Patents by Inventor Yasusuke Iwashita

Yasusuke Iwashita 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: 10247301
    Abstract: A servo control system including a servo motor, a driven member driven, a coupling mechanism coupled with the servo motor and the driven member, and a motor control part controlling the servo motor. The motor control part includes a position command generating part generating a position command value of the driven member, a force estimating part estimating the drive force acting on the driven member, a compensating part compensating the position command value based on the drive force estimated by the force estimating part, and a control signal output part outputting a control signal to the servo motor based on a position command value compensated by the compensating part.
    Type: Grant
    Filed: November 29, 2013
    Date of Patent: April 2, 2019
    Assignee: FANUC CORPORATION
    Inventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
  • Patent number: 9709975
    Abstract: A control system of servo motors in a machine tool, comprising a host control device which generates position command values for processing a workpiece, servo control devices which drive servo motors to operate a tool for processing using the position command values, and position detectors which detect positions of the servo motors or a tool position and further a position error computing part computes position error between the position command values and detected positions of the servo motors, a reference angle generating part calculates a reference point on a closed figure and a reference angle which varies monotonously from a current processing point under the condition that any position inside of the closed figure which the position command value forms as the center, and learning control parts use the reference angle and the position error as the basis to perform angle synchronization type learning control to control the servo motors.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: July 18, 2017
    Assignee: FANUC CORPORATION
    Inventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
  • Patent number: 9557731
    Abstract: A control device (1) of a gear processing machine has a bus (51) that communicates by directly connecting between a tool axis controller (22) and a workpiece axis controller (12), and, in this control device, the position of a tool axis (40) that is detected by a tool axis position detection sensor (25) is supplied to a workpiece axis controller via a bus, an upper controller (10) supplies a predetermined synchronization ratio and a superimposition command for applying a twisting operation to a workpiece axis controller, and the workpiece axis controller adds a value that is generated by multiplying the position of the tool axis that is supplied via the bus, by the synchronization ratio, and the superimposition command, and generates a motion command for a workpiece axis (30).
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: January 31, 2017
    Assignee: FANUC CORPORATION
    Inventors: Tadashi Okita, Yasusuke Iwashita
  • Patent number: 9448545
    Abstract: A servo control device in the present invention corrects a position command to a feed axis, so as to compensate for an amount of stretch or contraction of a ball screw during operation, by taking into account an influence of tension applied to the ball screw. The amount of stretch or contraction of the ball screw is calculated, based on the tension acting on the ball screw on the side farther from the servo motor, a distance between two fixed units supporting the ball screw at its opposite ends, a distance from the fixed unit situated closer to the servo motor to a moving body, and a torque command to the servo motor. An amount of position correction of the feed axis is calculated, based on the calculated amount of stretch or contraction of the ball screw.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: September 20, 2016
    Assignee: FANUC CORPORATION
    Inventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
  • Publication number: 20160033954
    Abstract: A control system of servo motors in a machine tool, comprising a host control device which generates position command values for processing a workpiece, servo control devices which drive servo motors to operate a tool for processing using the position command values, and position detectors which detect positions of the servo motors or a tool position and further a position error computing part computes position error between the position command values and detected positions of the servo motors, a reference angle generating part calculates a reference point on a closed figure and a reference angle which varies monotonously from a current processing point under the condition that any position inside of the closed figure which the position command value forms as the center, and learning control parts use the reference angle and the position error as the basis to perform angle synchronization type learning control to control the servo motors.
    Type: Application
    Filed: July 24, 2015
    Publication date: February 4, 2016
    Inventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
  • Patent number: 9048733
    Abstract: A motor driving device includes a converter that converts an input alternating current into a direct current, an inverter that inverts the direct current output by the converter into an alternating current for driving a motor, a voltage detecting unit that detects a voltage on a direct current output side of the converter, and a numerical control unit that causes the inverter to output a reactive current to increase electric power consumed in the motor, when the voltage detected by the voltage detecting unit exceeds a predetermined threshold.
    Type: Grant
    Filed: August 27, 2012
    Date of Patent: June 2, 2015
    Assignee: FANUC CORPORATION
    Inventors: Yasusuke Iwashita, Hajime Ogawa
  • Patent number: 9018886
    Abstract: A motor control system (10) which includes a difference calculating part (31) which calculates a difference between a first position detection value of a moving part and a second position detection value of a driven part, a judging part (32) which judges if a moving part has engaged with the driven part when the moving part is made to move from any initial position in a first and second drive directions, a holding part (33) which holds the difference as initial difference linked with the first or second drive direction, when the moving part has engaged with the driven part, and a correction amount calculating part (34) which calculates a backlash correction amount, the correction amount calculating part using the difference based on the current positions of the moving part and the driven part and the initial difference to calculate the backlash correction amount.
