Patents by Inventor Akihiro TSUMURA

Akihiro TSUMURA 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: 11527374
    Abstract: Provided is a touch sensing system that can make the life of a contact of an electromagnetic contactor longer. A touch sensing system includes a main operation circuit that connects a probe and a main operation power supply, and in which an electromagnetic contactor is provided; and a touch sensing circuit that is connected to the main operation circuit through the electromagnetic contactor in a branched manner, and connects the probe and a touch sensing power supply, is which a solid state relay switch is provided in the touch sensing circuit.
    Type: Grant
    Filed: March 27, 2020
    Date of Patent: December 13, 2022
    Assignee: FANUC CORPORATION
    Inventors: Akihiro Yanagita, Takeshi Tsumura, Takahisa Hasegawa
  • Patent number: 11509232
    Abstract: A power converter includes a rectifier configured to rectify an AC voltage supplied from an AC power supply, a booster circuit configured to boost the voltage rectified by the rectifier, a smoothing capacitor configured to smooth the voltage output from the booster circuit, a power module configured to convert a DC voltage obtained by smoothing the output voltage by the smoothing capacitor into an AC voltage, and a snubber capacitor configured to absorb a surge voltage superimposed on the DC voltage to be input to the power module. The snubber capacitor is mounted in the power module.
    Type: Grant
    Filed: February 16, 2018
    Date of Patent: November 22, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenta Yuasa, Akihiro Tsumura, Shigeo Takata, Shinsaku Kusube
  • Publication number: 20220345070
    Abstract: A motor control device includes a power converter that supplies a three-phase voltage to two motors being connected in parallel, a three-phase power line that connects between one of the two motors and the power converter, a branch three-phase power line that connects between the other of the two motors and the power converter, a switching device having two switches that are provided on the branch three-phase power line, a current detection device that detects three-phase currents flowing in the two motors, and a controller. The controller performs a failure determination of the switching device by identifying a phase of a power line in which no current flows in the three-phase power line and the branch three-phase power line, and, when a failure is detected in one of the two switches in the failure determination, controls to change a state of the other switch, which operates normally, to coincide with a state of the failed switch.
    Type: Application
    Filed: April 23, 2019
    Publication date: October 27, 2022
    Inventors: Toshiki ASAI, Akihiro TSUMURA, Yasuhiko WADA, Junji MORIMOTO, Shigeo TAKATA
  • Patent number: 11456684
    Abstract: An electric motor control device that drives and controls a plurality of electric motors connected in parallel, includes: a power conversion device; a current detection device; and a controller that includes a first control unit to perform first control on each of the plurality of electric motors based on the electric current, a second control unit to perform second control of controlling the plurality of electric motors such that an estimated speed of each of the plurality of electric motors obtained based on the current value follows the speed command value, and a switching determination unit to perform switching determination processing of switching between the first control performed by the first control unit and the second control performed by the second control unit according to drive information on at least one or more of the plurality of electric motors.
    Type: Grant
    Filed: November 2, 2018
    Date of Patent: September 27, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yasuhiko Wada, Akihiro Tsumura
  • Patent number: 11424698
    Abstract: A motor control device includes: an inverter circuit configured to convert a direct-current voltage into an alternating-current voltage, and to supply the alternating-current voltage to a plurality of motors connected in parallel; current detectors configured to detect motor currents flowing through the respective motors; a relay provided between at least one of the plurality of motors and the inverter circuit; and a controller configured to change the number of motors to be driven. When one of two or more motors under driving is stopped, the controller lowers a current instruction value to the two or more motors under driving. When a monitor current that is the motor current detected by the current detector of the motor connected to the relay is decreased, the controller switches the relay from an on state to an off state.
