Patents by Inventor Seiji Sawada

Seiji Sawada 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).

  • Patent number: 12034334
    Abstract: A resolver device with redundancy, wherein winding groups of different systems are arranged at different positions in a circumferential direction of a stator core. The winding groups of each system include: an excitation winding group consisting of a plurality of excitation windings, each of which is connected to a corresponding one of plural excitation circuits; and a first output winding group; and a second output winding group. Each of the stator teeth has a corresponding one of the excitation windings wound therearound. When two of the excitation windings belonging to different systems, arranged side by side in the circumferential direction of the stator core, are defined as a first end excitation winding and a second end excitation winding, respectively, the first end excitation winding and the second end excitation winding are supplied with excitation signals which generate magnetic fluxes in the same (not opposite) radial directions of the stator core.
    Type: Grant
    Filed: May 24, 2019
    Date of Patent: July 9, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroko Ikeda, Tatsuya Mori, Kenta Motoyoshi, Kodai Okazaki, Kenji Ikeda, Yosuke Sugino, Seiji Sawada, Kenta Kubo, Toshihiro Matsunaga
  • Patent number: 11936311
    Abstract: To provide a controller for motor which can reduce a torque ripple up to high frequency, without amplifying unnecessary noise and vibration. A controller for motor estimates an interlinkage flux based on the applied voltage and the detection value of current; estimates an output torque based on the detection value of current and the estimation value of interlinkage flux; extracts a pulsation component from the estimation value of output torque; calculates a voltage command correction value based on the extraction value of pulsation component; calculates a voltage command after superimposing by superimposing the voltage command correction value on the voltage command basic value; and applies voltage to winding based on the voltage command after superimposing.
    Type: Grant
    Filed: May 30, 2019
    Date of Patent: March 19, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiko Orii, Tatsuya Mori, Seiji Sawada, Kenta Kubo
  • Patent number: 11828591
    Abstract: Even using the redundant system resolver in which the magnetic interference between systems occurs, to provide an angle detection apparatus which can reduces the influence of the magnetic interference and can calculate the rotational angle with good accuracy, without performing synchronous control between systems in real time. An angle detection apparatus is provided with a resolver which has the first system windings and the second system windings in which magnetic interference occurs between systems; a first system removal processing unit that performs a second cycle component removal processing which removes component of the second cycle of the second system, to detection values of the first system winding output signals; and a first system angle calculation unit that calculates a first angle of rotor, based on the detection values of the first system winding output signals after the second cycle component removal processing.
    Type: Grant
    Filed: January 25, 2019
    Date of Patent: November 28, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tatsuya Mori, Toshihiro Matsunaga, Hiroko Ikeda, Seiji Sawada, Kenta Kubo, Kenji Ikeda
  • Patent number: 11529993
    Abstract: To provide a motor controller and an electric power steering apparatus which can suppress torque fluctuation resulting from low detection resolution of angle, with simple calculation, even in condition where the rotational speed of motor is low. A motor controller estimates an angle error correlation value correlated with the angle detection error based on the current command value when a change frequency of the angle detection value is lower than a cutoff frequency of feedback control system which controls a rotation state; corrects the current command value or the angle detection value based on the estimation value of angle error correlation value; and changes the estimation value of angle error correlation value so that the absolute value of angle detection error increases with respect to increase in the current command value, and the absolute value of angle detection error decreases with respect to decrease in the current command value.
    Type: Grant
    Filed: November 7, 2017
    Date of Patent: December 20, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenta Tanaka, Isao Kezobo, Akira Furukawa, Seiji Sawada
  • Publication number: 20220224172
    Abstract: In a redundancy resolver device, winding groups of different systems are arranged at different positions in a circumferential direction of a stator core. The winding groups of each system include: an excitation winding group consisting of a plurality of excitation windings, and being connected to corresponding one of excitation circuits; a first output winding group; and a second output winding group. Each of the teeth has corresponding one of the excitation windings wound therearound. When two of the excitation windings belonging to different systems and being arranged side by side is the circumferential direction of the stator core are defined as a first end excitation winding and a second end excitation winding, respectively, the first end excitation winding and the second end excitation winding are applied with excitation signals to generate magnetic fluxes in the same direction of radial directions of the stator core.
