Patents by Inventor Masanori Watahiki

Masanori Watahiki 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: 11958543
    Abstract: A motor control system includes an inverter, and a control calculation unit that feedback-controls the inverter. The control calculation unit includes a voltage control calculation unit that calculates a voltage command value indicating a voltage to be applied to the motor from the inverter on the basis of a current deviation between a current command value and an actual current detection value, a torque ripple compensation calculation unit that adds a compensation value for compensating a torque ripple in the motor to a signal value on at least one of an upstream side and a downstream side in a signal flow that passes through the voltage control calculation unit, and a current limit calculation unit that limits the current command value by adaptive control based on an actual angular velocity value indicating an angular velocity at which the motor rotates.
    Type: Grant
    Filed: February 13, 2019
    Date of Patent: April 16, 2024
    Assignee: NIDEC CORPORATION
    Inventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
  • Patent number: 11952057
    Abstract: A motor control system includes an inverter, a voltage control calculating a voltage command value indicating a voltage to be applied to a motor from the inverter based on a deviation between the current command value and the actual current detection value, and a torque ripple compensation unit adding a compensation value for compensating a torque ripple in the motor to a signal value on an upstream side in a signal flow that passes through the voltage control unit. The torque ripple compensation unit includes a phase compensator calculating a compensation value component in the voltage control unit based on an actual angular velocity value indicating an angular velocity at which the motor rotates, and an inverse characteristic processor calculating a compensation value component for compensating the torque ripple based on an inverse characteristic of an open loop transfer function in a feedback control.
    Type: Grant
    Filed: February 13, 2019
    Date of Patent: April 9, 2024
    Assignee: NIDEC CORPORATION
    Inventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
  • Patent number: 11366435
    Abstract: A control device to perform feedback control based on a current value, and output a first voltage value includes a feedforward controller using an inverse model of a plant; a feedforward voltage corrector to correct a voltage disturbance due to a modeling error between the plant and a model of the plant; a repetitive controller to learn periodic current disturbances; and a switch. The switch is ON when the current response is in a steady state, and the repetitive controller learns the disturbances and corrects a command current value. A feedback controller outputs the first voltage value by performing the feedback control based on a current value from the corrected command current value, and inputs the command current value to the inverse model to generate a second voltage value. The control device outputs a sum of the first and the second voltage value as a command voltage value.
    Type: Grant
    Filed: April 4, 2018
    Date of Patent: June 21, 2022
    Assignees: NIDEC CORPORATION, THE UNIVERSITY OF TOKYO
    Inventors: Hiroshi Fujimoto, Linfeng Lan, Tomonari Mori, Masanori Watahiki
  • Patent number: 11362608
    Abstract: One aspect of a noise compensation adjustment method includes: a measurement step of driving a motor to measure noise with respect to a coupled system including the motor and a driving body coupled to the motor and driven by the motor; an order identification step of, based on noise measured in the measurement step, identifying an order B of a component contributing to compensation of the noise from a k-th component and a 1/k-th component (k is an integer) in the rotation of the motor; an adjustment step of controlling driving of the motor using a component of the order B identified in the order identification step as a compensation value, and adjusting a component value of the order B to reduce the noise; and a recording step of recording the component value of the order B adjusted in the adjustment step as a compensation value for reducing the noise.
    Type: Grant
    Filed: February 8, 2019
    Date of Patent: June 14, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Shuji Endo, Akitoshi Harada, Tomoya Ueda, Masanori Watahiki, Tomonari Mori, Tokuji Tatewaki
  • Patent number: 11251731
    Abstract: A motor control system includes an inverter, and a control unit that feedback-controls the inverter. The control unit includes a voltage control unit that calculates a voltage command value indicating a voltage to be applied to the motor from the inverter based on a current deviation between a current command value and an actual current detection value, and a torque ripple compensation unit that adds a compensation value for compensating a torque ripple in the motor to a signal value on at least one of an upstream side and a downstream side in a signal flow passing through the voltage control unit. The torque ripple compensation unit calculates the compensation value based on an actual angular velocity at which the motor rotates and the target current command value, and based on advance angle control for compensating a response delay of the motor control system with respect to the compensation value.
