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.

Disclosed are a method and device for controlling the state switching of a fluid torque converter, a vehicle and a storage medium, the method including: obtaining a target instruction when the torque converter of the vehicle is in a locked state, the target instruction triggering a change in the torque transmission direction of a transmission system of the vehicle; obtaining a state parameter, and determining whether the current vehicle is in a target operating condition according to the state parameter; and if the current vehicle is in the target operating condition, switching the fluid torque converter to an open state, and switching the torque converter back to the locked state after maintaining the open state for a preset period of time.

The controller starts an output of an engagement instruction of the lockup clutch when a vehicle speed becomes a lockup start vehicle speed under a state where the lockup clutch is disengaged. When the vehicle speed, which is obtained a predetermined time after the output of the engagement instruction is started due to the vehicle speed becoming the lockup start vehicle speed, has reached a predetermined vehicle speed, the controller continues the output of the engagement instruction. When the vehicle speed has not reached the predetermined vehicle speed, the controller stops the output of the engagement instruction and restarts the output of the engagement instruction when the vehicle speed reaches a lockup restart vehicle speed which is set to a vehicle speed higher than the lockup start vehicle speed while the output is stopped.

A shift control device and a shift control method for a vehicle may include a storage to store a table having a target speed corresponding to a speed of the vehicle at a starting point of a coasting operation of the vehicle and a speed profile corresponding to each of gearshifting stages of the vehicle with respect to each downhill slope, and a controller to control gearshifting of the vehicle traveling in the coasting operation on a downhill road, according to the table and the speed profile, to control the speed of the vehicle, according to a driver intent of accelerating the vehicle and a driver intent of traveling the vehicle at a constant speed.

A shift control device and a shift control method for a vehicle may include a storage to store a table having a target speed corresponding to a speed of the vehicle at a starting point of a coasting operation of the vehicle and a speed profile corresponding to each of gearshifting stages of the vehicle with respect to each downhill slop, and a controller to control gearshifting of the vehicle traveling in the coasting operation on a downhill road, according to the table and the speed profile, to control the speed of the vehicle, according to a driver intent of accelerating the vehicle and a driver intent of traveling the vehicle at a constant speed.

The present invention provides a shift control method implemented in a vehicle equipped with an automatic transmission for controlling an input shaft rotation speed to a target input shaft rotation speed during a shift. The method includes setting of a basic target synchronization rotation speed that is a basic target value of the input shaft rotation speed during the shift, and setting of a corrected target input shaft rotation speed as the target input shaft rotation speed when the shift is a downshift without a requirement for a driving force of the vehicle, The corrected target input shaft rotation speed is obtained by decreasingly correcting the basic target synchronization rotation speed. Further, a decreasing correction amount of the basic target synchronization rotation speed is set so as to become larger as a deceleration of the vehicle becomes larger.

A method is disclosed for operating a multi-gear vehicle transmission in a motor vehicle during a coasting phase. The coasting phase includes an overrun phase with a driving gear engaged and a freewheeling phase with the neutral gear engaged. It is determined whether the motor vehicle is in the overrun phase of the coasting phase, whether a condition for a transition to the freewheeling phase of the coasting phase is fulfilled, and whether a transmission condition with elevated drag losses exists. If the motor vehicle is in the overrun phase of the coasting phase, if the condition for transition to the freewheeling phase is fulfilled, and if a transmission condition with elevated drag losses exists, then at least one further shifting element (D, E) is closed in addition to the shifting elements (A, B, C) of the driving gear, which are closed during the overrun phase of the motor vehicle.

An apparatus and a method for controlling a transmission of a vehicle may include a determining device configured to determine whether to perform a front-vehicle-based deceleration following control based on information on the vehicle and information on the front vehicle when coasting of the vehicle is started, a calculating device configured to determine a target speed of the vehicle and a target distance based on a position, a speed, and a moving distance of the front vehicle, when the front-vehicle-based deceleration following control is determined to be performed, a gearshifting stage deciding device configured to decide a final gearshifting stage of the transmission based on the determined target speed and the target distance by configuring a deceleration profile for each gearshifting stage of the transmission, and a controller to control the transmission based on the final gearshifting stage.

A method for operating a vehicle drivetrain (1) having a drive machine (2), an output (3) and a gearbox (4) with the gearbox (4) arranged in power flow between the drive machine (2) and the output (3) includes opening, in the presence of a demand for activation of a sailing operating function of the vehicle drivetrain (1) and a simultaneously activated engine start-stop function, a positively engaging shift element (F) while the drive machine (2) is left both decoupled from the output (3) and shut down.

A method for selecting a gear when Start-Stop Coasting (SSC) is released may include: determining whether a traveling vehicle satisfies a condition for releasing SSC after entry into SSC (S100); selecting a gear input to a transmission (S200) when the traveling vehicle satisfies the condition for releasing SSC after entry into SSC; determining a road gradient (S300) when the traveling vehicle satisfies the condition for releasing SSC after entry into SSC; and correcting the selected gear according to a pre-stored correction map so as to correspond to the determined road gradient.