit calculates the first voltage command and the second voltage command on the basis of the detected current value of the second winding when the current of the first winding is undetectable.
    Type: Application
    Filed: February 21, 2014
    Publication date: November 10, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Isao KEZOBO, Yoshihiko KIMPARA, Akira FURUKAWA
  • Publication number: 20160329849
    Abstract: This AC rotating machine control device includes: power limiting means 6 for limiting drive power supplied for driving the AC rotating machine; and power feed means 10 for, when sensor abnormality determination means 3 determines that the rotational position sensor is abnormal, on the basis of the estimated rotational position, supplying the AC rotating machine with power obtained by adding rotational position estimation power supplied for the rotational position estimation means 9 to estimate the rotational position, to the drive power limited by the power limiting means, wherein the power limiting means 6 limits drive current at least during a predetermined period since the sensor abnormality determination means 3 determines that the abnormality occurs until estimated error of the estimated rotational position falls within a predetermined range.
    Type: Application
    Filed: April 29, 2014
    Publication date: November 10, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shunsuke NAKAJIMA, Yuya TSUCHIMOTO, Isao KEZOBO, Yoshihiko KIMPARA
  • Patent number: 9397592
    Abstract: There is provided a motor control device for controlling a motor including plural sets of windings, which is configured so that, when a fault detection means detects a fault, inverters in the normal side other than in the fault side are continued to be controlled by normal-time current control means and further, inverters in the fault side are continued to be controlled by fault-time voltage commands generated by a fault-time current control means configured with a fault-time normal-side command generator and a fault-time fault-side command generator, so as to emphasis a torque ripple of the motor when a winding fault of the motor or an inverter fault occurs, to thereby cause a user to surely recognize the fault.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: July 19, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Kosuke Nakano, Yoshihito Asao, Akira Furukawa
  • Publication number: 20160204726
    Abstract: A control apparatus for an AC rotary machine includes a current detection unit that detects a current of a first winding and a current of a second winding, a basic voltage calculation unit that calculates a basic voltage on the basis of a current command value, a first voltage calculation unit that calculates a voltage command value of the first winding on the basis of the current command value, the basic voltage, and the current of the first winding, and a second voltage calculation unit that calculates a voltage command value of the second winding on the basis of the current command value, the basic voltage, and the current of the second winding. At least the first voltage calculation unit calculates the voltage command value of the first winding by further taking into account the current of the second winding.
    Type: Application
    Filed: November 8, 2013
    Publication date: July 14, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA, Yoshihiko KIMPARA, Isao KEZOBO
  • Publication number: 20160200352
    Abstract: Provided is a control device for a rotary machine including: a power feed unit configured to feed electric power in accordance with a power feed command to a rotary machine; a rotation-state detecting unit configured to detect a rotation state of the rotary machine; a torque detecting unit configured to detect an output torque output from the rotary machine; an abnormality determining unit configured to determine an abnormality in the rotation-state detecting unit or the torque detecting unit; and an excitation-command generating unit configured to generate an excitation command for oscillating the rotary machine, in which the power feed command is generated based at least on the excitation command, and the abnormality determining unit is configured to determine the abnormality in the detecting units based on a response of the rotation state and a response of the output torque to the excitation command.
    Type: Application
    Filed: November 13, 2013
    Publication date: July 14, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao KEZOBO, Yoshihiko KIMPARA, Akira FURUKAWA
  • Publication number: 20160072416
    Abstract: [Object] To effectively improve torque of a motor, the maximum rotation rate in driving with no load, and output at a high rotation rate, while suppressing torque ripple, noise, or vibration of the motor. [Solution] A brushless motor 301 has an armature iron core 310 wound with armature windings including plural winding sets 311 and 312 each of which includes multi-phase windings. Voltage application means 302 applies voltages to the plural winding sets. Control means 303 calculates a voltage command for the plural winding sets, and controls the voltage application means based on the voltage command. The control means 303 controls the voltage application means 302 so that induced voltages generated in the plural winding sets by rotation of the brushless motor have a trapezoidal waveform and a phase difference between the voltages for the plural winding sets becomes a value that reduces torque ripple caused by the induced voltages.
