Gear shift system for vehicle, control method and control device for automatic transmission

• US 8,301,351 B2
• Filed: 07/03/2008
• Issued: 10/30/2012
• Est. Priority Date: 07/10/2007
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kuwahara, Seiji, Kaigawa, Masato
• Primary Examiner(s): Mawari, Redhwan K
• Application Number:
  US12/216,421
• Publication Number:
  US 20090018738A1
• Time in Patent Office: 1,580 Days
• Field of Search: 701/55, 701/56, 701/65
• US Class Current: 701/65
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/10 Controlling shift hysteresis

Abstract

A parameter α(OUT) having an accelerator pedal position, a vehicle speed and a drive force as components is set according to information representing a driver'"'"'s operation and information representing running environment of a vehicle. A gear is set according to the parameter α(OUT) and a map determining the gear based on the accelerator pedal position, the vehicle speed and the drive force. A gear shift line is defined such that a rate of increase of the drive force with respect to the vehicle speed is zero or more. A down-shift line is defined such that the drive force decreases with increase in accelerator pedal position. Down-shift after up-shift as well as the up-shift after the down-shift are inhibited when both a condition that an amount of change of the accelerator pedal position after last gear shift is larger than a threshold and a condition that an amount of change of the drive force after the last gear shift is larger than the threshold are satisfied.

Claims

1. A gear shift system for a vehicle comprising:

an automatic transmission; and

a control unit,

said control unit being adapted in such a manner as to detect a vehicle speed, a first information representing a driver'"'"'s operation of an accelerator pedal or a brake pedal, and

a second information representing a running environment of said vehicle, characterized in that

said control unit sets a parameter having one of the detected vehicle speed, an accelerator pedal position and a throttle position as well as a drive force as components, wherein each of the accelerator pedal position, the throttle position and the drive force is set according to said first information and said second information,

said control unit sets a gear ratio according to said parameter and a map determining the gear ratio based on one of the accelerator pedal position and the throttle position as well as the vehicle speed and the drive force, and has down shift lines at which shifting is carried out in dependence on the vehicle speed and the drive force, wherein the shift-down lines change in accordance with changes of the accelerator pedal position or the throttle position such that the drive force decreases with an increase of the accelerator pedal position or the throttle position, and

controls said automatic transmission to shift the gear according to said set gear ratio.

2. A gear shift system for a vehicle comprising:

an automatic transmission; and

a control unit,

said control unit being adapted to detect a vehicle speed,

a first information representing a driver'"'"'s operation of an accelerator pedal or a brake pedal, and

a second information representing a running environment of said vehicle, characterized in that

said control unit sets a parameter having one of a detected vehicle speed, an accelerator pedal position and a throttle position as well as drive force as components, wherein each of said accelerator pedal position, said throttle position and said drive force is set according to said first information and said second information,

sets a gear ratio according to said parameter and a map determining the gear ratio based on one of the accelerator pedal position and the throttle position as well as the vehicle speed and the drive force,

controls said automatic transmission to shift the gear according to said set gear ratio,

allows down-shift after up-shift as well as the up-shift after the down-shift when at least one of a first condition that an amount of change of one of the accelerator pedal position and the throttle position after the last change of the gear ratio is larger than a threshold and a second condition that an amount of change of the drive force after the last change of the gear ratio is larger than the threshold is satisfied, and

inhibits the down-shift after the up-shift as well as the up-shift after the down-shift when neither said first nor said second condition is satisfied.

3. A control method for an automatic transmission mounted on a vehicle, comprising the steps of:

detecting a vehicle speed;

detecting a first information representing a driver'"'"'s operation of an accelerator pedal or a brake pedal;

detecting a second information representing a running environment of said vehicle;

setting a parameter using said control unit having one of the detected vehicle speed, an accelerator pedal position and a throttle position as well as a drive force as components, wherein each of said accelerator pedal position and said drive force is set according to said first information and said second information;

setting a gear ratio using said control unit according to said parameter and a map determining the gear ratio based on one of the accelerator pedal position and the throttle position as well as the vehicle speed and the drive force, and having shift-down lines at which shifting is carried out in dependence on the vehicle speed and the drive force, wherein said shift-down lines change in accordance with changes of the accelerator pedal position or the throttle position such that the drive force decreases with an increase of the accelerator pedal position or the throttle position; and

controlling said automatic transmission to shift the gear according to said set gear ratio.

4. A control method for an automatic transmission mounted on a vehicle, comprising the steps of;

detecting a vehicle speed;

detecting a first information representing a driver'"'"'s operation of an accelerator pedal or a brake pedal;

detecting a second information representing a running environment of said vehicle;

setting a parameter using said control unit having one of the detected vehicle speed, an accelerator pedal position and a throttle position as well as a drive force as components, wherein each of said accelerator pedal position and said drive force is set according to said first information and said second information;

setting a gear ratio using said control unit according to said parameter and a map determining the gear ratio based on one of the accelerator pedal position and the throttle position as well as the vehicle speed and the drive force;

controlling said automatic transmission to shift the gear according to said set gear ratio;

allowing down-shift after up-shift as well as the up-shift after the down-shift when at least one of a first condition that an amount of change of one of the accelerator pedal position and the throttle position after the last change of the gear ratio is larger than a threshold and a second condition that an amount of change of the drive force after the last change of the gear ratio is larger than the threshold is satisfied; and

inhibiting the down-shift after the up-shift as well as the up-shift after the down-shift when neither said first nor said second condition is satisfied.