A vehicle control system is provided. The vehicle control system includes a shift-by-wire device for shifting a shift gear of a speed variator mounted in a vehicle according to a requirement of an electrical signal; a vehicle speed detecting member for detecting a vehicle speed of the vehicle; a seat belt detecting member for detecting whether a seat belt provided in the vehicle is fastened or taken off; a door open/close member for detecting whether a door provided in the vehicle is opened or closed; a presence detecting member for detecting a presence state of a passenger in the vehicle; and an automatic parking control device for controlling the shift-by-wire device to shift the shift gear to a park gear when output results of one of the door open/close member and the presence detecting member, the vehicle speed detecting member, and the seat belt detecting member satisfy predetermined conditions.

A vehicle control system is provided. The vehicle control system includes a shift-by-wire device for shifting a shift gear of a speed variator mounted in a vehicle according to a requirement of an electrical signal; a vehicle speed detecting member for detecting a vehicle speed of the vehicle; a seat belt detecting member for detecting whether a seat belt provided in the vehicle is fastened or taken off; a door open/close member for detecting whether a door provided in the vehicle is opened or closed; a presence detecting member for detecting a presence state of a passenger in the vehicle; and an automatic parking control device for controlling the shift-by-wire device to shift the shift gear to a park gear when output results of one of the door open/close member and the presence detecting member, the vehicle speed detecting member, and the seat belt detecting member satisfy predetermined conditions.

A HST system for use in traveling of a vehicle includes a controller that controls a pump regulator that changes a displacement of a pump and a motor regulator that changes a displacement of a motor. The controller determines whether or not a particular downhill travel condition is satisfied based on a result of detection by a vehicle speed detector that detects a vehicle speed of the vehicle and a result of detection by a rotation number detector that detects a number of rotations of an engine per unit time. In a case where a depression amount of an accelerator pedal, which is detected by a depression amount detector, is zero and the particular downhill travel condition is satisfied, the controller controls the motor regulator to increase the displacement of the motor.

A hydraulic control system for a transmission is provided with a power source, two drive wheels, a power transmission device, a hydraulic pump, a main valve, and a controller. The power transmission device is configured to be set to a plurality of speed stages. The main valve is disposed between the hydraulic pump and the power transmission device and adjusts the main pressure of hydraulic fluid supplied from the hydraulic pump to the power transmission device. The controller controls the main valve. The controller sets the main pressure to a pressure value derived by correcting a clutch holding pressure of the set speed stage based on a load applied to each of the drive wheels.

A hydraulic control system for a transmission is provided with a power source, two drive wheels, a power transmission device, a hydraulic pump, a main valve, and a controller. The power transmission device is configured to be set to a plurality of speed stages. The main valve is disposed between the hydraulic pump and the power transmission device and adjusts the main pressure of hydraulic fluid supplied from the hydraulic pump to the power transmission device. The controller controls the main valve. The controller sets the main pressure to a pressure value derived by correcting a clutch holding pressure of the set speed stage based on a load applied to each of the drive wheels.

An embodiment power train for a vehicle includes a first input shaft configured to receive rotating forces from a first motor and an engine, a second input shaft configured to receive a rotating force from a second motor, an output shaft disposed in parallel with the first input shaft and the second input shaft, a transmission gear set in which a plurality of gear sets having different gear ratios are engaged with and coupled to the first input shaft and the output shaft, a shifting unit configured to select a gear set of the plurality of gear sets based on a traveling speed of the vehicle, and a motor-side transfer gear set engaged with and coupled to the second input shaft and the output shaft.

An embodiment power train for a vehicle includes a first input shaft configured to receive rotating forces from a first motor and an engine, a second input shaft configured to receive a rotating force from a second motor, an output shaft disposed in parallel with the first input shaft and the second input shaft, a transmission gear set in which a plurality of gear sets having different gear ratios are engaged with and coupled to the first input shaft and the output shaft, a shifting unit configured to select a gear set of the plurality of gear sets based on a traveling speed of the vehicle, and a motor-side transfer gear set engaged with and coupled to the second input shaft and the output shaft.

Disclosed is a method for operating a multi-speed vehicle transmission having a plurality of shift elements (A, B, C, D, E) for engaging the gears of the vehicle transmission. The method includes decoupling between an input (AN) and an output (AB) of the vehicle transmission in a neutral gear, and coupling the input (AN) and the output (AB) of the vehicle transmission in a drive gear for propelling the vehicle by closing at least one shift element (B). At least one transmission state is determined when the neutral gear is engaged, where a shift element (D) for a reverse gear of the vehicle transmission is closed at least partially if the transmission is in a state with increased drag losses when the neutral gear is engaged.

Disclosed is a method for operating a multi-speed vehicle transmission having a plurality of shift elements (A, B, C, D, E) for engaging the gears of the vehicle transmission. The method includes decoupling between an input (AN) and an output (AB) of the vehicle transmission in a neutral gear, and coupling the input (AN) and the output (AB) of the vehicle transmission in a drive gear for propelling the vehicle by closing at least one shift element (B). At least one transmission state is determined when the neutral gear is engaged, where a shift element (D) for a reverse gear of the vehicle transmission is closed at least partially if the transmission is in a state with increased drag losses when the neutral gear is engaged.

The control method for a constant speed running of a vehicle performs a vehicle speed control for downshifting the gear position of the automatic transmission when the acceleration/deceleration of the vehicle is larger than the determination value during the constant speed running control. In the control method, the automatic transmission includes a plurality of gear positions that can be downshifted during the constant speed running control, and among the plurality of gear positions, the determination value between the gear positions having a relatively large difference in the gear ratio between the gear positions is set to be larger than the determination value between the gear positions having a relatively small difference in the gear ratio between the gear positions.