Patent ID: 6085139
Filing Date: 2000-07-04
Classification: B60W,F16H,Y10T

Abstract:
An improved system for controlling automatic transmission of a vehicle having an engine mounted on the vehicle and a plurality of gears, including:vehicle speed detecting means for detecting a vehicle speed at which the vehicle is travelling;engine load detecting means for detecting a load of the engine;auto-shifting means for determining one of the gears to be shifted to in accordance with predetermined gearshift scheduling characteristics in response to the detected vehicle speed and the engine load;manual-shifting command generating means for generating a manual-shifting command in response to operation of a device manually operated by a vehicle driver;manual-shifting means for determining one of the gears to be shifted to in response to the manual-shift command;discriminating means for discriminating which of the auto-shifting means and the manual-shifting means is in operation;auto-downshifting means for determining one of the gears to be downshifted to if the detected vehicle speed is less than a threshold value when the manual-shifting means is in operation; andgearshift means for conducting gearshift such that the one of the gears is shifted to;wherein the improvement comprises:hill-climbing estimating means for estimating whether the vehicle is climbing a hill; andthreshold value increasing means for increasing the threshold value when the hill climbing means estimates that the vehicle is hill climbing.