Patents by Inventor Keiichiro Ohkawa

Keiichiro Ohkawa 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: 9203248
    Abstract: A battery system according to the present invention includes: a battery module comprising a plurality of cell groups connected in series, each comprising a plurality of cells connected in series; a plurality of integrated circuits provided to corresponding each cell group of the battery module, that perform detection of terminal voltages of the cells in the corresponding each cell group, and that also perform diagnosis; and a battery controller that, along with issuing commands to the plurality of integrated circuits, also receives results of detection and results of diagnosis by the plurality of integrated circuits; wherein the battery system comprises a writable non-volatile memory, and data is stored in the writable non-volatile memory specifying usage environment of the battery module, including a maximum voltage or a maximum current of the battery module and history data based upon operation history of the battery module.
    Type: Grant
    Filed: September 28, 2010
    Date of Patent: December 1, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Keiichiro Ohkawa, Masahiro Ueda
  • Publication number: 20150301115
    Abstract: The purpose of the present invention is to provide a battery control device that can appropriately verify the results of the estimation of the state of charge of a battery. This battery control device is provided with a charged state calculation unit that calculates the state of charge of the battery and a charged state verification unit that verifies the results of the calculation. The charged state verification unit calculates the charged state using a calculation procedure that is not being used by the charged state calculation unit.
    Type: Application
    Filed: January 25, 2013
    Publication date: October 22, 2015
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Keiichiro OHKAWA, Ryohei NAKAO, Youhei KAWAHARA, Naoyuki IGARASHI, Yoshinori AOSHIMA
  • Publication number: 20150108991
    Abstract: A battery control device calculates at least one of an allowable current and an allowable power during charge/discharge of a battery from a no-load voltage and an internal resistance of the battery, and corrects at least one of the no-load voltage and the internal resistance according to the states of charge/discharge of the battery.
    Type: Application
    Filed: May 24, 2012
    Publication date: April 23, 2015
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Yoshinori Aoshima, Hiroshi Morikawa, Kenji Nakai, Keiichiro Ohkawa
  • Publication number: 20140368206
    Abstract: A battery control device includes an acquisition portion that acquires measured values on the battery state every predetermined period, and a determination processing portion that determines the battery state. The determination processing portion determines that the battery state is abnormal when the number of times the measured value is out of a given range reaches a threshold until the measured value is acquired a predetermined standard number of times. If the number of times the measured value is out of range is less than the threshold when the measured number is acquired the standard number of times, the determination of the battery state is performed for an extended period until the number of times the measured value is out of the range reaches the threshold, or until the measured number is within the range, based on the measured value acquired more than the standard number of times.
    Type: Application
    Filed: December 9, 2011
    Publication date: December 18, 2014
    Applicant: HITACHI VEHICLE ENERGY, LTD.,
    Inventors: Yoshinori Aoshima, Keiichiro Ohkawa
  • Publication number: 20140339891
    Abstract: A battery controller that performs current limitation in consideration of limitation on other components than a battery main body and the state of health of a battery is provided. A battery controller limits a battery current using allowable average current information describing current average values respectively allowed for a plurality of time windows. When the battery is deteriorated, an allowable average current obtained by subtraction in response to the state of health is used. Further, when the battery current exceeds an upper limit value stored in advance, the battery current is controlled with the upper limit reduced by the excessive amount.
    Type: Application
    Filed: December 22, 2011
    Publication date: November 20, 2014
    Inventors: Keiichiro Ohkawa, Kenji Nakai, Hiroshi Morikawa
  • Publication number: 20140239914
    Abstract: A battery controller for charge and discharge control of an assembly battery so that a state of charge of each battery cell forming a battery does not deviate from a predetermined usage range. The battery controller controls an assembly battery comprising a plurality of battery cells. The battery controller calculates an actual average charge state CAVE, an average charge state upper limit value CAVEH, an average charge state lower limit value CAVEL, an average charge state ratio S indicating a position of the actual average charge state CAVE between the average charge state upper limit value CAVEH and the average charge state lower limit value CAVEL, and an assembly battery charge state CPACK based on the actual average charge state CAVE, the average charge state upper limit value CAVEH, the average charge state lower limit value CAVEL, and the average charge state ratio S.
    Type: Application
    Filed: October 6, 2011
    Publication date: August 28, 2014
    Applicant: HITACHI VEHICLE ENERGY, LTD.
