Patents by Inventor Takafumi Hara

Takafumi Hara 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: 11967915
    Abstract: The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error ??v representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ?r of a motor.
    Type: Grant
    Filed: November 4, 2020
    Date of Patent: April 23, 2024
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takaya Tsukagoshi, Takafumi Hara, Katsuhiro Hoshino, Toshiyuki Ajima
  • Publication number: 20240079103
    Abstract: An information processing device (40) according to one embodiment of the present disclosure includes: an analysis unit (41) being a first data generation unit that generates objective score data, which indicates objective scores in time series, based on a plurality of pieces of objective data regarding a patient; a processing unit (42) being a second data generation unit that generates subjective score data, which indicates subjective scores in time series, based on a plurality of pieces of subjective data obtained from the patient; and a generation unit (44) being an image generation unit that generates a score image indicating the objective score data and the subjective score data.
    Type: Application
    Filed: December 23, 2021
    Publication date: March 7, 2024
    Inventors: RITSUKO KANO, EIJIRO MORI, SHINSUKE NOGUCHI, KAZUMI HIRANO, TAKAFUMI YANAGIMOTO, KOJI SATO, HIROSHI HARA
  • Publication number: 20240042867
    Abstract: A motor control device connected to a power converter that performs power conversion from DC power to AC power and controls driving of an AC motor that is driven by using the AC power includes a voltage command generation unit that generates a three-phase voltage command; and a gate signal generation unit that performs pulse width modulation on the three-phase voltage command and generates a gate signal for controlling an operation of the power converter, in which the voltage command generation unit adjusts the three-phase voltage command by using a zero-phase voltage based on a power factor of the AC power in an overmodulation region in which a modulation factor according to a voltage amplitude ratio between the DC power and the AC power exceeds a predetermined threshold value, and the gate signal generation unit generates the gate signal by performing pulse width modulation on the adjusted three-phase voltage command.
    Type: Application
    Filed: September 29, 2021
    Publication date: February 8, 2024
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Kyoshiro ITAKURA, Takeshi TOKUYAMA, Takahiro ARAKI, Shigehisa AOYAGI
  • Publication number: 20230402953
    Abstract: A motor control device is connected to a power converter that performs power conversion from DC power to AC power and controls driving of an AC motor driven using the AC power, and the motor control device includes a carrier wave generation unit that generates a carrier wave, a carrier wave frequency adjustment unit that adjusts a frequency of the carrier wave, and a gate signal generation unit that performs pulse width modulation on a voltage command according to a torque command using the carrier wave and generates a gate signal for controlling an operation of the power converter, in which a phase difference between the voltage command and the carrier wave is randomly changed.
    Type: Application
    Filed: September 21, 2021
    Publication date: December 14, 2023
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Takaya TSUKAGOSHI, Shun TANIGUCHI, Takafumi HARA
  • Patent number: 11831265
    Abstract: A motor control device includes a PWM control unit, a carrier frequency setting unit, and a carrier frequency switching calculation unit. The PWM unite generates a signal to drive an inverter by pulse width modulation. The carrier frequency setting unit sets a carrier frequency used for pulse width modulation according to a number of rotations of a motor. The carrier frequency switching calculation unit calculates a frequency switching speed of the carrier frequency and is configured to perform a calculation method. The calculation method includes setting at least one of an emergency mode, a response priority mode, or a fluctuation suppression priority mode in response to various operating conditions.
    Type: Grant
    Filed: November 14, 2019
    Date of Patent: November 28, 2023
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Midori Takaoka, Takafumi Hara, Shigehisa Aoyagi, Hirokazu Matsui, Shigeyuki Nonomura
  • Publication number: 20230373228
    Abstract: A manufacturing method of a printed material that stores machine-readable information, includes forming, on a base material, a first layer including a first code symbol that is machine-readable and represents first information, using a first coloring material, and forming, on the first layer, a second layer including a second code symbol that is machine-readable and represents second information, using a second coloring material that is different from the first coloring material and decolorable at a particular temperature, such that the first code symbol is at least partly covered by the second coloring material.
    Type: Application
    Filed: January 20, 2023
    Publication date: November 23, 2023
    Inventors: Takafumi HARA, Maiko MIYOSHI, Mamoru NOMURA
  • Publication number: 20230223824
    Abstract: A motor control device of the present invention is connected to a power converter for converting power from direct current power to alternating current power, and controls the drive of an alternating current motor that is driven using said alternating current power, and the motor control device is provided with: a carrier wave generator; a carrier wave frequency adjuster that adjusts the frequency of the carrier wave; and a gate signal generator that uses the carrier wave to pulse width modulate a voltage command according to a torque command, and generates a gate signal for controlling operation of the power converter, wherein the carrier wave frequency adjuster adjusts the voltage command and carrier wave phase difference to reduce eddy current loss generated in rotor magnets of the alternating current motor according to a d-axis current flowing to the alternating current motor and the rotational speed of the alternating current motor.
    Type: Application
    Filed: March 1, 2021
    Publication date: July 13, 2023
    Applicant: Hitachi, Ltd.
