Patents by Inventor Satoshi Ikai

Satoshi Ikai 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: 20180131297
    Abstract: A servomotor control device that performs static friction correction for a servomotor, including: a position control loop for feedback controlling a position of a servomotor; a speed control loop for feedback controlling speed of the servomotor; a position command creation part that creates a position command value for the servomotor; a stop determination part that determines whether or not the servomotor is stopped; a static-friction correction amount calculation part that calculates a static-friction correction amount of the servomotor; and a static-friction correction amount modification part that performs a predetermined modification on the calculated static-friction correction amount, in a case of the servomotor stopping, and then starting to operate in the same direction as prior to stopping.
    Type: Application
    Filed: November 2, 2017
    Publication date: May 10, 2018
    Inventors: Ryoutarou TSUNEKI, Satoshi IKAI
  • Publication number: 20180104780
    Abstract: A motor control device for a machine tool having a plurality of axes includes a plurality of motor control units that control motors; an abnormality detection unit provided for at least one of the motor control units and configured to output an abnormality detection signal upon detecting an abnormality with respect to the axis driven by the motor controlled by the motor control unit provided with the abnormality detection unit; a safety operation control unit provided for a motor control unit that is not the motor control unit provided with the abnormality detection unit, the safety operation control unit configured to control the motor upon receiving the abnormality detection signal in such a way that the tool comes out of contact with the workpiece; and a communication unit that transmits the abnormality detection signal outputted by the abnormality detection unit to the safety operation control unit.
    Type: Application
    Filed: October 10, 2017
    Publication date: April 19, 2018
    Applicant: FANUC CORPORATION
    Inventors: Shougo Shinoda, Satoshi Ikai
  • Publication number: 20180095444
    Abstract: A servomotor control device includes a connection mechanism configured to connect a servomotor and a driven body, and transmit power of the servomotor to the driven body, a position command generation unit configured to generate a position command value for the driven body, a motor control unit configured to control the servomotor using the position command value, a force estimation part configured to estimate drive force acting on the driven body at a connecting part with the connection mechanism, a switching part configured to switch between a first force estimated value estimated by the force estimation part and a second force estimated value that is a fixed value, and a compensation amount generation part configured to generate a compensation amount for compensating the position command value generated by the position command generation part, based on the first or second force estimated value that was switched to by the switching part.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Inventors: Shougo SHINODA, Satoshi IKAI
  • Patent number: 9933759
    Abstract: A servo control apparatus includes a subtractor configured to calculate a difference between a first command value for controlling a servo motor, and a first detection value from the servo motor; an integral term creation unit configured to create an integral term based on an output of the subtractor; an internal division processing unit configured to internally divide the first command value; a subtractor configured to calculate a difference between an output of the internal division processing unit and the first detection value; a proportional term creation unit configured to create a proportional term based on the subtractor; and a adder configured to add an output of the integral term creation unit and an output of the proportional term creation unit, in which a calculation period calculated by the proportional term creation unit is shorter than a calculation period calculated by the integral term creation unit.
    Type: Grant
    Filed: April 20, 2017
    Date of Patent: April 3, 2018
    Assignee: FANUC CORPORATION
    Inventors: Ryoutarou Tsuneki, Satoshi Ikai
  • Publication number: 20180067469
    Abstract: A servomotor control device includes a servomotor; a driven body configured to be driven by the servomotor; a connection mechanism configured to connect the servomotor and driven body, and transmit power of the servomotor to the driven body; a position command generation unit configured to generate a position command value; a motor control unit configured to control the servomotor using the position command value; a position command compensation unit including a force estimation part configured to estimate a drive force acting on the driven body at the connection mechanism, and a compensation amount generation part configured to generate a compensation amount for compensating the position command value based on the estimated drive force; and a restriction part configured to restricting updating of the compensation amount when a command acceleration or a command velocity of the position command value is no more than a desired value.
