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).
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Publication number: 20240088808Abstract: 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: ApplicationFiled: December 24, 2021Publication date: March 14, 2024Inventors: Yutaka SAITO, Atsushi FUJITA, Shota ISHIGAMI
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Patent number: 11860002Abstract: 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 estimateType: GrantFiled: February 26, 2021Date of Patent: January 2, 2024Assignee: NIDEC CORPORATIONInventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
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Patent number: 11860003Abstract: 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 estimateType: GrantFiled: February 26, 2021Date of Patent: January 2, 2024Assignee: NIDEC CORPORATIONInventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
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Patent number: 11509248Abstract: 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: GrantFiled: October 24, 2019Date of Patent: November 22, 2022Assignee: NIDEC CORPORATIONInventors: Shota Ishigami, Atsushi Fujita, Tomohisa Tokunaga
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Patent number: 11448526Abstract: 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: GrantFiled: February 20, 2019Date of Patent: September 20, 2022Assignee: NIDEC CORPORATIONInventors: Shota Ishigami, Atsushi Fujita
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Publication number: 20220014129Abstract: 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: ApplicationFiled: October 24, 2019Publication date: January 13, 2022Inventors: Shota ISHIGAMI, Atsushi FUJITA, Tomohisa TOKUNAGA
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Publication number: 20220014126Abstract: 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: ApplicationFiled: October 24, 2019Publication date: January 13, 2022Inventors: Shota ISHIGAMI, Atsushi FUJITA, Tomohisa TOKUNAGA
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Publication number: 20210180989Abstract: 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 estimateType: ApplicationFiled: February 26, 2021Publication date: June 17, 2021Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI
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Publication number: 20210180990Abstract: 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 estimateType: ApplicationFiled: February 26, 2021Publication date: June 17, 2021Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI
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Patent number: 10976182Abstract: 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 estimateType: GrantFiled: December 18, 2015Date of Patent: April 13, 2021Assignee: NIDEC CORPORATIONInventors: Tomohiro Fukumura, Atsushi Fujita, Shota Ishigami
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Publication number: 20210003422Abstract: 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: ApplicationFiled: February 20, 2019Publication date: January 7, 2021Inventors: Shota ISHIGAMI, Atsushi FUJITA
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Patent number: 10505478Abstract: 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: GrantFiled: February 27, 2017Date of Patent: December 10, 2019Assignee: NIDEC CORPORATIONInventors: Atsushi Fujita, Shota Ishigami, Tomohiro Fukumura
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Publication number: 20190222152Abstract: 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: ApplicationFiled: February 27, 2017Publication date: July 18, 2019Inventors: Atsushi FUJITA, Shota ISHIGAMI, Tomohiro FUKUMURA
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Publication number: 20170343382Abstract: 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 estimateType: ApplicationFiled: December 18, 2015Publication date: November 30, 2017Inventors: Tomohiro FUKUMURA, Atsushi FUJITA, Shota ISHIGAMI