    Inventors: Takafumi HARA, Makoto ITO, Akeshi TAKAHASHI, Toshiyuki AJIMA
  • Publication number: 20230155534
    Abstract: An inverter control device 200 includes a PWM control unit 220 that generates a PWM pulse for controlling an inverter 100, and a pulse edge control unit 250 that performs pulse edge control for correcting (shifting) a phase of a pulse edge of the PWM pulse generated by the PWM control unit 220. The PWM control unit 220 generates a PWM pulse by using a modulation rate based on a voltage command (Vd*, Vq*). The pulse edge control unit 250 corrects the PWM pulse so that a phase difference between a zero cross point where the modulation wave changes across 0 and a pulse edge of the PWM pulse falls within a predetermined range.
    Type: Application
    Filed: January 22, 2021
    Publication date: May 18, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Toshiyuki AJIMA, Takafumi HARA, Akihiro ASHIDA, Hirokazu MATSUI, Kiyoshi KURODA
  • Publication number: 20230155533
    Abstract: An object of the present invention is to sufficiently suppress a vibration and noise generated in a motor. A motor control device includes a first inverter circuit and a second inverter circuit of a redundant system, the first inverter circuit and the second inverter circuit controlling a motor, and a control unit that controls the first inverter circuit and the second inverter circuit. The first inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a first carrier signal. The second inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a second carrier signal. The control unit shifts phases of the first carrier signal and the second carrier signal by using, as a reference, pulsation of an electromagnetic force caused by a magnetic circuit of the motor.
    Type: Application
    Filed: January 22, 2021
    Publication date: May 18, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Katsuhiro HOSHINO, Takafumi HARA, Takaya TSUKAGOSHI
  • Publication number: 20230141601
    Abstract: The present invention addresses the problem of properly performing motor control during overmodulation. In a motor control device 1, a carrier wave frequency adjusting unit 16 adjusts a carrier wave frequency fc so as to change a voltage phase error ??v representing the phase difference between three-phase voltage commands Vu*, Vv*, Vw* and a triangular wave signal Tr. When a modulation factor H in accordance with the voltage amplitude ratio between the DC power supplied from a high voltage battery to an inverter and AC power output from the inverter to a motor exceeds a predetermined value, for example, 1.15, a current control unit 14 corrects the amplitudes and phases of a d-axis voltage command Vd* and a q-axis voltage command Vq* on the basis of a carrier wave phase difference ??carr representing the phase of the triangular wave signal Tr.
    Type: Application
    Filed: January 22, 2021
    Publication date: May 11, 2023
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Takaya TSUKAGOSHI, Katsuhiro HOSHINO
  • Patent number: 11646690
    Abstract: A random value integration unit 175 outputs a random value output from a random value generation unit 174 in a diffusion width Rand output from a diffusion width generation unit 173 by a product of an output of the random value generation unit 174 and an output of the diffusion width generation unit 173. A triangular wave signal generation unit 176 generates a triangular wave signal corresponding to a second carrier frequency fc2 which is obtained by adding the random value output from the random value integration unit 175 to a first carrier frequency fc1 which is an output of a carrier frequency setting unit 171. That is, a frequency obtained by increasing the diffusion width of the first carrier frequency fc1 is used as the second carrier frequency fc2, and the second carrier frequency is used as the carrier frequency.
    Type: Grant
    Filed: September 12, 2019
    Date of Patent: May 9, 2023
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Takafumi Hara, Midori Takaoka, Toshiyuki Ajima, Hirokazu Matsui, Akihiro Ashida
  • Publication number: 20230035063
    Abstract: A deviation between a detection result of an output current of an inverter and an actual current is suppressed. A current detection unit 7 detects a three-phase AC current output from an inverter 3 or input to the inverter 3. An inverter control device 1 controls the inverter 3 based on a current detection value based on a detection result of the three-phase AC current by the current detection unit 7 and a predetermined current command value. The inverter control device 1 corrects the current detection value so as to correct a detection error of the three-phase AC current generated due to a delay time of a filter 72 which is a filter element provided in the current detection unit 7.
    Type: Application
    Filed: December 8, 2020
    Publication date: February 2, 2023
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Akihiro ASHIDA, Kiyoshi KURODA, Yoshinoi AOSHIMA
  • Patent number: 11555099
    Abstract: According to one embodiment, a high-definition and decolorable image is formed. A method for producing a colorable material according to an embodiment includes supplying a first solution containing a color developable agent and a first solvent to a color developing agent in the form of a powder which is insoluble in the first solvent so that a first mixture of the first solution and the color developing agent maintains the powder state, and removing the first solvent from the first mixture, thereby obtaining a powder of colorable particles containing the color developable agent and the color developing agent.
    Type: Grant
    Filed: May 10, 2021
    Date of Patent: January 17, 2023
    Assignee: TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Tsuyoshi Itou, Maiko Miyoshi, Takafumi Hara
  • Patent number: 11558000
    Abstract: An object of the present invention is to provide a motor control device that can suppress electromagnetic noises including a switching noise and to an electric vehicle system using the motor control device. A motor control device includes: a power converter that is controlled by a pulse width modulation signal; a motor that is driven by the power converter; and a controller that generates the pulse width modulation signal, based on a carrier signal. When switching between a first carrier frequency (fc1) of the carrier signal and a second carrier frequency (fc2) of the carrier signal, the controller varies proportions of the first carrier frequency and the second carrier frequency in accordance with a number of rotations of the motor, the second carrier frequency being higher than the first carrier frequency.
