Patents by Inventor Takumi Hisazumi

Takumi Hisazumi 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: 11325641
    Abstract: An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.
    Type: Grant
    Filed: June 13, 2016
    Date of Patent: May 10, 2022
    Assignee: Hitachi Astemo, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Mitsuo Sasaki, Yoshitaka Iwaji, Shigehisa Aoyagi, Takumi Hisazumi
  • Patent number: 11084523
    Abstract: A power steering device includes a steering mechanism structured to steer a steerable wheel in accordance with steering of a steering wheel. A first sensor is structured to sense a specific state quantity of steering. A second sensor is structured to sense the specific state quantity. A first actuation part is structured to apply a steering force to the steering mechanism. A second actuation part is structured to apply a steering force to the steering mechanism. A first microprocessor is configured to receive an output signal from the first sensor, and control driving of the first actuation part based on the output signal received from the first sensor. A second microprocessor is configured to receive an output signal from the first sensor and an output signal from the second sensor, and control driving of the second actuation part based on the output signal received from the first sensor.
    Type: Grant
    Filed: March 15, 2017
    Date of Patent: August 10, 2021
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Patent number: 10745045
    Abstract: A power steering device includes a steering mechanism, an electric motor for applying a steering assist force to the steering mechanism, and a first motor rotational position sensor for sensing as an actual axis phase a rotational position of a rotor of the electric motor. A control device is configured to: receive input of a signal of first actual axis phase outputted from the first motor rotational position sensor; receive input of a signal of value of electric current flowing through the electric motor; estimate as a control phase a phase of an induced voltage occurring in the electric motor, based on the signal of value of electric current; and determine whether or not the first motor rotational position sensor is abnormal, based on a difference between the first actual axis phase and the control phase.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: August 18, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi, Shigehisa Aoyagi
  • Publication number: 20200023887
    Abstract: A power steering device includes a steering mechanism structured to steer a steerable wheel in accordance with steering of a steering wheel. A first sensor is structured to sense a specific state quantity of steering. A second sensor is structured to sense the specific state quantity. A first actuation part is structured to apply a steering force to the steering mechanism. A second actuation part is structured to apply a steering force to the steering mechanism. A first microprocessor is configured to receive an output signal from the first sensor, and control driving of the first actuation part based on the output signal received from the first sensor. A second microprocessor is configured to receive an output signal from the first sensor and an output signal from the second sensor, and control driving of the second actuation part based on the output signal received from the first sensor.
    Type: Application
    Filed: March 15, 2017
    Publication date: January 23, 2020
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Patent number: 10411621
    Abstract: In the drive device for a three-phase synchronous motor, if one of the two rotational position detectors is defective, it is necessary to identify the rotational position detector having abnormal output and is in the detective state. To do this, three or more rotational position detectors are required, which increases costs of the rotational position detectors. By comparing the outputs of two rotational position detectors, an abnormality of ether one of the two detectors is detected. The abnormal detector is identified with the use of rotational position estimating means. The drive of the three-phase synchronous motor is controlled with the use of the output ? of the properly functioning one of the first and second rotational position detectors.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: September 10, 2019
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takafumi Hara, Toshiyuki Ajima, Shigehisa Aoyagi, Mitsuo Sasaki, Takumi Hisazumi
  • Publication number: 20190071116
    Abstract: Provided is a control apparatus for a power steering apparatus and a power steering apparatus capable of gradually increasing a steering reaction force felt by a driver since after a start of assist limitation when imposing the assist limitation for reducing power to be supplied to an electric motor that provides a steering force.
    Type: Application
    Filed: March 13, 2017
    Publication date: March 7, 2019
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI, Kazutoshi TANABE
  • Patent number: 10214235
    Abstract: Disclosed is a power steering device having at least two redundant steering torque sensor units, at least two redundant steering angel sensor units, at least two redundant motor position sensor units and a control unit configured to: in a normal state, perform steering assist control based on a steering torque detection signal of one of the steering torque sensor units, a steering angle detection signal of one of the steering angle sensor units and a motor position detection signal of one of the motor position sensor units; perform redundant monitoring on the steering torque sensor units, the steering angel sensor units and the motor position sensor units; and, upon detection of an abnormality in any sensor output signal by the redundant monitoring, switch the abnormal signal to an alternative signal.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: February 26, 2019
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Publication number: 20190023309
    Abstract: A power steering device includes a steering mechanism, an electric motor for applying a steering assist force to the steering mechanism, and a first motor rotational position sensor for sensing as an actual axis phase a rotational position of a rotor of the electric motor. A control device is configured to: receive input of a signal of first actual axis phase outputted from the first motor rotational position sensor; receive input of a signal of value of electric current flowing through the electric motor; estimate as a control phase a phase of an induced voltage occurring in the electric motor, based on the signal of value of electric current; and determine whether or not the first motor rotational position sensor is abnormal, based on a difference between the first actual axis phase and the control phase.
