Abstract: A system for controlling an automatic transmission of a vehicle which determines a downgrade or upgrade parameter based on the vehicle acceleration and selects one from among a plurality of shift programs based on the determined grade parameter to determine a gear ratio based on the selected shift program. The system includes a navigation system which determines the instantaneous vehicle position and outputs road information including upgrade/downgrade condition of road including the determined instantaneous vehicle position. In the system, the grade parameter is corrected based on the navigation information and the grade parameter such that the one from among a plurality of shift programs is selected based on the corrected grade parameter, thereby enhancing drivability during downgrade running, without being affected even if the navigation information is temporarily invalid.

Abstract: A constant-speed running controller which sets a target throttle opening of a throttle valve such that the speed of a vehicle is at a target vehicle speed, detects an amount of accelerator pedal operation as an accelerating pedal opening, adds the set target throttle opening and the detected accelerating pedal opening to generate an opening signal as the addition result, and drives the throttle valve and controls a transmission stage of an automatic transmission in accordance with the opening signal.

Abstract: A system for controlling an automatic transmission of a vehicle which determines a downgrade or upgrade parameter based on the vehicle acceleration and selects one from among a plurality of shift programs based on the determined grade parameter to determine a gear ratio based on the selected shift program. The system includes a navigation system which determines the instantaneous vehicle position and outputs road information including upgrade/downgrade condition of road including the determined instantaneous vehicle position. In the system, the grade parameter is corrected based on the navigation information and the grade parameter such that the one from among a plurality of shift programs is selected based on the corrected grade parameter, thereby enhancing drivability during downgrade running, without being affected even if the navigation information is temporarily invalid.

Abstract: A constant-speed running controller which sets a target throttle opening of a throttle valve such that the speed of a vehicle is at a target vehicle speed, detects an amount of accelerator pedal operation as an accelerating pedal opening, adds the set target throttle opening and the detected accelerating pedal opening to generate an opening signal as the addition result, and drives the throttle valve and controls a transmission stage of an automatic transmission in accordance with the opening signal.

Abstract: A system for controlling an automatic transmission of a vehicle which determines a downgrade or upgrade parameter based on the vehicle acceleration and selects one from among a plurality of shift maps (programs) based on the determined grade parameter to determine a gear ratio based on the selected shift program. The system includes a navigation system which stores the road information including the kinds of road. The system determines whether the vehicle runs on a relative road such an alley or a traffic jammed expressway based on the vehicle speed change, the vehicle-stopping-time and the navigation information and if it does, changes the upshift line of the level-road map in the direction in which the vehicle speed increases such that upshift is not likely to occur, or in the direction in which the vehicle speed decreases such that the upshift is more likely to occur, thereby enhancing driveability.