    Type: Application
    Filed: September 6, 2017
    Publication date: March 8, 2018
    Applicant: FANUC CORPORATION
    Inventors: Shougo SHINODA, Satoshi IKAI
  • Publication number: 20180052449
    Abstract: A motor control device includes a velocity controller configured to calculate a torque command from a velocity command and a motor velocity; a compensation torque calculation unit configured to calculate a compensation torque command by multiplying an error between the motor velocity and a velocity of a driven part by a compensation gain and a compensation filter; a torque control unit configured to control torque of a motor based on a value obtained by adding the torque command and the compensation torque command; and a setting change part configured to change a gain of the velocity controller according to an operating condition of the motor control device, and change at least one of the compensation gain and the compensation filter in accordance with a change in the gain of the velocity controller.
    Type: Application
    Filed: August 17, 2017
    Publication date: February 22, 2018
    Inventors: Tsutomu NAKAMURA, Satoshi IKAI
  • Patent number: 9893674
    Abstract: A motor control device includes: a power failure detection unit that detects a power failure; a voltage detection unit that detects a DC link voltage; a switch unit which connects a motor to an amplifier or a resistance; a voltage comparison unit which compares a DC link voltage with a threshold value; a limit value setting unit which sets a torque limit value in accordance with a result of comparison; a torque command limit unit which limits a torque command when a power failure is detected; a prediction value calculation unit which calculates, using an angular velocity, a torque prediction value of the motor when the motor is connected to the resistance; and a torque comparison unit which compares the torque limit value with the torque prediction value, in which in accordance with a result of comparison, the switch unit connects the motor to the amplifier or the resistance.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: February 13, 2018
    Assignee: FANUC CORPORATION
    Inventors: Satoshi Ikai, Yuuki Kumamoto
  • Patent number: 9893662
    Abstract: A servomotor control device includes a torque command creation part for creating a torque command value for driving a servomotor. The torque command creation part includes a proportional gain part and an integral gain part. An integral gain is set as a value calculated by multiplying an initial value, by a ratio J/Jm of total inertia of a machine relative to rotor inertia of the servomotor, and a value set smaller than the square of a velocity gain magnification according to delay time of the velocity control loop. A proportional gain is a value calculated by adding a value according to a difference in calculation cycle between the integral term and the proportional term, and the integral gain, to a value calculated by multiplying an initial value by the ratio J/Jm and the velocity gain magnification.
    Type: Grant
    Filed: July 17, 2017
    Date of Patent: February 13, 2018
    Assignee: FANUC CORPORATION
    Inventors: Ryoutarou Tsuneki, Satoshi Ikai
  • Publication number: 20180026561
    Abstract: A servomotor control device includes a torque command creation part for creating a torque command value for driving a servomotor. The torque command creation part includes a proportional gain part and an integral gain part. An integral gain is set as a value calculated by multiplying an initial value, by a ratio J/Jm of total inertia of a machine relative to rotor inertia of the servomotor, and a value set smaller than the square of a velocity gain magnification according to delay time of the velocity control loop. A proportional gain is a value calculated by adding a value according to a difference in calculation cycle between the integral term and the proportional term, and the integral gain, to a value calculated by multiplying an initial value by the ratio J/Jm and the velocity gain magnification.
    Type: Application
    Filed: July 17, 2017
    Publication date: January 25, 2018
    Applicant: FANUC CORPORATION
    Inventors: Ryoutarou TSUNEKI, Satoshi IKAI
  • Publication number: 20180011453
    Abstract: A servo control device includes a velocity command creation part configured to create a velocity command value for driving a servomotor; a velocity detection part configured to detect velocity of the servomotor; and a torque command creation part configured to create a torque command value using a difference between the velocity command value and the velocity detection value. The torque command creation part has an integral gain part and a proportional gain part, an integral gain and a proportional gain are obtained by multiplying a value calculated by multiplying an initial value by a ratio of load inertia of a machine relative to rotor inertia of the servomotor, by an integral gain magnification and a proportional gain magnification, respectively, and the integral gain magnification is set to a value smaller than the square of the proportional gain magnification according to a delay time of a velocity control loop.