    Type: Grant
    Filed: January 16, 2019
    Date of Patent: August 23, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akihiro Tsumura, Yuichi Shimizu, Yasuhiko Wada, Junji Morimoto
  • Publication number: 20220094284
    Abstract: A motor control device includes: a power converter to which a first motor and a second motor are connected in parallel, the power converter being configured to convert a direct-current voltage into an alternating-current voltage and supply the alternating-current voltage to the first motor and the second motor; a switching unit provided between the second motor and the power converter; a current detector configured to detect an electric current flowing through the first motor and the second motor; and a controller configured to control the power converter based on at least a current value detected by the current detector. The controller deactivates the power converter upon receiving from outside an abnormal step signal, attributed to the occurrence of an abnormality, that excludes a normal stop signal representing a stop command and switches the switching unit from an on state to an off state upon deactivation of the power converter.
    Type: Application
    Filed: March 7, 2019
    Publication date: March 24, 2022
    Inventors: Junki ISHIZAKI, Yasuhiko WADA, Akihiro TSUMURA
  • Publication number: 20220021318
    Abstract: A motor control device includes: an inverter circuit configured to convert a direct-current voltage into an alternating-current voltage, and to supply the alternating-current voltage to a plurality of motors connected in parallel; current detectors configured to detect motor currents flowing through the respective motors; a relay provided between at least one of the plurality of motors and the inverter circuit; and a controller configured to change the number of motors to be driven. When one of two or more motors under driving is stopped, the controller lowers a current instruction value to the two or more motors under driving. When a monitor current that is the motor current detected by the current detector of the motor connected to the relay is decreased, the controller switches the relay from an on state to an off state.
    Type: Application
    Filed: January 16, 2019
    Publication date: January 20, 2022
    Inventors: Akihiro TSUMURA, Yuichi SHIMIZU, Yasuhiko WADA, Junji MORIMOTO
  • Patent number: 11211875
    Abstract: A power converter that includes a rectifier rectifying a voltage supplied from a three-phase AC power supply, a voltage step-down circuit including a voltage step-down switching element, a reactor, a backflow prevention element, and a smoothing capacitor and stepping down a DC voltage supplied from the rectifier, and an inverter circuit converting the DC voltage smoothed by the smoothing capacitor into an AC voltage. The power converter includes an imbalance determining unit determining, based on states of the voltage step-down circuit and the smoothing capacitor, whether or not voltage imbalance has occurred in the three-phase AC power supply and a voltage step-down control unit performing switching of the voltage step-down switching element in a case where the imbalance determining unit determines that the voltage imbalance has occurred.
    Type: Grant
    Filed: September 8, 2017
    Date of Patent: December 28, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akihiro Tsumura, Shigeo Takata, Kazunori Sakanobe, Shinsaku Kusube
  • Patent number: 11196361
    Abstract: An electric motor control device controls driving of electric motors connected in parallel with each other and includes a power converter converting power from a power supply, and supply the converted power to each of the electric motors, a switching device to be turned on to electrically connect the power converter and at least one of the electric motors and to be turned off to electrically disconnect the power converter and the at least one of the electric motors, a current detection unit detecting a current that flows in the electric motors, and a controller controlling the power converter on the basis of operation of the switching device, rotation frequency command values from an external device, and a value of the current detected by the current detection unit. The controller turns the switching device from off to on so that start timing of control is different for each electric motor.
    Type: Grant
    Filed: October 3, 2017
    Date of Patent: December 7, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yasuhiko Wada, Akihiro Tsumura
  • Patent number: 11133762
    Abstract: A drive system includes a current detection unit that detects a current flowing to a main synchronous motor, and a current detection unit that detects a current flowing to a secondary synchronous motor. The drive system includes a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the main synchronous motor, and a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the secondary synchronous motor. The drive system includes a current control unit that outputs a voltage command, and a secondary torque current pulsating component extraction unit that extracts a pulsating component. The drive system includes a subtracter that determines an angle difference, and a magnetic flux current command determination unit that determines a magnetic flux current command.
