Patents by Inventor Akira Furukawa

Akira Furukawa 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: 20180252511
    Abstract: Included are: a sensor magnet which rotates integrally with a rotating shaft centering on the rotating shaft, and generates a magnetic field for angle detection which is for detecting the angle of rotation; a first sensor and a second sensor each of which is arranged opposite to the sensor magnet at a position separated in angle by 90 degrees on the circumference centered on the rotating shaft, and outputs a signal corresponding to the magnetic field for angle detection; and an angle calculator that calculates a rotation angle by using the signals from the first sensor and the second sensor.
    Type: Application
    Filed: May 31, 2016
    Publication date: September 6, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Yu KAWANO, Yuji TAKIZAWA
  • Publication number: 20180244308
    Abstract: Provided is an electric power steering device capable of continuing control while ensuring a satisfactory level of a steering feeling of a driver at a time of occurrence of failure of one motor winding set. A control part is configured to detect a failure of each component of the electric power steering device, and when control is continued with field-weakening control by a normal motor winding and an inverter circuit depending on the detected failure, restrict a d-axis current based on a torque ripple that occurs in a steering wheel of a vehicle with respect to the field-weakening control of a state in which the failure has not occurred.
    Type: Application
    Filed: November 2, 2015
    Publication date: August 30, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Yu KAWANO
  • Publication number: 20180245914
    Abstract: Provided is an angle detection device including: a correction signal calculator configured to generate corrected signals from a sine signal and a cosine signal acquired from an angle detector; and an angle calculator configured to calculate an angle signal for a rotary machine from the corrected signals. When one of the sine signal and the cosine signal is defined as a first detection signal, and another one thereof is defined as a second detection signal, the correction signal calculator calculates a corrected first detection signal and a corrected second detection signal, and the angle calculator calculates the angle signal for the rotary machine from the corrected first detection signal and the corrected second detection signal.
    Type: Application
    Filed: October 3, 2016
    Publication date: August 30, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Wataru OZAKI, Yu KAWANO
  • Publication number: 20180237058
    Abstract: In an electric power steering device including a controller, which is configured to carry out feedback control for a motor including independent two coil winding groups and being configured to rotate a steering mechanism of a vehicle, when one of the two groups recovers from a failure that has occurred in the one group while control is continued solely by another group due to the failure, the controller resumes cooperative control by the two groups, and when starting the cooperative control, sets target current values of the one group and the another group to values different from a final target current value based on an actual current value or a target current value of the another group at a time of the recovery, to thereby output respective control amounts for the cooperative control.
    Type: Application
    Filed: October 22, 2015
    Publication date: August 23, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Akihiko MORI, Eiji IWAMI
  • Publication number: 20180219506
    Abstract: To provide an AC rotary machine control device which can superimpose the 5th order and the 7th order harmonic voltages on the AC voltage applied to the AC rotary machine by calculation processing of low processing load, and an electric power steering device provided with the same. An AC rotary machine control device performs middle voltage offset processing that adds offset value to middle voltage command when middle voltage command in three phase basic voltage commands is larger than vibration center voltage, and subtracts offset value from middle voltage command when middle voltage command is smaller than vibration center voltage.
    Type: Application
    Filed: October 13, 2015
    Publication date: August 2, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • 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
  • Patent number: 9935575
    Abstract: Provided are a power conversion device, relating to control of detecting a bus current in operation, and capable of acquiring an average current through a small amount of calculation and being implemented by an inexpensive microcomputer. A variation in a winding current flowing through a multi-phase winding of an AC rotating machine, namely, a phase current, is small at a timing at which voltage vectors on both sides of an axis having a larger inductance out of d and q axes of the AC rotating machine are output. Thus, switching signals are generated at timings at which the voltage vectors on both sides of the axis having the larger inductance out of the d and q axes are output, and the bus current is detected in accordance with the switching signals, thereby acquiring a value close to an average of the winding current.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: April 3, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa
  • Publication number: 20180079449
    Abstract: The invention includes an electric motor that causes a vehicle steering device to rotate, and a control unit that controls the electric motor, wherein the electric motor has a stator including two independent sets of coil winding group, the control unit has a control portion that computes and outputs a control amount and a drive circuit that independently drives each winding group of the electric motor, and the control portion detects a multiple of failures, categorizes the failures into at least two kinds of failure mode, continues control on a normal side after detecting a first failure, and continues control by employing a set in which control nearer to that at a normal time can be carried out, including a past failure, when detecting a second or subsequent failure.
    Type: Application
    Filed: August 28, 2015
    Publication date: March 22, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Akihiko MORI
  • Patent number: 9923504
    Abstract: In a control device for an AC rotary machine that includes a first three-phase winding and a second three-phase winding having a phase difference, a voltage is applied to each phase of the first three-phase winding at an ON interval or an OFF interval equaling or exceeding a first predetermined value. When a first three-phase current is determined to be undetectable, a first voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of the voltage applied to the first three-phase winding are within a second predetermined value that is smaller than the first predetermined value, and when a second three-phase current is determined to be undetectable, a second voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of a voltage applied to the second three-phase winding are within the second predetermined value.
    Type: Grant
    Filed: January 21, 2015
    Date of Patent: March 20, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Akira Furukawa
  • Publication number: 20180034397
    Abstract: A control device for an AC rotary machine includes an AC rotary machine having x-phase windings where x is at least three, an angle detector, a current detector, a voltage command calculator, and a power converter, wherein, when a current of at least one phase of the x phases is detectable and currents of at most (x?1) phases are undetectable at a present current detection timing, the current detector estimates the currents of the (x?1) phases that are undetectable at the present current detection timing by calculation on the basis of detected currents of x phases obtained at a past current detection timing, the detected current of the single phase that is detectable at the present current detection timing, and an angle variation amount from the past current detection timing to the present current detection timing.
