A pre-engaged piston starter system of an automobile vehicle includes an engine having a flywheel to start the engine connected to the engine by an engine shaft. A starter motor provides rotational energy to a starter gear. A pinion gear transfers rotational energy of the starter gear to the flywheel. A solenoid is energized to shift the pinion gear to an engaged position between the flywheel and the starter gear. An auto-stop mode is entered when an engine speed is decreased below a calibrated threshold speed defining approximately 250 rpm. A calculated pinion pre-engagement engine speed allows engagement of the pinion gear when the engine speed is below the calibrated threshold speed.

An engine start control device includes an pass determination section that performs a pass determination process of determining, based on a rotation state of the engine output shaft, whether a piston in a cylinder of the engine can pass over a compression top dead center for a rotation drop period in response to an occurrence of the start request. The engine start control device also includes a start control section that when it is determined that the piston cannot pass over the compression top dead center, starts driving of the motor in a low reaction force period to start the engine, the low reaction force period being a period in which a reaction force applied to the piston by a cylinder internal pressure in the cylinder is a predetermined value or less.

The vehicle includes an engine comprising a crankshaft, a crankshaft position sensor (CKP) configured to generate a pulse signal corresponding to a rotation of the crankshaft, a battery, a hybrid starter generator (HSG) configured to start the engine based on a power of the battery and charge the battery, and a motor controller unit (MCU) configured to determine a rotation angle of the crankshaft based on the pulse signal received from the CKP, and control the HSG based on the determined rotation angle.

An internal-combustion engine includes a belt-driven starter generator and makes an idling stop while a vehicle is at a stop. In the process of the engine revolution speed decreasing with cutting of fuel to stop the vehicle, to suppress the reduction in restart responsiveness caused by slack in a belt, preliminary powering of the starter generator is performed. The belt tension during deceleration microscopically changes periodically between a relatively high-tension period and a relatively low-tension period due to pulsation of the engine revolution speed. Slack in the belt does not occur in the high tension period, and thus preliminary powering torque is applied only in the low-tension period.

There is provided a vehicle-mounted control device that, when a restart request is generated during a time interval between the fulfillment of an engine automatic stop condition and complete stop, decreases a charging efficiency of an engine by means of at least one of a throttle valve and an intake valve to prevent an increase in the reverse rotational frequency of the engine, thereby ensuring the durability of the starting device of the engine, and preventing an accelerator response from deteriorating when a restart request based on the accelerator operation is generated. In the vehicle-mounted control device that controls a charging efficiency of the engine on the basis of the requested engine output amount, the engine is automatically stopped when a predetermined automatic stop condition is fulfilled, and a charging efficiency at the time when a restart condition of the engine has been fulfilled on the basis of an engine output request generated during a time interval between the fulfillment of the automatic stop condition and complete stop of the engine is made lower than a charging efficiency for the requested engine output amount.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine reaches a predetermined threshold speed, then a first restart sequence is initiated. If a restart request is made when the engine speed is less than the predetermined threshold speed but still greater than 0, then a second restart sequence is initiated.

The vehicle includes an engine comprising a crankshaft, a crankshaft position sensor (CKP) configured to generate a pulse signal corresponding to a rotation of the crankshaft, a battery, a hybrid starter generator (HSG) configured to start the engine based on a power of the battery and charge the battery, and a motor controller unit (MCU) configured to determine a rotation angle of the crankshaft based on the pulse signal received from the CKP, and control the HSG based on the determined rotation angle.

Disclosed is a method for estimating a physical stoppage of an engine of a motor vehicle, subject to bounce-back, a target equipped with teeth being borne by the crankshaft and successive passes of the teeth past a sensor being detected, a first time count incrementing since a last detection of the passing of a tooth and being associated with a first time threshold with the first count being reset to zero when the time between passes of two successive teeth is below the first threshold. A second count associated with a second time threshold is performed, with this count being suspended when and for as long as a time between the passes of two successive teeth is below the second threshold, the engine being estimated to have stopped as soon as the counts have respectively reached the first and second thresholds.

If an internal combustion engine that has been automatically stopped is to be restarted under a decreased engine speed, a control unit of the internal combustion engine starts cranking when a crank angle of a cylinder in compression stroke of the internal combustion engine is closer to bottom dead center than a threshold value set in advance. More specifically, if an engine speed of the internal combustion engine is in forward rotation, the cranking is begun when the crank angle of the cylinder in compression stroke is closer to the bottom dead center than a threshold value set in advance. If the engine speed of the internal combustion engine is in backward rotation, the cranking is begun when the crank angle of the cylinder in compression stroke is closer to the bottom dead center than another threshold value set in advance.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine reaches a predetermined threshold speed, then a first restart sequence is initiated. If a restart request is made when the engine speed is less than the predetermined threshold speed but still greater than 0, then a second restart sequence is initiated.