摘要:
A method for operating a multi-step automatic transmission arranged in a drive train of a vehicle with a combustion engine. When downshifting from the third gear ratio to a second gear ratio, higher inertia must be shifted than when shifting from the third gear ratio to the first gear ratio. Upon a demand for a coasting downshift from the third gear ratio to the second gear ratio or to the first gear ratio with no performance demand on the combustion engine, the coasting downshift to the second gear ratio is not executed and the first gear ratio is engaged when the requirements for downshifting to the first gear ratio are met.
摘要:
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.
摘要:
A shift control method and apparatus of an automatic transmission for controlling a shift from one speed, achieved by engagement of a first and a second frictional element, to another speed, achieved by engagement of a third and a fourth frictional element. The method includes detecting a rotation speed of a turbine, detecting a rotation speed of at least one operating member of at least one planetary gear set of the automatic transmission, and controlling the shift according to the rotation speeds of the turbine and the operating member. The control includes overlapping a first shift, from the one speed to an additional speed, with a second shift, from the additional speed to the other speed. The additional speed has a gear ratio that is near a gear ratio of the one speed.
摘要:
A method of controlling a clutch-to-clutch transmission. The method includes detecting transmission slip speed that exceeds a predetermined amount for a predetermined time period. Based on the detecting, a shift of a gear ratio of the transmission is forced. When this method is implemented in a vehicle, loss of driver control of the vehicle can be prevented in the event of a non-commanded neutral condition in the transmission.
摘要:
A method for controlling an automatic transmission in a vehicle is provided. The method selectively provides automatic engine braking for the vehicle. When it is determined that automatic engine braking is desired, the upshift schedule is increased, such that a higher vehicle speed is required to upshift for any given accelerator pedal position. The transmission is automatically downshifted to a lower gear to provide engine braking for the vehicle, when a vehicle acceleration threshold is exceeded. The automatic downshifting of the transmission can occur when the brake pedal is engaged, and when the brake pedal is disengaged.
摘要:
A method for controlling an automatic transmission in a vehicle is provided. The method selectively provides automatic engine braking for the vehicle. When it is determined that automatic engine braking is desired, the upshift schedule is increased, such that a higher vehicle speed is required to upshift for any given accelerator pedal position. The transmission is automatically downshifted to a lower gear to provide engine braking for the vehicle, when a vehicle acceleration threshold is exceeded. The automatic downshifting of the transmission can occur when the brake pedal is engaged, and when the brake pedal is disengaged.