An engine drive system comprises a processor and a control module coupled to the processor. The control module receives a signal from a crank sensor system, the signal being indicative of at least one of a speed and load of a crankshaft. Based on the signal received from the crank sensor system, the control module determines whether a load on the crankshaft is greater than a threshold value. Based on the determination, the control module controls an electrical machine coupled to the crankshaft to rotate the electrical machine in one of a forward direction and a reverse direction.

A method for starting a compression ignition engine having at least one cylinder with a reciprocating piston located therein, an intake valve configured to control the intake of air to an intake port of the cylinder and an exhaust valve configured to control the expulsion of gas from an exhaust port of the cylinder. The method includes the steps of: cranking the engine, conditioning intake air at the intake port of the cylinder to raise the temperature of air in the cylinder, controlling a valve timing the intake valve and/or the exhaust valve to allow the piston to compress the air within the cylinder, thereby increasing the temperature of the air within the cylinder, and injecting fuel into the cylinder when the air within the cylinder has been heated to a temperature sufficient to support compression ignition of a gasoline and air mixture within the cylinder.

A method for operating an engine that includes a turbocharger with a wastegate is described. In one example, the method includes oscillating a position of the wastegate during cold engine starting as a function of a speed of an engine. The wastegate position may be adjusted to follow a square wave, sinusoidal wave, or triangle wave.

A method for operating an engine that includes a turbocharger with a wastegate is described. In one example, the method includes oscillating a position of the wastegate during cold engine starting as a function of a speed of an engine. The wastegate position may be adjusted to follow a square wave, sinusoidal wave, or triangle wave.

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.

Methods and systems are provided for relieving pressure from a compression locked engine. The engine may be compression locked during an engine start attempt due to operator application of a manual transmission clutch at or around the time of a first combustion event of the engine start. A direct injector of the compression locked cylinder is commanded open to relieve the pressure into the fuel rail.

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.

An engine start control device that is capable of winding back a crankshaft more quickly at the time of an idling stop includes a swingback controller for performing a swingback control process for reversing a crankshaft when an engine is started by operating a starter switch, a windback reverse controller for performing a windback control process for reversing the crankshaft immediately after the engine is stopped by the idling stop control process, and a motor brake controller for performing a motor brake control process for braking the crankshaft reversed by the windback control process by rotating the crankshaft in the normal direction after the windback control process performed by the windback reverse controller. The value of a motor current supplied at the time the crankshaft is reversed by the windback reverse controller is set as a value equal to or larger than the value of a motor current supplied at the time the crankshaft is reversed by the swingback controller.