    Type: Grant
    Filed: February 8, 2019
    Date of Patent: February 15, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
  • Publication number: 20210103258
    Abstract: A control device that outputs a command voltage value includes: a feedback controller to perform feedback control based on a current value, and output a first voltage value; a feedforward controller established by using an inverse model of a plant to be controlled; a feedforward voltage corrector to correct a voltage disturbance that occurs due to a modeling error between a plant model and the actual plant; a repetitive controller to learn periodic current disturbances; and a switch to control input/output to the repetitive controller. The switch is turned ON when the current response is in a steady state, and the repetitive controller learns the current disturbances and corrects a command current value. The feedback controller outputs the first voltage value by performing the feedback control based on a current value that is acquired from the corrected command current value. The feedforward controller inputs the command current value to the inverse model to generate a second voltage value.
    Type: Application
    Filed: April 4, 2018
    Publication date: April 8, 2021
    Inventors: Hiroshi FUJIMOTO, Linfeng LAN, Tomonari MORI, Masanori WATAHIKI
  • Publication number: 20210044234
    Abstract: A motor control system includes an inverter, and a control unit that feedback-controls the inverter. The control unit includes a voltage control unit that calculates a voltage command value indicating a voltage to be applied to the motor from the inverter based on a current deviation between a current command value and an actual current detection value, and a torque ripple compensation unit that adds a compensation value for compensating a torque ripple in the motor to a signal value on at least one of an upstream side and a downstream side in a signal flow passing through the voltage control unit. The torque ripple compensation unit calculates the compensation value based on an actual angular velocity at which the motor rotates and the target current command value, and based on advance angle control for compensating a response delay of the motor control system with respect to the compensation value.
    Type: Application
    Filed: February 8, 2019
    Publication date: February 11, 2021
    Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
  • Publication number: 20200406957
    Abstract: A motor control system includes an inverter, a voltage control calculating a voltage command value indicating a voltage to be applied to a motor from the inverter based on a deviation between the current command value and the actual current detection value, and a torque ripple compensation unit adding a compensation value for compensating a torque ripple in the motor to a signal value on an upstream side in a signal flow that passes through the voltage control unit. The torque ripple compensation unit includes a phase compensator calculating a compensation value component in the voltage control unit based on an actual angular velocity value indicating an angular velocity at which the motor rotates, and an inverse characteristic processor calculating a compensation value component for compensating the torque ripple based on an inverse characteristic of an open loop transfer function in a feedback control.
    Type: Application
    Filed: February 13, 2019
    Publication date: December 31, 2020
    Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
  • Publication number: 20200406958
    Abstract: A motor control system includes an inverter and a control calculation unit. The control calculation unit includes a voltage control calculation unit that calculates a voltage command value indicating a voltage to be applied to a motor from the inverter on the basis of a current deviation between the current command value and the actual current detection value, and a compensation calculation unit that compensates at least one of a k-th component and a 1/k-th component in the motor with respect to a signal value on at least one of an upstream side and a downstream side in a signal flow that passes through the voltage control calculation unit. The compensation calculation unit calculates a compensation value on the basis of an actual angular velocity value indicating an angular velocity at which the motor rotates and the target current command value, while also taking into account advance angle control.
    Type: Application
    Filed: February 8, 2019
    Publication date: December 31, 2020
    Inventors: Shuji ENDO, Akitoshi HARADA, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI, Tokuji TATEWAKI
  • Publication number: 20200395877
    Abstract: One aspect of a noise compensation adjustment method includes: a measurement step of driving a motor to measure noise with respect to a coupled system including the motor and a driving body coupled to the motor and driven by the motor; an order identification step of, based on noise measured in the measurement step, identifying an order B of a component contributing to compensation of the noise from a k-th component and a 1/k-th component (k is an integer) in the rotation of the motor; an adjustment step of controlling driving of the motor using a component of the order B identified in the order identification step as a compensation value, and adjusting a component value of the order B to reduce the noise; and a recording step of recording the component value of the order B adjusted in the adjustment step as a compensation value for reducing the noise.
