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 control system, which creates a neutral condition if a vehicle is stationary with the brake of the vehicle being actuated and the accelerator for the engine being turned off while the transmission is set in a drive range, is equipped with a brake switch (36), which detects the operational condition of the brake, and a output rotation sensor (40), which detects the rotational speed of the output member of the transmission. If the control system detects the rotation of the output member by the output rotation sensor (40), then the control system terminates the neutral condition in spite of the operational condition of the brake, which is detected by the brake switch (36).

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 control system, which creates a neutral condition if a vehicle is stationary with the brake of the vehicle being actuated and the accelerator for the engine being turned off while the transmission is set in a drive range, is equipped with a brake switch 36, which detects the operational condition of the brake, and a output rotation sensor 40, which detects the rotational speed of the output member of the transmission. If the control system detects the rotation of the output member by the output rotation sensor 40, then the control system terminates the neutral condition in spite of the operational condition of the brake, which is detected by the brake switch 36.

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.

Abstract: A control system for an automatic vehicle transmission which has auto-shifting means or auto-shift mode for determining a gear to be shifted to in accordance with predetermined gearshift scheduling characteristics in response to the detected vehicle speed and the engine load, and manual-shifting means or manual-shift mode for determining a gear to be shifted to in response to a manual-shift command generated by the vehicle driver. The system further includes auto-downshifting means or sub-auto-shift mode for determining a gear to be downshifted to if the detected vehicle speed is less than a threshold value when the manual-shifting means is in operation. In the system it is estimated whether the vehicle is hill climbing or hill descending, and the threshold value is increasing when the vehicle is hill climbing or descending. With the arrangement, it becomes possible to downshift before the drivability or driver's comfort is degraded during the hill climbing or descending.

Abstract: At downshifting, hydraulic pressure of hydraulic clutch on engaging side (ON clutch pressure) is increased when an input and output speed ratio ("Gratio") has fallen below a predetermined value YGDNS. YGDNS is variably set depending on the vehicle speed and the engine temperature so that it becomes a lower value at a high vehicle speed than at a low vehicle speed, and a higher value at a low engine temperature than at a high temperature. When a downshifting command to a still lower speed stage is issued during downshifting control (when FTBD=1), a downshifting completion processing is performed in the course of the downshifting control (step in S111). Oil pressure in a hydraulic engaging element on the disengaging side QDNOFF and oil pressure in a hydraulic engaging element on the engaging side QDNON are switched to the oil pressures at the time of completion of downshifting, to thereby complete the first step downshifting control at an early time.

Abstract: The disadvantage in the conventional transmission in which a high speed stage is established during the initialization operation by the starting up of an electronic control circuit, is eliminated. The disadvantage is that the rotational speed of an engine lowers due to the establishment of the high speed stage during the initialization operation at the time of running in a low speed stage, with the result that the recovery of the driving force after the completion of the initialization operation is delayed. To solve this disadvantage, valves that can switch the transmission to a neutral condition in the running range are provided. During the initialization operation of the electronic control circuit (20), a neutral signal which shifts the transmission (1) to the neutral condition is output (S902) to the valves.

Abstract: When slipping is generated during the upshifting from a first gear shift stage to a second gear shift stage on ice or the like, a control for prohibiting the upshifting from the second gear shift stage to a third gear shift stage can be carried out precisely. A control system is designed so that when a slipping state is detected on ice having a lower road surface friction coefficient by a slipping state determining device, the upshifting of an automatic transmission from a second gear shift stage to a third gear shift stage is prohibited. In this control system, the time required for the upshifting from a first gear shift stage to the second gear shift stage is measured. If such time is shorter than a first predetermined time, it is determined that a slipping has been generated during the upshifting, and the upshifting from the second gear shift stage to the third gear shift stage is prohibited for a second predetermined time.

Abstract: A control system for an automatic vehicle transmission having an auto-shifting device for determining an auto-shifting gearshift signal indicative of a gear to be shifted to in accordance with predetermined gearshift scheduling characteristics in response to a detected vehicle speed and an engine load, and a manual-shifting device for determining a manual-shifting signal indicative of a gear to be shifted to in response to a manual-shift command. A gearshift is conducted in response to one of the auto-shifting gearshift signal and the manual-shifting gearshift signal. In the system, the manual-shifting command is inhibited from being accepted for a predetermined period since the gearshift device conducted a gearshift in response to the auto-shifting gearshift signal. With this arrangement, it is possible to prevent down shifting from occurring consecutively so as to prevent drivability or driver's comfort from being degraded.

Abstract: When switching to a forward running is made while a vehicle is running in a reverse direction, a switching to the forward running condition is made at an early time to thereby prevent the deterioration of the durability of the hydraulic engaging element due to slipping. For that purpose, when a vehicle speed (V) has exceeded a predetermined value (YVa) in a reverse range (R) and also when the vehicle speed (V) has never fallen below the predetermined value (YVa) in a neutral range (N), a reverse signal (FREV=1) is outputted. If FREV=1 at the time of switching to the forward range, the relationship between the vehicle speed and the speed stage (speed change map) is set to one (a reverse-running-measure speed change map) which is different from that at an ordinary time, to thereby determine the speed stage to be established. Then, a low speed stage is established even at a relatively high vehicle speed.

Abstract: A control system of a vehicle automatic transmission in which an engine load and a vehicle speed are detected and used to determine a vehicle acceleration in accordance with the preestablished characteristics. An actual vehicle acceleration is at the same time calculated in response to the detected vehicle speed. The difference therebetween is then calculated and the calculated value is added to a difference calculated earlier to obtain an average therebetween. Five gear shifting scheduling maps, for example one for moderate hill climbing, one for level-road running, one for steep hill descent, are preestablished and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. A driver's intention to decelerate is estimated and is compared with a reference value which increases with increasing said average indicative of the grade of hill that the vehicle is descending.

Abstract: A control system of a vehicle automatic transmission in which an engine load and a vehicle speed are detected and used to determine a vehicle acceleration in accordance with the preestablished characteristics. An actual vehicle acceleration is at the same time calculated in response to the detected vehicle speed. The difference therebetween is then calculated and the calculated value is added to a difference calculated earlier to obtain an average therebetween. Five gear shifting scheduling maps, for example one for moderate hill climbing, one for level-road running, one for steep hill descent, are preestablished and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. The actual vehicle acceleration is corrected by the altitude where the vehicle is traveling so as to compensate for the engine output decrease due to the charging efficiency drop.