Patents by Inventor Tomohiro Fukumura
Tomohiro Fukumura 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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Patent number: 12040729Abstract: A motor control device includes an inverter circuit to convert a DC power source voltage into a three-phase AC voltage and supply the three-phase AC voltage to the three-phase motor and a controller to generate three-phase PWM signals based on three-phase duty command values updated at a predetermined updating cycle and control the inverter circuit based on the three-phase PWM signals. The controller is configured or programmed to shift, when duty command values of at least two phases of the three-phase duty command values updated at a first update timing are the same, the duty command value of one phase of the duty command values of the two phases by a predetermined shift amount and shifts a duty command value of the one phase of the three-phase duty command values updated at a second update timing which is an update timing next to the first update timing by the shift amount in a direction opposite to a shift direction at the first update timing.Type: GrantFiled: June 23, 2022Date of Patent: July 16, 2024Assignees: NIDEC CORPORATION, NIDEC ELESYS CORPORATIONInventors: Takashi Koikegami, Isao Sanbonmatsu, Akihiro Okamura, Tomohiro Fukumura, Kotaro Kataoka
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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: 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: 11863093Abstract: A first torque estimator determines a first torque estimation value according to a cross product method, and a second torque estimator determines a second torque estimation value according to an energy method. A torque weight adjuster adjusts, using a weighting coefficient calculated in accordance with a predetermined condition, weightings respectively applied to these two types of torque estimation values, and outputs a torque estimation value.Type: GrantFiled: August 20, 2020Date of Patent: January 2, 2024Assignee: NIDEC CORPORATIONInventors: Tomohiro Fukumura, Linfeng Lan
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Patent number: 11652435Abstract: A command generation device according to an exemplary embodiment of the present invention includes a command receiving unit that receives a high-level command value related to motion of a motor from a host device, and an internal target generation unit that generates an internal target value of the motor, including a position target value and a rotational speed target value, based on the high-level command value. The internal target generation unit includes a feedback calculator that generates the internal target value corrected based on a difference between the high-level command value and the internal target value, and generates the internal target value corrected in a cycle shorter than a cycle of receiving the high-level command value with the command receiving unit.Type: GrantFiled: January 10, 2019Date of Patent: May 16, 2023Assignee: NIDEC CORPORATIONInventors: Linfeng Lan, Tomohiro Fukumura, Koichi Takae
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Publication number: 20220416712Abstract: A motor control device includes an inverter circuit to convert a DC power source voltage into a three-phase AC voltage and supply the three-phase AC voltage to the three-phase motor and a controller to generate three-phase PWM signals based on three-phase duty command values updated at a predetermined updating cycle and control the inverter circuit based on the three-phase PWM signals. The controller is configured or programmed to shift, when duty command values of at least two phases of the three-phase duty command values updated at a first update timing are the same, the duty command value of one phase of the duty command values of the two phases by a predetermined shift amount and shifts a duty command value of the one phase of the three-phase duty command values updated at a second update timing which is an update timing next to the first update timing by the shift amount in a direction opposite to a shift direction at the first update timing.Type: ApplicationFiled: June 23, 2022Publication date: December 29, 2022Inventors: Takashi KOIKEGAMI, Isao SANBONMATSU, Akihiro OKAMURA, Tomohiro FUKUMURA, Kotaro KATAOKA
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Publication number: 20220329190Abstract: A first torque estimator determines a first torque estimation value according to a cross product method, and a second torque estimator determines a second torque estimation value according to an energy method.Type: ApplicationFiled: August 20, 2020Publication date: October 13, 2022Inventors: Tomohiro FUKUMURA, Linfeng LAN
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Publication number: 20220294378Abstract: In a DC/DC converter, a voltage input from a power source is converted into a predetermined voltage, a harmonic component generated by a harmonic signal generator is superimposed on the converted voltage, and a result is output to the inverter as power to drive an electric motor. As a result, the electric motor can be driven by the signal on which the harmonic components are superimposed without being limited to the upper limit of the switching frequency of the inverter.Type: ApplicationFiled: July 22, 2020Publication date: September 15, 2022Inventors: Tomohiro FUKUMURA, Linfeng LAN
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Patent number: 11437892Abstract: An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor that is arranged at a predetermined mechanical angle with respect to the first magnetic sensor and detects the rotational position of the rotor; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generator that converts an output signal of the signal amplifier into a pulse signal.Type: GrantFiled: April 6, 2020Date of Patent: September 6, 2022Assignee: NIDEC CORPORATIONInventors: Masaki Yoshinaga, Tomohiro Fukumura, Taro Amagai, Akiko Ikeda, Kengo Araki