    Inventors: Naoyuki Igarashi, Keiichiro Ohkawa, Youhei Kawahara
  • Publication number: 20140217982
    Abstract: To satisfactorily carry out balancing even when balancing control is suspended. It is selected according to a condition which of battery cell information (old state information) by the last balancing stored in a storage device and battery cell information (new state information) acquired during a start of this time is used, and the balancing control is performed.
    Type: Application
    Filed: May 23, 2011
    Publication date: August 7, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Youhei Kawahara, Ryouhei Nakao
  • Publication number: 20140184169
    Abstract: A battery control apparatus is provided which can keep an inter-terminal voltage of each single cell within a permitted range while permitted power is controlled in units of a battery pack. The battery control apparatus of the invention restricts the permitted power of the battery pack according to a degree of closeness of a close circuit voltage of the single cell to an upper limit or a lower limit of the permitted range.
    Type: Application
    Filed: May 16, 2011
    Publication date: July 3, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Kenichiro Tsuru, Akinori Tada, Hiroshi Morikawa, Keiichiro Ohkawa, Yoshinori Aoshima
  • Publication number: 20140184166
    Abstract: A battery control device capable of carrying out current limitation in consideration of constraints on other components than a battery main body is provided. A battery control device according to the invention has an average current table describing an average current allowed for each of plural time window widths, and limits a battery current in accordance with the description.
    Type: Application
    Filed: June 10, 2011
    Publication date: July 3, 2014
    Inventors: Keiichiro Ohkawa, Ryouhei Nakao, Youhei Kawahara
  • Publication number: 20140184236
    Abstract: A battery control apparatus which can calculate a state of charge of a battery with high accuracy is provided. The battery control apparatus of the invention determines whether or not an open circuit voltage of a battery cell is within a high sensitivity range in which the open voltage of the battery cell changes by a specified amount or more with respect to a change in the state of charge of the battery cell, and if within the high sensitivity range, calculates the state of charge by using a previously held correspondence relation table between the state of charge of the battery and the open voltage, and if not within the high sensitivity range, uses a previous state of charge calculation result stored in a storage part.
    Type: Application
    Filed: June 10, 2011
    Publication date: July 3, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Youhei Kawahara, Ryouhei Nakao
  • Publication number: 20140111164
    Abstract: An object of the invention is to provide a battery control apparatus capable of accurately obtaining permissible charging or discharging power in keeping with variation of the internal resistance of a battery. The battery control apparatus of this invention includes an internal resistance table in which the internal resistance value of single cells corresponding to the temperature and state of charge thereof are described in association with each of charging or discharging duration time of the single cells. The battery control apparatus calculates a permissible charging current or a permissible discharging current by using the internal resistance value described in the internal resistance table and controls the charging or discharging of the single cells in accordance with the current value thus obtained.
    Type: Application
    Filed: June 10, 2011
    Publication date: April 24, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Ryouhei Nakao, Youhei Kawahara
  • Publication number: 20140055100
    Abstract: A battery state estimation system estimates a state of charge of a chargeable battery. A SOCv computing unit calculates a state of charge of the battery using a voltage applied across the battery. A SOCi computing unit integrates a current flowing through the battery to calculate a state of charge of the battery. A SOCw computing unit which performs weighted addition to the state of charge of the battery calculated by the SOCv computing unit and the state of charge of the battery calculated by the SOCi computing unit, wherein when the temperature of the battery is a threshold value or less and the current flowing through the battery is a threshold value or less, the SOCw computing unit sets the specific gravity at the state of charge of the battery calculated by the SOCi computing unit larger than that in other cases upon the weighted addition.
