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).

  • Patent number: 7355361
    Abstract: A motor control apparatus can protect circuit elements in an appropriate manner while preventing an incorrect abnormality determination when a motor is in regeneration operation, etc. The apparatus includes a target current calculation section (51), a drive control section (52) that generates a drive signal based on a current deviation ?I between a target current (IMT) and a detected current (IMS), an abnormality determination section (53) that generates an abnormality determination signal based on the target current (IMT) and the detected current (IMS), and a regeneration operation determination section (59) that determines whether the motor (4) is in a regeneration operation state. When it is determined that the motor (4) is in a regeneration operation, a determination threshold of the abnormality determination section (53) is set to a value larger than a determination threshold during power running operation.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: April 8, 2008
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takayuki Kifuku, Masaki Matsushita, Hiroyuki Kozuki
  • Patent number: 7336456
    Abstract: An objective is to detect a resolver malfunction without fail, using a low-cost resolver having the small number of the poles, and a control-motor system having advantage in small sizing and high-power outputting. In the control-motor system, the system for driving a 2m-pole motor based on a rotor rotation angle ? detected by a 2n-pole resolver, where m and n being counting numbers, is characterized in that: the sum of the square of a signal modulated by sin ? and the square of a signal modulated by cos ? in the resolver in which an excitation signal generated in said system is modulated by sin ? and cos ? in response to the rotor rotation angle ? of the resolver is compared to a predetermined malfunction threshold value, so that malfunction determination related to the resolver is performed, and also, given that the sum is a2 when the resolver is recognized to be in normal operation, the malfunction determination threshold value is made to be not smaller than {a×cos((?/2)/(m/n))}2.
    Type: Grant
    Filed: July 11, 2005
    Date of Patent: February 26, 2008
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masaki Matsushita, Takayuki Kifuku, Hideki Doi, Katsuhiko Ohmae
  • Publication number: 20080040001
    Abstract: A vehicular steering system can suppress steering of steerable road wheels in a direction not intended by a driver. A steering mechanism steers the steerable road wheels in accordance with a steering wheel and an auxiliary steering angle superposition mechanism. A calculation section calculates a target auxiliary steering angle corresponding to a steering wheel angle of the steering wheel. A detection section accurately detects the auxiliary steering angle based on detection signals of a rotation angle sensor that detects a rotation angle of a rotational member. A driving section controls the auxiliary steering angle superposition mechanism so as to make the auxiliary steering angle coincide with the target auxiliary steering angle. An auxiliary steering angle detection abnormality monitoring section detects abnormality of the auxiliary steering angle detection section.
    Type: Application
    Filed: January 29, 2007
    Publication date: February 14, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kenji Ogawa, Takayuki Kifuku, Masayoshi Yamamoto, Masafumi Okazaki
  • Publication number: 20080017439
    Abstract: Provided is a power steering apparatus capable of suppressing an abrupt change in steering force and preventing a deterioration in steering feeling even in the event of a transition from power steering to manual steering. The power steering apparatus includes a torque sensor, a motor of a permanent magnet field type, and a controller having a motor driving unit and an abnormality monitoring unit, for controlling the driving of the motor. The motor driving unit includes an inverter for driving the motor, and a drive signal generating unit for calculating a target current caused to flow through the motor and outputting a drive signal of the inverter based on the target current. The abnormality monitoring unit includes an abnormality processing unit for constituting a closed-loop circuit including the motor in stopping the driving of the motor.
    Type: Application
    Filed: November 14, 2006
    Publication date: January 24, 2008
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Seiji Sawada, Takayuki Kifuku
  • Patent number: 7294985
    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: November 30, 2004
    Date of Patent: November 13, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Kifuku
  • Publication number: 20070252547
    Abstract: A motor control apparatus can protect circuit elements in an appropriate manner while preventing an incorrect abnormality determination when a motor is in regeneration operation, etc. The apparatus includes a target current calculation section (51), a drive control section (52) that generates a drive signal based on a current deviation ?I between a target current (IMT) and a detected current (IMS), an abnormality determination section (53) that generates an abnormality determination signal based on the target current (IMT) and the detected current (IMS), and a regeneration operation determination section (59) that determines whether the motor (4) is in a regeneration operation state. When it is determined that the motor (4) is in a regeneration operation, a determination threshold of the abnormality determination section (53) is set to a value larger than a determination threshold during power running operation.
    Type: Application
    Filed: September 19, 2006
    Publication date: November 1, 2007
    Inventors: Takayuki Kifuku, Masaki Matsushita, Hiroyuki Kozuki
  • Publication number: 20070235249
    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: June 14, 2007
    Publication date: October 11, 2007
    Inventor: Takayuki KIFUKU
  • Patent number: 7272479
    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: Grant
    Filed: November 3, 2004
    Date of Patent: September 18, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Kifuku
  • Publication number: 20070199764
    Abstract: An electric power steering control apparatus can limit a motor impression voltage thereby to maintain an appropriate motor output even upon occurrence of a failure of a motor current detection circuit or a motor current feedback control system. The apparatus includes a motor that generates an assist force to the steering system, an input processing section that takes in a steering torque signal from a torque sensor, an output processing section that drives the motor, and a processing unit that provides an instruction to the output processing section based on the steering torque signal. The processing unit includes an impression voltage calculation section that calculates an amount of operation to the motor in accordance with the steering torque signal, and an impression voltage limiting section that limits the impression voltage to predetermined limit values or less corresponding to the direction of the steering torque signal.
    Type: Application
    Filed: July 27, 2006
    Publication date: August 30, 2007
    Inventors: Takayuki Kifuku, Masaki Matsushita, Hiroyuki Kozuki
  • Publication number: 20070152614
    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 of f set signal generator within the controller.
    Type: Application
    Filed: March 14, 2007
    Publication date: July 5, 2007
    Inventor: Takayuki Kifuku
  • Patent number: 7176651
    Abstract: An inverter fault detection system of the present invention is provided with: bus voltage monitor means for monitoring the bus voltage of a three-phase inverter; output voltage monitor means for summing the phase output voltages coming from the three-phase PWM inverter, and for outputting the resulting summed output voltage through a filter having a low-pass characteristic of passing through only the cutoff frequency lower than the PWM carrier frequency; and fault determination means for determining that the three-phase PWM inverter is in the faulty state when the output voltage coming from the output voltage monitor means is almost the same as the voltage value corresponding to 3/2 times of the bus voltage monitored by the bus voltage monitor means.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: February 13, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Masaki Matsushita
  • Patent number: 7165646
    Abstract: A steering control apparatus of a simple configuration is adaptable so as to construct a redundant system from an input to an output system at low cost in a reliable manner. A torque sensor detects a steering torque, and a motor (3) provides torque to a steering system. A motor drive circuit (56) drives the motor, and a steering control section (53a) calculates at least a target current for the motor based on the steering torque. A motor control section (53b) provides an instruction to the motor drive circuit (56) based on the target current. A steering control verification section (54a) verifies an operation of the steering control section (53a) based on the steering torque and the target current. A motor control verification section (54b) verifies an operation of the motor control section (53b) based on a predetermined state quantity of the motor drive circuit (56) or the motor (3).
    Type: Grant
    Filed: April 5, 2005
    Date of Patent: January 23, 2007
    Assignee: Itsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Hiroyuki Kozuki, Yasuaki Hori
  • Patent number: 7161317
    Abstract: An objective is to provide a specific realization means for easily determining malfunction of a system in an electromotive power steering controller. The electromotive power steering controller includes: a voltage controller for controlling voltage applying to a motor based on a d-axis current command value and a q-axis current command value that are set by a d-q-command-value setting unit, and a d-axis current detection value and a q-axis current detection value that are obtained by, using the d-q coordinate system, transforming three-phase ac current that has been actually flowing in the motor and has been detected by a current detector; and a malfunction determining unit for determining that malfunction has occurred in the control system if at least one of the phase-current detection value is out of a first predetermined permissible range.
    Type: Grant
    Filed: August 26, 2005
    Date of Patent: January 9, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masaki Matsushita, Takayuki Kifuku, Hiroyuki Kozuki
  • Patent number: 7141948
    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: Grant
    Filed: February 28, 2005
    Date of Patent: November 28, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Hiroyuki Kozuki, Masaki Matsushita
  • Patent number: 7106017
    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: Grant
    Filed: June 19, 2001
    Date of Patent: September 12, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Masaki Matsushita
  • Publication number: 20060076832
    Abstract: An objective is to provide a specific realization means for easily determining malfunction of a system in an electromotive power steering controller. The electromotive power steering controller includes: a voltage controller for controlling voltage applying to a motor based on a d-axis current command value and a q-axis current command value that are set by a d-q-command-value setting unit, and a d-axis current detection value and a q-axis current detection value that are obtained by, using the d-q coordinate system, transforming three-phase ac current that has been actually flowing in the motor and has been detected by a current detector; and a malfunction determining unit for determining that malfunction has occurred in the control system if at least one of the phase-current detection value is out of a first predetermined permissible range.
    Type: Application
    Filed: August 26, 2005
    Publication date: April 13, 2006
    Inventors: Masaki Matsushita, Takayuki Kifuku, Hiroyuki Kozuki
  • Publication number: 20060076182
    Abstract: A steering control apparatus of a simple configuration is adaptable so A steering control apparatus of a simple configuration is adaptable so as to construct a redundant system from an input to an output system at low cost in a reliable manner. A torque sensor detects a steering torque, and a motor (3) provides torque to a steering system. A motor drive circuit (56) drives the motor, and a steering control section (53a) calculates at least a target current for the motor based on the steering torque. A motor control section (53b) provides an instruction to the motor drive circuit (56) based on the target current. A steering control verification section (54a) verifies an operation of the steering control section (53a) based on the steering torque and the target current. A motor control verification section (54b) verifies an operation of the motor control section (53b) based on a predetermined state quantity of the motor drive circuit (56) or the motor (3).
    Type: Application
    Filed: April 5, 2005
    Publication date: April 13, 2006
    Inventors: Takayuki Kifuku, Hiroyuki Kozuki, Yasuaki Hori
  • Patent number: 7019486
    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: Grant
    Filed: March 9, 2005
    Date of Patent: March 28, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takayuki Kifuku, Katsuhiko Ohmae
  • Publication number: 20060056206
    Abstract: An inverter fault detection system of the present invention is provided with: bus voltage monitor means for monitoring the bus voltage of a three-phase inverter; output voltage monitor means for summing the phase output voltages coming from the three-phase PWM inverter, and for outputting the resulting summed output voltage through a filter having a low-pass characteristic of passing through only the cutoff frequency lower than the PWM carrier frequency; and fault determination means for determining that the three-phase PWM inverter is in the faulty state when the output voltage coming from the output voltage monitor means is almost the same as the voltage value corresponding to 3/2 times of the bus voltage monitored by the bus voltage monitor means.
    Type: Application
    Filed: January 28, 2005
    Publication date: March 16, 2006
    Inventors: Takayuki Kifuku, Masaki Matsushita
  • Publication number: 20060055243
    Abstract: An objective is to detect a resolver malfunction without fail, using a low-cost resolver having the small number of the poles, and a control-motor system having advantage in small sizing and high-power outputting. In the control-motor system, the system for driving a 2m-pole motor based on a rotor rotation angle ? detected by a 2n-pole resolver, where m and n being counting numbers, is characterized in that: the sum of the square of a signal modulated by sin ? and the square of a signal modulated by cos ? in the resolver in which an excitation signal generated in said system is modulated by sin ? and cos ? in response to the rotor rotation angle ? of the resolver is compared to a predetermined malfunction threshold value, so that malfunction determination related to the resolver is performed, and also, given that the sum is a2 when the resolver is recognized to be in normal operation, the malfunction determination threshold value is made to be not smaller than {a×cos((?/2)/(m/n))}2.
    Type: Application
    Filed: July 11, 2005
    Publication date: March 16, 2006
    Inventors: Masaki Matsushita, Takayuki Kifuku, Hideki Doi, Katsuhiko Ohmae