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).
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Patent number: 11070113Abstract: In an electric rotating machine including an output shaft, a magnetic body fixed inside a case surrounding the output shaft, a sensor magnet fixed to the output shaft and generating a magnetic field for detecting a rotational angle of the output shaft and a rotation sensor fixed inside the case, arranged between the magnetic body and the sensor magnet in an axial direction of the output shaft and outputting a signal in accordance with the intensity of the magnetic field for detecting the rotational angle, N-pole and S-pole are magnetized in a circumferential direction around the output shaft in the sensor magnet and the rotation sensor is arranged in an area in which amplitudes of a radial-direction component Br around the output shaft and a circumferential-direction component B? in a magnetic flux density B of the magnetic field are equivalent.Type: GrantFiled: April 22, 2016Date of Patent: July 20, 2021Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Akihiko Mori
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Patent number: 11063544Abstract: An inverter device includes: an inverter, a power supply current detection sensor, a phase current detection sensor, a three-phase voltage command calculator, and an inverter on/off signal generation unit. The phase current detection sensor detects a phase current in one phase of the inverter. The inverter on/off signal generation unit generates on/off signals based on the phase voltage commands. The three-phase voltage command calculator uses the power supply current and the phase current detected by the power supply current detection sensor and the phase current detection sensor, respectively, so as to calculate phase voltage commands directed to the inverter, and at a center time point of a period in which an upper arm switching element corresponding to one phase out of two phases for which the phase current detection sensor is not provided is on, and lower arm switching elements corresponding to the other two phases are on.Type: GrantFiled: July 4, 2017Date of Patent: July 13, 2021Assignee: Mitsubishi Electric CorporationInventors: Tatsuya Mori, Akira Furukawa, Isao Kezobo
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Publication number: 20210199175Abstract: A damping device includes: a housing; a drive-side actuator that includes a drive-side stator and a drive-side mover and is connected to the housing; a damping-side actuator that includes a damping-side stator and a damping-side mover and is connected to the housing; a first signal calculator that generates a drive signal for the drive-side actuator based on a control command; and a second signal calculator that generates, when the drive-side actuator changes from a large to a small jerk state, a drive signal for the damping-side actuator based on a signal obtained by subtracting a displacement suppression command suppressing a displacement of the damping-side mover from a vibration suppression command reducing or offsetting, by a vibration component of the housing produced by driving of the damping-side actuator, a natural frequency component of the housing produced by driving of the drive-side actuator based on the control command.Type: ApplicationFiled: June 5, 2019Publication date: July 1, 2021Applicant: Panasonic Intellectual Property Management Co., Ltd.Inventors: Akira Furukawa, Hiroshi Fujiwara
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Publication number: 20210175781Abstract: In an electric rotating machine including an output shaft, a magnetic body fixed inside a case surrounding the output shaft, a sensor magnet fixed to the output shaft and generating a magnetic field for detecting a rotational angle of the output shaft and a rotation sensor fixed inside the case, arranged between the magnetic body and the sensor magnet in an axial direction of the output shaft and outputting a signal in accordance with the intensity of the magnetic field for detecting the rotational angle, N-pole and S-pole are magnetized in a circumferential direction around the output shaft in the sensor magnet and the rotation sensor is arranged in an area in which amplitudes of a radial-direction component Br around the output shaft and a circumferential-direction component B? in a magnetic flux density B of the magnetic field are equivalent.Type: ApplicationFiled: April 22, 2016Publication date: June 10, 2021Applicant: Mitsubishi Electric CorporationInventors: Akira FURUKAWA, Akihiko MORI
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Patent number: 11014601Abstract: An electric power steering apparatus including: a steering torque detector to detect a steering torque of a driver; a motor to assist a steering force of the driver; an estimated speed calculator to calculate an estimated speed, which is an estimated value of a rotation speed of the motor; an estimated speed corrector to correct the estimated speed based on the steering torque; an estimated angle calculator to calculate an estimated angle of the motor by integrating the estimated speed after the correction; and an electric power supply to supply electric power to the motor based on the estimated angle, wherein the estimated speed corrector corrects the estimated speed when a determination signal, which is based on a value obtained by removing a frequency component of steering of the driver from a derivative of the steering torque, the steering torque, and the estimated speed have the same signs.Type: GrantFiled: May 18, 2017Date of Patent: May 25, 2021Assignee: Mitsubishi Electric CorporationInventors: Yuya Tsuchimoto, Isao Kezobo, Akira Furukawa, Yuji Takatsuka
