Patents by Inventor Sojiro Yokoyama

Sojiro Yokoyama 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: 7828093
    Abstract: A controller for a vehicle including at least one motor driving wheels, an inverter driving the motor, and a boosting converter supplying a dc power supply current to the inverter, is provided with a control portion performing rectangular wave control and non-rectangular wave control on the inverter in a switched manner. The control portion has an emergency switching condition for switching control from the rectangular wave control to the non-rectangular wave control, as a determination reference, and when the emergency switching condition is satisfied while the rectangular wave control is being executed (YES at step S5), the control portion instructs the boosting converter to lower target output voltage (S7). Preferably, the control portion determines that the emergency switching condition is satisfied when a q-axis current supplied from the inverter to the motor exceeds a prescribed threshold value.
    Type: Grant
    Filed: August 24, 2006
    Date of Patent: November 9, 2010
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hideto Hanada, Sojiro Yokoyama
  • Patent number: 7692940
    Abstract: A voltage transformer, which is placed between a DC power source (B) and a motor (M1), includes: a voltage sensor (10) and an electric current sensor (11), which senses input and output of electric power to and from the DC power source (B); a buck-boost converter (12) having power control elements, which is placed in a path connecting between power lines (PL1) and (PL2) that establish the connection to the DC power source (B) and the connection to the motor (M1), respectively; and a controller (30) for controlling the buck-boost converter (12). The controller (30) monitors the change in the regenerated power that is supplied to the DC power source (B), based on the outputs from the voltage sensor (10) and the electric current sensor (11), and, if the amount of change in the regenerated power is greater than a predetermined amount, the controller (30) changes the operation mode of the buck-boost converter (12) from a rapid operation mode to a slow operation mode.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: April 6, 2010
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kiyoe Ochiai, Masaki Okamura, Sojiro Yokoyama
  • Publication number: 20090159350
    Abstract: A controller for a vehicle including at least one motor driving wheels, an inverter driving the motor, and a boosting converter supplying a dc power supply current to the inverter, is provided with a control portion performing rectangular wave control and non-rectangular wave control on the inverter in a switched manner. The control portion has an emergency switching condition for switching control from the rectangular wave control to the non-rectangular wave control, as a determination reference, and when the emergency switching condition is satisfied while the rectangular wave control is being executed (YES at step S5), the control portion instructs the boosting converter to lower target output voltage (S7). Preferably, the control portion determines that the emergency switching condition is satisfied when a q-axis current supplied from the inverter to the motor exceeds a prescribed threshold value.
    Type: Application
    Filed: August 24, 2006
    Publication date: June 25, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hideto Hanada, Sojiro Yokoyama
  • Publication number: 20090128117
    Abstract: A voltage transformer, which is placed between a DC power source (B) and a motor (M1), includes: a voltage sensor (10) and an electric current sensor (11), which senses input and output of electric power to and from the DC power source (B); a buck-boost converter (12) having power control elements, which is placed in a path connecting between power lines (PL1) and (PL2) that establish the connection to the DC power source (B) and the connection to the motor (M1), respectively; and a controller (30) for controlling the buck-boost converter (12). The controller (30) monitors the change in the regenerated power that is supplied to the DC power source (B), based on the outputs from the voltage sensor (10) and the electric current sensor (11), and, if the amount of change in the regenerated power is greater than a predetermined amount, the controller (30) changes the operation mode of the buck-boost converter (12) from a rapid operation mode to a slow operation mode.
    Type: Application
    Filed: December 14, 2006
    Publication date: May 21, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kiyoe Ochiai, Masaki Okamura, Sojiro Yokoyama
  • Patent number: 7042190
    Abstract: A control device measures time intervals T1 to T12 from the reference time until when each of the rotational angles ?bn1, ?bn2 output from each of resolvers becomes n×60 degrees (n=1 to 12, i.e., 60 degrees to 720 degrees). Then, the control device calculates a deviation angle ??n at each of the rotational angles at the intervals of 60 degrees by calculating T1/T12 to T11/T12 using the measured T1 to T12. By substituting the calculated deviation angle ??n into an equation, n×60°+??n (n=1 to 11), the control device corrects the rotational angles at the intervals of 60 degrees. The control device generates each of drive signals DRV1, DRV2 using each of the corrected rotational angles, and outputs each of the drive signals DRV1, DRV2 to each of inverters. The inverters drive each of AC motors (M1, M2) based on each of the drive signals DRV1, DRV2.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: May 9, 2006
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hideaki Yaguchi, Sojiro Yokoyama
  • Publication number: 20040150359
    Abstract: A control device measures time intervals T1 to T12 from the reference time until when each of the rotational angles &thgr;bn1, &thgr;bn2 output from each of resolvers becomes n×60 degrees (n=1 to 12, i.e., 60 degrees to 720 degrees). Then, the control device calculates a deviation angle &Dgr;&thgr;n at each of the rotational angles at the intervals of 60 degrees by calculating T1/T12 to T11/T12 using the measured T1 to T12. By substituting the calculated deviation angle &Dgr;&thgr;n into an equation, n×60°+&Dgr;&thgr;n (n=1 to 11), the control device corrects the rotational angles at the intervals of 60 degrees. The control device generates each of drive signals DRV1, DRV2 using each of the corrected rotational angles, and outputs each of the drive signals DRV1, DRV2 to each of inverters. The inverters drive each of AC motors (M1, M2) based on each of the drive signals DRV1, DRV2.
    Type: Application
    Filed: January 16, 2004
    Publication date: August 5, 2004
    Inventors: Hideaki Yaguchi, Sojiro Yokoyama