A control for an internal combustion engine by pressure ratio management. The ratio of combustion chamber pressure to motored pressure is determined for several predetermined crankshaft rotational angles. These pressure ratios are used to control ignition timing for MBT, diluent gas flow rate (EGR) and...http://www.google.de/patents/US4622939?utm_source=gb-gplus-sharePatent US4622939 - Engine combustion control with ignition timing by pressure ratio management
