Patents by Inventor Yukio Toyozawa

Yukio Toyozawa 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: 20120059506
    Abstract: A servo control system capable of using an angle-based synchronization learning control, even when a reference position is not given, while maintaining the advantage of the angle-based synchronization method. The servo control system has X-, y- and z-axes servo controllers, each configured to control x-, y- and z-axes servomotors, respectively. Each of x- and y-axes servo controllers has a reference signal generating part configured to generate a reference signal which monotonically increases or varies in one direction, based on the position command of each axis transmitted from a higher-level controller.
    Type: Application
    Filed: August 23, 2011
    Publication date: March 8, 2012
    Applicant: FANUC Corporation
    Inventors: Tadashi OKITA, Yukio Toyozawa, Kazuomi Maeda, Naoto Sonoda
  • Patent number: 8098038
    Abstract: A servomotor control system that includes a numerical control unit and servo control unit enables the use of learning control based on an angle synchronization method in high-speed oscillating motion performed by, for example, a jig grinder. The numerical control unit calculates a reference angle ?(=?t), and also calculates a cyclic oscillation command F(t) according to the reference angle ? and a machining condition (angular velocity ?). The servo control unit calculates a difference between the value in the oscillation command F(t) and the position of the servomotor (positional difference ?) at intervals of a predetermined cycle, and performs learning control according to the reference angle ?, oscillation command F(t), and positional difference ?.
    Type: Grant
    Filed: September 9, 2010
    Date of Patent: January 17, 2012
    Assignee: FANUC Ltd
    Inventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
  • Patent number: 8067918
    Abstract: A servomotor controller capable of properly generating reference positions, by which learning control of angle based method may be applied to the periodically reciprocating motion of an object. The learning controller obtains a first positional deviation of a driven object at every predetermined sampling period of time, and the first positional deviation is converted, by a first converting part, to a second positional deviation associated with each reference position in one periodic reciprocating motion of the driven object. After a first correction amount of an immediately previous reciprocating motion of the driven object, stored in a memory, is added to the second positional deviation, the second positional deviation is stored in the memory as a renewed first correction amount. The first correction amount is converted to a second correction amount associated with the sampling period, by a second converting part.
    Type: Grant
    Filed: April 19, 2010
    Date of Patent: November 29, 2011
    Assignee: Fanuc Ltd
    Inventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
  • Publication number: 20110133681
    Abstract: A servomotor control system that includes a numerical control unit and servo control unit enables the use of learning control based on an angle synchronization method in high-speed oscillating motion performed by, for example, a jig grinder. The numerical control unit calculates a reference angle ?(=?t), and also calculates a cyclic oscillation command F(t) according to the reference angle ? and a machining condition (angular velocity ?). The servo control unit calculates a difference between the value in the oscillation command F(t) and the position of the servomotor (positional difference ?) at intervals of a predetermined cycle, and performs learning control according to the reference angle ?, oscillation command F(t), and positional difference ?.
    Type: Application
    Filed: September 9, 2010
    Publication date: June 9, 2011
    Applicant: FANUC LTD
    Inventors: Tadashi OKITA, Yukio Toyozawa, Naoto Sonoda
  • Patent number: 7932689
    Abstract: A motor drive system is provided with a plurality of axis control parts for outputting PWM commands using a position command, a plurality of current supply parts which supply current to the respective windings based on the PWM commands of the respective axis control parts, and which are connected to the respective windings, a motor position detector for outputting a signal of a rotor position of the motor, a first signal supply part for supplying the output signal to one current supply part of the plurality of current supply parts, and a second signal supply part for supplying the signal supplied through the first signal supply part to an axis control part corresponding to one current supply part, and the corresponding axis control part outputs a PWM command based on the signal supplied from the one current supply part through the second signal supply part to the corresponding axis control part and the position command, and the remaining axis control part outputs the PWM command based on the signal supplied f
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: April 26, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Yukio Toyozawa, Kazuomi Maeda
  • Patent number: 7915848
    Abstract: A servo control apparatus that performs dual-position feedback control and thereby achieves a reduction in position error according to the purpose of machining.
