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: 20180323613
    Abstract: A control unit of an electric motor control device includes an inverter circuit 6 that supplies power to an electric motor, a current control unit that outputs a voltage command value as a drive command of the inverter circuit, a current detecting unit that detects current flowing to each phase of the electric motor, and a failed phase identifying unit that identifies a location of a failure in the current detecting unit. The failed phase identifying unit determines whether or not a magnitude or a phase of a frequency component of the test voltage command included in a detected current value when the inverter circuit is driven with a test voltage command having a frequency higher than a rotational frequency of the electric motor as a drive command is within a predetermined range, and determines that a failure has occurred in a phase that is not within the predetermined range.
    Type: Application
    Filed: January 14, 2016
    Publication date: November 8, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Chiaki FUJIMOTO, Kenta TANAKA, Tatsuya MORI, Isao KEZOBO
  • Patent number: 10116250
    Abstract: When there is an error between an actual resistance value of an AC rotary machine (ACRM) and an estimated resistance value estimated from a detected external temperature of the ACRM, the ACRM cannot be rotated smoothly. In view of this, provided are a control device for an ACRM and the like, including a resistance value estimation unit (10) configured to calculate an estimated resistance value (Rest) by adding to a basic estimated resistance value (Rest0), which is a value obtained by estimating a resistance value from a detected external temperature of the ACRM, an estimated resistance correction value (Radd), which is determined such that a range that can be taken by an error (?R) of the resistance value estimated in advance falls within a range of the error of the resistance value that enables the ACRM to be rotated smoothly.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: October 30, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuya Tsuchimoto, Isao Kezobo, Yoshihiko Kimpara, Shunsuke Nakajima
  • Publication number: 20180294755
    Abstract: This invention is concerning a control device of an AC rotating machine that estimates, as an estimated rotational position, a rotational position of an AC rotating machine having N sets of three-phase windings where N is a natural number equal to or greater than 2, the device being made up of: a voltage sum calculator that calculates a voltage sum from N sets of voltage commands for applying AC voltage to the N sets of three-phase windings; a current sum calculator that calculates a current sum from N sets of currents respectively flowing in the N sets of three-phase windings; and a rotational position estimator that calculates an estimated rotational position on the basis of calculation results of the voltage sum calculator and the current sum calculator.
    Type: Application
    Filed: April 27, 2015
    Publication date: October 11, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Shunsuke NAKAJIMA, Isao KEZOBO
  • Publication number: 20180257701
    Abstract: When the state where steering torque detected by a torque detection unit is normal and the value of the steering torque is the same as or larger than a threshold value continues, an assist command generation unit that generates an assist command corresponding to steering torque produced by a driver limits the assist command; a failure determination unit includes a first failure determination unit that performs determination on a failure regardless of the limitation of the assist command and a second failure determination unit that performs determination on a failure while the assist command is limited, and stops driving of a motor when the second failure determination unit determines that there exists a failure.
    Type: Application
    Filed: December 2, 2015
    Publication date: September 13, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuya TSUCHIMOTO, Isao KEZOBO, Shunsuke NAKAJIMA
  • Patent number: 9954472
    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: Grant
    Filed: November 8, 2013
    Date of Patent: April 24, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa, Yoshihiko Kimpara, Isao Kezobo
  • Publication number: 20180105201
    Abstract: When an AC rotary machine having a rotor structure for generating saliency, and including first three-phase windings and second three-phase windings is controlled, a first position estimation command to be superimposed on a voltage command or a current command directed to each of the first three-phase windings and a second position estimation command to be superimposed on a voltage command or a current command directed to each of the second three-phase windings are set to have the same frequency, and caused to have a phase difference, thereby increasing an estimation accuracy of a rotation position of the AC rotary machine.
    Type: Application
    Filed: May 27, 2015
    Publication date: April 19, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Shunsuke NAKAJIMA, Isao KEZOBO
  • Patent number: 9912274
    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: Grant
    Filed: April 29, 2014
    Date of Patent: March 6, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shunsuke Nakajima, Yuya Tsuchimoto, Isao Kezobo, Yoshihiko Kimpara
  • Patent number: 9876458
    Abstract: A control device for an AC rotating machine includes an electric-power converter that has two or more switching devices connected with an AC rotating machine and applies a voltage to the AC rotating machine, a switch that opens or closes an electric connection path between the AC rotating machine and the electric-power converter, a switching device controller that controls opening and closing of the switching devices, and a switch controller that controls opening and closing of the switch; when a failure occurs in the electric-power converter, the AC rotating machine, or the electric connection path therebetween, the switch controller controls opening and closing of the switch in accordance with rotation information on the AC rotating machine.
    Type: Grant
    Filed: March 19, 2014
    Date of Patent: January 23, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Tatsuya Mori, Yoshihiko Kimpara, Shunsuke Nakajima, Akira Furukawa
  • Patent number: 9871481
    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: Grant
    Filed: April 29, 2014
    Date of Patent: January 16, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shunsuke Nakajima, Yuya Tsuchimoto, Isao Kezobo, Yoshihiko Kimpara
  • Patent number: 9800196
    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: Grant
    Filed: April 23, 2014
    Date of Patent: October 24, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Isao Kezobo, Yoshihiko Kimpara, Masaya Sakai, Akira Furukawa, Yu Kawano, Rei Araki
  • Publication number: 20170282968
    Abstract: An inverter system failure is detected on the basis of the currents of respective phases detected by a current detection unit when carrying out switching control in accordance with a first drive mode in which all switching elements on a lower-side arm are switched on and all switching elements on an upper-side arm are switched off, and the currents of respective phases detected by the current detection unit when carrying out switching control in accordance with a second drive mode in which all of the switching elements on the upper-side arm are switched on and all of the switching elements on the lower-side arm are switched off.
