Various systems and methods are described for controlling an engine in a vehicle, the engine being coupled to a transmission. One example method comprises, under selected braking conditions, shutting-off the engine and spinning-down the engine to rest while the vehicle is traveling, and in response to a foot-off-brake event, restarting the engine by at least partially engaging the transmission and adjusting engine torque control actuators.

Methods and systems are provided for dealing with a change of mind event during an automatic shut-down of an engine in which the speed at which a starter motor used to restart the engine is disengaged is based upon the comparison of current engine speed (N) with a cranking speed limit (S.sub.LIM). In one example, during an engine restart while the engine is spinning down, the starter motor may crank the engine to a threshold cranking engine speed adjusted based on a position of the gear.

A control apparatus controls the operation of a starter such that, after an idling stop is executed and before a request for starting an engine is subsequently issued, the control apparatus executes a preset which causes a pinion to engage a ring gear. A control apparatus controls the operation of a starter such that, after an idling stop is executed and before a request for starting an engine is subsequently issued, the control apparatus executes a preset which causes a pinion to engage a ring gear. It is determined that the preset condition has been cancelled, and the preset is again executed. In that case, the pinion is already engaged with the ring gear at the time point when a request for starting the engine is issued. In that way it is unnecessary for the control apparatus to push out the pinion after a start request is issued.

A method of controlling a powertrain of a vehicle includes opening and/or closing one or more of a first switching device, a second switching device, a third switching device, and engaging and/or disengaging at least one of a pair of actuators for a starter mechanism or a motor/generator clutch. Many different control modes are provided for the powertrain by changing the operation of a motor-generator between a motor or a generator, and changing the electrical connections between a first energy storage device, a second energy storage device, an auxiliary electric system, the starter mechanism, and the motor-generator.

An engine start system which may be employed in automotive idle stop systems. To start an engine, the system brings a pinion gear into engagement with a ring gear coupled to the engine and turns on an electric motor to rotate the ring gear through the pinion gear to crank the engine. When it is requested to start the engine during deceleration of the engine before stop thereof, the system thrusts the pinion into engagement with the ring gear and then turns on the motor to rotate the pinion gear, in other words, delays the activation of the motor until after the pinion gear has engaged the ring gear. This minimizes mechanical impact or noise arising from the engagement of the pinion gear with the ring gear and improves the reliability in engagement with the ring gear during the deceleration of the engine and durability of the system.

An engine control method includes determining an intention of a driver for acceleration during vehicle traveling, stopping fuel supply to an engine when a determination is made that the driver does not have the intention for acceleration, detecting a speed of the vehicle during inertial traveling, with fuel supply to the engine kept stopped, permitting restart of the engine when a determination is made that the driver has the intention for acceleration after stopping the fuel supply to the engine, prohibiting the restart of the engine until an engine rotational speed drops to or below a predetermined rotational speed threshold, even when the restart of the engine is permitted, restarting the engine after the engine rotational speed drops to or below the predetermined rotational speed threshold, and changing the rotational speed threshold depending on the detected speed. The rotational speed threshold increases with increase in the detected speed.

An engine starting apparatus including a starter including a motor configured to generate a rotational force, and a pinion configured to transfer the rotational force of the motor to a ring gear. The starter is configured to crank an engine at a specific revolution-speed increase rate to increase a revolution speed of the engine to a predetermined revolution speed equal to or greater than 450 rpm. The apparatus further includes an ignition-timing setter configured to set an ignition timing at which fuel in a combustion chamber of the engine is ignited while the revolution speed of the engine is increased during cranking of the engine by the starter or during coasting of the engine after termination of cranking of the engine by the starter, and an engine-speed predictor configured to predict a revolution speed of the engine at the ignition timing based on the specific revolution-speed increase rate.

Provided is a device for automatically stopping an engine when an automatic stop condition is satisfied and restarting the engine thereafter when a restart condition is satisfied, the device including: a ring gear (12) to be coupled to a crankshaft of the engine; a starter motor (14) for starting the engine; a pinion gear (16) for transmitting rotation of the starter motor to the ring gear; pinion-gear moving means (17) for moving the pinion gear by energization to bring the pinion gear into meshing engagement with the ring gear; and starter control means (11) for controlling a voltage to be applied to the pinion-gear moving means so as to fall within a predetermined range when the pinion gear and the ring gear are brought into meshing engagement by moving the pinion gear by the pinion-gear moving means.

Various systems and methods are described for controlling an engine in a vehicle, the engine being coupled to a transmission. One example method comprises, under selected braking conditions, shutting-off the engine and spinning-down the engine to rest while the vehicle is traveling, and in response to a foot-off-brake event, restarting the engine by at least partially engaging the transmission and adjusting engine torque control actuators.

A control device for an engine of the invention executes an automatic stop control for stopping stop a rotation of a crank shaft when a predetermined automatic stop condition is satisfied. The device acquires a focused peak value of the engine speed appearing after a time when a rotation direction of the crank shaft first reverses while the automatic stop control has been executed, determines, based on the focused peak value, whether there will be an excessive peak value expected to depart from a predetermined permission range after the focused peak value appears, and executes a starter start control for driving the starter, restarting the fuel supply and igniting the fuel to restart an operation of the engine when a predetermined restart condition is satisfied, the engine speed is within the predetermined permission range and it has been determined that there will be no excessive peak value.