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).
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Publication number: 20240356389Abstract: A stator core has tooth portions each including a body and an umbrella portion. The umbrella portion includes a first vertex closest to one side in the circumferential direction in a surface facing the side end and the other side in the radial direction, a second vertex farthest from the side end portion toward the one side in the circumferential direction, a third vertex closest to the other side in the circumferential direction in a surface facing the other side in the radial direction, and a fourth vertex farthest from the side end portion toward the other side in the circumferential direction. Lx is between side end portions facing in the circumferential direction on a virtual straight line passing through the second and fourth vertices, Ly1 is between the side end portion and the second vertex, Ly2 is between the side end portion and the fourth vertex, 0<Ly1/Lx<0.4 and 0<Ly2/Lx<0.4.Type: ApplicationFiled: July 29, 2022Publication date: October 24, 2024Inventors: Masanori WATAHIKI, Kan AKATSU
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Patent number: 12017707Abstract: 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: GrantFiled: February 8, 2019Date of Patent: June 25, 2024Assignee: NIDEC CORPORATIONInventors: Shuji Endo, Akitoshi Harada, Tomoya Ueda, Masanori Watahiki, Tomonari Mori, Tokuji Tatewaki
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Patent number: 11958543Abstract: 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: GrantFiled: February 13, 2019Date of Patent: April 16, 2024Assignee: NIDEC CORPORATIONInventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
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Patent number: 11952057Abstract: 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: GrantFiled: February 13, 2019Date of Patent: April 9, 2024Assignee: NIDEC CORPORATIONInventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
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Patent number: 11366435Abstract: 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: GrantFiled: April 4, 2018Date of Patent: June 21, 2022Assignees: NIDEC CORPORATION, THE UNIVERSITY OF TOKYOInventors: Hiroshi Fujimoto, Linfeng Lan, Tomonari Mori, Masanori Watahiki
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Patent number: 11362608Abstract: 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: GrantFiled: February 8, 2019Date of Patent: June 14, 2022Assignee: NIDEC CORPORATIONInventors: Shuji Endo, Akitoshi Harada, Tomoya Ueda, Masanori Watahiki, Tomonari Mori, Tokuji Tatewaki
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Patent number: 11251731Abstract: 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: GrantFiled: February 8, 2019Date of Patent: February 15, 2022Assignee: NIDEC CORPORATIONInventors: Shuji Endo, Tokuji Tatewaki, Tomoya Ueda, Masanori Watahiki, Tomonari Mori
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Publication number: 20210103258Abstract: 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: ApplicationFiled: April 4, 2018Publication date: April 8, 2021Inventors: Hiroshi FUJIMOTO, Linfeng LAN, Tomonari MORI, Masanori WATAHIKI
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Publication number: 20210044234Abstract: 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: ApplicationFiled: February 8, 2019Publication date: February 11, 2021Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
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Publication number: 20200406958Abstract: 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: ApplicationFiled: February 8, 2019Publication date: December 31, 2020Inventors: Shuji ENDO, Akitoshi HARADA, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI, Tokuji TATEWAKI
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Publication number: 20200406957Abstract: 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: ApplicationFiled: February 13, 2019Publication date: December 31, 2020Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
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Publication number: 20200395877Abstract: 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: ApplicationFiled: February 8, 2019Publication date: December 17, 2020Inventors: Shuji ENDO, Akitoshi HARADA, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI, Tokuji TATEWAKI
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Patent number: 10862415Abstract: 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: GrantFiled: August 8, 2019Date of Patent: December 8, 2020Assignees: NIDEC CORPORATION, NIDEC ELESYS CORPORATIONInventors: Masanori Watahiki, Tomonari Mori, Tomoya Ueda, Shuji Endo, Tokuji Tatewaki
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Publication number: 20200377144Abstract: 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: ApplicationFiled: February 13, 2019Publication date: December 3, 2020Inventors: Shuji ENDO, Tokuji TATEWAKI, Tomoya UEDA, Masanori WATAHIKI, Tomonari MORI
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Patent number: 10848088Abstract: 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: GrantFiled: December 8, 2017Date of Patent: November 24, 2020Assignee: NIDEC CORPORATIONInventors: Masanori Watahiki, Tomonari Mori, Tomoya Ueda
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Publication number: 20200059182Abstract: 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: ApplicationFiled: August 8, 2019Publication date: February 20, 2020Inventors: Masanori WATAHIKI, Tomonari MORI, Tomoya UEDA, Shuji ENDO, Tokuji TATEWAKI
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Publication number: 20190372496Abstract: 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: ApplicationFiled: December 8, 2017Publication date: December 5, 2019Inventors: Masanori WATAHIKI, Tomonari MORI, Tomoya UEDA
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Patent number: 6867027Abstract: 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: GrantFiled: July 6, 1998Date of Patent: March 15, 2005Assignees: The Institute of Physical and Chemical Research, Nippon Gene Co., Ltd., Nippon Genetech Co., Ltd.Inventors: Yoshihide Hayashizaki, Masanori Watahiki
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Publication number: 20040259089Abstract: 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: ApplicationFiled: August 4, 2004Publication date: December 23, 2004Inventors: Masanori Watahiki, Yuko Yoneda
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Publication number: 20040234981Abstract: 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: ApplicationFiled: July 6, 2004Publication date: November 25, 2004Inventors: Masanori Watahiki, Yuko Yoneda