    Type: Application
    Filed: May 24, 2019
    Publication date: July 14, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroko IKEDA, Tatsuya MORI, Kenta MOTOYOSHI, Kodai OKAZAKI, Kenji IKEDA, Yosuke SUGINO, Seiji SAWADA, Kenta KUBO, Toshihiro MATSUNAGA
  • Publication number: 20220166356
    Abstract: To provide a controller for rotary electric machine which can suppress the increase in the switching frequency by the voltage for estimation while reducing the estimation delay of the magnetic pole position (the rotational angle). A controller for rotary electric machine turns on and off switching devices which the inverter has and applies voltage to the winding, based on a comparison result between the voltage command and the carrier wave; generates the voltage command for estimation of a preliminarily set one period on a stationary coordinate system fixed to the winding; generates the carrier wave of the same one period as the one period of the voltage command for estimation; extracts the frequency component of the one period of the voltage command for estimation from the current detection value; and estimates a rotational angle based on the frequency component.
    Type: Application
    Filed: June 4, 2019
    Publication date: May 26, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Jun KITAGAWA, Tatsuya MORI, Isao KEZOBO, Seiji SAWADA, Kenta KUBO
  • Publication number: 20220103102
    Abstract: To provide a controller for motor which can reduce a torque ripple up to high frequency, without amplifying unnecessary noise and vibration. A controller for motor estimates an interlinkage flux based on the applied voltage and the detection value of current; estimates an output torque based on the detection value of current and the estimation value of interlinkage flux; extracts a pulsation component from the estimation value of output torque; calculates a voltage command correction value based on the extraction value of pulsation component; calculates a voltage command after superimposing by superimposing the voltage command correction value on the voltage command basic value; and applies voltage to winding based on the voltage command after superimposing.
    Type: Application
    Filed: May 30, 2019
    Publication date: March 31, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Isao KEZOBO, Masahiko ORII, Tatsuya MORI, Seiji SAWADA, Kenta KUBO
  • Publication number: 20220018646
    Abstract: Even using the redundant system resolver in which the magnetic interference between systems occurs, to provide an angle detection apparatus which can reduces the influence of the magnetic interference and can calculate the rotational angle with good accuracy, without performing synchronous control between systems in real time. An angle detection apparatus is provided with a resolver which has the first system windings and the second system windings in which magnetic interference occurs between systems; a first system removal processing unit that performs a second cycle component removal processing which removes component of the second cycle of the second system, to detection values of the first system winding output signals; and a first system angle calculation unit that calculates a first angle of rotor, based on the detection values of the first system winding output signals after the second cycle component removal processing.
    Type: Application
    Filed: January 25, 2019
    Publication date: January 20, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tatsuya MORI, Toshihiro MATSUNAGA, Hiroko IKEDA, Seiji SAWADA, Kenta KUBO, Kenji IKEDA
  • Patent number: 10892018
    Abstract: A semiconductor memory device includes a memory array including a plurality of memory blocks, an address allocation information storage unit which stores address allocation information, a block selection circuit which selects one memory block which corresponds to an input address which is input on the basis of the address allocation information and a refresh control circuit which controls a refreshing operation. One of the memory blocks is allotted to a surplus memory block. The refresh control circuit transfers data which is stored in one memory block which is a refreshing object to the surplus memory block and thereafter allocates address information of the memory block which was the refreshing object to the surplus memory block to which the data is transferred and newly allots the memory block which was the refreshing object to the surplus memory block.