    Type: Application
    Filed: November 4, 2014
    Publication date: October 5, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao KEZOBO, Yoshihiko KIMPARA, Shunsuke NAKAJIMA
  • Patent number: 9780712
    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 voltage commands , 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: Grant
    Filed: February 21, 2014
    Date of Patent: October 3, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Isao Kezobo, Yoshihiko Kimpara, Akira Furukawa
  • Patent number: 9738307
    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: Grant
    Filed: April 8, 2013
    Date of Patent: August 22, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masaya Endo, Hidetoshi Ikeda, Isao Kezobo, Kenji Ogawa, Taizo Toda
  • Patent number: 9712096
    Abstract: This invention is concerning obtaining a control apparatus and a control method for an AC rotary machine, with which a voltage command can be used up to a saturation voltage in each group of windings even when dimension differences exist between the groups of windings. A voltage saturation determination unit determines whether or not voltage saturation has occurred in a first winding group or a second winding group on the basis of at least one of a voltage and a current relating to the first winding group and the second winding group, and when determination is made that voltage saturation has occurred in either the first winding group or the second winding group, generates a voltage saturation determination signal for reducing a gain of at least one axial direction component on a rotational two-axis coordinate system.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: July 18, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Isao Kezobo, Tatsuya Mori
  • Publication number: 20170080970
    Abstract: An input/output device is connected, via an in-vehicle communication network, to a control device for controlling a motor provided in an electric power steering apparatus that is provided in a vehicle. The input/output device generates an excitation start instruction signal for starting excitation in the motor on the basis of an externally input excitation start instruction, transmits the generated excitation start instruction signal to the control device over the in-vehicle communication network, and receives response data relating to the excitation of the electric power steering apparatus, the response data being detected by the control device while the excitation is underway, from the control device over the in-vehicle communication network.
    Type: Application
    Filed: April 9, 2015
    Publication date: March 23, 2017
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Isao KEZOBO, Yoshihiko KINPARA, Hidetoshi IKEDA
  • Patent number: 9575127
    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: Grant
    Filed: May 7, 2012
    Date of Patent: February 21, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiro Iezawa, Susumu Zeniya, Eiji Iwami, Yusuke Fujiki, Hiroyuki Kishioka, Sadaaki Kamei, Yoshihiko Kimpara, Jiro Okada
  • Publication number: 20170047883
    Abstract: When there is an error between an actual resistance value of an AC rotary machine (ACRM) and an estimated resistance value estimated from a detected external temperature of the ACRM, the ACRM cannot be rotated smoothly. In view of this, provided are a control device for an ACRM and the like, including a resistance value estimation unit (10) configured to calculate an estimated resistance value (Rest) by adding to a basic estimated resistance value (Rest0), which is a value obtained by estimating a resistance value from a detected external temperature of the ACRM, an estimated resistance correction value (Radd), which is determined such that a range that can be taken by an error (?R) of the resistance value estimated in advance falls within a range of the error of the resistance value that enables the ACRM to be rotated smoothly.
    Type: Application
    Filed: June 16, 2014
    Publication date: February 16, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuya TSUCHIMOTO, Isao KEZOBO, Yoshihiko KIMPARA, Shunsuke NAKAJIMA
  • Patent number: 9571017
    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: Grant
    Filed: February 12, 2013
    Date of Patent: February 14, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yu Hirotani, Yuji Takizawa, Tatsuya Mori, Isao Kezobo, Yoshihiko Kimpara
  • Publication number: 20170033724
    Abstract: A control device for an AC rotating machine includes an electric-power converter that has two or more switching devices connected with an AC rotating machine and applies a voltage to the AC rotating machine, a switch that opens or closes an electric connection path between the AC rotating machine and the electric-power converter, a switching device controller that controls opening and closing of the switching devices, and a switch controller that controls opening and closing of the switch; when a failure occurs in the electric-power converter, the AC rotating machine, or the electric connection path therebetween, the switch controller controls opening and closing of the switch in accordance with rotation information on the AC rotating machine.
    Type: Application
    Filed: March 19, 2014
    Publication date: February 2, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao KEZOBO, Tatsuya MORI, Yoshihiko KIMPARA, Shunsuke NAKAJIMA, Akira FURUKAWA
  • Publication number: 20170019048
    Abstract: This invention is concerning obtaining a control apparatus and a control method for an AC rotary machine, with which a voltage command can be used up to a saturation voltage in each group of windings even when dimension differences exist between the groups of windings. A voltage saturation determination unit determines whether or not voltage saturation has occurred in a first winding group or a second winding group on the basis of at least one of a voltage and a current relating to the first winding group and the second winding group, and when determination is made that voltage saturation has occurred in either the first winding group or the second winding group, generates a voltage saturation determination signal for reducing a gain of at least one axial direction component on a rotational two-axis coordinate system.
    Type: Application
    Filed: April 28, 2014
    Publication date: January 19, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Isao KEZOBO, Tatsuya MORI