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: 8680805
    Abstract: A control device that drives one driven object by a first motor and a second motor. A first processor has a first correction amount calculation unit configured to calculate an amount of correction for a torque command to the first motor based on a speed value difference between a speed value of the first motor and a speed value of the second motor in order to suppress vibrations. A second processor has a second correction amount calculation unit configured to calculate an amount of correction for a torque command to the second motor based on a speed value difference between a speed value of the first motor and a speed value of the second motor in order to suppress vibrations.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: March 25, 2014
    Assignee: Fanuc Corporation
    Inventors: Naoto Sonoda, Yasusuke Iwashita
  • Publication number: 20140062378
    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: Application
    Filed: September 4, 2013
    Publication date: March 6, 2014
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI
  • Patent number: 8664897
    Abstract: A motor drive apparatus includes a rectifier which converts AC power to DC power and DC power to AC power, an inverter which converts the DC power output by the rectifier to AC power and supplies the AC power to a motor, and which converts regenerative power from the motor to DC power and returns the DC power to the rectifier, a DC voltage detection unit which detects a DC output voltage of the rectifier, an AC voltage detection unit which detects an AC output voltage of the rectifier, a frequency calculation unit which calculates the frequency of the AC voltage; a storage unit which stores as a reference value the DC voltage at the start of the regenerative operation, and a power failure detection unit which determines the presence or absence of a power failure by using the DC voltage, the reference value, and the AC voltage frequency.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: March 4, 2014
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Tadashi Okita, Masakazu Niwa
  • Patent number: 8649130
    Abstract: A motor driving apparatus capable of detecting during operation a ground fault and a phase-to-phase short circuit by distinguishing one from the other is provided while minimizing an increase in cost. The sum of three-phase AC currents supplied from a three-phase AC power supply to an AC/DC converter is detected by a current sensor. When overcurrent is detected by an overcurrent detector, if the sum of the currents detected by the current sensor is zero, it is determined that the fault is a phase-to-phase short circuit, but if the sum is not zero, it is determined that the fault is a ground fault.
    Type: Grant
    Filed: February 11, 2011
    Date of Patent: February 11, 2014
    Assignee: Fanuc Corporation
    Inventors: Shinichi Horikoshi, Takashi Harada, Masatomo Shirouzu, Yasusuke Iwashita
  • Patent number: 8633663
    Abstract: An estimated torque constant calculation unit calculates an estimated torque constant relating to the permanent magnet synchronous motor from a current representative value and an acceleration representative value acquired from a plurality of current values and a plurality of acceleration values in the same operation state over a plurality of periods of a sinusoidal command signal and a predetermined inertia relating to the permanent magnet synchronous motor. A demagnetization detection unit detects whether or not irreversible demagnetization has occurred in the permanent magnet of the permanent magnet synchronous motor based on a difference between the estimated torque constant and a predetermined torque constant relating to the permanent magnet synchronous motor.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: January 21, 2014
    Assignee: Fanuc Corporation
    Inventors: Naoto Sonoda, Yasusuke Iwashita
  • Patent number: 8624538
    Abstract: A motor driving apparatus is provided that performs AC/DC conversion by suppressing harmonics of the input at the time of normal operation, while on the other hand, allowing system operation to continue in the event of an overload by avoiding system stoppage.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: January 7, 2014
    Assignee: FANUC Corporation
    Inventors: Tomokazu Yoshida, Takashi Harada, Shinichi Horikoshi, Yasusuke Iwashita
  • Publication number: 20130342143
    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: Application
    Filed: June 13, 2013
    Publication date: December 26, 2013
    Inventors: Naoto SONODA, Yasusuke IWASHITA
  • Publication number: 20130320908
    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: Application
    Filed: June 3, 2013
    Publication date: December 5, 2013
    Inventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI
  • Publication number: 20130278197
    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: Application
    Filed: March 8, 2013
    Publication date: October 24, 2013
    Applicant: FANUC CORPORATION
    Inventors: Taku SASAKI, Yasusuke IWASHITA
  • Publication number: 20130271048
    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: Application
    Filed: February 28, 2013
    Publication date: October 17, 2013
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Hajime OGAWA