    Type: Application
    Filed: June 30, 2017
    Publication date: January 11, 2018
    Applicant: FANUC CORPORATION
    Inventors: Ryoutarou TSUNEKI, Satoshi IKAI
  • Publication number: 20170351247
    Abstract: A motor control device includes: a force command unit that designates a force to be applied to a workpiece to be machined by a machining device having a motor as a driving source; a force detecting unit that detects the force applied to the workpiece; a velocity-command calculating unit that calculates a velocity command based on the designated force and the detected force; a torque-command calculating unit that calculates a torque command based on the velocity command and the velocity of the motor; a motor control unit that controls the motor based on the torque command; a determining unit that determines the machining stage of the workpiece based on the detected force; and a gain changing unit that changes at least one of gains individually provided in the velocity-command calculating unit and the torque-command calculating unit in accordance with the determined machining stage.
    Type: Application
    Filed: May 23, 2017
    Publication date: December 7, 2017
    Inventors: Tsutomu NAKAMURA, Satoshi IKAI
  • Publication number: 20170315513
    Abstract: A servo control apparatus includes a subtractor configured to calculate a difference between a first command value for controlling a servo motor, and a first detection value from the servo motor; an integral term creation unit configured to create an integral term based on an output of the subtractor; an internal division processing unit configured to internally divide the first command value; a subtractor configured to calculate a difference between an output of the internal division processing unit and the first detection value; a proportional term creation unit configured to create a proportional term based on the subtractor; and a adder configured to add an output of the integral term creation unit and an output of the proportional term creation unit, in which a calculation period calculated by the proportional term creation unit is shorter than a calculation period calculated by the integral term creation unit.
    Type: Application
    Filed: April 20, 2017
    Publication date: November 2, 2017
    Inventors: Ryoutarou TSUNEKI, Satoshi IKAI
  • Patent number: 9798295
    Abstract: A motor controller according to one aspect of the present invention is a motor controller for controlling a servo motor that drives a machine, including: a position command unit for outputting a position command of the machine; a position detector for detecting the position of the machine; a position controller for generating a motor velocity command based on the position command output by the position command unit and the machine position detected by the position detector; and a velocity controller for controlling the motor velocity in accordance with the motor velocity command, and is constructed such that the position controller includes a filter F(s) that approximates the inverse characteristic of the transfer characteristic from the motor velocity command to the machine velocity.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: October 24, 2017
    Assignee: FANUC CORPORATION
    Inventors: Tsutomu Nakamura, Satoshi Ikai
  • Patent number: 9785125
    Abstract: A motor control device includes a first position detecting unit for detecting a position of a movable part, a second position detecting unit for detecting a position of a driven part, an error computing unit for computing an error between a first position detection value detected by the first position detecting unit and a second position detection value detected by the second position detecting unit, a memory unit for memorizing, as an initial error, an error computed when the movable part engages with the driven part, a compensation amount computing unit for computing a backlash compensation amount for compensating backlash, a compensation gain computing unit for computing a compensation gain based on the acceleration command, and a compensation amount computing unit for computing the backlash compensation amount using the compensation gain.
    Type: Grant
    Filed: October 27, 2016
    Date of Patent: October 10, 2017
    Assignee: FANUC CORPORATION
    Inventors: Tsutomu Nakamura, Satoshi Ikai
  • Publication number: 20170288596
    Abstract: A control device for a motor is provided that can determine the states of current controllers controlling the current flowing to windings, as well as reducing the load of arithmetic processing. A control device for a motor having windings includes: a main current controller that is connected with a numerical control and controls current flowing to the winding; and sub-current controllers that are connected with the main current controller and control current flowing to the windings, respectively, in which the main current controller: calculates states of the main current controller and the sub-current controllers, compares between the states of the main current controller and the sub-current controllers thus calculated, and determines whether an abnormality is occurring in the main current controller and the sub-current controllers based on a result of comparing between the states of the main current controller and the sub-current controllers.
