Patents by Inventor Shota ISHIGAMI

Shota ISHIGAMI 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: 20240088808
    Abstract: One aspect of a position estimation method of the present invention includes: a learning step of acquiring learning data necessary for estimation of a rotational position of a rotor on the basis of an input sensor signal; and a position estimation step of estimating the rotational position of the rotor on the basis of the input sensor signal and the learning data. The learning step is performed, thereby acquiring, as the learning data, data indicating the correspondence relationship between a segment number associated with a section included in each of a plurality of quadrants and a pole pair number representing a pole pair position. The position estimation step is performed, thereby determining an initial position of the rotor on the basis of the input sensor signal and the learning data.
    Type: Application
    Filed: December 24, 2021
    Publication date: March 14, 2024
    Inventors: Yutaka SAITO, Atsushi FUJITA, Shota ISHIGAMI
  • Patent number: 11860002
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Grant
    Filed: February 26, 2021
    Date of Patent: January 2, 2024
    Assignee: NIDEC CORPORATION
    Inventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
  • Patent number: 11860003
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Grant
    Filed: February 26, 2021
    Date of Patent: January 2, 2024
    Assignee: NIDEC CORPORATION
    Inventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
  • Patent number: 11509248
    Abstract: A position estimation device acquires detection values of magnetic field strength at three or more locations of a rotor in a range where a rotor angle is less than one rotation. A section is selected based on a detection value of the magnetic field strength from predetermined sections for a pole pair number of the rotor. A feature amount calculator is provided to calculate feature amounts of a waveform of the magnetic field strength based on a combination of the detection values of the magnetic field strength according to the section selected. An estimator is provided to determine, for each segment associated with the section selected, whether or not a magnitude relationship of the feature amounts learned in advance coincides with a magnitude relationship of the feature amounts calculated, and estimating, as a rotation position of the rotor, the pole pair number associated with the segment having the same magnitude relationship.
    Type: Grant
    Filed: October 24, 2019
    Date of Patent: November 22, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Shota Ishigami, Atsushi Fujita, Tomohisa Tokunaga
  • Patent number: 11448526
    Abstract: A position estimation method of the present disclosure includes: acquiring learning data from a storage medium that stores the learning data including a sequence of a plurality of measurement values which define a waveform characteristic of a first electrical signal output from a sensor device when a rotor R is rotating; acquiring a sequence of a plurality of detection values which define a waveform characteristic of a second electrical signal output from the sensor device when the rotor starts rotating from a stopped state; and performing matching between an increase/decrease pattern of the sequence of the plurality of measurement values and an increase/decrease pattern of the sequence of the plurality of detection values to estimate a relationship between a rotation position of the rotor when the first electrical signal is output and a rotation position of the rotor when the second electrical signal is output.
    Type: Grant
    Filed: February 20, 2019
    Date of Patent: September 20, 2022
    Assignee: NIDEC CORPORATION
    Inventors: Shota Ishigami, Atsushi Fujita
  • Publication number: 20220014129
    Abstract: A position estimation device acquires detection values of magnetic field strength at three or more locations of a rotor in a range where a rotor angle is less than one rotation. A section is selected based on a detection value of the magnetic field strength from predetermined sections for a pole pair number of the rotor. A feature amount calculator is provided to calculate feature amounts of a waveform of the magnetic field strength based on a combination of the detection values of the magnetic field strength according to the section selected. An estimator is provided to determine, for each segment associated with the section selected, whether or not a magnitude relationship of the feature amounts learned in advance coincides with a magnitude relationship of the feature amounts calculated, and estimating, as a rotation position of the rotor, the pole pair number associated with the segment having the same magnitude relationship.