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Publication number: 20210146991Abstract: A control device for an AC rotary machine includes: a DC power supply; an inverter; a magnetic flux generator; an angle detector; and a control arithmetic unit; wherein the control arithmetic unit is configured to: calculate, based on a positional relationship between a current path and the angle detector, a correction signal for correcting signal errors of a cosine signal and a sine signal, which are caused by a noise magnetic flux component due to at least one of a DC current flowing between the DC power supply and the inverter and multi-phase AC currents flowing between the inverter and armature windings; and control the inverter by using angle information obtained from values after the correction by the correction signal.Type: ApplicationFiled: July 31, 2017Publication date: May 20, 2021Applicant: Mitsubishi Electric Corporation 7Inventor: Akira FURUKAWA
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Patent number: 11005402Abstract: A control device for a motor, comprising: a power converter for performing ON/OFF control on an upper switching element and a lower switching element in accordance with a drive command from a current controller, and thereby supplying power to a motor; a current sensor provided to the lower switching element; and a fault determining unit for determining a fault in the current sensor. When the lower switching element for each phase is OFF, the current sensor detects the current error in each phase. The fault determining unit obtains a current error determination value on the basis of the value obtained by converting, to Cartesian coordinates, the current error for each phase or the magnitude of the sum of current error vectors for each phase in which the value for the current error for each phase is held as the magnitude, and determines a fault.Type: GrantFiled: May 2, 2017Date of Patent: May 11, 2021Assignee: Mitsubishi Electric CorporationInventors: Yuya Tsuchimoto, Isao Kezobo, Shunsuke Nakajima, Akira Furukawa
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Patent number: 11005405Abstract: When a switching device cutoff failure determination unit determines a failure in a switching device cutoff switching unit, output torque produced based on the first armature winding and output torque produced based on the second armature winding are produced in such a way that the respective directions thereof are opposite to each other.Type: GrantFiled: November 16, 2016Date of Patent: May 11, 2021Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Munenori Yamamoto
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Patent number: 10998834Abstract: A power conversion device is configured to output, to each of two inverters configured to invert a DC voltage output from a DC power supply to three-phase AC voltages, on/off signals for switching on and off respective semiconductor switching elements of each of the inverters so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a voltage command vector that is based on a voltage command value calculated for each of the inverters are formed.Type: GrantFiled: August 21, 2017Date of Patent: May 4, 2021Assignee: Mitsubishi Electric CorporationInventors: Tatsuya Mori, Akira Furukawa
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Publication number: 20210114652Abstract: To provide a motor control device capable of reducing noise without requiring preparation of a plurality of PWM carrier waves, an offset voltage is added equally to each phase of three-phase voltage command values from an inverter to output modified three-phase voltage command values, which are compared to a PWM carrier wave to output three-phase terminal voltages to a motor, and an offset voltage is switched among n offset candidate voltages (n is a natural number of three or more) having different values at set time intervals for output to vary timings to turn on and timings to turn off the three-phase terminal voltages equally for all phases.Type: ApplicationFiled: January 11, 2017Publication date: April 22, 2021Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Takayuki KIFUKU, Akira FURUKAWA
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Patent number: 10965239Abstract: A power conversion device including: a first and second multi-phase inverters (MPI1,MPI2) to receive a DC voltage (Vdc) and convert into AC voltages (Vacs), when fc represents a frequency of a PWM signal output from each of the MPI1 and the MPI2, fr represents a lower limit frequency defined by noise regulation of the power conversion device, an absolute value of a differential voltage being a difference between: a first average voltage, which is an average value of first voltage commands of respective phases as command values for the Vacs of MPI1; and a second average voltage, which is an average value of second voltage commands of respective phases as command values for the Vacs of MPI2, is set equal to or less than k2·fc/fr·Vdc [V] (k2 is an odd number equal to or more than one), to reduce noise in a frequency band defined by noise regulation.Type: GrantFiled: July 3, 2017Date of Patent: March 30, 2021Assignee: Mitsubishi Electric CorporationInventors: Tatsuya Mori, Akira Furukawa
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Publication number: 20210058018Abstract: A control device includes: a first power converter applying a voltage to a first winding; a second power converter applying a voltage to a second winding; a first power supply circuit supplying power to the first power converter; a second power supply circuit supplying power to the second power converter; a current command calculator; a first current controller; and a second current controller. The second power supply circuit supplies power at a voltage higher than a voltage of the first power supply circuit. The current command calculator calculates a first voltage usage state, which is an indicator value correlated with a magnitude of the output voltage of the first power converter with respect to a power supply voltage output at a time of supply of power by the first power supply circuit, and calculates the second current command based on the first voltage usage state.Type: ApplicationFiled: March 13, 2018Publication date: February 25, 2021Applicant: Mitsubishi Electric CorporationInventors: Yuya TSUCHIMOTO, Isao KEZOBO, Akira FURUKAWA