    Type: Grant
    Filed: March 3, 2010
    Date of Patent: March 29, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Yukio Toyozawa, Kazuomi Maeda
  • Patent number: 7902780
    Abstract: A controller and a control system capable of estimating inertia of an article to be driven in a short period of time, with a small operation range of an electric motor. The controller for the motor has an inertia estimating part which includes a sine-wave command generating part which adds a sine-wave command to a torque command for the motor; a current feedback sampling part which obtains a current value of the motor; a speed feedback sampling part which obtains a speed feedback of the motor; an acceleration calculating part which calculates an acceleration value based on the speed feedback; and an estimated inertia calculating part which estimates the inertia of the article, based on a representative current value, a representative acceleration value and a torque constant of the motor, which are calculated from current and acceleration values in a plurality of cycles of the sine-wave command and stored in a sampling data storing part.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: March 8, 2011
    Assignee: Fanuc Ltd
    Inventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
  • Publication number: 20110050146
    Abstract: A controller estimates Coulomb friction itself together with inertia and viscous friction, and reduces the influence of the Coulomb friction on the accuracy of the estimated inertia. In addition, the controller estimates inertia, viscous friction and Coulomb friction simultaneously with sequential adaptation in which a Fourier transformer is not used but an inverse transfer function model is used in order to minimize the estimated error. Data sampled for a predetermined time need not be accumulated, as a result, a large amount of data memory is unnecessary.
    Type: Application
    Filed: June 24, 2010
    Publication date: March 3, 2011
    Applicant: FANUC LTD
    Inventors: Tadashi OKITA, Yukio Toyozawa, Naoto Sonoda
  • Publication number: 20100295496
    Abstract: A servomotor controller capable of properly generating reference positions, by which learning control of angle based method may be applied to the periodically reciprocating motion of an object. The learning controller obtains a first positional deviation of a driven object at every predetermined sampling period of time, and the first positional deviation is converted, by a first converting part, to a second positional deviation associated with each reference position in one periodic reciprocating motion of the driven object. After a first correction amount of an immediately previous reciprocating motion of the driven object, stored in a memory, is added to the second positional deviation, the second positional deviation is stored in the memory as a renewed first correction amount. The first correction amount is converted to a second correction amount associated with the sampling period, by a second converting part.
    Type: Application
    Filed: April 19, 2010
    Publication date: November 25, 2010
    Applicant: FANUC LTD
    Inventors: Tadashi OKITA, Yukio TOYOZAWA, Naoto SONODA
  • Publication number: 20100295495
    Abstract: A servo control apparatus that performs dual-position feedback control and thereby achieves a reduction in position error according to the purpose of machining.
    Type: Application
    Filed: March 3, 2010
    Publication date: November 25, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi Okita, Yukio Toyozawa, Kazuomi Maeda
  • Patent number: 7808199
    Abstract: A control apparatus of the present invention comprising a control unit outputting a control signal controlling a servo motor and suppressing natural vibration of a controlled object including a motor and a machine driven by the motor while controlling the controlled object, comprising a frequency analysis unit analyzing a frequency component included in a torque command, an analysis control unit controlling the start or stopping of the frequency analysis unit, a detection unit detecting a natural frequency of the controlled object from an analysis result of the frequency analysis unit, a-band rejection filter receiving as input the torque command, stripping the command of the natural frequency component, and outputting the resultant command to the motor through a current control unit and servo amplifier, and a filter characteristic setting unit setting the frequency to be stripped at the filter based on the natural frequency detected by the detection unit.
    Type: Grant
    Filed: June 25, 2008
    Date of Patent: October 5, 2010
    Assignee: Fanuc Ltd
    Inventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
  • Publication number: 20100219787
    Abstract: A motor drive system is provided with a plurality of axis control parts for outputting PWM commands using a position command, a plurality of current supply parts which supply current to the respective windings based on the PWM commands of the respective axis control parts, and which are connected to the respective windings, a motor position detector for outputting a signal of a rotor position of the motor, a first signal supply part for supplying the output signal to one current supply part of the plurality of current supply parts, and a second signal supply part for supplying the signal supplied through the first signal supply part to an axis control part corresponding to one current supply part, and the corresponding axis control part outputs a PWM command based on the signal supplied from the one current supply part through the second signal supply part to the corresponding axis control part and the position command, and the remaining axis control part outputs the PWM command based on the signal supplied f
    Type: Application
    Filed: December 21, 2009
    Publication date: September 2, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Yukio TOYOZAWA, Kazuomi MAEDA
  • Publication number: 20100181955
    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: Application
    Filed: September 25, 2009
    Publication date: July 22, 2010
    Applicant: FANUC LTD
    Inventors: Kazuomi MAEDA, Yukio Toyozawa, Yasusuke Iwashita
  • Publication number: 20100148714
    Abstract: A controller and a control system capable of estimating inertia of an article to be driven in a short period of time, with a small operation range of an electric motor. The controller for the motor has an inertia estimating part which includes a sine-wave command generating part which adds a sine-wave command to a torque command for the motor; a current feedback sampling part which obtains a current value of the motor; a speed feedback sampling part which obtains a speed feedback of the motor; an acceleration calculating part which calculates an acceleration value based on the speed feedback; and an estimated inertia calculating part which estimates the inertia of the article, based on a representative current value, a representative acceleration value and a torque constant of the motor, which are calculated from current and acceleration values in a plurality of cycles of the sine-wave command and stored in a sampling data storing part.