    Type: Application
    Filed: July 29, 2016
    Publication date: January 24, 2019
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI, Shigehisa AOYAGI
  • Patent number: 10166977
    Abstract: One aspect of the present invention increases or reduces an amplitude or amplitudes of a steering angle sensor output signal and/or a motor rotational angle signal, and outputs a motor instruction signal based on a substitute signal for a torque sensor output signal that is calculated based on at least one of the steering angle sensor output signal and the motor rotational angle signal that is subjected to the adjustment of the amplitude thereof, and the other of the steering angle sensor output signal and the motor rotational angle signal, when an abnormality is detected in the torque sensor output signal.
    Type: Grant
    Filed: August 6, 2015
    Date of Patent: January 1, 2019
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Publication number: 20180201303
    Abstract: An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.
    Type: Application
    Filed: June 13, 2016
    Publication date: July 19, 2018
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Mitsuo SASAKI, Yoshitaka IWAJI, Shigehisa AOYAGI, Takumi HISAZUMI
  • Publication number: 20180183366
    Abstract: In the drive device for a three-phase synchronous motor, if one of the two rotational position detectors is defective, it is necessary to identify the rotational position detector having abnormal output and is in the detective state. To do this, three or more rotational position detectors are required, which increases costs of the rotational position detectors. By comparing the outputs of two rotational position detectors, an abnormality of ether one of the two detectors is detected. The abnormal detector is identified with the use of rotational position estimating means. The drive of the three-phase synchronous motor is controlled with the use of the output ? of the properly functioning one of the first and second rotational position detectors.
    Type: Application
    Filed: June 14, 2016
    Publication date: June 28, 2018
    Inventors: Takafumi HARA, Toshiyuki AJIMA, Shigehisa AOYAGI, Mitsuo SASAKI, Takumi HISAZUMI
  • Patent number: 9988080
    Abstract: In a power steering device and a control device for a vehicle-mounted instrument, an abnormality detection accuracy of sensor output signals is increased. In an electric power steering device and a control device for a vehicle-mounted instrument, judgment for the abnormality of the sensor output signals is carried out by using at least four or more sensor output signals, in which when the sensor output signals satisfy both a first condition (viz., the number of the output signals showing an identical value is the largest) and a second condition (viz., the number is equal to or larger than “n+1”) (n=the largest number of the sensor output signals that have a common factor), judgement is so made that the sensor output signals that satisfy the first and second conditions are normal and the other signals are abnormal.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: June 5, 2018
    Assignee: HITACHI AUTOMOTIVE SYSTEMS STEERING, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Patent number: 9975572
    Abstract: An in-vehicle device controller has at least two redundant operating condition detection units. Under normal circumstances, the controller performs actuator drive control based on an operating condition detection signal of one of the operating condition detection units. Upon detection of an abnormality in the signal transmission state, data state or operating status of one of the at least two operating condition detection units, the controller performs actuator drive control based on an operating condition detection signal of another one of the at least two operating condition detection units in which no abnormality is present. By this control, the actuator function is preserved even in the event of the abnormality in the operating condition detection unit or operating condition detection signal.
    Type: Grant
    Filed: February 5, 2015
    Date of Patent: May 22, 2018
    Assignee: HITACHI AUTOMOTIVES SYSTEMS, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Patent number: 9796409
    Abstract: In a power steering device and a vehicle-mounted instrument, an abnormality detection accuracy of a state quantity detection means is increased. In an electric power steering device and a vehicle-mounted instrument that are each provided with a plurality of state quantity detection means, an abnormality detection for the state quantity detection means is carried out by comparing detection signals issued from the state quantity detection means provided on a redundant system, and by comparing the detection signals issued from the state quantity detection means with signals that are issued from other state quantity detecting means and calculated to be matched with the same unit as the compared detection signals, a value or close value that is possessed by the largest number of signals is set as a normal value.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: October 24, 2017
    Assignee: HITACHI AUTOMOTIVE SYSTEMS STEERING, LTD.