    Type: Application
    Filed: August 19, 2013
    Publication date: February 27, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Naoyuki IGARASHI, Keiichiro OHKAWA
  • Patent number: 8484266
    Abstract: An embedded control system capable of ensuring precision in arithmetic with data in the floating-point format and also avoiding a shortage of the storage area of a memory is provided. According to an embedded control system in the present invention, when discrete data in the floating-point format is stored in a read-only memory, the discrete data in the floating-point format is converted into data in a significand-reduced floating-point format before being stored. Here, a significand-reduced floating-point number is a number obtained by deleting low-order bits of the significand of a floating-point number. Further, an interpolation search is performed using discrete data, the discrete data in the significand-reduced floating-point format stored in the read-only memory is brought back to the discrete data in the floating-point format before an interpolation search being performed.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: July 9, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Shinya Fujimoto, Keiichiro Ohkawa
  • Patent number: 8417990
    Abstract: A vehicle control system for controlling a device mounted on a vehicle includes a plurality of processor cores, and a computation process unit that is required for the control of the device is executed on the plurality of cores. A core failure determination unit compares a result of a computation process executed by the computation process unit at a particular timing on a particular one of the plurality of cores, with a result of a computation process executed at a timing different from the particular timing on another core different from the particular core, to determine that a failure has occurred on the specific core.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: April 9, 2013
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventor: Keiichiro Ohkawa
  • Publication number: 20120175953
    Abstract: A battery system according to the present invention includes: a battery module comprising a plurality of cell groups connected in series, each comprising a plurality of cells connected in series; a plurality of integrated circuits provided to corresponding each cell group of the battery module, that perform detection of terminal voltages of the cells in the corresponding each cell group, and that also perform diagnosis; and a battery controller that, along with issuing commands to the plurality of integrated circuits, also receives results of detection and results of diagnosis by the plurality of integrated circuits; wherein the battery system comprises a writable non-volatile memory, and data is stored in the writable non-volatile memory specifying usage environment of the battery module, including a maximum voltage or a maximum current of the battery module and history data based upon operation history of the battery module.
    Type: Application
    Filed: September 28, 2010
    Publication date: July 12, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Keiichiro Ohkawa, Masahiro Ueda
  • Publication number: 20100138693
    Abstract: A vehicle control multi-core system for controlling a device mounted on a vehicle by using a plurality of cores, includes a computation process unit that is executed on the plurality of cores and required for the control of the device, and a core failure determination unit that compares a result of a computation process executed by the computation process unit at a specific timing on a specific core among the plurality of cores, with a result of a computation process executed by the computation process unit at a timing different from the specific timing on another core different from the specific core among the plurality of cores to determine that a failure occurs on the specific core.
    Type: Application
    Filed: November 24, 2009
    Publication date: June 3, 2010
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventor: Keiichiro OHKAWA
  • Publication number: 20090249040
    Abstract: An embedded control system capable of ensuring precision in arithmetic with data in the floating-point format and also avoiding a shortage of the storage area of a memory is provided. According to an embedded control system in the present invention, when discrete data in the floating-point format is stored in a read-only memory, the discrete data in the floating-point format is converted into data in a significand-reduced floating-point format before being stored. Here, a significand-reduced floating-point number is a number obtained by deleting low-order bits of the significand of a floating-point number. Further, an interpolation search is performed using discrete data, the discrete data in the significand-reduced floating-point format stored in the read-only memory is brought back to the discrete data in the floating-point format before an interpolation search being performed.
    Type: Application
    Filed: February 19, 2009
    Publication date: October 1, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Shinya FUJIMOTO, Keiichiro Ohkawa
  • Publication number: 20050160410
    Abstract: A code generation system is provided which optimizes a code generation for a control system applicable to an embedded control system without the need to increase its memory capacity. A total control unit 110 causes to read a model diagram and an operation diagram which depict a software specification stored in a memory 104, and starts specification analysis unit 106 to execute lexical and grammatical analyses thereof. Then, object-oriented function removing unit 107 is started to determine any function which is not used according to a function select item stored in the memory 104. Then, code generation unit 108 is started to generate a code on the basis of the result of the lexical and grammatical analyses of the software specification, and of an output code pattern determined by the object-oriented function removing unit 107.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 21, 2005
    Applicant: Hitachi, Ltd.
    Inventors: Fumio Narisawa, Hidemitsu Naya, Takanori Yokoyama, Keiichiro Ohkawa
  • Patent number: 6851106
    Abstract: A code generation system is provided which optimizes a code generation for a control system applicable to an embedded control system without the need to increase its memory capacity. A total control unit 110 causes to read a model diagram and an operation diagram which depict a software specification stored in a memory 104, and starts specification analysis unit 106 to execute lexical and grammatical analyses thereof. Then, object-oriented function removing unit 107 is started to determine any function which is not used according to a function select item stored in the memory 104. Then, code generation unit 108 is started to generate a code on the basis of the result of the lexical and grammatical analyses of the software specification, and of an output code pattern determined by the object-oriented function removing unit 107.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: February 1, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Narisawa, Hidemitsu Naya, Takanori Yokoyama, Keiichiro Ohkawa