    Type: Application
    Filed: October 24, 2019
    Publication date: January 13, 2022
    Inventors: Shota ISHIGAMI, Atsushi FUJITA, Tomohisa TOKUNAGA
  • Publication number: 20220014126
    Abstract: A position estimation device acquires detection values of a magnetic field strength at three or more locations of a rotor in accordance with a rotor angle in a range where the rotor angle is less than one rotation. A feature amount calculator is provided to calculate feature amounts of a waveform of the magnetic field strength based on the detection values of the magnetic field strength. An estimator is provided to determine, for each pole pair number of the rotor, whether or not a pattern of a magnitude relationship of the feature amounts learned in advance coincides with a pattern of a magnitude relationship of the feature amounts calculated, and to estimate, as a rotation position of the rotor, the pole pair number with which a pattern of the magnitude relationship coincides.
    Type: Application
    Filed: October 24, 2019
    Publication date: January 13, 2022
    Inventors: Shota ISHIGAMI, Atsushi FUJITA, Tomohisa TOKUNAGA
  • Publication number: 20210180989
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Application
    Filed: February 26, 2021
    Publication date: June 17, 2021
    Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI
  • Publication number: 20210180990
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Application
    Filed: February 26, 2021
    Publication date: June 17, 2021
    Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI
  • Patent number: 10976182
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: April 13, 2021
    Assignee: NIDEC CORPORATION
    Inventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
  • Publication number: 20210003422
    Abstract: A position estimation method of the present disclosure includes: acquiring learning data from a storage medium that stores the learning data including a sequence of a plurality of measurement values which define a waveform characteristic of a first electrical signal output from a sensor device when a rotor R is rotating; acquiring a sequence of a plurality of detection values which define a waveform characteristic of a second electrical signal output from the sensor device when the rotor starts rotating from a stopped state; and performing matching between an increase/decrease pattern of the sequence of the plurality of measurement values and an increase/decrease pattern of the sequence of the plurality of detection values to estimate a relationship between a rotation position of the rotor when the first electrical signal is output and a rotation position of the rotor when the second electrical signal is output.
    Type: Application
    Filed: February 20, 2019
    Publication date: January 7, 2021
    Inventors: Shota ISHIGAMI, Atsushi FUJITA
  • Patent number: 10505478
    Abstract: In one implementation, a motor module according to the present invention includes: a motor driving circuit 10 to drive a motor M; and a position estimation device 30 to output an estimated position signal of a rotor R of the motor M. It also includes: a motor control circuit 20 to supply a command voltage value to the motor driving circuit 10 in response to a pulse signal; and a variable step-size memory 40 storing variable step-size information, which defines an amount of displacement of the rotor R per pulse of the pulse signal. The estimated position signal is an analog or digital signal. Upon receiving a pulse signal, the motor control circuit 20 determines the command voltage value based on an estimated position value of the rotor R acquired from the position estimation device 30 and the variable step-size information read from the variable step-size memory 40. The motor driving circuit 10 changes the position of the rotor R based on the command voltage value.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: December 10, 2019
    Assignee: NIDEC CORPORATION
    Inventors: Atsushi Fujita, Shota Ishigami, Tomohiro Fukumura
  • Publication number: 20190222152
    Abstract: In one implementation, a motor module according to the present invention includes: a motor driving circuit 10 to drive a motor M; and a position estimation device 30 to output an estimated position signal of a rotor R of the motor M. It also includes: a motor control circuit 20 to supply a command voltage value to the motor driving circuit 10 in response to a pulse signal; and a variable step-size memory 40 storing variable step-size information, which defines an amount of displacement of the rotor R per pulse of the pulse signal. The estimated position signal is an analog or digital signal. Upon receiving a pulse signal, the motor control circuit 20 determines the command voltage value based on an estimated position value of the rotor R acquired from the position estimation device 30 and the variable step-size information read from the variable step-size memory 40. The motor driving circuit 10 changes the position of the rotor R based on the command voltage value.
    Type: Application
    Filed: February 27, 2017
    Publication date: July 18, 2019
    Inventors: Atsushi FUJITA, Shota ISHIGAMI, Tomohiro FUKUMURA
  • Publication number: 20170343382
    Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
    Type: Application
    Filed: December 18, 2015
    Publication date: November 30, 2017
    Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI