An internal combustion engine (ICE) includes a crankshaft, a cylinder head defining in part a variable combustion chamber of the ICE, a direct fuel injector mounted on the cylinder head, a power source, an electric turning machine (ETM) rotating the crankshaft, an absolute position sensor providing an indication of an angular position of a rotor of the ETM, and an engine control unit (ECU) operatively connected to the absolute position sensor. The ECU controls a delivery of electric power from the power source to the ETM based on the angular position of the rotor of the ETM and causes the direct fuel injector to inject fuel directly in the combustion chamber at a time selected based on the angular position reached by the rotor of the ETM.

A method for controlling delivery of electric power between a power source and an electric turning machine (ETM) comprises applying a start signal to a start-up power electronic switch to cause turning on of the start-up power electronic switch and to allow delivery of electric power from the power source to the ETM via the start-up power electronic switch. A recharge signal is applied to a run-time power electronic switch to cause turning on of the run-time power electronic switch for delivery of electric power from the ETM to the power source via the run-time power electronic switch. A circuit comprises a discharging circuit including the start-up power electronic switch for delivering the electric power when the start-up power electronic switch is turned on. A charging circuit includes the run-time power electronic switch for delivering the electric power when the run-time power electronic switch is turned on.

A method and system for controlling a stop rotation position of an engine is described. In one example, the system includes an integrated starter/generator that may be selectively coupled to the engine. The integrated starter/generator may rotate the engine in a first direction (e.g., reverse direction) or a second direction (e.g., a forward direction) in response to a position at which the engine stops rotating following cessation of combustion in the engine.

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.

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.

There is provided an engine starting device, including: a motor generator coupled to a crankshaft of an engine; and a starter including a pinion provided in a detachable manner from a ring gear provided on the crankshaft, and configured to mesh with the ring gear when the engine is started, wherein the engine is cranked through simultaneous cranking by both of the motor generator and the starter when a condition set in advance is satisfied, and wherein, in the simultaneous cranking, the starter starts rotating after the motor generator starts rotating.

An internal combustion engine has one or more combustion chambers defined by one of more cylinders, corresponding pistons, and a cylinder head. A crankshaft is operatively connected to the pistons and to an electric turning machine. To start the engine, the electric turning machine rotates the crankshaft in a first direction toward a reversal point corresponding to a local maximum drag torque of the internal combustion engine, this rotation being made without rotating the crankshaft beyond the reversal point. The electric turning machine then rotates the crankshaft in a second direction opposite from the first direction, a momentum impressed on the crankshaft by compression obtained when rotating in the first direction increasing a speed of the crankshaft in the second direction. Thereafter, fuel is injected in one of the combustion chambers in which the corresponding piston first reaches a top dead center position and the fuel is ignited.

A method for operating a vehicle that may be automatically stopped and started is described. In one example, the method includes starting an engine via expansion stroke combustion in response to a request to urgently start the engine. In addition, the method includes adjusting a position of a compression relief valve in response to a predicted urgency of an engine start.

A vehicle equipped with an automatic stop/restart system for an internal combustion engine includes a hydraulic continuously variable transmission and a parking mechanism. The continuously variable transmission changes power of the internal combustion engine using hydraulic pressure boosted by rotational driving force of the internal combustion engine. The parking mechanism holds the vehicle stationary by locking, with a locking member, the rotation of a power transmitting member between the internal combustion engine and driving wheels when a shift position is in a parking range. In an automatic stop state of the internal combustion engine, when the shift position is in the parking range and brakes are turned off, an electronic control unit executes restart if an inclination angle of the vehicle is greater than or equal to a predetermined value, and maintains the automatic stop state if the inclination angle is smaller than the predetermined value.

A method for operating a vehicle that includes a DC/DC converter is described. In one example, the method includes adjusting an output voltage of the DC/DC converter to increase torque of a belt integrated starter/generator. The output voltage of the DC/DC converter may be adjusted before and during engine cranking.