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: 20040064228
    Abstract: A motor-driven power steering control apparatus for determining pertinent timings for starting/stopping application of steering assist torque includes a motor (7) for applying an assist torque, a sensor (2) for detecting a steering torque, a driving unit (13,14,121,124) for operating the motor (7) in dependence on a detected steering torque, a command unit (12;122,123) for commanding starting and stopping of operation of the motor (7), and a motor operation decision unit (12;122,123). When stopping of operation of the motor (7) is commanded by the command unit (122,123), the motor operation decision unit (122,123) stops driving operation of the motor (7) while commanding the driving unit (13,14,121,124) 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: Application
    Filed: March 7, 2003
    Publication date: April 1, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Munenori Yamamoto, Takayuki Kifuku
  • Patent number: 6711484
    Abstract: In the conventional electric power steering control system, a gain by which an approximate differentiation value of a torque signal is multiplied comes to be large at high speed driving. Therefore, a problem exits in that unstable feel of steering increases, thereby steering convergence getting worse. An electric power steering control system includes a variable type torque differential operation device 104A that makes variable a differential time constant at the time of outputting a second motor current, and a time constant determining device 105X that commands the time constant to the variable type torque differential operation device 104A. The time constant determining device 105X determines the time constant in response to any change in not less than one signal selected and used in an arbitrary manner out of a speed signal 81, a torque signal 82, a yaw rate signal 83 and a steering rate signal 84.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: March 23, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Seiji Sakanishi, Sadaaki Kamei
  • Patent number: 6694237
    Abstract: A steering control device is provided, which comprises a motor driving circuit for driving a motor and a microprocessor for supplying an applied voltage signal, which is found based on a motor current detection value detected by a motor current detecting unit, a motor voltage detection value detected by a motor voltage detecting unit, a steering torque detected by a torque sensor and a vehicle speed detected by a vehicle speed sensor, to the motor driving circuit such that the motor driving circuit increases or decreases the motor current according to an average value of motor current detection values over a time period and increases or decreases the motor current by detecting that a steering is in the vicinity of a maximum steering angle based on the detected steering torque.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: February 17, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Munenori Yamamoto
  • Publication number: 20040026161
    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: August 6, 2003
    Publication date: February 12, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Yuji Takatsuka, Katsuhiko Ohmae, Norihiro Yamaguchi, Susumu Zeniya, Takayuki Kifuku, Shigeki Ohtagaki
  • Patent number: 6687590
    Abstract: The present invention is an electric power steering apparatus which includes a multi-phase motor that assists steering effort of a driver, a motor drive circuit provided with at least an upper switching element that connects or disconnects the winding of each phase of the multi-phase motor and a power supply, and a lower switching element that connects or disconnects the winding of each phase of the multi-phase motor and grounding, a logic circuit that determines ON/OFF of the upper switching element and the lower switching element, and first and second microcontrollers that control the motor drive circuit via this logic circuit, in which the logic circuit determines ON/OFF of the upper switching element and the lower switching element so that the power to the winding of the each phase of the multi-phase motor is stopped according to the instruction of either the first microcontroller or the second microcontroller.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: February 3, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto
  • Publication number: 20030179004
    Abstract: A judgment is made of an abnormal condition of a motor due to an influence of a disturbance voltage without addition of hardware by estimating the disturbance voltage on the basis of a target voltage and an actual current of the motor.
