In an ignition control device for controlling operation of an ignition apparatus, an ignition section has first and second electrodes disposed in a combustion chamber of an internal combustion engine. A voltage application between the first and second electrodes enables a discharge to be generated between the first and second electrodes for igniting a gas mixture in the combustion chamber. A voltage application section performs at least one application of a determination voltage between the first and second electrodes. An occurrence ratio acquisition section acquires a discharge occurrence ratio at the ignition section for the at least one application of the determination voltage. A comparison section compares the discharge occurrence ratio acquired by the occurrence ratio acquisition section with a predetermined determination threshold to thereby determine a degree of wear of at least one of the first and second electrodes.

An electronic ignition system for an internal combustion engine. The system includes a coil having a primary winding with a first terminal and a second terminal and a secondary winding connected to a spark plug. A high voltage switch is serially connected to the primary winding. A control terminal carries a control signal to control the opening or closing of the high voltage switch. A first switch is interposed between a battery voltage and the first terminal of the primary winding, a second switch is interposed between the first terminal of the primary winding and a reference voltage, a third switch is interposed between the second terminal of the primary winding and said reference voltage. A driving unit is configured to generate signals to control the switches during a charging phase, during a transfer of energy phase, and during a measure phase of ionization current.

A method for extracting characterizing features from an ion current trace retrieved from spark plugs of cylinders of an internal combustion engine, comprises the steps of: i. dividing the ion current signal into crank angle subintervals; 5 ii. calculating a measure of ion current in each crank angle subinterval; and iii. Performing a calculation on the measure of ion currents from different subintervals such that the result of the calculation is dimension free. Further it relates to a method of monitoring combustion processes where a plurality of ion current signals from a number of spark plugs (4A, 4B) are 10 retrieved and used in combination.

A method for controlling the operation of a spark ignition internal combustion engine is described. The engine includes: a combustion chamber, an intake duct for placing the combustion chamber in communication with the external, a throttle valve arranged inside the intake duct, a carburetor for introducing fuel into the intake duct to form an air/fuel mixture to be intaken into the combustion chamber, and a spark plug arranged inside the combustion chamber to generate a spark for igniting the combustion of the air/fuel mixture. The method includes: monitoring the opening degree of the throttle valve; monitoring the speed of the engine, preventing the spark plug from generating the spark, if the opening degree of the throttle valve drops below a first opening degree threshold value and the speed of the engine is greater than a first engine speed threshold value.

A method for extracting characterizing features from an ion current trace retrieved from spark plugs of cylinders of an internal combustion engine, comprises the steps of: i. dividing the ion current signal into crank angle subintervals; ii. calculating a measure of ion current in each crank angle subinterval; and iii. Performing a calculation on the measure of ion currents from different subintervals such that the result of the calculation is dimension free. Further it relates to a method of monitoring combustion processes where a plurality of ion current signals from a number of spark plugs (4A, 4B) are retrieved and used in combination.

A method and a device for operating a combustion engine which features an injection of a cooling fluid into a combustion chamber of the combustion engine, in which a knocking risk is determined during a current combustion in the combustion chamber, and an injection of the cooling fluid into the combustion chamber takes place when the knocking risk exceeds a threshold value.

A GDCI engine control system includes a heated catalyst in an engine exhaust port that is in close proximity to a combustion chamber and is used to heat rebreathed exhaust gases. The engine more quickly reaches operating temperatures, and emissions are reduced during cold running.

An ionization detector that reduces the filtering effects of the ignition coil inductances by shorting an inductance of a primary winding of the ignition coil. The ionization detector includes a bias voltage source and an inductance control switch. The bias voltage source supplies electric voltage across an electric gap of a spark plug for detecting ionization within the combustion chamber. The inductance control switch is electrically parallel with a primary winding of an ignition coil and is operable to short an inductance of the primary winding.

A system and method is provided for the use of the ion current signal characteristics for onboard cycle-by-cycle, cylinder-by-cylinder measurement. The system may also control the engine operating parameters based on a predicted NOx emission level, CO emission level, CO.sub.2 emission level, O.sub.2 emission level, unburned hydrocarbon (HC) emission level, cylinder pressure, or a cylinder temperature measurement according to characteristics of the ion current signal.

A process and a system for preventing pre-ignition in an internal combustion engine (ICE) includes detecting an ionization level of a combusted gas from a cylinder of the ICE during gas exchange and for a given combustion cycle i. When the ionization level is greater than a reference ionization level a pre-ignition countermeasure prior to and/or during an immediate subsequent combustion cycle i+1 is executed. The ionization sensor may be part of a spark initiating device of the ICE or be a separate ionization sensor.