Patents by Inventor Yoshifumi Yagi

Yoshifumi Yagi 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: 5459661
    Abstract: A traction control apparatus provided in an automotive vehicle includes a determining part for determining a slip ratio of driving wheels of the vehicle, a drive torque control part for performing a traction control process in which a driving force of the driving wheels is controlled such that the driving force is lowered to a smaller value when the slip ratio determined by the determining part is greater than a reference value, a detecting part for detecting a stalling condition of the vehicle, and a changing part for changing the traction control process performed by the drive torque control part when a stalling condition is detected by the detecting part, so as to increase the driving force of the driving wheels.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: October 17, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yoshifumi Yagi, Hirohito Nishikata, Showichi Miyago, Kiyoyuki Uchida
  • Patent number: 5418726
    Abstract: A traction control apparatus for carrying out a traction control process of an automotive vehicle in order to control a throttle position of a throttle valve.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: May 23, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Yoshifumi Yagi
  • Patent number: 5405301
    Abstract: In an automatic transmission control system provided for an internal combustion engine having an automatic transmission system equipped with a traction control system in which a throttle valve is adjusted towards a closed state from a throttle position corresponding to an operation of an accelerator pedal when wheel slippage occurs, a detection unit detects a degree of operation of the accelerator pedal. A shift point changing unit changes a shift point so that gear shifting occurs on the basis of the degree of operation of the accelerator pedal in a normal state and gear shifting occurs at an engine speed lower than a predetermined engine speed at which gear shifting normally occurs when the degree of operation of the accelerator pedal is equal to or greater than a predetermined value.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: April 11, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yoshifumi Yagi, Kiyoyuki Uchida
  • Patent number: 5405302
    Abstract: A shifting control apparatus for an automatic transmission of an automotive vehicle includes a throttle valve part, a traction control part for carrying out a traction control process for adjusting the throttle valve part to reach a first throttle position value when the vehicle is operating under prescribed operating conditions, the first throttle position value being smaller than a second throttle position value corresponding to a displacement of an accelerator pedal set by a vehicle operator, a throttle position setting part for setting a mean throttle position value by taking a weighted average of the first throttle position value set while the traction control process is being carried out and the second throttle position value corresponding to the displacement of the accelerator pedal, and a control part for carrying out a shifting control process for the automatic transmission in accordance with the mean throttle position value from the throttle position setting part.
    Type: Grant
    Filed: March 18, 1993
    Date of Patent: April 11, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yoshifumi Yagi, Hirohito Nishikata
  • Patent number: 5403247
    Abstract: A traction control apparatus for an automotive vehicle with an automatic transmission includes a first sensing part for outputting a shift signal indicating a shifting condition of the automatic transmission, a second sensing part for outputting an engine speed signal indicating an engine speed of an engine of the vehicle, a traction control part for carrying out a traction control process for controlling slipping of driving wheels of the vehicle by adjusting an engine torque based on the shift signal, and for performing, when a shifting request occurs, a shifting process in which the engine torque is decreased in preference to the traction control process, and a return torque setting part for setting a return position of a throttle valve of the engine at an end of the shifting process, the setting being based on the engine speed signal output at a time of a shifting started in the automatic transmission and based on a gear ratio associated with the shifting, the traction control part performs the traction co
    Type: Grant
    Filed: February 2, 1993
    Date of Patent: April 4, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Yoshifumi Yagi
  • Patent number: 5311433
    Abstract: A device for controlling the slip between driving wheels and a road surface during a start and an acceleration of a vehicle is maintained at a level which ensures a good acceleration and straight line running stability. The device determines a target speed of the rotation of the driving wheels, and controls a drive torque of the driving wheels in such a manner that the actual speed of the rotation of the driving wheels coincides with the target speed. Also, the device detects a friction coefficient between the driving wheels and the road surface, and the slippage of the driving wheels is controlled on the basis of the friction coefficient. Further, the device determines the reliability of the detected friction coefficient, and uses the detected friction coefficient only when the detected friction coefficient is determined to be reliable.
    Type: Grant
    Filed: November 19, 1991
    Date of Patent: May 10, 1994
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hiroshi Igata, Takayoshi Nakatomi, Kiyoyuki Uchida, Yoshifumi Yagi
  • Patent number: 5248010
    Abstract: An acceleration slip control device for a vehicle, by which the slip between driving wheels and a road surface during a start and an acceleration of a vehicle is maintained at level ensuring a good acceleration and straight line running stability. The device controls the slippage of the driving wheel by adjusting a drive torque according to the amount of a deviation of the actual speed of rotation of the driving wheels from a target speed of the driving wheels. The drive torque is controlled in such a manner that the rate of change of the drive torque includes a component proportional to the rate of change of the slippage of the driving wheels and the proportional factor is selected in such a manner that the proportional factor is larger when the component acts to increase the drive torque and is smaller when the component acts to decrease the drive torque.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: September 28, 1993
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yoshifumi Yagi, Takayoshi Nakatomi, Kiyoyuki Uchida, Hiroshi Igata