    Type: Application
    Filed: February 8, 2019
    Publication date: December 17, 2020
    Inventors: Shuji ENDO, Akitoshi HARADA, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI, Tokuji TATEWAKI
  • Patent number: 10862415
    Abstract: A motor controller includes an inverter that drives a motor, an operation controller that controls the inverter according to a current command value, and a torque ripple compensation generator that adds a compensation value to compensate for a torque ripple in the motor to the current command value. The operation controller uses, as the current command value, a q-axis current command value indicating a q-axis current in a rotational coordinate system of the motor, and also uses, as the current command value, at least temporarily a d-axis current command value indicating a d-axis current in the rotational coordinate system, and the torque ripple compensation generator calculates a phase difference of the compensation value with respect to the q-axis current command value according to an equation using the q-axis current command value and the d-axis current command value as variables.
    Type: Grant
    Filed: August 8, 2019
    Date of Patent: December 8, 2020
    Assignees: NIDEC CORPORATION, NIDEC ELESYS CORPORATION
    Inventors: Masanori Watahiki, Tomonari Mori, Tomoya Ueda, Shuji Endo, Tokuji Tatewaki
  • Publication number: 20200377144
    Abstract: A motor control system includes an inverter, and a control calculation unit that feedback-controls the inverter. The control calculation unit includes a voltage control calculation unit that calculates a voltage command value indicating a voltage to be applied to the motor from the inverter on the basis of a current deviation between a current command value and an actual current detection value, a torque ripple compensation calculation unit that adds a compensation value for compensating a torque ripple in the motor to a signal value on at least one of an upstream side and a downstream side in a signal flow that passes through the voltage control calculation unit, and a current limit calculation unit that limits the current command value by adaptive control based on an actual angular velocity value indicating an angular velocity at which the motor rotates.
    Type: Application
    Filed: February 13, 2019
    Publication date: December 3, 2020
    Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
  • Patent number: 10848088
    Abstract: A motor control apparatus includes a first circuit that determines a d-axis 0th-order current and a q-axis 0th-order current, a second circuit that determines a d-axis 6th-order harmonic current and a q-axis 6th-order harmonic current according to a position of the rotor, and a third circuit that determines, respectively, a value obtained by superposing the d-axis 6th-order harmonic current on the d-axis 0th-order current and a value obtained by superposing the q-axis 6th-order harmonic current on the q-axis 0th-order current as a d-axis current command value and a q-axis current command value.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: November 24, 2020
    Assignee: NIDEC CORPORATION
    Inventors: Masanori Watahiki, Tomonari Mori, Tomoya Ueda
  • Publication number: 20200059182
    Abstract: A motor controller includes an inverter that drives a motor, an operation controller that controls the inverter according to a current command value, and a torque ripple compensation generator that adds a compensation value to compensate for a torque ripple in the motor to the current command value. The operation controller uses, as the current command value, a q-axis current command value indicating a q-axis current in a rotational coordinate system of the motor, and also uses, as the current command value, at least temporarily a d-axis current command value indicating a d-axis current in the rotational coordinate system, and the torque ripple compensation generator calculates a phase difference of the compensation value with respect to the q-axis current command value according to an equation using the q-axis current command value and the d-axis current command value as variables.
    Type: Application
    Filed: August 8, 2019
    Publication date: February 20, 2020
    Inventors: Masanori WATAHIKI, Tomonari MORI, Tomoya UEDA, Shuji ENDO, Tokuji TATEWAKI
  • Publication number: 20190372496
    Abstract: A motor control apparatus includes a first circuit that determines a d-axis 0th-order current and a q-axis 0th-order current, a second circuit that determines a d-axis 6th-order harmonic current and a q-axis 6th-order harmonic current according to a position of the rotor, and a third circuit that determines, respectively, a value obtained by superposing the d-axis 6th-order harmonic current on the d-axis 0th-order current and a value obtained by superposing the q-axis 6th-order harmonic current on the q-axis 0th-order current as a d-axis current command value and a q-axis current command value.