    Type: Grant
    Filed: January 18, 2018
    Date of Patent: September 28, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenji Takahashi, Tsukasa Masumura, Akihiro Tsumura, Yasuhiko Wada, Akane Hongyo
  • Publication number: 20210184604
    Abstract: An electric motor control device that drives and controls a plurality of electric motors connected in parallel, includes: a power conversion device; a current detection device; and a controller that includes a first control unit to perform first control on each of the plurality of electric motors based on the electric current, a second control unit to perform second control of controlling the plurality of electric motors such that an estimated speed of each of the plurality of electric motors obtained based on the current value follows the speed command value, and a switching determination unit to perform switching determination processing of switching between the first control performed by the first control unit and the second control performed by the second control unit according to drive information on at least one or more of the plurality of electric motors.
    Type: Application
    Filed: November 2, 2018
    Publication date: June 17, 2021
    Inventors: Yasuhiko WADA, Akihiro TSUMURA
  • Patent number: 11012011
    Abstract: A motor control device includes an inverter configured by a plurality of arms, a smoothing unit supplying a direct-current voltage to the inverter, a shunt resistor inserted between a lower-arm switching element for each phase of the inverter and a negative-electrode side of the smoothing unit, a master motor current sensor outputting a voltage according to a current flowing in a first motor connected in parallel to the inverter, and a computing unit generating driving signals for a plurality of switching elements based on an output of the master motor current sensor and an output corresponding to a voltage drop on the shunt resistor.
    Type: Grant
    Filed: April 27, 2017
    Date of Patent: May 18, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Keisuke Uemura, Kenji Takahashi, Yasuhiko Wada, Akihiro Tsumura
  • Publication number: 20210067066
    Abstract: A drive system includes a current detection unit that detects a current flowing to a main synchronous motor, and a current detection unit that detects a current flowing to a secondary synchronous motor. The drive system includes a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the main synchronous motor, and a magnetic pole position estimation unit that estimates the magnetic pole position of the rotor of the secondary synchronous motor. The drive system includes a current control unit that outputs a voltage command, and a secondary torque current pulsating component extraction unit that extracts a pulsating component. The drive system includes a subtracter that determines an angle difference, and a magnetic flux current command determination unit that determines a magnetic flux current command.
    Type: Application
    Filed: January 18, 2018
    Publication date: March 4, 2021
    Inventors: Kenji TAKAHASHI, Tsukasa MASUMURA, Akihiro TSUMURA, Yasuhiko WADA, Akane HONGYO
  • Publication number: 20210006185
    Abstract: An electric motor control device controls driving of electric motors connected in parallel with each other and includes a power converter converting power from a power supply, and supply the converted power to each of the electric motors, a switching device to be turned on to electrically connect the power converter and at least one of the electric motors and to be turned off to electrically disconnect the power converter and the at least one of the electric motors, a current detection unit detecting a current that flows in the electric motors, and a controller controlling the power converter on the basis of operation of the switching device, rotation frequency command values from an external device, and a value of the current detected by the current detection unit. The controller turns the switching device from off to on so that start timing of control is different for each electric motor.
    Type: Application
    Filed: October 3, 2017
    Publication date: January 7, 2021
    Inventors: Yasuhiko WADA, Akihiro TSUMURA
  • Publication number: 20200358365
    Abstract: A power converter includes a rectifier configured to rectify an AC voltage supplied from an AC power supply, a booster circuit configured to boost the voltage rectified by the rectifier, a smoothing capacitor configured to smooth the voltage output from the booster circuit, a power module configured to convert a DC voltage obtained by smoothing the output voltage by the smoothing capacitor into an AC voltage, and a snubber capacitor configured to absorb a surge voltage superimposed on the DC voltage to be input to the power module. The snubber capacitor is mounted in the power module.
    Type: Application
    Filed: February 16, 2018
    Publication date: November 12, 2020
    Inventors: Kenta YUASA, Akihiro TSUMURA, Shigeo TAKATA, Shinsaku KUSUBE
  • Publication number: 20200220470
    Abstract: A power converter that includes a rectifier rectifying a voltage supplied from a three-phase AC power supply, a voltage step-down circuit including a voltage step-down switching element, a reactor, a backflow prevention element, and a smoothing capacitor and stepping down a DC voltage supplied from the rectifier, and an inverter circuit converting the DC voltage smoothed by the smoothing capacitor into an AC voltage. The power converter includes an imbalance determining unit determining, based on states of the voltage step-down circuit and the smoothing capacitor, whether or not voltage imbalance has occurred in the three-phase AC power supply and a voltage step-down control unit performing switching of the voltage step-down switching element in a case where the imbalance determining unit determines that the voltage imbalance has occurred.