    Type: Grant
    Filed: September 4, 2013
    Date of Patent: April 28, 2015
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
  • Patent number: 8988032
    Abstract: A numerical controller capable of visually and accurately analyzing a change of the tool trajectory before and after changing a processing condition, whereby a parameter of a drive axis can be properly adjusted. The numerical controller comprises a numeric controlling part which controls each drive axis based on a predetermined position command; a position data obtaining part which obtains position data of each drive axis controlled by the numerical controlling part; a tool coordinate calculating part which calculates a coordinate of a tool center point based on position feedback or obtained position data of each drive axis and information of a mechanical structure of a machine tool; a tool trajectory storing part which stores the calculated coordinate of the tool center point as a feedback trajectory; and a displaying part which displays the stored feedback trajectory on a display.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: March 24, 2015
    Assignee: FANUC Corporation
    Inventors: Yasusuke Iwashita, Hajime Ogawa
  • Patent number: 8924004
    Abstract: A numerical controller calculates the distance (rotation radius) between the rotation center axis of a rotary axis and a control target point using the machine conditions (including the axis structure and tool length) of a machine tool having a rotary axis and the coordinate values of the respective axes of the machine tool. Then, the preset positioning completion widths of the respective axes are compensated by the calculated rotation radius and a positioning completion check of the rotary axis is carried out using the compensated positioning completion widths.
    Type: Grant
    Filed: September 29, 2011
    Date of Patent: December 30, 2014
    Assignee: FANUC Corporation
    Inventors: Yasusuke Iwashita, Junichi Tezuka
  • Patent number: 8903518
    Abstract: A control apparatus for a motor includes, a position detection unit which detects the position of a driven body, a positional error acquiring unit which acquires for each sampling cycle a positional error representing a deviation between the position command given to the motor and the position of the driven body detected by the position detection unit, a dead-zone processing unit which outputs the positional error by replacing the positional error with zero if the positional error acquired by the positional error acquiring unit lies within a predetermined dead-zone range, and a repetitive control unit which calculates an amount of correction such that the positional error output from the dead-zone processing unit is reduced to zero, and wherein: the motor is controlled based on the positional error acquired by the positional error acquiring unit and the amount of correction calculated by the repetitive control unit.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: December 2, 2014
    Assignee: FANUC Corporation
    Inventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
  • Patent number: 8901866
    Abstract: A motor drive apparatus includes an AC/DC converter which converts AC power supplied from a power supply to DC power, a DC/AC converter which converts DC power to AC power and vice versa, a DC link unit which connects the DC side of the AC/DC converter to the DC side of the DC/AC converter and delivers the DC power from one to the other and vice versa, an energy storage unit which includes at least one capacitor storage unit and at least one flywheel storage unit each of which is connected to the DC link unit and stores or supplies the DC power, and an energy control unit which performs control so that the energy storage unit stores or supplies the DC power.
    Type: Grant
    Filed: May 15, 2012
    Date of Patent: December 2, 2014
    Assignee: Fanuc Corporation
    Inventors: Koujirou Sakai, Yasusuke Iwashita
  • Patent number: 8896255
    Abstract: A servo controller, capable of controlling the motion of a movable body with high accuracy, without depending on the position of the movable body which is moved on a ball screw. The servo controller has a position command generating part which generates a position command value; a velocity command generating part which generates a velocity command value based on the position command value and a position detection value; a torque command generating part which generates a torque command value based on the velocity command value and a velocity detection value; and a position compensation calculating part which calculates an amount of expansion/contraction of the ball screw based on a distance from the servomotor to a nut threadably engaged with the ball screw and the torque command value, and calculates a position compensation based on the amount of expansion/contraction.
