Patents by Inventor Kiyoshi Ohishi
Kiyoshi Ohishi 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: 20230402942Abstract: A power conversion device comprises: power conversion circuitry for converting DC power into AC power and supplying it into a load according to a switching state quantity defined by combinations among switching parameters of switching devices; a voltage output calculation device for calculating a voltage output value on the power conversion circuitry, based on the switching state quantity; an integration value calculation device for acquiring a voltage reference integration value and a voltage output integration value by integrating a voltage reference value and the calculated voltage output value; a switching update-determination unit for outputting an update signal of the switching state quantity, based on the voltage reference integration value, its allowance value, and the voltage output integration value; and a switching determination table for determining a switching state quantity of the switching devices, based on the voltage reference integration value, the voltage output integration value and the upType: ApplicationFiled: November 18, 2021Publication date: December 14, 2023Applicants: Mitsubishi Electric Corporation, National University Corporation Nagaoka University of TechnologyInventors: Tenjiro HIWATARI, Sota SANO, Akira SATAKE, Kiyoshi OHISHI, Yuki YOKOKURA, Yuto KOBAYASHI
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Patent number: 11177757Abstract: The present invention includes a control amount calculation unit which calculates two or more control amounts each indicating a driving condition of a rotary electric machine on the basis of output current from and a switching state in a power converter; a limitation range-provided command value generation unit which generates limitation range-provided command values relative to command values for the control amounts; and a switching state determination unit which determines a switching state such that each control amount falls within the limitation range of the corresponding limitation range-provided command value. For at least one of the limitation range-provided command values, the limitation range thereof is temporally changed on the basis of the driving condition of the rotary electric machine.Type: GrantFiled: December 7, 2017Date of Patent: November 16, 2021Assignees: MITSUBISHI ELECTRIC CORPORATION, NATIONAL UNIVERSITY CORPORATION NAGAOKA UNIVERSITY OF TECHNOLOGYInventors: Sota Sano, Akira Satake, Kiyoshi Ohishi, Yuki Yokokura, Tenjiro Hiwatari
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Publication number: 20210203261Abstract: The present invention includes a control amount calculation unit which calculates two or more control amounts each indicating a driving condition of a rotary electric machine on the basis of output current from and a switching state in a power converter; a limitation range-provided command value generation unit which generates limitation range-provided command values relative to command values for the control amounts; and a switching state determination unit which determines a switching state such that each control amount falls within the limitation range of the corresponding limitation range-provided command value. For at least one of the limitation range-provided command values, the limitation range thereof is temporally changed on the basis of the driving condition of the rotary electric machine.Type: ApplicationFiled: December 7, 2017Publication date: July 1, 2021Applicants: Mitsubishi Electric Corporation, National University Corporation Nagaoka University of TechnologyInventors: Sota SANO, Akira SATAKE, Kiyoshi OHISHI, Yuki YOKOKURA, Tenjiro HIWATARI
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Patent number: 10042343Abstract: This application discloses a control device for controlling a motor configured to drive an oscillatory cyclo-speed reducer including an oscillatory gear portion formed with at least one hole at an eccentric position. The control device includes an angle acquirer for acquiring input information about an input rotational angle indicating a rotational angle of the motor, an estimator for estimating an angular error between the input rotational angle and an output rotational angle indicating a rotational angle of the oscillatory cyclo-speed reducer based on a quantity of the hole(s) and a corrector for determining a compensation current value in correspondence to the angular error and setting a magnitude of a current to be supplied to the motor by correcting a command current value using the compensation current value.Type: GrantFiled: September 1, 2015Date of Patent: August 7, 2018Assignees: NATIONAL UNIVERSITY CORPORATION NAGAOKA UNIVERSITY OF TECHNOLOGY, NABTESCO CORPORATIONInventors: Kiyoshi Ohishi, Yuki Yokokura, Yosei Hirano, Koji Nakamura, Masataka Sato
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Publication number: 20160070247Abstract: This application discloses a control device for controlling a motor configured to drive an oscillatory cyclo-speed reducer including an oscillatory gear portion formed with at least one hole at an eccentric position. The control device includes an angle acquirer for acquiring input information about an input rotational angle indicating a rotational angle of the motor, an estimator for estimating an angular error between the input rotational angle and an output rotational angle indicating a rotational angle of the oscillatory cyclo-speed reducer based on a quantity of the hole(s) and a corrector for determining a compensation current value in correspondence to the angular error and setting a magnitude of a current to be supplied to the motor by correcting a command current value using the compensation current value.Type: ApplicationFiled: September 1, 2015Publication date: March 10, 2016Inventors: Kiyoshi OHISHI, Yuki YOKOKURA, Yosei HIRANO, Koji NAKAMURA, Masataka SATO
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Patent number: 8588371Abstract: An inverter circuit allowing a single drive circuit to perform both tracking control for tracking resonance frequency fluctuations caused by load fluctuations, and power control, thereby reducing switching loss. An inverter drive circuit part obtains a phase difference between output current and output voltage directed to a load circuit connected to a midpoint of two arm circuits of the inverter circuit, and controls a phase of the driving signal directed to each semiconductor switch such that the phase difference becomes zero or a predetermined value, enabling an operating frequency of the inverter circuit part to track a resonance frequency of the load circuit, and enabling a current phase to be delayed with respect to a voltage phase, thereby achieving ZCS. Since the phase difference is used, an auxiliary circuit is not necessary for measuring a current value in proximity to the semiconductor switches.Type: GrantFiled: November 5, 2009Date of Patent: November 19, 2013Assignees: Hitachi Medical Corporation, Institute of National College of Technology, National University Cooperation Nagaoka University of TechnologyInventors: Mina Ogawa, Itaru Ando, Kiyoshi Ohishi, Shoutaro Shindo
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Publication number: 20110222651Abstract: There is provided an inverter circuit which allows a single drive circuit to carry out both the tracking control for tracking resonance frequency fluctuations caused by load fluctuations, and the power control, thereby reducing switching loss. An inverter drive circuit part obtains a phase difference between output current and output voltage directed to a load circuit which is connected to a midpoint of two arm circuits of the inverter circuit, and controls a phase of the driving signal directed to each of the semiconductor switches in such a manner that the phase difference becomes zero or a predetermined value. This allows an operating frequency of the inverter circuit part to track a resonance frequency of the load circuit. In addition, this enables a current phase to be delayed with respect to a voltage phase, thereby achieving ZCS.Type: ApplicationFiled: November 5, 2009Publication date: September 15, 2011Applicants: HITACHI MEDICAL CORPORATION, Institute of National Colleges of Technology, Japan, National University Corporation Nagaoka University of TechnologyInventors: Mina Ogawa, Itaru Ando, Kiyoshi Ohishi, Shoutaro Shindo
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Patent number: 5986424Abstract: A control system which comprises a reduction gear unit containing gears, a motor being disposed on an input side of said reduction gear unit, a sensor for detecting a turning angle of said motor, and control means for inputting output from said sensor and controlling turning of said motor. The control system further includes gear output angle variation estimation means for estimating a gear output angle variation of said reduction gear unit based on the motor turning angle. An angle transmission error is estimated based on the motor turning angle, whereby load tip locus accuracy can be improved without lowering responsivity of the control system.Type: GrantFiled: February 20, 1998Date of Patent: November 16, 1999Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Takashi Nakatsuka, Atsumi Hashimoto, Yasushi Mukai, Kiyoshi Ohishi