An internal combustion engine comprises a number of cylinders (usually four, arranged in line) provided with respective pistons connected to a cranked crankshaft by means of connecting rods; the shaft of an electric starter motor, which is powered by a battery of the motor vehicle, is also connected mechanically to the crankshaft of the internal combustion engine. In order to start the internal combustion engine, the electric motor sets the crankshaft in rotation from an initial position in which said crankshaft is stationary; as soon as the crankshaft begins to rotate, fuel is injected (directly or indirectly) into the cylinders in order to attempt to achieve a first explosion in the shortest possible time and so enable the internal combustion engine to become self-sustaining.
The “stop-and-start” mode provides for the internal combustion engine to be turned off when the vehicle is at rest or nearly stopped (typically for reasons associated with traffic, such as a red traffic light or a junction that does not have priority) and for the internal combustion engine to be restarted as soon as the driver presses on the accelerator.
During the starting phase, a considerable amount of electrical energy is consumed by the electric starter motor, which consequently places a great load on and entails considerable loss of electric charge in the battery of the motor vehicle. Obviously, when “stop-and-start” mode is activated, the battery of the motor vehicle is subjected to intensive use due to the high frequency at which the internal combustion engine is started, particularly when the motor vehicle is being driven in urban traffic.
US2003224902A1 discloses a method for automatic operation of a vehicle comprising an engine, a starter motor, an engine clutch, and a plurality of vehicle systems. After detecting that the engine is running, the vehicle systems are checked to ensure an acceptable status for shutting down the engine. A negative torque is applied to the engine to shut it down. Vehicle systems are monitored until they indicate that the engine should be restarted. The engine is restarted, and a successful start of the engine is then confirmed. Similarly, there is provided a method for the cold start of a vehicle as above. The starter motor is powered up with an initial torque and vehicle systems are monitored to determine whether the engine should be started. The engine is started from the torque of the starter motor, and a successful start of the engine is then confirmed.
US6358180B1 discloses an engine control system, which reduces driver's feeling of unease relating to the operation of driving a vehicle which is idle-controlled so as to reduce the exhaust gas discharge, thereby improving the driving operability. The method comprising the steps of detecting a switch of the driving mode of the vehicle from a first normal driving range to a second normal driving range different from the first normal driving range; detecting whether the engine is currently in a stopped state due to an automatic stop operation; detecting whether a brake for stopping the vehicle is currently being operated; and automatically starting the engine if it is determined that the engine is currently in a stopped state due to the automatic stop operation, and that the driving mode has been switched to the second normal driving range, and that the brake is not currently being operated.
JP10325346A1 discloses an automatic stop/start device of an internal combustion engine for a vehicle to prevent the engine from being not restarted because of shortage of a charged amount by controlling the automatic stop of the engine based on the detected value of the charged amount of a battery for supplying electricity to a starting dinamo-electric machine and the other auxiliaries and the estimated value of electric energy required to drive the auxiliaries for predetermined period.
JP06257482A1 discloses an automatic start/stop device for an internal combustion engine to surely prevent battery exhaustion by means of a simple and inexpensive constitution by detecting a current consumer in a vehicle and controlling to start an engine when the current consumer is generated during an engine stop so as to correspond to an alteration of program. A control part controls the engine so that it starts when a current consumer is generated while the engine stops; in this way, exhaustion of a battery can be surely prevented by means of simple and inexpensive constitution.