    Type: Application
    Filed: March 5, 2003
    Publication date: September 25, 2003
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kouji Fukusumi, Masahiko Kurishige, Noriyuki Inoue, Seiji Sakanishi, Kenichi Kawakami, Takayuki Kifuku
  • Publication number: 20030155879
    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: Application
    Filed: October 10, 2002
    Publication date: August 21, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Katsuhiko Ohmae
  • Patent number: 6600983
    Abstract: A steering control apparatus includes a first power supply, a second power supply for outputting a voltage lower than the voltage of the first power supply, a motor for generating an auxiliary steering power, a controller for controlling the motor, and a driver for driving the motor in response to the output of the controller, wherein power is supplied from the first power supply to the driver and that power is supplied from the second power supply to the controller.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: July 29, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Kifuku
  • Publication number: 20030069675
    Abstract: In the conventional electric power steering control system, a gain by which an approximate differentiation value of a torque signal is multiplied comes to be large at the time of high speed travelling. Therefore upon conducting a quick steering for a lane change or avoidance of danger, a problem exits in that unstable feel of steering increases thereby steering convergence of vehicle getting worse. In the invention, there are provided a variable type torque differential operation device 104A that makes variable a differential time constant at the time of outputting a second motor current, and a time constant determining device 105X that commands the time constant to the variable type torque differential operation device 104A. The time constant determining device 105X determines the time constant in response to any change in not less than one signal selected and used in an arbitrary manner out of a vehicle speed signal 81, a steering torque signal 82, a yaw rate signal 83 and a steering rate signal 84.
    Type: Application
    Filed: April 15, 2002
    Publication date: April 10, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Seiji Sakanishi, Sadaaki Kamei
  • Publication number: 20030045981
    Abstract: A steering control device is provided, which comprises a motor driving circuit for driving a motor and a microprocessor for supplying an applied voltage signal, which is found based on a motor current detection value detected by a motor current detecting unit, a motor voltage detection value detected by a motor voltage detecting unit, a steering torque detected by a torque sensor and a vehicle speed detected by a vehicle speed sensor, to the motor driving circuit such that the motor driving circuit increases or decreases the motor current according to an average value of motor current detection values over a time period and increases or decreases the motor current by detecting that a steering is in the vicinity of a maximum steering angle based on the detected steering torque.
    Type: Application
    Filed: April 15, 2002
    Publication date: March 6, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Munenori Yamamoto
  • Patent number: 6522097
    Abstract: A position detecting apparatus includes: a position sensor 10 that inputs an excitation signal having a given period waveform and outputs a first amplitude modified signal induced in accordance with a detected position from a first output winding and outputs a second amplitude modified signal induced in accordance with a detected position from a second output winding; a first phase shifting circuit 23 for electrically shifting a phase of the first amplitude modified signal by a given angle; a second phase shifting circuit 24 for electrically shifting a phase of the second amplitude modified signal by a given angle; converting means 15,16 for converting the signal outputted from the first phase shifting circuit 23 and the signal outputted from the second phase shifting circuit 24 into a phase modulated signal; and calculating means 17-22 for obtaining a detected position on the basis of the phase of the phase modulated signal outputted from the converting means 15,16.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: February 18, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Chiaki Fujimoto, Masaki Matsushita, Takayuki Kifuku
  • Publication number: 20030011334
    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: September 26, 2001
    Publication date: January 16, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventor: Takayuki Kifuku
  • Publication number: 20020179363
    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: November 29, 2001
    Publication date: December 5, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Yuji Takatsuka, Katsuhiko Ohmae, Norihiro Yamaguchi, Susumu Zeniya, Takayuki Kifuku, Shigeki Ohtagaki
  • Patent number: 6490514
    Abstract: A power steering control system is provided with a road surface reaction torque detector in which a motor inertia torque is subtracted from a value obtained by adding steering torque and motor torque, and the value is passed through two stages of primary filters to obtain a road surface reaction torque. In such a computation, the inertia term of the steering wheel manipulation force does not depend on frequency and high frequency components do not bring about any unusually large steering wheel return force. Therefore, a driver can drive without difficulty in adapting to the power steering.
    Type: Grant
    Filed: February 1, 2001
    Date of Patent: December 3, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Kurishige, Noriyuki Inoue, Toshihide Satake, Takayuki Kifuku, Shunichi Wada
  • Publication number: 20020177932
    Abstract: To provide an electric power steering apparatus capable of constructing a microcomputer redundant system that controls the motor with an extremely small amount of calculation and improving the reliability of the apparatus.