  • Publication number: 20130271049
    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: Application
    Filed: March 11, 2013
    Publication date: October 17, 2013
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Taku SASAKI
  • Publication number: 20130264988
    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: Application
    Filed: March 14, 2013
    Publication date: October 10, 2013
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Satoshi IKAI
  • Patent number: 8483865
    Abstract: Coordinate values of a tool center point is calculated by obtaining coordinate values at each time of respective drive axes driven by a numerical controller. A tool radius compensation vector connecting the calculated tool center point at each time and an actual machining point is obtained. Then, coordinate values of the actual machining point are calculated based on the calculated coordinate values of the tool center point and the obtained tool radius compensation vector, and the trajectory of the actual machining point is displayed on a display.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: July 9, 2013
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Tadashi Okita, Junichi Tezuka
  • Publication number: 20130134910
    Abstract: A motor drive apparatus includes a rectifier which converts AC power to DC power and DC power to AC power, an inverter which converts the DC power output by the rectifier to AC power and supplies the AC power to a motor, and which converts regenerative power from the motor to DC power and returns the DC power to the rectifier, a DC voltage detection unit which detects a DC output voltage of the rectifier, an AC voltage detection unit which detects an AC output voltage of the rectifier, a frequency calculation unit which calculates the frequency of the AC voltage; a storage unit which stores as a reference value the DC voltage at the start of the regenerative operation, and a power failure detection unit which determines the presence or absence of a power failure by using the DC voltage, the reference value, and the AC voltage frequency.
    Type: Application
    Filed: September 13, 2012
    Publication date: May 30, 2013
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Masakazu NIWA
  • Patent number: 8436565
    Abstract: In position tandem control in which one movable member is driven by two motors, an output of the integral element of the velocity control unit in the control system for one motor is copied to the integral element of the velocity control unit in the control system for the other motor. A preload is added to a torque command output from each of the velocity control units in the motor control systems for two motors so that torques in mutually opposite directions are generated to suppress backlash between gears.
    Type: Grant
    Filed: September 25, 2009
    Date of Patent: May 7, 2013
    Assignee: FANUC Ltd
    Inventors: Kazuomi Maeda, Yukio Toyozawa, Yasusuke Iwashita
  • Publication number: 20130110278
    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: Application
    Filed: August 10, 2012
    Publication date: May 2, 2013
    Applicant: FANUC CORPORATION
    Inventors: Tadashi OKITA, Yasusuke IWASHITA
  • Publication number: 20130106336
    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: Application
    Filed: September 10, 2012
    Publication date: May 2, 2013
    Applicant: FANUC Corporation
    Inventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
  • Patent number: 8432120
    Abstract: A numerical controller calculates a first position command from a machining program, converts the first position command into a second position command for restricting a tangential speed of a tool, and delivers the second position command and a status signal indicative of the achievement of the conversion of the first position command into the second position command to a tool path display apparatus. The tool path display apparatus displays the path of the tool in a color corresponding to the status signal and can thereby determine the point on the tool path at which the speed restriction is performed.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: April 30, 2013
    Assignee: Fanuc Corporation
    Inventors: Yasusuke Iwashita, Tadashi Okita, Junichi Tezuka
  • Publication number: 20130099705
    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: Application
    Filed: August 27, 2012
    Publication date: April 25, 2013
    Applicant: FANUC CORPORATION
    Inventors: Yasusuke IWASHITA, Hajime OGAWA
  • Patent number: 8415906
    Abstract: When the output of motor reaches or exceeds a predetermined value during acceleration of the motor, the control target value of the DC link voltage which is the voltage of a power storage device is gradually lowered in corresponding relationship to the motor output. When the motor enters a constant speed control mode, the DC link control target value is maintained at a constant level. When the motor enters a deceleration control mode, the DC link control target value is gradually raised in corresponding relationship to the motor output, and regenerative power is recovered by the power storage device and reused in the next control cycle.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: April 9, 2013
    Assignee: FANUC Corporation
    Inventors: Yasusuke Iwashita, Masakazu Niwa, Takashi Harada, Koujirou Sakai, Shinichi Horikoshi