    Type: Application
    Filed: March 12, 2015
    Publication date: February 1, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventor: Akira FURUKAWA
  • Publication number: 20180022378
    Abstract: A control device for an AC rotary machine includes an AC rotary machine having m sets of n-phase windings, a current detector, a power converter, and a control unit that calculates voltage commands on the basis of respective differences between a current command for the AC rotary machine and current detection values obtained by the current detector, and outputs ON/OFF signals to high potential side switching elements and low potential side switching elements of the power converter by comparing applied voltages calculated on the basis of the voltage commands with a carrier wave signal, wherein the current detector, when detecting currents flowing through the n-phase windings on the basis of currents flowing through current detection resistance elements that are inserted in series into the low potential side switching elements, obtains current detection values at two or more fixed timings over a single period of the carrier wave signal.
    Type: Application
    Filed: March 12, 2015
    Publication date: January 25, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventor: Akira FURUKAWA
  • 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
  • Publication number: 20180006590
    Abstract: In a control device for an AC rotary machine, having an angle detector for detecting an electrical angle of the AC rotary machine, a detection error produced by the angle detector due to a noise magnetic field generated by a multi-phase alternating current flowing through an inverter connection unit is corrected using a correction signal having a phase and an amplitude that are determined in accordance with a relative positional relationship between the inverter connection unit and the angle detector and a current vector of the multi-phase alternating current, whereupon an inverter is controlled on the basis of the corrected electrical angle. As a result, a simple, low-cost control device for an AC rotary machine with which an angular position of a rotor can be detected with a high degree of precision is obtained.
    Type: Application
    Filed: January 23, 2015
    Publication date: January 4, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventor: Akira FURUKAWA
  • Publication number: 20180006547
    Abstract: A first offset voltage which is added to voltage commands in a first three-phase voltage command calculated on the basis of a control command for an AC rotary machine, and a second offset voltage which is added to voltage commands in a second three-phase voltage command calculated on the basis of a control command for the AC rotary machine, are set in such a manner that a period during which one of a first power converter and a second power converter outputs an effective vector and the other thereof outputs a zero vector occurs during a carrier period of a first carrier wave signal and a second carrier wave signal.
    Type: Application
    Filed: February 16, 2015
    Publication date: January 4, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • Publication number: 20180006594
    Abstract: Provided is an electric drive device which controls a current supplied to coils during normal operation so as to be less than a current limit value when normal, which is determined from heat generating properties and heat radiating properties of a thermally coupled body that includes the coils and an inverter circuit. When an abnormality in each group or each phase of the coils and the inverter circuit is detected, the supply of current to all phases of a group suffering an abnormality in the coils, or to a phase that is not capable of continuous operation, is stopped or reduced; and the limit value of the current supplied to a coil that is capable of continuous operation is reset to a current limit value in the event of abnormality, which is larger than the current limit value when normal, within the range of improvement of the heat generating properties of the thermally coupled body due to the stopping or reduction of the supply of current.
    Type: Application
    Filed: February 23, 2015
    Publication date: January 4, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Yu KAWANO
  • Publication number: 20170331405
    Abstract: In a control device for an AC rotary machine that includes a first three-phase winding and a second three-phase winding having a phase difference, a voltage is applied to each phase of the first three-phase winding at an ON interval or an OFF interval equaling or exceeding a first predetermined value. When a first three-phase current is determined to be undetectable, a first voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of the voltage applied to the first three-phase winding are within a second predetermined value that is smaller than the first predetermined value, and when a second three-phase current is determined to be undetectable, a second voltage command is generated such that ON timings or OFF timings relating respectively to at least two phases of a voltage applied to the second three-phase winding are within the second predetermined value.
    Type: Application
    Filed: January 21, 2015
    Publication date: November 16, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Akira FURUKAWA
  • Publication number: 20170324363
    Abstract: This invention is concerning a controller for an AC rotating machine, this controller having an estimated sum current computing unit configured to output, as estimated sum current, a sum of current of a first winding and current of a second winding when it is determined that the current of the first winding can be detected, and maintain the estimated sum current which has been outputted as a previous value when it is determined that the current of the first winding cannot be detected. When it is determined that the current of the first winding cannot be detected, a first voltage command for the first winding is computed based on an estimated current value of the first winding, which has been calculated by subtracting the current of the second winding detected by the second current detector, from the estimated sum current output from the estimated sum current computing unit.
    Type: Application
    Filed: January 22, 2015
    Publication date: November 9, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Tatsuya MORI
  • 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
  • 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
  • Publication number: 20170274926
    Abstract: Provided is a power conversion device for suppressing a variation amount of a bus current to decrease a power loss in consideration of control of detecting the bus current during operation. In control by a power conversion part in accordance with a switching signal, a voltage vector is caused to bring a mode into a power running mode at a timing of detecting the bus current when an AC rotating machine is in a power running operation state, and the voltage vector is caused to bring the mode into a regeneration mode at a timing of detecting the bus current when the AC rotating machine is in a regeneration operation state, thereby decreasing the power loss due to the variation in the bus current.
    Type: Application
    Filed: October 8, 2014
    Publication date: September 28, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akira FURUKAWA, Tatsuya MORI