    Type: Grant
    Filed: October 4, 2018
    Date of Patent: January 12, 2021
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Seiji Sawada
  • Publication number: 20200255067
    Abstract: To provide a motor controller and an electric power steering apparatus which can suppress torque fluctuation resulting from low detection resolution of angle, with simple calculation, even in condition where the rotational speed of motor is low. A motor controller estimates an angle error correlation value correlated with the angle detection error based on the current command value when a change frequency of the angle detection value is lower than a cutoff frequency of feedback control system which controls a rotation state; corrects the current command value or the angle detection value based on the estimation value of angle error correlation value; and changes the estimation value of angle error correlation value so that the absolute value of angle detection error increases with respect to increase in the current command value, and the absolute value of angle detection error decreases with respect to decrease in the current command value.
    Type: Application
    Filed: November 7, 2017
    Publication date: August 13, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenta TANAKA, Isao KEZOBO, Akira FURUKAWA, Seiji SAWADA
  • Patent number: 10339335
    Abstract: A semiconductor device includes a first storage unit including twin cells which are electrically rewritable and complementarily store 1-bit data based on a difference in a threshold voltage, a second storage unit including a memory cell which is electrically rewritable, data stored in the memory cell being erased when data in the twin cells is erased, at least one scrambler subjecting first data to a scramble processing by using scramble data to generate second data, a first write circuit which writes the second data into the twin cells in the first storage unit, a second write circuit which writes the scramble data into the memory cell in the second storage unit, and at least one descrambler subjecting the second data read from the first storage unit to a descramble processing by using the scramble data read from the second storage unit.
    Type: Grant
    Filed: August 20, 2018
    Date of Patent: July 2, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Seiji Sawada
  • Publication number: 20190172541
    Abstract: A semiconductor memory device includes a memory array including a plurality of memory blocks, an address allocation information storage unit which stores address allocation information, a block selection circuit which selects one memory block which corresponds to an input address which is input on the basis of the address allocation information and a refresh control circuit which controls a refreshing operation. One of the memory blocks is allotted to a surplus memory block. The refresh control circuit transfers data which is stored in one memory block which is a refreshing object to the surplus memory block and thereafter allocates address information of the memory block which was the refreshing object to the surplus memory block to which the data is transferred and newly allots the memory block which was the refreshing object to the surplus memory block.
    Type: Application
    Filed: October 4, 2018
    Publication date: June 6, 2019
    Inventor: Seiji SAWADA
  • Publication number: 20190043586
    Abstract: To prolong the lifetime of a semiconductor memory device without performing complicated control. A semiconductor memory device according to one embodiment is equipped with a bank A and a bank B operable complementarily to each other, and a bank selection circuit which selects either one of the banks A and B. The bank selection circuit alternately switches the bank to be selected, each time an erase command to instruct erasing of data in either one of the banks A and B is issued.
    Type: Application
    Filed: July 5, 2018
    Publication date: February 7, 2019
    Inventor: Seiji SAWADA
  • Publication number: 20180357441
    Abstract: A semiconductor device includes a first storage unit including twin cells which are electrically rewritable and complementarily store 1-bit data based on a difference in a threshold voltage, a second storage unit including a memory cell which is electrically rewritable, data stored in the memory cell being erased when data in the twin cells is erased, at least one scrambler subjecting first data to a scramble processing by using scramble data to generate second data, a first write circuit which writes the second data into the twin cells in the first storage unit, a second write circuit which writes the scramble data into the memory cell in the second storage unit, and at least one descrambler subjecting the second data read from the first storage unit to a descramble processing by using the scramble data read from the second storage unit.
    Type: Application
    Filed: August 20, 2018
    Publication date: December 13, 2018
    Inventor: Seiji SAWADA
  • Patent number: 10073982
    Abstract: A scramble unit subjects data to be written into twin cells in a first storage unit to scramble processing with the use of scramble data. A write unit writes write data subjected to the scramble processing into the twin cells in the first storage unit. A write unit writes scramble data into a memory cell in a second storage unit. A descramble unit subjects the data read from the first storage unit to descramble processing with the use of scramble data read from the second storage unit.
