Patents by Inventor Takayuki Kifuku

Takayuki Kifuku 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).

  • Publication number: 20060055348
    Abstract: In a motor control apparatus in which a higher voltage is directly applied to a driving unit for a motor from a battery and a lower voltage stepped down by a switching regulator from the battery is also supplied to a control unit, the switching regulator is started its switching by a starting signal supplied from the outside of the motor control apparatus and is stopped its switching by the first stopping signal from the outside of a motor control apparatus and the second stopping signal derived from the control unit.
    Type: Application
    Filed: March 9, 2005
    Publication date: March 16, 2006
    Inventor: Takayuki Kifuku
  • Publication number: 20060055365
    Abstract: A control device of a motor used in, for example, electric power steering control of a vehicle has to monitor the operation thereof to execute such a processing as stopping the control without delay upon detection of error. However, conventional monitoring devices have a disadvantage of taking a long time period the detection or not being able to detect an error of no output. A three-phase inverter circuit 52 having a substantially constant operation period is employed. The inverter 52 outputs an output waveform also at the moment of not driving the motor 2. An inverter period monitoring circuit 555 is provided to monitor a period of the output waveform. When the period comes to be too large or too small as compared with a carrier period of the inverter, an alarm is outputted, and control of the inverter is stopped.
    Type: Application
    Filed: March 9, 2005
    Publication date: March 16, 2006
    Inventors: Takayuki Kifuku, Katsuhiko Ohmae
  • Publication number: 20060049788
    Abstract: The object of the present invention is to provide an electric power steering controller in which a redundant system equal to that with a relay is configured, without incurring the upsizing or deterioration in reliability, of the controller. An electric power steering controller involving the present invention is provided with a motor for providing a steering system with output torque; a motor driving circuit for driving the motor; a microcontroller for calculating a current to be applied to the motor; a gate driver for driving a plurality of switching devices constituting a bridge circuit, based on the result of the calculation by the microcontroller; and a switching portion for cutting off the power supply to the gate driver.
    Type: Application
    Filed: July 15, 2005
    Publication date: March 9, 2006
    Inventors: Takayuki Kifuku, Kazuto Kusakabe
  • Publication number: 20060043917
    Abstract: An objective is to provide, in a motor controller used for an electromotive power steering system, a concrete realistic method for easily performing abnormality judgments in its control system.
    Type: Application
    Filed: February 28, 2005
    Publication date: March 2, 2006
    Inventors: Takayuki Kifuku, Hiroyuki Kozuki, Masaki Matsushita
  • Patent number: 6992449
    Abstract: In an electric power steering apparatus in which a third motor target current is determined from a first motor target current determined on the basis of a detection torque from a steering torque detection means and a second motor target current determined using at least a detection value of the motor current detection circuit as one of inputs, and a motor drive signal is calculated on the basis of the third motor target current and a detection current from the motor current detection circuit to control a motor current, there is included a motor current detection circuit failure judgment means for judging a failure of the motor current detection circuit, and when a judgment of failure is made, at least the second motor target current is limited.
    Type: Grant
    Filed: October 7, 2004
    Date of Patent: January 31, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Eiji Iwami, Susumu Zeniya, Takayuki Kifuku
  • Patent number: 6992448
    Abstract: A motor control apparatus capable of protecting a motor from overheat while changing smoothly a motor output characteristic as a function of time lapse and mitigating overhead involved in arithmetic operation includes a current command value generator for generating current command values for a motor (1) having a polyphase winding, and motor current value detecting circuits (3u, 3v) for detecting motor current values (iu, iv), to drive the motor (1) on the basis of the motor current values and current command values. The apparatus further includes a PWM inverter (4) for driving the motor (1) and a microcontroller (5) for controlling the PWM inverter (4). The microcontroller (5) limits the motor current values in dependence on integrated values of function values determined by fitting transformed current values determined through predetermined coordinate transformation of the phase currents (iu, iv, iw) to a predetermined function.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: January 31, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Chiaki Fujimoto, Takayuki Kifuku
  • Patent number: 6987371
    Abstract: A steering controlling device comprising a power source, a motor connected to a steering system, a motor driving circuit converting a power source voltage to a predetermined voltage and applying the voltage to the motor, and a controlling means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit so as to boost the power source voltage when a rotational speed of the motor is a predetermined value or more, whereby a sufficient motor output torque is obtainable under various steering conditions in use of a converter, an efficiency is improved by suppressing a frequency of operating the converter, and an appropriate fail safe treatment is conducted when the converter is disordered.