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Patent number: 11431230Abstract: An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a position shifted by ?/N in a rotation direction of the rotor with respect to the first magnetic sensor when the number of pole pairs is N; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.Type: GrantFiled: April 6, 2020Date of Patent: August 30, 2022Assignee: NIDEC CORPORATIONInventors: Masaki Yoshinaga, Tomohiro Fukumura, Taro Amagai, Akiko Ikeda, Kengo Araki
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Publication number: 20220266700Abstract: A torque control of an in-vehicle motor is performed in consideration of a slip prevention control. Filtering processing is performed by a first filter processor on a high-order torque command value from a high-order device, and filtering processing is performed by a second filter processor on an angular velocity detected by an angular velocity detector. A driving torque command value to drive an electric motor is calculated based on filtering processing results. Each of the filter processors changes a time constant of the filtering processing according to a road surface friction coefficient as disturbance information.Type: ApplicationFiled: July 21, 2020Publication date: August 25, 2022Inventors: Linfeng LAN, Tomohiro FUKUMURA, Tomonari MORI
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Patent number: 11349374Abstract: A motor according to a disclosed embodiment includes: a plurality of magnetic sensors that output sine wave signals having a certain phase difference in order in accordance with rotation of a rotor; a signal amplifier that amplifies a difference between an output signal of each of the plurality of magnetic sensors and an average signal that is an average of the output signals of the plurality of magnetic sensors; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.Type: GrantFiled: April 13, 2020Date of Patent: May 31, 2022Assignee: NIDEC CORPORATIONInventors: Masaki Yoshinaga, Tomohiro Fukumura, Taro Amagai, Akiko Ikeda, Kengo Araki
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Patent number: 11277083Abstract: A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a rotation center of the rotor; a signal amplifier that amplifies a difference between a first signal, which is a signal output from the first magnetic sensor, and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.Type: GrantFiled: March 31, 2020Date of Patent: March 15, 2022Assignee: NIDEC CORPORATIONInventors: Masaki Yoshinaga, Tomohiro Fukumura, Taro Amagai, Akiko Ikeda, Kengo Araki
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Publication number: 20210367547Abstract: A command generation device according to an exemplary embodiment of the present invention includes a command receiving unit that receives a high-level command value related to motion of a motor from a host device, and an internal target generation unit that generates an internal target value of the motor, including a position target value and a rotational speed target value, based on the high-level command value. The internal target generation unit includes a feedback calculator that generates the internal target value corrected based on a difference between the high-level command value and the internal target value, and generates the internal target value corrected in a cycle shorter than a cycle of receiving the high-level command value with the command receiving unit.Type: ApplicationFiled: January 10, 2019Publication date: November 25, 2021Inventors: Linfeng LAN, Tomohiro FUKUMURA, Koichi TAKAE
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Patent number: 11050326Abstract: An SR motor includes a rotor including N rotor salient poles where N is an integer of 2 or more, a stator including M stator salient poles where M is an integer of 3 or more, a shaft rotatably connected to the rotor, a sensor magnet that is fixed to an outer circumference of the shaft and includes an S pole and an N pole alternately arranged in the circumferential direction of the shaft, and three magnetic sensors opposed to the sensor magnet. The number of poles of the sensor magnet is N.Type: GrantFiled: October 27, 2017Date of Patent: June 29, 2021Assignee: NIDEC CORPORATIONInventors: Yuichi Takano, Keita Fukushima, Tomohiro Fukumura
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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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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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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: 20200366162Abstract: A motor according to a disclosed embodiment includes: a plurality of magnetic sensors that output sine wave signals having a certain phase difference in order in accordance with rotation of a rotor; a signal amplifier that amplifies a difference between an output signal of each of the plurality of magnetic sensors and an average signal that is an average of the output signals of the plurality of magnetic sensors; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.Type: ApplicationFiled: April 13, 2020Publication date: November 19, 2020Inventors: Masaki YOSHINAGA, Tomohiro FUKUMURA, Taro AMAGAI, Akiko IKEDA, Kengo ARAKI
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Publication number: 20200336048Abstract: An offset of an output voltage of a magnetic sensor caused by an external magnetic field is removed. A motor according to a disclosed embodiment includes: a first magnetic sensor that detects a rotational position of a rotor; a second magnetic sensor arranged at a position shifted by ?/N in a rotation direction of the rotor with respect to the first magnetic sensor when the number of pole pairs is N; a signal amplifier that amplifies a difference between a first signal which is a signal output from the first magnetic sensor and a second signal which is a signal output from the second magnetic sensor; and a pulse signal generation unit that converts an output signal of the signal amplifier into a pulse signal.Type: ApplicationFiled: April 6, 2020Publication date: October 22, 2020Inventors: Masaki YOSHINAGA, Tomohiro FUKUMURA, Taro AMAGAI, Akiko IKEDA, Kengo ARAKI