    Type: Grant
    Filed: August 15, 2013
    Date of Patent: September 11, 2018
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventor: Seiji Sawada
  • Publication number: 20180144807
    Abstract: The present disclosure provides a semiconductor device that can reduce the power consumption. The semiconductor device includes memory cells arranged in a matrix form, and a verify circuit that performs a verify operation to verify whether or not data is written to a memory cell. The verify circuit performs the verify operation when write data is in a first state, and dose not perform the verify operation when the write data is in a second state.
    Type: Application
    Filed: November 21, 2017
    Publication date: May 24, 2018
    Applicant: Renesas Electronics Corporation
    Inventor: Seiji SAWADA
  • Publication number: 20160203328
    Abstract: A scramble unit (501) subjects data to be written into twin cells (505) in a first storage unit (502) to scramble processing with the use of scramble data. A write unit (509) writes write data subjected to the scramble processing into the twin cells (505) in the first storage unit (502). A write unit (511) writes scramble data into a memory cell (510) in a second storage unit (503). A descramble unit (504) subjects the data read from the first storage unit (502) to descramble processing with the use of scramble data read from the second storage unit (503).
    Type: Application
    Filed: August 15, 2013
    Publication date: July 14, 2016
    Inventor: Seiji SAWADA
  • Patent number: 8326493
    Abstract: A motor-driven power steering control apparatus is achieved, which uses a small-amplitude pass filter, the filter filtering out a component having a small amplitude, to remove a steering component from dynamic state quantity such as a rotational speed signal, and to accurately extract only a vibration component having a small amplitude compared with the steering component, and controls the vibration component to be reduced.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: December 4, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Isao Kezobo, Masahiko Kurishige, Masaya Endo, Takayuki Kifuku, Seiji Sawada, Masaki Matsushita
  • Patent number: 8294395
    Abstract: A storage section stores three-phase detection currents and outputs them as three-phase storage detection currents and also stores three-phase voltage commands and outputs them as three-phase storage voltage commands. A second voltage command calculating section outputs three-phase voltage commands on the basis of the three-phase storage detection currents and the three-phase storage voltage commands, which are acquired from the storage section, and the three-phase detection currents acquired from a current detecting means. A voltage command output means outputs, to a voltage application means, three-phase voltage commands acquired on the basis of the three-phase voltage commands from the storage section and the three-phase voltage commands from the second voltage command calculating section. The voltage application means applies a voltage to an AC rotary machine on the basis of the three-phase voltage commands from the voltage command output means.
    Type: Grant
    Filed: October 14, 2010
    Date of Patent: October 23, 2012
    Assignee: Mitsubishi Electric Corp.
    Inventors: Yoshihiko Kimpara, Seiji Sawada, Takayuki Kifuku
  • Publication number: 20120016067
    Abstract: To achieve improvement in initial conversion efficiency of solar cell modules, inhibition of deterioration in transparency of a resin, inhibition of degradation in adhesive properties with respect to a protective member over time, and inhibition of degradation in conversion efficiency. A resin composition for solar cell-sealing material according to the present invention includes an ethylene copolymer, and further includes at least one of: (i) a compound represented by the following general formula (1); (ii) a calcined product of the (i); (iii) a compound represented by the following general formula (2); and (iv) a calcined product of the (iii). The (i) has an average plate surface diameter of 0.01 to 0.9 ?m and a refractive index of 1.45 to 1.55, and the (iii) has an average plate surface diameter of 0.02 to 0.9 ?m and a refractive index of 1.48 to 1.6. Mg1-n.Ala(OH)2.Ann?a/n.bH2O??General formula (1) (0.25?a?0.35, 0?b?1, An: an n-valent anion); (McMg1-c)1-d.Ald(OH)2.Bmm?d/m.
    Type: Application
    Filed: August 4, 2010
    Publication date: January 19, 2012
    Applicants: TOYOCHEM CO., LTD, TOYO INK SC HOLDINGS CO., LTD
    Inventors: Keisuke Masuko, Yasuhiro Fukudome, Yusuke Onodo, Seiji Sawada, Satoshi Ooi, Hideki Takahashi