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: 7923956
    Abstract: A control device, for a servo die cushion, capable of improving a response after overshoot generated by collision of a slide and a die cushion. The control device has a local maximum point judging part which judges a local maximum point based on the detected speed of the servomotor; a speed correction value calculating part which calculates a speed correction value for the servomotor based on the judgment result and the detected speed of the slide; a second force commanding part which generates a second force command value, the second force command value decreasing from an initial value to a first force command value, the initial value being equal to the force detected value when reaching generally the local maximum point. The force command value is switched from the first force command value to the second force command value, when the force detected value reaches the local maximum point.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: April 12, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura, Satoshi Ikai
  • 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
  • Publication number: 20110063122
    Abstract: Signals from a plurality of sensors (vibration sensors, temperature sensors, and humidity sensors) disposed at places on a machine are input through a communication circuit to a numerical controller that controls the machine. The numerical controller uses vibration information, temperature information and humidity information obtained from these sensors to determine whether the machine is in an abnormal state.
    Type: Application
    Filed: July 8, 2010
    Publication date: March 17, 2011
    Applicant: FANUC LTD
    Inventors: Shunsuke MATSUBARA, Yasusuke Iwashita, Shinichi Horikoshi, Akira Hirai, Hiroyasu Sato
  • Publication number: 20110057599
    Abstract: A trajectory display device capable of correctly quantifying an error of a three-dimensional trajectory of a machine tool, and displaying or outputting the error. The trajectory display device has a command line segment defining part adapted to define a command line segment which connects two temporally adjacent points, in relation to each commanded position; an error calculating part adapted to define a normal line extending from the actual position to each command line segment and calculate an error of the actual position relative to a commanded trajectory, the error being determined as a shorter one between a length of a shortest normal line among the defined normal lines and a length of a line segment extending from the actual position to a commanded position which is the nearest from the actual position.
    Type: Application
    Filed: June 24, 2010
    Publication date: March 10, 2011
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi Okita, Junichi Tezuka, Kazuyuki Sugiyama
  • Publication number: 20110046773
    Abstract: Time information t and positional information about each axis are obtained, and the three-dimensional coordinates of tool center point Pe at time t are calculated to display the path of the tool center point Pe at time t. Then, whether a fixed time has elapsed or not is decided. If the fixed time has elapsed, the coordinates of the tool vector start point Ps at time t are calculated to display a line segment connecting between tool vector start point Ps and tool center point Pe, which is the end point of the tool vector. This display enables the orientation of the tool at each tool center point to be grasped at a glance.
    Type: Application
    Filed: June 3, 2010
    Publication date: February 24, 2011
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Junichi TEZUKA, Kazuyuki SUGIYAMA
  • Patent number: 7868569
    Abstract: A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: January 11, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Mamoru Yaeshima, Yuuichi Yamada, Masatomo Shirouzu, Koujirou Sakai
  • Patent number: 7863853
    Abstract: An excitation current processor of a current controller processes the excitation current corresponding to the magnetic flux instruction from the magnetic flux instruction processor. It multiplies this excitation current with a boost coefficient to obtain an excitation current instruction. Here, the boost coefficient is determined based on the difference obtained by subtracting the magnetic flux estimation value processed by the magnetic flux processor based on the excitation current feedback from the voltage conversion device from the magnetic flux instruction input from the magnetic flux instruction processor. Further, the boost coefficient can be found from the function of time from the start of the rise of the magnetic flux.
    Type: Grant
    Filed: June 3, 2008
    Date of Patent: January 4, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Takahiro Akiyama, Masakazu Niwa, Tomohisa Tsutsumi
  • Patent number: 7847502
    Abstract: A device for controlling a feed motion of a feed control axis and a rotary motion of a rotary control axis, both axes being provided in a machine tool so that the rotary control axis is fed along the feed control axis. The device includes an interference estimating section estimating an interference generated between the feed control axis and the rotary control axis, based on a position command instructed to at least one of the feed control axis and the rotary control axis and a position and mass information of an eccentric load carried by the rotary control axis; and a command correcting section correcting a current command given to at least one of the feed control axis and the rotary control axis, based on the interference estimated by the interference estimating section.
    Type: Grant
    Filed: January 2, 2008
    Date of Patent: December 7, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura, Chengbin Ma
  • Patent number: 7845205
    Abstract: A die cushion controller, for driving a die cushion, disposed in opposition to a slide of a press machine, by controlling a servo motor, including: a pressure command portion which prepares a pressure command value for exerting a predetermined pressure to a press material disposed between the slide and the die cushion; a pressure detecting portion which detects an actual pressure exerted on the press material; a speed correction value preparing portion which prepares a speed correction value by multiplying a differential value of the pressure command value prepared by the pressure command portion by a coefficient; and a first speed command portion which prepares a speed command value to be instructed to the servo motor based on the pressure command value prepared by the pressure command portion, the actual pressure detected by the pressure detecting portion, and the speed correction value prepared by the speed correction value preparing portion.