    Inventors: Mitsuo Sasaki, Takumi Hisazumi
  • Publication number: 20170240168
    Abstract: One aspect of the present invention increases or reduces an amplitude or amplitudes of a steering angle sensor output signal and/or a motor rotational angle signal, and outputs a motor instruction signal based on a substitute signal for a torque sensor output signal that is calculated based on at least one of the steering angle sensor output signal and the motor rotational angle signal that is subjected to the adjustment of the amplitude thereof, and the other of the steering angle sensor output signal and the motor rotational angle signal, when an abnormality is detected in the torque sensor output signal.
    Type: Application
    Filed: August 6, 2015
    Publication date: August 24, 2017
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Publication number: 20170015348
    Abstract: Disclosed is a power steering device having at least two redundant steering torque sensor units TS1 and TS2, at least two redundant steering angel sensor units AS1 and AS2, at least two redundant motor position sensor units 61 and 62 and a control unit configured to: in a normal state, perform steering assist control based on a steering torque detection signal of one of the steering torque sensor units TS1 and TS2, a steering angle detection signal of one of the steering angle sensor units AS1 and AS2 and a motor position detection signal of one of the motor position sensor units 61 and 62; perform redundant monitoring on the steering torque sensor units TS1 and TS2, the steering angel sensor units AS1 and AS2 and the motor position sensor units 61 and 62; and, upon detection of an abnormality in any sensor output signal by the redundant monitoring, switch the abnormal signal to an alternative signal.
    Type: Application
    Filed: January 14, 2015
    Publication date: January 19, 2017
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Publication number: 20160332660
    Abstract: An in-vehicle device controller has at least two redundant operating condition detection units. Under normal circumstances, the controller performs actuator drive control based on an operating condition detection signal of one of the operating condition detection units. Upon detection of an abnormality in the signal transmission state, data state or operating status of one of the at least two operating condition detection units, the controller performs actuator drive control based on an operating condition detection signal of another one of the at least two operating condition detection units in which no abnormality is present. By this control, the actuator function is preserved even in the event of the abnormality in the operating condition detection unit or operating condition detection signal.
    Type: Application
    Filed: February 5, 2015
    Publication date: November 17, 2016
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Publication number: 20160229445
    Abstract: In a power steering device and a control device for a vehicle-mounted instrument, an abnormality detection accuracy of sensor output signals is increased. In an electric power steering device and a control device for a vehicle-mounted instrument, judgment for the abnormality of the sensor output signals is carried out by using at least four or more sensor output signals, in which when the sensor output signals satisfy both a first condition (viz., the number of the output signals showing an identical value is the largest) and a second condition (viz., the number is equal to or larger than “n+1”) (n=the largest number of the sensor output signals that have a common factor), judgement is so made that the sensor output signals that satisfy the first and second conditions are normal and the other signals are abnormal.
    Type: Application
    Filed: July 30, 2014
    Publication date: August 11, 2016
    Applicant: Hitachi Automotive Systems Steering, Ltd.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Publication number: 20160200353
    Abstract: In a power steering device and a vehicle-mounted instrument, an abnormality detection accuracy of a state quantity detection means is increased. In an electric power steering device and a vehicle-mounted instrument that are each provided with a plurality of state quantity detection means, an abnormality detection for the state quantity detection means is carried out by comparing detection signals issued from the state quantity detection means provided on a redundant system, and by comparing the detection signals issued from the state quantity detection means with signals that are issued from other state quantity detecting means and calculated to be matched with the same unit as the compared detection signals, a value or close value that is possessed by the largest number of signals is set as a normal value.
    Type: Application
    Filed: July 30, 2014
    Publication date: July 14, 2016
    Applicant: HITACHI AUTOMOTIVE SYSTEMS STEERING, LTD.
    Inventors: Mitsuo SASAKI, Takumi HISAZUMI
  • Patent number: 8886411
    Abstract: In a power steering system, at least one of phase open relays in which a contact weld (an abnormality) occurs is detected. That is to say, the power steering system comprises an abnormality monitor section (57) configured to output vector control command signals to supply only a d-axis current in a positive side direction toward the motor, with all of phase open relays (58v, 58w) in an interruption state, and to determine an abnormality in at least one of the phase open relays in a case where a current value is detected by a current detection circuit which detects a current flowing into an inverter. In a case of three phase open relays installed between respective three phases of motor windings, a potential difference is detected at a neutral position of a star connection to determine the abnormality of at least two of the phase open relays.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: November 11, 2014
    Assignee: Hitachi Automotive Systems Steering, Ltd.
    Inventors: Takumi Hisazumi, Atsushi Yoshitake