    Type: Application
    Filed: November 15, 2001
    Publication date: November 28, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Kazumichi Tsutsumi, Chiaki Fujimoto
  • Publication number: 20020175645
    Abstract: A position detecting apparatus includes: a position sensor 10 that inputs an excitation signal having a given period waveform and outputs a first amplitude modified signal induced in accordance with a detected position from a first output winding and outputs a second amplitude modified signal induced in accordance with a detected position from a second output winding; a first phase shifting circuit 23 for electrically shifting a phase of the first amplitude modified signal by a given angle; a second phase shifting circuit 24 for electrically shifting a phase of the second amplitude modified signal by a given angle; converting means 15, 16 for converting the signal outputted from the first phase shifting circuit 23 and the signal outputted from the second phase shifting circuit 24 into a phase modulated signal; and calculating means 17-22 for obtaining a detected position on the basis of the phase of the phase modulated signal outputted from the converting means 15,16.
    Type: Application
    Filed: November 6, 2001
    Publication date: November 28, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Chiaki Fujimoto, Masaki Matsushita, Takayuki Kifuku
  • Patent number: 6459971
    Abstract: In an electric power steering control system, a road surface reaction torque estimator estimates a road surface reaction torque on the basis of steering wheel angle. A neutral point learning unit and a neutral point compensator learn a neutral point of the steering wheel on the basis of the road surface reaction torque with respect to the steering wheel angle. A return torque for returning the steering wheel to the neutral point is computed from a difference between a current angle of the motor and the learned neutral point. As a result, the steering wheel returns to the neutral point under the current driving condition without application of any force to the steering wheel by the driver.
    Type: Grant
    Filed: August 20, 2001
    Date of Patent: October 1, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Kurishige, Noriyuki Inoue, Ryoji Nishiyama, Kazumichi Tsutsumi, Takayuki Kifuku
  • Patent number: 6450287
    Abstract: An electric power steering controller including a motor for generating torque for assisting the steering torque of a driver to assist the steering force of a steering system. The controller includes a road reaction torque detector for detecting road reaction torque received by tires from the surface of a road, and a road detection torque addition control for controlling the torque of the motor based on the road reaction torque. The electric power steering controller enables the steering wheel to be returned to its starting point without adding torque in a direction in which the driver returns the steering wheel when the driver contgrols the steering wheel with the small road reaction torque of the tires, for example, when turning at an intersection at a low speed or when turning at a gently curved portion of a road at a high speed.
    Type: Grant
    Filed: June 26, 2000
    Date of Patent: September 17, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Kurishige, Noriyuki Inoue, Ryoji Nishiyama, Takayuki Kifuku, Shunichi Wada
  • Patent number: 6445987
    Abstract: An electric power steering controller and a control method for assisting a driver during handling a steering wheel in a condition of a small road surface reaction torque of a tire by generating an auxiliary return torque for letting the steering wheel return to its original position. A first road surface reaction torque is estimated from a steering torque of a driver detected by a steering torque detector, a motor acceleration detected by a motor acceleration detector, and a motor current detected by a motor current detector. A second road surface reaction torque is estimated from a steering angle detected by a steering angle sensor, and a vehicle speed detected by a vehicle speed detector. Then, first and second auxiliary return torque signals of the steering wheel are computed from a road surface reaction torque, and, based on the computed result, a torque of the motor is controlled in direction so the steering wheel is returned to its original position.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: September 3, 2002
    Assignee: Mitsubushi Denki Kabushiki Kaisha
    Inventors: Masahiko Kurishige, Noriyuki Inoue, Ryoji Nishiyama, Shunichi Wada, Takayuki Kifuku
  • Publication number: 20020109474
    Abstract: A motor control device for a multiple-phase motor includes a drive circuit (PWM inverter) which drives the multiple-phase motor (three-phase DC brushless motor), and a micro-controller that controls the drive circuit, wherein the micro-controller limits a motor current in accordance with an integrated value of a predetermined function of a phase current.
    Type: Application
    Filed: June 19, 2001
    Publication date: August 15, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takayuki Kifuku, Masaki Matsushita