    Type: Grant
    Filed: October 17, 2006
    Date of Patent: December 7, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura, Satoshi Ikai
  • Patent number: 7843152
    Abstract: A motor control apparatus comprises a control processing unit (3) creating a motor drive command, power supply processing units (2A to 2D) supplying a driving voltage to a motor, and a signal relay processing unit (4) supplying the motor drive command received from unit (3) to power supply processing units (2A to 2D). Control processing unit (3) transmits a preparation request flag to power supply processing units (2A to 2D) via signal relay processing unit (4), which includes a preparation complete flag register storing preparation complete flags each transmitted from each of power supply processing units (2A to 2D) to indicate the completion of preparation for supplying power to the motor, and transmits a preparation complete flag enabled state to control processing unit (3) if contents of the preparation complete flag register indicate that the preparation is completed in all units (2A to 2D).
    Type: Grant
    Filed: November 9, 2007
    Date of Patent: November 30, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura, Satoshi Ikai
  • 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
  • Publication number: 20100264867
    Abstract: A control device for a machine tool including a feed axis driving motor; a first power consumption calculating portion calculating power consumption of the feed axis driving motor; a second power consumption calculating portion calculating power consumption of equipment adapted to be operated by constant power; and a motor control portion determining a target time constant correlated with at least one of acceleration time and deceleration time of the feed axis driving motor, based on a summation of the power consumption calculated by the first power consumption calculating portion and the power consumption calculated by the second power consumption calculating portion, and controlling the feed axis driving motor based on the target time constant.
    Type: Application
    Filed: April 15, 2010
    Publication date: October 21, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke Iwashita, Tadashi Okita, Junichi Tezuka
  • Patent number: 7791305
    Abstract: The control apparatus 10 of a servo motor of the present invention has a position control unit 11 controlling the position of a servo motor 33, a speed control unit 12 controlling a speed of the servo motor 33, a distributing unit 13 dividing the speed command output by the position control unit 11 into a filtered part Vf which is filtered to suppress vibration and a nonfiltered part Vnf, a filtering unit 14 receiving as input the filtered part Vf and filtering and outputting the filtered part Vf, and an adder unit 15 adding the filtered part Vf filtered by the filtering unit 14 and the nonfiltered part Vnf and outputting the result to the speed control unit 12.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: September 7, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura
  • 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: 20100214809
    Abstract: Disclosed is a PWM rectifier in which switching losses in a semiconductor device are reduced without degrading the response of a control system. In a PWM overmodulation region, the modulation scheme is set to a three-phase modulation scheme. In other regions, a switchover condition such as the amplitude of an input current is acquired and compared with a switchover level. If the switchover condition equals or exceeds the switchover level, the modulation scheme is switched over to a modified two-phase modulation scheme which reduces the number of switching operations to two thirds for the same PWM frequency.
    Type: Application
    Filed: December 18, 2009
    Publication date: August 26, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Masakazu NIWA, Kenta YAMAMOTO
  • Publication number: 20100207566
    Abstract: A control device, for a servo die cushion, capable of improving a response after overshoot generated by collision of a slide and a die cushion. The control device has a local maximum point judging part which judges a local maximum point based on the detected speed of the servomotor; a speed correction value calculating part which calculates a speed correction value for the servomotor based on the judgment result and the detected speed of the slide; a second force commanding part which generates a second force command value, the second force command value decreasing from an initial value to a first force command value, the initial value being equal to the force detected value when reaching generally the local maximum point. The force command value is switched from the first force command value to the second force command value, when the force detected value reaches the local maximum point.
    Type: Application
    Filed: October 30, 2009
    Publication date: August 19, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Hiroyuki KAWAMURA, Satoshi IKAI
  • 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
  • Patent number: 7757526
    Abstract: A method for changing a force control gain expressed as a ratio of force error to velocity command value in a control circuit performing a force control of a servo motor driving a die cushion disposed opposite to a slide in a press machine. The method includes: obtaining a difference between a displacement of the slide and a displacement of the die cushion in a state in which the slide and the die cushion collide with and are exerting force on each other; detecting the force when the difference of the displacements is obtained; calculating a spring constant of a structural portion based on a proportionality between the difference of the displacements and the force, when regarding the structural portion including the slide and the die cushion as an elastic structure; and changing the force control gain based on the spring constant using a fixed proportionality that exists between the force control gain and a reciprocal of the spring constant.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: July 20, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Tadashi Okita, Hiroyuki Kawamura, Satoshi Ikai
  • Patent number: 7719218
    Abstract: A motor control apparatus for computing or outputting motor load information, comprises: a storage unit which stores a function or table obtained in advance based on parameters used for the computation of the load information and on an actually measured value of a motor output or motor torque; and a load meter computing unit which computes the load information from the function or table stored in the storage unit by using the parameters used for the computation of the load information. With the above configuration, the load meter is computed in such a manner as to accurately indicate the load condition of a motor in real time over the entire speed range of the motor including the nonlinear control region of the motor, and the motor is controlled using the thus computed value or the computed value is displayed on a display unit.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: May 18, 2010
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Takahiro Akiyama, Masakazu Niwa, Geng Li
  • Publication number: 20100117568
    Abstract: A controller of an industrial machine provided with an electric motor, a peripheral apparatus and an amplifier for the motor.
    Type: Application
    Filed: October 30, 2009
    Publication date: May 13, 2010
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Tadashi OKITA, Hiroyuki KAWAMURA, Junichi TEZUKA, Kenta YAMAMOTO