    Type: Grant
    Filed: January 24, 2019
    Date of Patent: January 17, 2023
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Akihiro Ashida
  • Publication number: 20230008549
    Abstract: The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error ??v representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ?r of a motor.
    Type: Application
    Filed: November 4, 2020
    Publication date: January 12, 2023
    Inventors: Takaya TSUKAGOSHI, Takafumi HARA, Katsuhiro HOSHINO, Toshiyuki AJIMA
  • Publication number: 20220390872
    Abstract: A method for producing a capsule toner includes preparing core particles; preparing a shell fine particle dispersion liquid having a surface tension of 50 mN/m or more, as measured at 25° C., by dissolving a polyester resin in an organic solvent, thereafter performing neutralization with a neutralizer, and thereafter forming the polyester resin into fine particles; adjusting the surface tension of the shell fine particle dispersion liquid to less than 50 mN/m, as measured at 25° C., by adding a substance that does not include a surfactant to the shell fine particle dispersion liquid; and adhering the shell fine particle dispersion liquid to the surfaces of the core particles. The substance dissolves in or mixes with water and (i) has a vapor pressure equal to or greater than the vapor pressure of water or (ii) has a vapor pressure less than the vapor pressure of water and can be azeotropic with water.
    Type: Application
    Filed: August 18, 2022
    Publication date: December 8, 2022
    Applicant: TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Takafumi HARA, Satoshi ARAKI
  • Publication number: 20220345060
    Abstract: Conventionally, there is a problem that switching loss of an inverter increases in a case where a change such as improvement in a switching frequency is involved. The battery voltage E and the torque command T* are input to the first current command generation unit 111. The battery voltage E, the torque command T*, and a voltage utilization rate obtained by dividing a line voltage effective value by a battery voltage (DC voltage) are input to a second current command generation unit 112. A magnet temperature Tmag of a rotor magnet is input to a current command selection unit 113, and a current command output from the first current command generation unit 111 is selected in normal operation, and the second current command generation unit 112 is selected in a case where the magnet temperature exceeds a predetermined value. The second current command generation unit 112 is configured not to obtain the voltage utilization rate of 0.3 to 0.4.
    Type: Application
    Filed: August 14, 2020
    Publication date: October 27, 2022
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Katsuhiro HOSHINO, Noriyuki MAEKAWA
  • Patent number: 11482961
    Abstract: An object of the present invention is to effectively reduce vibration or noise caused by a motor. An inverter circuit 300 generates an alternating current from a direct current supplied from a direct current power supply 10 by using a plurality of IGBTs 311 which are switching elements, supplies the generated alternating current to a motor 100, and drives the motor 100. This alternating current includes a fundamental harmonic current corresponding to a rotational speed of the motor 100, and a harmonic current of a switching operation of the IGBTs 311. A controller 200 controls a second phase such that a first phase and the second phase are not superimposed on each other at a predetermined motor rotational speed, the first phase being a phase of an excitation force cyclically produced in the motor 100 by the fundamental harmonic current, and the second phase being a phase of an excitation force cyclically produced in the motor 100 by the harmonic current.
    Type: Grant
    Filed: January 17, 2018
    Date of Patent: October 25, 2022
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Katsuhiro Hoshino, Takafumi Hara, Masaru Yamasaki, Yosuke Tanabe, Masanori Watanabe
  • Patent number: 11451179
    Abstract: Disclosed are a motor control device that can accurately estimate a rotor position based on a neutral point potential even when a load increases, and a brake control device that is driven by the motor control device. The motor control device 3 includes a three-phase synchronous motor 4 including a three-phase winding, an inverter 31 connected to the three-phase winding, a control unit 6 for controlling the inverter based on a rotor position of the three-phase synchronous motor, and a rotational position estimation unit 2 for estimating a rotor position ?d based on a neutral point potential Vn of the three-phase winding. The rotational position estimation unit estimates a rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding.
    Type: Grant
    Filed: October 10, 2018
    Date of Patent: September 20, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Shigehisa Aoyagi, Hiroyuki Ota, Kenichiro Matsubara
  • Patent number: 11427726
    Abstract: According to one embodiment, an ink which can be decolored upon heating is provided. Colored images can be formed with the ink by various methods, such as ink jetting or the like, then later the images can be decolored with heat. An ink according to an embodiment contains a color developable compound, a color developing agent that causes the color developable compound to develop a color, a nonaqueous solvent, and a decoloring agent that is insoluble in the nonaqueous solvent and decolors the color developable compound upon heating.
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: August 30, 2022
    Assignee: TOSHIBA TEC KABUSHIKI KAISHA
    Inventors: Maiko Miyoshi, Tsuyoshi Itou, Takafumi Hara