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Publication number: 20200412285Abstract: A control device applies voltages to an AC rotating machine based on voltage command values on stationary coordinates. Currents in a plurality phases flowing the rotating machine are detected as detection currents. Coordinate conversion is applied to those detection currents based on any phase in the rotating machine, for generate detection currents on rotational coordinates. Voltage command values on the rotational coordinates are generated based on current command values on the rotational coordinates and the detection currents. Coordinate conversion is applied to those voltage command values based on the any phase, for generate first voltage command values on the stationary coordinates. Phases of one of the first voltage command values and generated second voltage command values on the stationary coordinates are corrected to generate the second voltage command values. One of the second and the first voltage command values are selected as the voltage command values on the stationary coordinates.Type: ApplicationFiled: March 5, 2018Publication date: December 31, 2020Applicant: Mitsubishi Electric CorporationInventor: Akira FURUKAWA
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Publication number: 20200400720Abstract: Magnetic sensors each disposed to face each of current paths for each of windings with 2n phases (n is a multiple of three) in an AC rotating machine are included, and when each of a DC component and an AC component in a d-axis sum current and a q-axis sum current obtained by performing a dq-transformation into a two-axis coordinate system on 2n detection currents on the assumption that all current amplitudes of the windings are the same is represented collectively with each of terms expressed by sine functions with different phases to one another, each of the current paths at each of 2n current path arrangement positions is arranged to have a positional relationship where error components are reduced by cancellation among coefficients included at least in one of the terms or by cancellation among values of the terms.Type: ApplicationFiled: April 22, 2020Publication date: December 24, 2020Applicant: Mitsubishi Electric CorporationInventors: Akira FURUKAWA, Kenichi AKITA, Daisuke SASAKI
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Publication number: 20200400722Abstract: Magnetic sensors each disposed to face each of current paths for each of windings with 2n phases (n is a multiple of three) in an AC rotating machine are included, and when each of a DC component and an AC component in a d-axis sum current and a q-axis sum current obtained by performing a dq-transformation into a two-axis coordinate system on 2n detection currents on the assumption that all current amplitudes of the windings are the same is represented collectively with each of terms expressed by sine functions with different phases, each of the current paths at each of 2n current path arrangement positions is arranged to have a positional relationship where error components are reduced by cancellation among coefficients included at least in one of the term or by cancellation among values of the terms.Type: ApplicationFiled: April 22, 2020Publication date: December 24, 2020Applicant: Mitsubishi Electric CorporationInventors: Akira Furukawa, Kenichi Akita, Daisuke Sasaki
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Patent number: 10871365Abstract: 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: GrantFiled: May 31, 2016Date of Patent: December 22, 2020Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Yu Kawano, Yuji Takizawa
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Publication number: 20200373869Abstract: A power conversion device is configured to output on/off signals for switching on and off respective semiconductor switching elements of an inverter configured to invert a DC voltage output from a DC power supply into three-phase AC voltages so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a current vector that is based on currents supplied as a result of output of the three-phase AC voltages from the inverter are formed.Type: ApplicationFiled: August 21, 2017Publication date: November 26, 2020Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Akira FURUKAWA
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Patent number: 10836423Abstract: 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: GrantFiled: October 22, 2015Date of Patent: November 17, 2020Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Akihiko Mori, Eiji Iwami
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Patent number: 10797620Abstract: A control unit includes: control command generation means for generating a first control command and a second control command that specifies currents to flow through a first winding set and second winding set respectively; voltage calculation means for calculating a first voltage command from the first control command and calculating a second voltage command from the second control command; and first voltage application means and second voltage application means for applying voltages to the first winding set and the second winding set of a rotating machine on the basis of the first voltage command and the second voltage command, wherein discharge control for electric charge of a smoothing capacitor is performed while torque generated by current flowing from the smoothing capacitor to the first winding set and torque generated by current flowing from the capacitor to the second winding set are cancelled out with each other.Type: GrantFiled: August 24, 2016Date of Patent: October 6, 2020Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Munenori Yamamoto
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Patent number: 10788319Abstract: 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: GrantFiled: October 3, 2016Date of Patent: September 29, 2020Assignee: Mitsubishi Electric CorporationInventors: Akira Furukawa, Wataru Ozaki, Yu Kawano