    Type: Application
    Filed: December 8, 2017
    Publication date: December 5, 2019
    Inventors: Masanori WATAHIKI, Tomonari MORI, Tomoya UEDA
  • Patent number: 6867027
    Abstract: Disclosed are RNA polymerases consisting of a wild type RNA polymerase provided that at least one of amino acids in the wild type RNA polymerase has been modified to enhance its ability for incorporating 3?-deoxyribonucleotides and derivatives thereof in comparison with the corresponding wild type RNA polymerases. Specifically, disclosed are, for example, the RNA polymerases wherein at least one amino acid present in a nucleotide binding sites of the wild type RNA polymerases such as phenylalanine has been replaced with tyrosine. The RNA polymerases of the present invention are a RNA polymerase which exhibits little or no bias for incorporation between ribonucleotides and 3?-deoxyribonucleotide as well as among ribonucleotides having different base groups and among deoxyribonucleotides having. different base groups.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: March 15, 2005
    Assignees: The Institute of Physical and Chemical Research, Nippon Gene Co., Ltd., Nippon Genetech Co., Ltd.
    Inventors: Yoshihide Hayashizaki, Masanori Watahiki
  • Publication number: 20040259089
    Abstract: It is intended to provide novel mutant RNA polymerases enabling a transcriptional sequencing method whereby a high SN ratio can be achieved in sequence analysis with the use of capillary and longer and more accurate base sequencial data can be obtained by a single reaction. More specifically, a mutant RNA polymerase derived from a wild type RNA polymerase by substitution of at least one amino acid and deletion of at least one amino acid, or a mutant RNA polymerase derived from a wild type RNA polymerase by deletion of at least one amino acid, wherein the above-described substitution and/or deletion of amino acid(s) have been performed so that the resultant mutant RNA polymerase has an enhanced ability to incorporate 3′-deoxynucleotide as a substrate compared with the wild type RNA polymerase corresponding thereto.
    Type: Application
    Filed: August 4, 2004
    Publication date: December 23, 2004
    Inventors: Masanori Watahiki, Yuko Yoneda
  • Publication number: 20040234981
    Abstract: A transcriptional sequence method whereby a high SN ratio can be obtained in sequence analysis with the use of capillary and longer and more accurate base sequence data can be obtained in a single reaction. More specifically, a method of determining a DNA base sequence involving the step of obtaining a nucleic acid transcription product with the use of an RNA polymerase, a template DNA having a promoter sequence for the RNA polymerase and substrates of the RNA polymerase. The substrates of the RNA polymerase involve a 3′-deoxynucleotide derivative. The RNA polymerase is a mutant RNA polymerase derived from a wild type RNA polymerase by substitution of at least one amino acid or deletion of at least one amino acid. The substitution and/or deletion of the amino acid(s) are performed so that the mutant RNA polymerase has an enhanced capability of incorporating the 3′-deoxynucleotide derivative as a substrate compared with the corresponding wild type RNA polymerase.
    Type: Application
    Filed: July 6, 2004
    Publication date: November 25, 2004
    Inventors: Masanori Watahiki, Yuko Yoneda
  • Patent number: 6544736
    Abstract: cDNA including the 5′-terminal sequence of full-length mRNA with a cap structure is synthesized from a mRNA sample containing the full-length mRNA with the cap structure and non-full-length mRNA without any cap structure in mixture. At the first step, the phosphate group at 5′-terminus of the non-full-length mRNA in the mRNA sample is removed. At the second step, the cap structure at the 5′-terminus of the full-length mRNA in the mRNA sample is removed. At the third step, an oligoribonucleotide is ligated to the phosphate group at 5′-terminus of mRNA generated through the first and second steps. At the fourth step, mRNA with the oligoribonucleotide ligated at the 5′-terminus thereof at the third step is subjected to a reverse transcriptase process using a short-chain oligonucleotide capable of being annealed to an intermediate sequence within the mRNA as primer, to synthesize a first-strand cDNA.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: April 8, 2003
    Assignees: Nippon Gene Co., Ltd., Agene Research Institute Co., Ltd.
    Inventors: Akira Shimamoto, Yasuhiro Furuichi, Yuko Shibata, Hiroko Funaki, Eiji Ohara, Masanori Watahiki