    Type: Application
    Filed: September 8, 2017
    Publication date: July 9, 2020
    Inventors: Akihiro TSUMURA, Shigeo TAKATA, Kazunori SAKANOBE, Shinsaku KUSUBE
  • Publication number: 20200059173
    Abstract: A motor control device includes an inverter configured by a plurality of arms, a smoothing means supplying a direct-current voltage to the inverter, a shunt resistor inserted between a lower-arm switching element for each phase of the inverter and a negative-electrode side of the smoothing means, a master motor current sensor outputting a voltage according to a current flowing in a first motor connected in parallel to the inverter, and a computing unit generating driving signals for a plurality of switching elements based on an output of the master motor current sensor and an output corresponding to a voltage drop on the shunt resistor.
    Type: Application
    Filed: April 27, 2017
    Publication date: February 20, 2020
    Inventors: Keisuke UEMURA, Kenji TAKAHASHI, Yasuhiko WADA, Akihiro TSUMURA
  • Patent number: 10404196
    Abstract: A backflow preventing device includes a backflow preventing element that is connected between a power supply and a load and that prevents electric current from flowing backward from the load side toward the power supply side, and a commutating device that performs a commutation operation for causing the electric current to flow to a commutation path connected in parallel with the backflow preventing element. A plurality of elements including at least one or more of elements constituting the commutating device are configured as a module, so that, for example, the device can be reduced in size. Moreover, a simplified heat-dissipation design and a simplified air-duct design can be achieved.
    Type: Grant
    Filed: July 2, 2014
    Date of Patent: September 3, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takuya Shimomugi, Koichi Arisawa, Takashi Yamakawa, Keisuke Uemura, Noriyuki Matsubara, Shinsaku Kusube, Kenta Yuasa, Akihiro Tsumura
  • Patent number: 10263539
    Abstract: A power converter includes a transformation circuit configured to transform a rectified voltage, and a converter control unit configured to control a switching element of the transformation circuit. The converter control unit calculates a current command value based on a line voltage or the phase voltage, calculates a current deviation between the current command value and the reactor current, and calculates a switching command value from the current deviation. The converter control unit includes a plurality of integrators for the respective different phase angles of a power supply voltage. The integrator corresponding to a power supply phase angle is caused to accumulate the current deviation, and the integrator corresponding to a phase angle that is advanced by a set delay phase from the power supply phase angle is caused to output the control amount. A switching signal is generated with use of the control amount and the switching command value.
    Type: Grant
    Filed: October 1, 2015
    Date of Patent: April 16, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenta Yuasa, Shuta Ishikawa, Akihiro Tsumura, Shinsaku Kusube
  • Patent number: 10116205
    Abstract: Provided is a power conversion device configured to convert electric power from a power source to a load, including: a boosting device including a boost rectification unit configured to prevent backflow of a current from the load side to the power source side, the boosting device being configured to change a voltage of power from the power source to a predetermined voltage based on a drive signal; a commutation device configured to perform commutation operation in which a current flowing through the boosting device is caused to flow into an other path based on a commutation signal; and a signal generating module device configured as a module to generate and send an output signal based on an input signal that is input thereto. The input signal has an on-pulse width greater than a length of time where the output signal generated by the signal generating module device is turned on.
    Type: Grant
    Filed: July 2, 2014
    Date of Patent: October 30, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koichi Arisawa, Takuya Shimomugi, Takashi Yamakawa, Keisuke Uemura, Noriyuki Matsubara, Shinsaku Kusube, Kenta Yuasa, Akihiro Tsumura