    Type: Application
    Filed: March 21, 2017
    Publication date: October 5, 2017
    Inventors: Satoshi IKAI, Kenichi TAKAYAMA
  • Publication number: 20170277150
    Abstract: A motor controller according to the present invention includes a position command unit for commanding the position of a driven unit, a compensation filter unit for compensating a position command, and a servo control unit for controlling the operation of a servomotor based on a compensated position command. The compensation filter unit includes an inverse characteristic filter for approximating an inverse characteristic of a transfer characteristic from a motor position to a mechanical position, and a high frequency cutoff filter for reducing a high frequency component of the position command. The inverse characteristic filter is a filter for reducing a gain at a mechanical resonance frequency ?0. The high frequency cutoff filter has a constant “a” times high frequency cutoff frequency a?0 using a constant “a” of 1 or more, with respect to the mechanical resonance frequency ?0 determined in the inverse characteristic filter.
    Type: Application
    Filed: March 14, 2017
    Publication date: September 28, 2017
    Applicant: FANUC CORPORATION
    Inventors: Tsutomu Nakamura, Satoshi Ikai
  • Patent number: 9772622
    Abstract: A motor control system of the present invention includes a servo electricity supply unit supplying electricity to a servo motor, and a controller controlling the servo motor, a mechanical brake and the servo electricity supply unit. The controller controls the servo electricity supply unit to stop the supply of electricity to the servo motor when a signal receiving unit receives a signal for actuating the mechanical brake and to resume the supply of electricity to the servo motor when an abnormality determining unit determines that abnormality exists in the mechanical brake.
    Type: Grant
    Filed: August 3, 2016
    Date of Patent: September 26, 2017
    Assignee: FANUC CORPORATION
    Inventors: Satoshi Ikai, Tomoyuki Aizawa
  • Patent number: 9766614
    Abstract: A motor control apparatus of the present invention is a motor control apparatus for compensating elastic deformation between a servo motor and a driven part, driven by the servo motor, which includes a position command generator for generating a position command of the motor, a compensation filter for compensating the position command generated by the position command generator and a servo control unit for controlling the movement of the motor based on a position command after compensation, i.e., the compensated position command by the compensation filter, and is constructed such that the compensation filter includes a filter F(s) having an inertia JL of the driven part, a stiffness coefficient K of an elastically deformable part and a damping coefficient C of the elastically deformable part as the elements of filter coefficients.
    Type: Grant
    Filed: January 15, 2016
    Date of Patent: September 19, 2017
    Assignee: FANUC CORPORATION
    Inventors: Tsutomu Nakamura, Satoshi Ikai
  • Patent number: 9760082
    Abstract: A motor control apparatus includes an error calculation unit which calculates an error between a position of a movable unit and a position of a driven unit, a memory unit which memorizes the error in association with a torque command value as an initial error, and a compensation amountcompensation amount calculation unit which calculates a compensation amountcompensation amount for compensating an elastic deformation amount of an elastic factor between the movable unit and the driven unit. The compensation amountcompensation amount calculation unit calculates the compensation amountcompensation amount based on the initial error held by the memory unit, the torque command value held in association with the initial error, and a torque command value calculated by a torque command calculation unit when a motor rotates reversely.
    Type: Grant
    Filed: October 6, 2015
    Date of Patent: September 12, 2017
    Assignee: FANUC CORPORATION
    Inventors: Satoshi Ikai, Tsutomu Nakamura
  • Publication number: 20170250643
    Abstract: A motor control device which controls a motor in a machine tool or an industrial machine includes: a power outage detection unit that detects a power outage of a power source which supplies electric power for driving the motor; a DC link voltage detection unit that detects a value of a DC link voltage applied to an amplifier which drives the motor; a comparison unit which compares the value of the DC link voltage with a predetermined threshold value; a torque command generation unit which generates a torque command for driving the motor; a torque limit value setting unit which sets a torque limit value in accordance with a result of a comparison by the comparison unit; and a torque command limit unit which limits the torque command to the torque limit value when a power outage is detected by the power outage detection unit.
    Type: Application
    Filed: February 27, 2017
    Publication date: August 31, 2017
    Applicant: FANUC CORPORATION
    Inventors: Satoshi Ikai, Yuuki Kumamoto