Disclosed are a hybrid electric vehicle which may minimize fuel efficiency loss by shift intervention, and a method of controlling shift thereof. The method of controlling shift of the hybrid electric vehicle includes predicting torque of an input terminal of a transmission at a shift time, predicting an RPM of a motor at the shift time, predicting a quantity of intervention using the predicted torque of the input terminal of the transmission and the predicted RPM of the motor, determining whether or not intervention using the motor alone at the shift time is feasible based on the predicted quantity of intervention, and executing shift corresponding to a result of the determination.

A control apparatus for a vehicle having a step-variable transmission. The control apparatus includes: a shift control portion to temporarily increase an input torque of the step-variable transmission beyond a required value, the shift control portion commanding an engaging-side coupling device which is the coupling device placed in a released state, to be brought into an engaged state, when the input speed has been raised to a predetermined value; and a torque increasing amount setting portion to set an amount of increase of the input torque of the step-variable transmission beyond the required value, such that the amount of increase is smaller when a rate of change of a running speed of the vehicle is relatively low than when the rate of change is relatively high, the rate of change of the running speed having a negative value in a decelerating state of the vehicle.

While a vehicle is coasting with an engine being automatically stopped and a power transmission path between the engine and wheels being disengaged, when a deceleration request is made and the engine is restarted with the power transmission path being engaged, a deceleration level increases relative to the deceleration level required by a driver or the vehicle, thereby lowering drivability. A vehicle control apparatus includes a deceleration level control unit that controls the deceleration level of the vehicle such that, during travelling of the vehicle continuing to travel with a power transmission mechanism between the engine and the wheels being disengaged, when the deceleration request is made and the engine is started by an engagement of the power transmission mechanism, the deceleration level becomes a target deceleration level calculated from a first target deceleration level generated after the engagement of the power transmission mechanism is complete and a second target deceleration level generated in response to the deceleration request.

A method for controlling a vehicle installed with an automatic transmission, includes: a sudden stop determination step in which a controller determines whether the vehicle has stopped at a speed greater than or equal to a reference deceleration speed and whether a post-stop elapsed time is within a first reference time; a takeoff determination step in which the controller determines whether an input torque of the transmission exceeds zero within the first reference time when a shift range is in a driving range; a pressure control step in which, when the vehicle takes off, the controller elevates a line pressure of the transmission; a limitation determination step in which if a slippage extent of a turbine exceeds a reference slippage value for a second reference time, the controller limits the takeoff; and a torque reduction step in which the controller reduces a takeoff torque input of the transmission.

A belt pulley control method of a continuously variable transmission may include setting, a controller, a permission change rate map by adding a predetermined margin to an output shaft rotation speed change rate of a normal road surface according to a high friction road condition; and controlling, the controller, a hydraulic pressure of the belt pulley to be raised when the output shaft rotation speed change rate of the current vehicle is equal to or greater than a set value of the permission change rate map.

A transmission control system and method involve receiving, by a controller and from a turbine shaft speed sensor, a rotational speed of a turbine shaft of an automatic transmission, receiving, by the controller and from an output shaft speed sensor, a plurality of rotational speeds of an output shaft of the transmission, determining, by the controller, a shift time modifier based on the turbine shaft speed and a gradient of the output shaft speed, modifying, by the controller, a shift time for a pedal-off downshift of the transmission based on the shift time modifier to obtain a modified shift time, and controlling, by the controller, the pedal-off downshift of the transmission based on the modified shift time.

A speed control device includes: a vehicle information output unit that outputs at least two, as vehicle information, of measurement information on forward/backward acceleration of a vehicle measured by an acceleration sensor, forward/backward actual acceleration of the vehicle obtained from an output rotation of an automatic transmission, and a traveling driving force based on a driving force output by a driving source and an air resistance acting on the vehicle; and a setting unit that selects a shift mode by comparing the vehicle information with a predetermined selection threshold and sets a shift point for controlling the automatic transmission provided in the vehicle based on the shift mode.

A vehicle control method is provided for controlling a vehicle in which a clutch provided on a power transmission path between an engine and a drive wheel is disconnected when a shift range is a non-driving range and the clutch is connected when the shift range is a driving range. The vehicle control method controls the engine to a prescribed idling speed, controls engine torque to a negative torque by delaying an ignition timing of the engine; and causes the prescribed idling speed to drop within a prescribed amount of time needed for the clutch to switch from being disconnected to being connected when the shift range is switched from the non-driving range to the driving range.

The torque transmission device includes side gears having a same axis of rotation coupled to rear wheels, a case disposed around the outer circumferential side of the side gears, and rotating around the axis of the side gears, and a pinion gear rotatably supported by the case and engaged with the side gears in a straddling manner. The side gears are spur gears having a different number of teeth, and the pinion gear is a spur gear driven by a motor and having an axis of rotation that is parallel to the axis of rotation of the side gears. Forming the side gears and pinion gear from spur gears advantageously allows the side gears to be compactly arranged along their axis of rotation.

A vehicle control apparatus includes: a transmission shifting control portion configured to implement a shifting action of a step-variable transmission, by controlling a releasing action of a releasing coupling device and an engaging action of an engaging coupling device; a torque control portion configured, during the shifting action of the step-variable transmission, to implement a feedback control to control an input torque inputted to the step-variable transmission, such that a value representing a state of a rotary motion of an input rotary member of the step-variable transmission coincides with a target value dependent on a degree of progress of the shifting action; and a backup control portion configured, when it is determined that the drive wheels are slipped, to inhibit the feedback control, and to compensate a transmitted torque to be transmitted through an initiative coupling device, such that the shifting action is facilitated by compensation of the transmitted torque.