Patents by Inventor Yasushi Ikawa

Yasushi Ikawa 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: 6903948
    Abstract: A power converter includes a first sampling device 5 which samples a first command current value for a power conversion device 2 during a second cycle and produces a second command current value; a second sampling device 6 which samples a first detected current value pertaining to a load 3 and produces a second detected current value; a command voltage value calculator 9 for calculating a command voltage value from the second command current value and the second detected current value; a comparator 11 for comparing the second command voltage value with a triangular wave carrier signal, to thereby produce a first pulse width modulation (PWM) signal; and a multi-pulse prevention device 12.
    Type: Grant
    Filed: July 18, 2002
    Date of Patent: June 7, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiko Yoshida, Masahiro Kimata, Yasushi Ikawa
  • Publication number: 20040232897
    Abstract: A power converter comprises a first sampler (5) which samples a first current command value of the power converter (2) by the second period and generates a second current command value, a second sampler (6) which samples a first current detection value of a load (3) and generates a second current detection value, a voltage command value calculator (9) which calculates the voltage command value based on the second current command value and the second current detection value, and a comparator (11) which compares the second voltage command value with the triangular wave carrier and generates a first PWM signal, and a multi-pulsification preventer (12) having an inversion detecting means for detecting the inversion of the first PWM signal and an inversion suppressing means which drives the power converter (2) by a second PWM signal which is the first PWM signal whose inversion is suppresed according to the detection of the inversion detecting means.
    Type: Application
    Filed: July 30, 2003
    Publication date: November 25, 2004
    Inventors: Masahiko Yoshida, Masahiro Kimata, Yasushi Ikawa
  • Patent number: 6057664
    Abstract: A motor driving control apparatus comprises a current detecting section for detecting an output current from an inverter section; a current control section for outputting a voltage instruction to a PWM section from the detected current value, a current instruction from an external device, and from a positional signal of an encoder connected to a motor; and a PWM section for outputting a PWM signal to the inverter section according to a voltage instruction, and an encoder I/F section for receiving a positional signal for the encoder is provided in an external interface section, the current control section and PWM section are provided in an N potential control section connected to the external interface section, and the external interface section transmits the current instruction and the positional signal inputted into the encoder I/F section through serial communications via an insulating section.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: May 2, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasushi Ikawa, Kiyonari Kawajiri
  • Patent number: 5652491
    Abstract: A position controller includes: a compensation torque control circuit which outputs a second torque signal T.sub.2 * and an initial value of an integration torque T.sub.iset on the basis of a real speed signal .omega..sub.M, a rotation angle instruction signal .theta..sub.M *, a real rotation angle signal .theta..sub.M, an integration torque signal T.sub.i of a speed control circuit, and a reference .theta..sub.drp *; a speed control circuit which outputs a first torque signal T.sub.1 * and the integration output T.sub.i on the basis of a speed instruction signal .omega..sub.M * and the real speed signal .omega..sub.M ; an adder which adds the first torque signal T.sub.1 * to the second torque signal T.sub.2 * and outputs a torque instruction signal; and a torque control circuit which controls the torque of the motor in accordance with the torque instruction signal.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: July 29, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasushi Ikawa, Masanori Ozaki, Shizuo Kumekawa, Tetsuaki Nagano, Fumio Kumazaki
  • Patent number: 5442273
    Abstract: An apparatus and method for controlling driving of a apparatus such as a motor. A signal representing the position and/or velocity of the motor is received by a drive control unit. A microprocessor in the drive control unit provides a division ratio signal and a rotation judging signal to a clock pulse divider and two-phase pulse generator, respectively, and also calculates the velocity of the apparatus in accordance with the condition data. The clock pulse divider divides a clock pulse signal in accordance with the division ratio signal and outputs a divided clock pulse signal. The two-phase pulse generator generates two-phase pulses having a 90-degree phase shift of a given polarity with respect to one another in accordance with the divided pulse signal, and reverses the polarity of the phase shift in accordance with the rotation judging signal. The microprocessor further outputs a control signal to control driving of the apparatus in accordance with the calculated velocity and the two-phase pulses.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: August 15, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasushi Ikawa, Seisuke Tsutsumi
  • Patent number: 5414336
    Abstract: A system for inverter control of a servo motor where in the inverter is connected to a velocity control section and a position detection section is connected to the servo motor. Primary and back-up power for operating the velocity control section and the position detection section is provided by power sources that are located in the velocity control section and are connected to the position detection section by cables. The cables used to provide signal transmission between the position detecting section and the velocity control section are switched by relays to transmit the power of a power failure back-up power supply at the time of a power failure. Also, a transmission signal transmitted from one of the position detecting section and the velocity control section to the other via a first cable connection is returned via a second cable connection and a connection fault may be judged depending on whether or not the return signal matches the transmission signal.
    Type: Grant
    Filed: October 26, 1993
    Date of Patent: May 9, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Seisuke Tsutsumi, Yasushi Ikawa, Akira Shima