Patent ID: 10801430

Abstract:
Air to fuel ratio management comprises sensing a power output request for the engine and determining a fuel-efficient air to fuel ratio. A current air to fuel ratio is sensed in one or both of an intake manifold and an exhaust manifold connected to the engine. An air to fuel ratio adjustment is determined based on the fuel-efficient air to fuel ratio and based on the current air to fuel ratio. An in-cylinder exhaust gas recirculation technique is selected. The in-cylinder exhaust gas recirculation technique adjusts an oxygen and particulate content of exhaust gas resulting from combustion. A number of cylinders of the multiple-cylinder engine are selected to implement the in-cylinder exhaust gas recirculation technique. The intake valves and the exhaust valves are controlled to adjust the oxygen and particulate content of the exhaust gas by applying a second compression stroke of the respective reciprocating pistons to the exhaust gas.