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: January 17, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Kifuku
  • Publication number: 20050280383
    Abstract: The invention proposes an electrically operated power steering controller for inputting a driving electric current offset value of higher accuracy and being able to make an offset correction of a driving electric current by using this driving electric current offset value of higher accuracy, and an adjusting method of this driving electric current offset. Therefore, an electric motor driving electric current measuring device of accuracy higher than that of an electric motor driving electric current detector assembled into a controller CNT is prepared separately from this electric motor driving electric current detector. The driving electric current offset value of high accuracy is outputted by this electric motor driving electric current measuring device. An input device for receiving the driving electric current offset value of high accuracy from the driving electric current measuring device is arranged in an offset correcting device or an offset signal generator within the controller.
    Type: Application
    Filed: November 3, 2004
    Publication date: December 22, 2005
    Inventor: Takayuki Kifuku
  • Publication number: 20050258791
    Abstract: In an electric power steering apparatus in which a third motor target current is determined from a first motor target current determined on the basis of a detection torque from a steering torque detection means and a second motor target current determined using at least a detection value of the motor current detection circuit as one of inputs, and a motor drive signal is calculated on the basis of the third motor target current and a detection current from the motor current detection circuit to control a motor current, there is included a motor current detection circuit failure judgment means for judging a failure of the motor current detection circuit, and when a judgment of failure is made, at least the second motor target current is limited.
    Type: Application
    Filed: October 7, 2004
    Publication date: November 24, 2005
    Inventors: Eiji Iwami, Susumu Zeniya, Takayuki Kifuku
  • Publication number: 20050162113
    Abstract: A motor control apparatus capable of protecting a motor from overheat while changing smoothly a motor output characteristic as a function of time lapse and mitigating overhead involved in arithmetic operation includes a current command value generator for generating current command values for a motor (1) having a polyphase winding, and motor current value detecting circuits (3u, 3v) for detecting motor current values (iu, iv), to drive the motor (1) on the basis of the motor current values and current command values. The apparatus further includes a PWM inverter (4) for driving the motor (1) and a microcontroller (5) for controlling the PWM inverter (4). The microcontroller (5) limits the motor current values in dependence on integrated values of function values determined by fitting transformed current values determined through predetermined coordinate transformation of the phase currents (iu, iv, iw) to a predetermined function.
    Type: Application
    Filed: July 22, 2004
    Publication date: July 28, 2005
    Inventors: Chiaki Fujimoto, Takayuki Kifuku
  • Patent number: 6902028
    Abstract: Conventionally, there was a problem that in cases when it is difficult to place a temperature sensor in the vicinity of a heat-generating portion, overheating could not be prevented.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: June 7, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yuji Takatsuka, Katsuhiko Ohmae, Norihiro Yamaguchi, Susumu Zeniya, Takayuki Kifuku, Shigeki Ohtagaki
  • Patent number: 6903524
    Abstract: In an electric motor-driven power steering apparatus which comprises a bridge circuit for connecting a power source between input terminals and also connecting an electric motor between output terminals and energizes the electric motor by this bridge circuit and operates electric motor power to a steering system, the bridge circuit includes a predetermined number of arms constructed by connecting circuits for connecting switching elements in parallel with diodes in series so that the diodes mutually become reverse polarity.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: June 7, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Yasuhiro Hosaka
  • Publication number: 20050092541
    Abstract: A steering controlling device comprising a power source, a motor connected to a steering system, a motor driving circuit converting a power source voltage to a predetermined voltage and applying the voltage to the motor, and a controlling means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit so as to boost the power source voltage when a rotational speed of the motor is a predetermined value or more, whereby a sufficient motor output torque is obtainable under various steering conditions in use of a converter, an efficiency is improved by suppressing a frequency of operating the converter, and an appropriate fail safe treatment is conducted when the converter is disordered.
