Method for igniting a motor vehicle combustion engine

A non-transitory computer-readable medium on which is stored a set of program code instructions, which, when executed by one or more processors, configure the one or more processors to implement a method for igniting a motor vehicle combustion engine, said method being implemented by an electronic control unit of an ignition circuit of a motor vehicle combustion engine, said ignition circuit including a transformer including a primary coil, a secondary coil, and a spark plug electronically connected to the secondary coil of the transformer, the primary coil being configured to charge and discharge into the secondary coil, a discharge duration of the primary coil being predefined, the spark plug being configured to generate a spark during the discharge of the primary coil into the secondary coil, the method comprising:

• requesting to start a combustion cycle of the combustion engine;
• generating a main spark in a first phase comprising:
• activating charging of the primary coil,
• continuously measuring the current in the primary coil during the charging of the primary coil, and
• deactivating the charging of the primary coil and activating the discharging of the primary coil into the secondary coil for the predefined discharge duration when a measured current value that is received is equal to a predefined reference maximum current value;
• and
• generating at least one subsidiary spark in a second phase after the first phase, the second phase comprising:
• activating the charging of the primary coil for a predefined charging duration,
• measuring a repeat current in the primary coil at the moment of activating the charging of the primary coil in the second phase, and
• determining the difference between the repeat current value and a reference repeat current value, then
• increasing the value of the discharge duration, in a case in which the measured repeat current value is greater than the reference repeat current value, and
• decreasing the value of the discharge duration, in a case in which the measured repeat current value is less than the reference repeat current value,
• continuously measuring the current in the primary coil during the charging of the primary coil, and
• when the measured current value measured during the charging of the primary coil is equal to a predefined reference maximum current value, one of:
• deactivating the charging of the primary coil and activating the discharge into the secondary coil for the increased discharge duration or the decreased discharge duration, and
• deactivating the charging of the primary coil and activating the discharging of the primary coil into the secondary coil for the predefined discharge duration, and requesting to start another combustion cycle of the combustion engine, a second first phase, and a second second phase in which the activation of the discharge into the secondary coil takes place for the increased discharge duration or the decreased discharge duration.

An electronic control unit comprising:

• one or more processors configured to control an ignition circuit of a motor vehicle combustion engine, said ignition circuit comprising a transformer comprising a primary coil and a secondary coil, and a spark plug electronically connected to the secondary coil of the transformer, the primary coil being configured to charge, and configured to discharge into the secondary coil, a discharge duration of the primary coil being predefined, the one or more processors being configured to control the activation and deactivation of the charging of the primary coil and the activation of the discharging of the primary coil into the secondary coil, and configured to receive the value of the current in the primary coil, the one or more processors being configured to
• request to start a combustion cycle of the combustion engine,
• generate a main spark in a first phase comprising:
• activating charging of the primary coil,
• continuously measuring the current in the primary coil during the charging of the primary coil, and
• deactivating the charging of the primary coil and activating the discharging of the primary coil into the secondary coil for the predefined discharge duration when a measured current value that is received is equal to a predefined reference maximum current value, and
• generate at least one subsidiary spark in a second phase after the first phase, the second phase comprising:
• activating the charging of the primary coil for a predefined charging duration,
• measuring a repeat current in the primary coil at the moment of activating the charging of the primary coil in the second phase, and
• determining the difference between the repeat current value and a reference repeat current value, then
• increasing the value of the discharge duration, in a case in which the measured repeat current value is greater than the reference repeat current value, and
• decreasing the value of the discharge duration, in a case in which the measured repeat current value is less than the reference repeat current value,
• continuously measuring the current in the primary coil during the charging of the primary coil, and
• when the measured current value measured during the charging of the primary coil is equal to a predefined reference maximum current value, one of:
• deactivating the charging of the primary coil and activating the discharge into the secondary coil for the increased discharge duration or the decreased discharge duration, and
• deactivating the charging of the primary coil and activating the discharging of the primary coil into the secondary coil for the predefined discharge duration, and requesting to start another combustion cycle of the combustion engine, a second first phase, and a second second phase in which the activation of the discharge into the secondary coil takes place for the increased discharge duration or the decreased discharge duration.