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).
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Patent number: 10247301Abstract: 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: GrantFiled: November 29, 2013Date of Patent: April 2, 2019Assignee: FANUC CORPORATIONInventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
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Patent number: 9709975Abstract: 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: GrantFiled: July 24, 2015Date of Patent: July 18, 2017Assignee: FANUC CORPORATIONInventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
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Patent number: 9557731Abstract: 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: GrantFiled: August 10, 2012Date of Patent: January 31, 2017Assignee: FANUC CORPORATIONInventors: Tadashi Okita, Yasusuke Iwashita
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Patent number: 9448545Abstract: 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: GrantFiled: October 29, 2013Date of Patent: September 20, 2016Assignee: FANUC CORPORATIONInventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
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Publication number: 20160033954Abstract: 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: ApplicationFiled: July 24, 2015Publication date: February 4, 2016Inventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
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Patent number: 9048733Abstract: 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: GrantFiled: August 27, 2012Date of Patent: June 2, 2015Assignee: FANUC CORPORATIONInventors: Yasusuke Iwashita, Hajime Ogawa
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Patent number: 9018886Abstract: 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: GrantFiled: September 4, 2013Date of Patent: April 28, 2015Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
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Patent number: 8988032Abstract: 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: GrantFiled: August 2, 2012Date of Patent: March 24, 2015Assignee: FANUC CorporationInventors: Yasusuke Iwashita, Hajime Ogawa
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Patent number: 8924004Abstract: 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: GrantFiled: September 29, 2011Date of Patent: December 30, 2014Assignee: FANUC CorporationInventors: Yasusuke Iwashita, Junichi Tezuka
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Patent number: 8903518Abstract: 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: GrantFiled: September 10, 2012Date of Patent: December 2, 2014Assignee: FANUC CorporationInventors: Naoto Sonoda, Yukio Toyozawa, Yasusuke Iwashita
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Patent number: 8901866Abstract: 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: GrantFiled: May 15, 2012Date of Patent: December 2, 2014Assignee: Fanuc CorporationInventors: Koujirou Sakai, Yasusuke Iwashita
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Patent number: 8896255Abstract: 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: GrantFiled: June 3, 2013Date of Patent: November 25, 2014Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Kenichi Takayama, Satoshi Ikai
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Patent number: 8786239Abstract: 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: GrantFiled: December 21, 2012Date of Patent: July 22, 2014Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Masakazu Niwa, Kenta Yamamoto
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Patent number: 8779704Abstract: 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: GrantFiled: March 11, 2013Date of Patent: July 15, 2014Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Taku Sasaki
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Patent number: 8754601Abstract: 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: GrantFiled: June 13, 2013Date of Patent: June 17, 2014Assignee: Fanuc CorporationInventors: Naoto Sonoda, Yasusuke Iwashita
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Patent number: 8754599Abstract: 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: GrantFiled: March 8, 2013Date of Patent: June 17, 2014Assignee: Fanuc CorporationInventors: Taku Sasaki, Yasusuke Iwashita
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Publication number: 20140156080Abstract: 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: ApplicationFiled: November 29, 2013Publication date: June 5, 2014Applicant: FANUC CORPORATIONInventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI
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Servo motor control device for controlling servo motor configured to drive feed axis of machine tool
Patent number: 8736217Abstract: 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: GrantFiled: March 14, 2013Date of Patent: May 27, 2014Assignee: FANUC CorporationInventors: Yasusuke Iwashita, Satoshi Ikai -
Patent number: 8716965Abstract: 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: GrantFiled: February 28, 2013Date of Patent: May 6, 2014Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Hajime Ogawa
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Publication number: 20140121818Abstract: 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: ApplicationFiled: October 29, 2013Publication date: May 1, 2014Applicant: FANUC CORPORATIONInventors: Yasusuke IWASHITA, Kenichi TAKAYAMA, Satoshi IKAI