    Type: Application
    Filed: October 9, 2009
    Publication date: June 17, 2010
    Applicant: FANUC LTD
    Inventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
  • Patent number: 7656106
    Abstract: There is provided a servo controller for synchronously controlling a master side drive source to drive one drive axis and a slave side drive source to drive the other drive axis. The servo controller includes a correction data calculation means for calculating correction data to correct a positional deviation of a slave side drive source according to a synchronization error which is a difference between a positional deviation of a master side drive source and a positional deviation of the slave side drive source, in which the correction data is added to the positional deviation of the slave side drive source.
    Type: Grant
    Filed: July 7, 2006
    Date of Patent: February 2, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Yukio Toyozawa, Kazuomi Maeda
  • Publication number: 20090102409
    Abstract: A control device for electric motors, capable of precisely moving one object by using two electric motors based on periodically repeated commands. The control device includes a first learning controller for calculating an amount of correction so that a positional deviation of a first electric motor is minimized, and a second learning controller for calculating an amount of correction so that a positional deviation of a second electric motor is minimized. The first and second learning controllers are independent from each other, and configured to minimize the positional deviation of the corresponding electric motor. The parameters set in the learning controllers, each defining the response of learning control of each electric motor, are equal to each other.
    Type: Application
    Filed: September 17, 2008
    Publication date: April 23, 2009
    Applicant: FANUC LTD
    Inventors: Tadashi OKITA, Yukio TOYOZAWA, Naoto SONODA
  • Patent number: 7498761
    Abstract: A motor control apparatus 1 that controls a rotation speed of a motor driven according to a speed command includes an abnormal-rotation detector 21 which determines that the motor is in an abnormal-rotation state, such as a runaway, when a speed deviation Ver obtained by subtracting a detection speed TSA of a motor rotation from a speed command VCMD is equal to or larger than a threshold value, when a sign of a product of acceleration ?TSA obtained by subtracting a last detection speed from a detection speed this time that is detected in a predetermined cycle and a torque command Tc obtained by proportionally integrating the speed deviation is negative, and when an integration value VerSUM of the speed deviation Ver exceeds a predetermined value ALMlevel. With this arrangement, an abnormal rotation of the motor can be instantly detected even during acceleration or deceleration of the motor, thereby increasing the performance of protecting the motor.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: March 3, 2009
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Yukio Toyozawa, Kenji Takahashi
  • Patent number: 7479750
    Abstract: A controller including a learning control unit for determining learning data based on a positional deviation between a target-position command commanding superimposed-type motion including repetitive motion and a positional fed-back variable obtained from an output portion of an electric motor; and an operation control section for controlling the electric motor based on a corrected positional deviation. The learning control unit includes a first learning section for periodically determining, based on the positional deviation, and storing, first learning data according to a first learning period; a learning-data correcting section for correcting the first learning data to eliminate an influence of a local change included in the target-position command or the positional fed-back variable and periodically arising according to a period different from the first learning period; and a positional-deviation correcting section for correcting the positional deviation by using corrected learning data.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: January 20, 2009
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Kazuomi Maeda, Yukio Toyozawa
  • Publication number: 20090009128
    Abstract: A control apparatus of the present invention comprising a control unit outputting a control signal controlling a servo motor and suppressing natural vibration of a controlled object including a motor and a machine driven by the motor while controlling the controlled object, comprising a frequency analysis unit analyzing a frequency component included in a torque command, an analysis control unit controlling the start or stopping of the frequency analysis unit, a detection unit detecting a natural frequency of the controlled object from an analysis result of the frequency analysis unit, a-band rejection filter receiving as input the torque command, stripping the command of the natural frequency component, and outputting the resultant command to the motor through a current control unit and servo amplifier, and a filter characteristic setting unit setting the frequency to be stripped at the filter based on the natural frequency detected by the detection unit.
    Type: Application
    Filed: June 25, 2008
    Publication date: January 8, 2009
    Applicant: FANUC LTD
    Inventors: Tadashi OKITA, Yukio TOYOZAWA, Naoto SONODA
  • Publication number: 20080218116
    Abstract: A servo controller for synchronously controlling a master driving source for driving a driving shaft and a slave driving source for driving a driven shaft, having a position control section that performs a position control based on a positional deviation which is a difference between a position command value given to the slave driving source and a feedback value detected from the slave driving source, an operational section that calculates a synchronization error which is a difference of the positional deviation between the master driving source and the slave driving source, and a correction data calculating section that calculates first correction data for correcting the positional deviation of the slave driving source.
    Type: Application
    Filed: March 7, 2008
    Publication date: September 11, 2008
    Applicant: FANUC LTD
    Inventors: Kazuomi MAEDA, Naoto SONODA, Yukio TOYOZAWA