    Type: Application
    Filed: February 12, 2013
    Publication date: March 10, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yu HIROTANI, Yuji TAKIZAWA, Tatsuya MORI, Isao KEZOBO, Yoshihiko KIMPARA
  • Patent number: 9254862
    Abstract: Provided is a control device for an electric power steering device, the control device configured to control an output torque of a motor that provides an assist torque to a steering torque, the output being controlled based on a steering-torque signal from a torque sensor that detects a steering torque, the control device controls the output torque using a correction signal to damp a vibration at a natural frequency determined in accordance with a transfer characteristic from the steering-torque signal to the output torque.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: February 9, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Yoshihiko Kimpara, Takayuki Kifuku, Tatsuya Mori, Takashi Iwasaki, Masashi Iwane, Yuji Takatsuka
  • Publication number: 20160001814
    Abstract: Provided are a steering control device and the like, including the steps of: calculating a steering assist torque to be applied to an actuator for applying the steering assist torque to a steering system of a vehicle in order to improve return characteristics of the steering system; determining a steering state of a driver; correcting the steering assist torque depending on a result of the steering state determination; and controlling the actuator depending on the corrected steering assist torque, in which the step of determining a steering state of a driver includes determining the steering state of the driver based on a combination of at least two of the following: a manually-operating steering state determination; an abrupt steering wheel return determination; a high-acceleration steering wheel return determination; a manual return steering determination; and an additional-steering determination.
    Type: Application
    Filed: April 8, 2013
    Publication date: January 7, 2016
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masaya ENDO, Hidetoshi IKEDA, Isao KEZOBO, Kenji OGAWA, Taizo TODA
  • Patent number: 8981704
    Abstract: Provided are a motor controller for suppressing a torque pulsation with a simple configuration and obtaining a sufficient output torque in the case of an open-type fault occurring in any one of windings of a motor and inverters, and an electric power steering device using the motor controller. In the motor controller for controlling a current supplied from and a voltage applied from a power source with respect to the motor including winding sets of a plurality of systems, when a fault determination unit (31) determines the occurrence of the open-type fault, the supply of the currents to the windings of one of the systems in which the fault has occurred is stopped by control performed on switching elements included in the inverter of the faulty system, whereas the supply of the currents to the windings of the normal system in which the fault has not occurred is continued.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: March 17, 2015
    Assignee: Mitsubishi Electronic Corporation
    Inventors: Masaya Endo, Isao Kezobo, Yoshihiko Kimpara, Jiro Okada
  • Patent number: 8878477
    Abstract: An electric motor driving apparatus having a failure detection circuit includes: a bridge circuit driving an electric motor; a PWM control circuit generating voltage instruction for driving the electric motor; a PWM signal generation circuit generating a PWM signal; a DC current detection circuit detecting DC current of the bridge circuit; a phase current calculation circuit calculating output phase current of the bridge circuit, based on the DC current and PWM signal; and a failure detection circuit detecting failure of the DC current detection circuit. The failure detection circuit determines failure of the DC current detection circuit from the DC current detected values in a zero voltage period in which the high-potential-side arms of the bridge circuit are all ON and in a zero voltage period in which the low-potential-side arms are all ON.
    Type: Grant
    Filed: January 10, 2013
    Date of Patent: November 4, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kosuke Nakano, Tetsuya Kojima, Satoshi Azuma, Isao Kezobo, Ryuichi Takiguchi
  • Patent number: 8878474
    Abstract: Provided is a motor control device (10) for controlling a motor (5) provided with a plurality of sets of windings, in which, when a current control unit (23) detects a short-circuit failure as a primary failure, the current control unit (23) continues the control, and, further, when the current control unit (23) detects a secondary failure, the current control unit (23) provides control of opening a power supply relay (3). Accordingly, in a case where a failure of a winding of a motor or an inverter occurs, a torque pulsation is restrained and a sufficient output torque is provided, and further, in a case where a secondary failure occurs, excessive heat generation and current consumption are prevented and the cost of the device is reduced.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: November 4, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Kosuke Nakano, Yoshihito Asao
  • Publication number: 20140246999
    Abstract: There is provided a motor control device for controlling a motor including plural sets of windings, which is configured so that, when a fault detection means detects a fault, inverters in the normal side other than in the fault side are continued to be controlled by normal-time current control means and further, inverters in the fault side are continued to be controlled by fault-time voltage commands generated by a fault-time current control means configured with a fault-time normal-side command generator and a fault-time fault-side command generator, so as to emphasis a torque ripple of the motor when a winding fault of the motor or an inverter fault occurs, to thereby cause a user to surely recognize the fault.
    Type: Application
    Filed: January 27, 2012
    Publication date: September 4, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Kosuke Nakano, Yoshihito Asao, Akira Furukawa
  • Publication number: 20140054103
    Abstract: Provided are a motor control device (1) for controlling a motor (2) having a plurality of phases, for quickly and accurately detecting a phase in which an open-state fault has occurred when the open-state fault occurs in a target phase. When a power-supply voltage (Vb) is equal to or higher than a predetermined voltage (Vthr), a motor rotation speed (?) is equal to or lower than a predetermined speed (?thr), a target x-phase voltage command (Vx*) is not in the vicinity of zero, a current (Ix) of the target x-phase is equal to or lower than a predetermined current (Iu_thr), and a state in which a control error is equal to or larger than a predetermined error is detected over a predetermined time period or longer, occurrence of an open-state fault in the target phase is determined.
    Type: Application
    Filed: May 7, 2012
    Publication date: February 27, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Masahiro Iezawa, Susumu Zeniya, Eiji Iwami, Yusuke Fujiki, Hiroyuki Kishioka, Sadaaki Kamei, Yoshihiko Kimpara, Jiro Okada
  • Publication number: 20140058630
    Abstract: Provided is a control device for an electric power steering device, for controlling an output torque of a motor for outputting an assist torque based on a steering-torque signal from a torque sensor for detecting a steering torque, the control device for negatively feeding back a correction signal based on a motor-speed signal from motor-speed detection means for detecting a rotation speed of a rotary shaft of the motor to damp a vibration at a natural frequency determined in accordance with a transfer characteristic from the steering-torque signal to the output torque.
    Type: Application
    Filed: February 29, 2012
    Publication date: February 27, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao Kezobo, Yoshihiko Kimpara, Takayuki Kifuku, Tatsuya Mori, Takashi Iwasaki, Masashi Iwane, Yuji Takatsuka
  • Patent number: 8626394
    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: Grant
    Filed: October 21, 2010
    Date of Patent: January 7, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiko Kurishige, Masaya Endo, Takayuki Kifuku
  • Publication number: 20130299271
    Abstract: Provided are a motor controller for suppressing a torque pulsation with a simple configuration and obtaining a sufficient output torque in the case of an open-type fault occurring in any one of windings of a motor and inverters, and an electric power steering device using the motor controller. In the motor controller for controlling a current supplied from and a voltage applied from a power source with respect to the motor including winding sets of a plurality of systems, when a fault determination unit (31) determines the occurrence of the open-type fault, the supply of the currents to the windings of one of the systems in which the fault has occurred is stopped by control performed on switching elements included in the inverter of the faulty system, whereas the supply of the currents to the windings of the normal system in which the fault has not occurred is continued.
    Type: Application
    Filed: February 21, 2013
    Publication date: November 14, 2013
    Inventors: Masaya ENDO, Isao KEZOBO, Yoshihiko KIMPARA, Jiro OKADA
  • Publication number: 20130257332
    Abstract: An electric motor driving apparatus having a failure detection circuit includes: a bridge circuit driving an electric motor; a PWM control circuit generating voltage instruction for driving the electric motor; a PWM signal generation circuit generating a PWM signal; a DC current detection circuit detecting DC current of the bridge circuit; a phase current calculation circuit calculating output phase current of the bridge circuit, based on the DC current and PWM signal; and a failure detection circuit detecting failure of the DC current detection circuit. The failure detection circuit determines failure of the DC current detection circuit from the DC current detected values in a zero voltage period in which the high-potential-side arms of the bridge circuit are all ON and in a zero voltage period in which the low-potential-side arms are all ON.
    Type: Application
    Filed: January 10, 2013
    Publication date: October 3, 2013
    Inventors: Kosuke NAKANO, Tetsuya KOJIMA, Satoshi AZUMA, Isao KEZOBO, Ryuichi TAKIGUCHI
  • Publication number: 20130200827
    Abstract: Provided is a motor control device (10) for controlling a motor (5) provided with a plurality of sets of windings, in which, when a current control unit (23) detects a short-circuit failure as a primary failure, the current control unit (23) continues the control, and, further, when the current control unit (23) detects a secondary failure, the current control unit (23) provides control of opening a power supply relay (3). Accordingly, in a case where a failure of a winding of a motor or an inverter occurs, a torque pulsation is restrained and a sufficient output torque is provided, and further, in a case where a secondary failure occurs, excessive heat generation and current consumption are prevented and the cost of the device is reduced.
    Type: Application
    Filed: September 12, 2012
    Publication date: August 8, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao KEZOBO, Kosuke NAKANO, Yoshihito ASAO
  • Patent number: 8437915
    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: Grant
    Filed: January 30, 2008
    Date of Patent: May 7, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masaya Endo, Masahiko Kurishige, Isao Kezobo