    Type: Application
    Filed: November 30, 2004
    Publication date: May 5, 2005
    Inventor: Takayuki Kifuku
  • Patent number: 6876910
    Abstract: To improve a steering feeling, an estimated value of static friction of a steering system is obtained by static friction computing means and a static friction compensation current is computed based on this estimated value of static friction by static friction compensation current computing means to compensate for the static friction of the steering system.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: April 5, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Kifuku
  • Patent number: 6860361
    Abstract: Conventionally, there was a problem that in cases when it is difficult to place a temperature sensor in the vicinity of a heat-generating portion, overheating could not be prevented.
    Type: Grant
    Filed: August 6, 2003
    Date of Patent: March 1, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yuji Takatsuka, Katsuhiko Ohmae, Norihiro Yamaguchi, Susumu Zeniya, Takayuki Kifuku, Shigeki Ohtagaki
  • Patent number: 6831477
    Abstract: An identification is made of an abnormal condition in a motor due to an influence of a disturbance voltage, without addition of hardware, by estimating the disturbance voltage based on a target voltage and actual current flowing in the motor.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: December 14, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kouji Fukusumi, Masahiko Kurishige, Noriyuki Inoue, Seiji Sakanishi, Kenichi Kawakami, Takayuki Kifuku
  • Publication number: 20040222037
    Abstract: Conventionally, there was a problem that in cases when it is difficult to place a temperature sensor in the vicinity of a heat-generating portion, overheating could not be prevented.
    Type: Application
    Filed: June 10, 2004
    Publication date: November 11, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Yuji Takatsuka, Katsuhiko Ohmae, Norihiro Yamaguchi, Susumu Zeniya, Takayuki Kifuku, Shigeki Ohtagaki
  • Patent number: 6816765
    Abstract: A motor-driven power steering control apparatus for determining pertinent timings for starting/stopping application of steering assist torque includes a motor for applying an assist torque, a sensor for detecting a steering torque, a driving unit for operating the motor in dependence on a detected steering torque, a command unit for commanding starting and stopping of operation of the motor, and a motor operation decision unit. When stopping of operation of the motor is commanded by the command unit, the motor operation decision unit stops driving operation of the motor while commanding the driving unit to stop application of the steering assist torque when a state in which a steering torque is not greater than a predetermined value for stoppage has continued for a predetermined time period.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: November 9, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Munenori Yamamoto, Takayuki Kifuku
  • Publication number: 20040200663
    Abstract: In an electric motor-driven power steering apparatus which comprises a bridge circuit for connecting a power source between input terminals and also connecting an electric motor between output terminals and energizes the electric motor by this bridge circuit and operates electric motor power to a steering system, the bridge circuit includes a predetermined number of arms constructed by connecting circuits for connecting switching elements in parallel with diodes in series so that the diodes mutually become reverse polarity.
    Type: Application
    Filed: October 8, 2003
    Publication date: October 14, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Yasuhiro Hosaka
  • Patent number: 6741053
    Abstract: A steering control device is realized which is capable of handling a variety of torque sensors through the same signal processing circuit, and in which a cost increase is suppressed while taking sufficient failsafe measures, having a torque sensor for detecting a signal corresponding to a steering torque in a steering system; a first microcontroller for outputting a steering torque signal equivalent to the steering torque; a second microcontroller for controlling an actuator based on the steering torque signal outputted; actuator driving means for driving the actuator controlling the steering system; and storage means in which a steering torque neutral point compensation data is stored in advance; wherein the first microcontroller compensates a neutral point of the steering torque signal based on the neutral point compensation data stored in the storage means.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: May 25, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Katsuhiko Ohmae