A vehicle driving device includes: an engine; a brake booster including a negative pressure chamber, the brake booster amplifying a brake pressure by a negative pressure determined corresponding to a pressure inside the negative pressure chamber; a power transmission clutch disposed between the engine and a driving wheel; and a negative pressure pump configured to drive by using at least one of a torque from the engine and a torque from the driving wheel, the negative pressure pump being configured to vary the negative pressure inside the negative pressure chamber. In the vehicle driving device included in a vehicle that performs freewheeling in a state where the power transmission clutch is released and the engine is stopped, the negative pressure pump includes a control chamber configured to reduce a capacity of the negative pressure pump as a magnitude of the negative pressure inside the negative pressure chamber increases.

A vehicle control device includes a controller configured to perform: ignition starting of an engine when a detected crank angle is within a first area in which the ignition starting of the engine may be performed with probability not smaller than a first predetermined value; and the ignition starting of the engine while increasing an engine speed by engaging a clutch to transmit torque of a drive wheel to a crankshaft when the crank angle is within a second area in which the ignition starting of the engine may be performed with probability not smaller than a second predetermined value smaller than the first predetermined value and smaller than the first predetermined value, the instruction is output based on a signal indicating that a braking unit is turned on, and a gear of a transmission is not in neutral.

The invention concerns a method for automatically controlling a motor vehicle (10) for switching from a “normal” mode to a “freewheel” mode, the vehicle (10) comprising an engine (12) capable of providing engine torque to drive wheels (14) via an automatically controlled clutch device (18) that comprises a drive shaft (15) and a driven shaft (16). A transition step (E1) is interposed chronologically between the “normal” mode and the “freewheel mode” during which the engine (12) is automatically controlled in such a way that the driven shaft (16) and the drive shaft (15) turn at the same speed without transmitting torque to the drive wheels (14).

For a hybrid vehicle including: an engine and a motor, each of which is mounted as a driving source; a generator driven by the engine; a high-voltage battery and a low-voltage battery, each of which can be charged and discharged; a converter connected between the high-voltage battery and the low-voltage battery; and an auxiliary load that consumes electric power supplied from the high-voltage battery via the converter or electric power supplied from the low-voltage battery, a control device includes a control unit that executes converter limit control that stops the converter or reduces output of the converter when a state of charge of the high-voltage battery is lower than or equal to a predetermined threshold.

A system and method for operating a hybrid vehicle having an engine and an eMachine coupled by a clutch using a hybrid controller is presented. The method determines an idle fuel rate of the engine, determines a hybrid efficiency index for the hybrid vehicle, determines an expected energy storage rate increase for an operating condition where the engine is decoupled from a vehicle transmission using said clutch, multiplies the expected energy storage rate increase by the hybrid efficiency index to determine an expected fuel rate reduction of the engine in the operating condition; and decouples the engine from the vehicle transmission using the clutch if the expected fuel rate reduction is greater than the idle fuel rate.

A vehicle control system includes a controller that is programmed to, in response to an accelerator lift-pedal event, generate a drag torque, with at least one of an engine and electric machine, having a magnitude that is based on a deceleration fuel shut-off torque of the engine and a desired power output of the electric machine, and limit the drag torque to a threshold value that is based on the deceleration fuel shut-off torque.

A method of controlling an engine and a transmission of a vehicle, which is a hybrid vehicle, includes the following steps that are carried out by a controller: determining whether the vehicle is under NCC (Neutral Coasting Control), determining whether an engine RPM reaches an engine RPM control point if it is determined that the NCC is in effect, determining an RPM and a gear stage of a vehicle transmission if it is determined that the engine RPM has reached the engine RPM control point, determining an engine target RPM of the vehicle, determining whether the engine RPM has reached a mild hybrid starter & generator (MHSG) control point, and controlling the MHSG according to a condition if it is determined that the engine RPM has reached the MHSG control point.

A vehicle control device disengages a clutch provided between an engine and a driving wheel at a brake-off and an accelerator-off during traveling of the vehicle, and stops the engine and carries out inertia traveling. The vehicle control device starts the engine by the push-start by engaging the clutch and by transmitting the power of the driving wheel to the engine, if it is determined that a brake pedal has been depressed during the inertia traveling.

A method for controlling a drive train of a hybrid vehicle which includes an internal combustion engine, an electric machine that is operated as a motor or generator, and a transmission. Energy is recovered in the overrun operation of the vehicle by operating the electric machine in generator mode. The transmission has at least one free-wheel-connected low forward gear that only transmits traction torque, and at least one free-wheel-free high forward gear. When the free-wheel-connected low forward gear is engaged and the vehicle transitions into the overrun operation, or the driver requests a transition into the overrun operation by selecting the free-wheel-connected low forward gear, an overrun torque is set via the free-wheel-free high forward gear by a generator operation of the electric machine for energy recovery. The overrun torque thereby substantially corresponds to an overrun torque of a free-wheel-free configuration of the free-wheel-connected low forward gear.

An electronic control unit permits a shift operation to a neutral position, by which a manual transmission 14 is switched to neutral, during coasting control. Accordingly, shifting to the neutral position can be performed only by the shift operation. Thus, power transmission can be blocked after termination of the coasting control. In addition, the electronic control unit prohibits the shift operation to a particular gear after the transmission is switched to neutral. Thus, overreving or underreving at the termination of the coasting control can be suppressed.