Programmed multi-firing and duty cycling for a coil-on-plug ignition system with knock detection

A method for applying multiple high voltage signals to a spark plug of a spark ignition internal combustion engine utilizing an ignition system having a controller, a timing element including at least three timers, a distribution element, a coil-on-plug transformer, and an engine position sensor, said method comprising the steps of:

• sensing the position of the engine;
• providing a position signal to the controller;
• calculating appropriate timing signals based on engine parameters;
• loading the timing signals into the timing element;
• triggering a third timer of the timing element to count-down to a predetermined engine position of the combustion cycle;
• timing-out the third timer at said predetermined engine position;
• triggering a second timer of the timing element at the timing-out of the third timer;
• enabling a first timer of the timing element by the triggering of the second timer, the first timer outputting a continuous series of control signals to the distribution element when enabled;
• distributing the series of control signals to the transformer;
• applying a series of high voltage pulses from the transformer to the spark plug at the predetermined engine position of the combustion cycle;
• timing-out the second timer;
• and
• disabling the first timer at the timing-out of the second timer.

A method for applying multiple high voltage signals to a spark plug of a spark ignition internal combustion engine and utilizing an ignition system to detect the occurrence of auto-ignition in a combustion chamber of the engine, the ignition system including a controller, a timing element having a first timer, a second timer and a third timer, a DC/DC converter, a distribution element, a pulse transformer, an engine position sensor and a discharge circuit, said method comprising the steps of:

• sensing engine position and providing a position signal to the controller;
• determining appropriate timing signals to be used in detecting auto-ignition based on engine parameters;
• loading the timing signals into the timing element;
• triggering the third timer of said timing element to begin a count-down sequence;
• timing-out the third timer at an engine position which corresponds to that portion of the combustion cycle where auto-ignition is likely to occur;
• triggering the second timer at the timing-out of the third timer;
• enabling the first timer at the triggering of the second timer, the first timer outputting a continuous series of controls signals to the distribution element;
• distributing the series of voltage signals from the DC/DC converter and corresponding to the control signals to the transformer;
• applying a series of high voltage pulses to the spark plug from the transformer during that portion of the combustion cycle where auto-ignition is likely to occur;
• monitoring the spark plug for the discharging of at least one high voltage pulse of the series of high voltage pulses across the spark plug;
• signaling the controller upon the detection of the discharging of at least one high voltage pulse across the spark plug;
• timing-out the second timer;
• and
• disabling the first timer at the timing-out of the second timer.