Apparatus and method for controlling air/fuel ratio using ionization measurements

An air/fuel ratio control system for an internal combustion engine to reduce emissions and increase engine efficiencies comprising:

• an ionization apparatus for measuring ionization within a combustion chamber of the engine and generating an ionization signal based upon the ionization measurements;
• an air/fuel ratio controller coupled to the ionization apparatus and controlling the air/fuel ratio in the combustion chamber based upon the ionization signal;
• and
• an exhaust gas recirculation system coupled to the controller, wherein the controller further controls an exhaust gas recirculation level based upon a second local peak in the ionization signal.

A method for reducing emissions and increasing engine efficiencies in an internal combustion engine comprising:

• detecting ionization within a combustion cylinder of the engine with an ionization apparatus;
• generating an ionization signal with the ionization apparatus based upon the ionization detection;
• and
• adjusting an air/fuel mixture injected into the cylinder based upon at least one of (i) substantially maximizing a first local peak in the ionization signal and (ii) a second local peak in the ionization signal.

A method for reducing emissions and increasing engine efficiencies in an internal combustion engine comprising:

• detecting ionization within a combustion cylinder of the engine with an ionization apparatus;
• generating an ionization signal with the ionization apparatus based upon the ionization detection;
• and
• adjusting an air/fuel mixture injected into the cylinder based upon comparing a first local peak of the ionization signal of a first cylinder with a first local peak of an ionization signal of a second cylinder.