    Type: Grant
    Filed: June 3, 2013
    Date of Patent: November 25, 2014
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
  • Patent number: 8786239
    Abstract: A motor drive PWM rectifier includes a control section which generates the PWM signal in accordance with either a three-phase modulation scheme or a two-phase modulation scheme in which a PWM voltage command for one phase selected from among three phases each constituting the PWM voltage command in the three-phase modulation scheme is set and held at a level equivalent to a maximum value or minimum value of the PWM carrier and in which a PWM voltage command for the other two phases created by also applying an offset, required to achieve the setting, to the other two phases, a detecting section which detects three-phase AC current and outputs a detected current value, and a selecting section which selects the two-phase modulation scheme when the detected current value is larger than a first threshold value but smaller than a second threshold value, and otherwise selects the three-phase modulation scheme.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: July 22, 2014
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Masakazu Niwa, Kenta Yamamoto
  • Patent number: 8779704
    Abstract: A motor control apparatus includes a power conversion unit which supplies drive power to a motor, a current detection unit which detects the value of a current flowing from the power conversion unit to the motor, a delta-sigma modulation AD converter which converts the current value into digital data by using a modulation clock as a system clock, and which starts to count the number of clock pulses of the modulation clock upon reception of a reference signal and, when the number of clock pulses counted reaches a predetermined count value, outputs the digital data obtained during a prescribed time interval which contains the reception time of the reference signal, and a command generating unit which generates, using the digital data supplied from the delta-sigma modulation AD converter, a drive command for commanding the power conversion unit to output commanded drive power.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: July 15, 2014
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Taku Sasaki
  • Patent number: 8754601
    Abstract: The controller of the synchronous motor of the present invention includes: an allowable energy value acquisition unit (4) which acquires an allowable energy value until which a dynamic brake resistor, which is for short-circuiting the input terminal of the synchronous motor at a time of failure, can bear; an inertia estimation unit (6) which estimates inertia of a driven object based on a speed value and an electric current value; an allowable maximum speed calculation unit (5) which calculates an allowable maximum speed value of the synchronous motor from the inertia and the allowable energy value; and a speed control unit (2) which controls the amplifier for operating the synchronous motor at a predetermined commanded speed, in which the speed control unit (2) acquires the allowable maximum speed value from the allowable maximum speed calculation unit (5), and limits the commanded speed to the allowable maximum speed value or lower.
    Type: Grant
    Filed: June 13, 2013
    Date of Patent: June 17, 2014
    Assignee: Fanuc Corporation
    Inventors: Naoto Sonoda, Yasusuke Iwashita
  • Patent number: 8754599
    Abstract: A motor control apparatus includes a power conversion unit which supplies drive power to a motor, a current detection unit which detects the value of a current flowing from the power conversion unit to the motor, a delta-sigma modulation AD converter to which the current value detected by the current detection unit is input as analog data, and which includes a modulator and a plurality of digital low-pass filters and outputs digital data in accordance with the filter characteristics of the respective digital low-pass filters, and a command generating unit which is connected to the digital low-pass filter to be used for motor drive control among the plurality of digital low-pass filters, and which generates a drive command to the power conversion unit by using the digital data output from the motor drive controlling digital low-pass filter.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: June 17, 2014
    Assignee: Fanuc Corporation
    Inventors: Taku Sasaki, Yasusuke Iwashita
  • Publication number: 20140156080
    Abstract: A servo control system including a servo motor, a driven member driven, a coupling mechanism coupled with the servo motor and the driven member, and a motor control part controlling the servo motor. The motor control part includes a position command generating part generating a position command value of the driven member, a force estimating part estimating the drive force acting on the driven member, a compensating part compensating the position command value based on the drive force estimated by the force estimating part, and a control signal output part outputting a control signal to the servo motor based on a position command value compensated by the compensating part.
    Type: Application
    Filed: November 29, 2013
    Publication date: June 5, 2014
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI
  • Patent number: 8736217
    Abstract: An arithmetic coefficient setting unit sets a feedback control arithmetic coefficient to a value between a first feedback control arithmetic coefficient value for a cutting-feed and a second feedback control arithmetic coefficient value for a rapid-traverse operation smaller than the first feedback control arithmetic coefficient value. An arithmetic coefficient change unit continuously changes the feedback control arithmetic coefficient from the second feedback control arithmetic coefficient value to the first feedback control arithmetic coefficient value over a first period between a first time, which is an arbitrary time during the rapid-traverse operation, and the second time after the first time or a second period between a third time after the first time and before the second time, and the second time if it is predicted at the first time that the operating command switches from the rapid-traverse operation command to the cutting-feed command at the second time.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: May 27, 2014
    Assignee: FANUC Corporation
    Inventors: Yasusuke Iwashita, Satoshi Ikai
  • Patent number: 8716965
    Abstract: A second q-axis current command value, which is set by a q-axis current command value setting unit when an alternating-current power source fails at the time of driving of a synchronous motor, and a second d-axis current command value, which is set by a d-axis current command value setting unit when the alternating-current power source fails at the time of the driving of the synchronous motor, are set so that an absolute value of power per unit time of the synchronous motor is equal to loss per unit time of the synchronous motor.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: May 6, 2014
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Hajime Ogawa
  • Publication number: 20140121818
    Abstract: A servo control device in the present invention corrects a position command to a feed axis, so as to compensate for an amount of stretch or contraction of a ball screw during operation, by taking into account an influence of tension applied to the ball screw. The amount of stretch or contraction of the ball screw is calculated, based on the tension acting on the ball screw on the side farther from the servo motor, a distance between two fixed units supporting the ball screw at its opposite ends, a distance from the fixed unit situated closer to the servo motor to a moving body, and a torque command to the servo motor. An amount of position correction of the feed axis is calculated, based on the calculated amount of stretch or contraction of the ball screw.
    Type: Application
    Filed: October 29, 2013
    Publication date: May 1, 2014
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI