Method and apparatus for controlling emissions from internal combustion engines

A method of controlling an internal combustion engine during a steady state operation, the internal combustion engine having at least one combustion chamber, an exhaust manifold and at least one exhaust valve for selectively fluidly connecting the at least one combustion chamber with the exhaust manifold, the method comprising:

• causing a first combustion event in at least one cylinder, the first combustion event having at least one combustion characteristic;
• actuating at least one exhaust valve to provide a first exhaust gas pressure in the exhaust manifold by transferring exhaust gas from the at least one cylinder to the exhaust manifold;
• using the first exhaust gas pressure to achieve a first desired level of a first emission parameter during a second combustion event, the second combustion event having the at least one combustion characteristic;
• adjusting the at least one combustion characteristic between the first and second combustion events;
• causing the second combustion event in the at least one cylinder;
• actuating the at least one exhaust valve to transfer exhaust gas from the at least one cylinder to the exhaust manifold to change the first exhaust gas pressure to a second exhaust gas pressure in the exhaust manifold;
• repeating the first combustion event and the second combustion event, wherein repeating the first and second combustion events includes repeatedly modifying an amount of exhaust gas transferred into the at least one cylinder using the first or second exhaust gas pressure by changing the at least one combustion characteristic;
• and
• using the second exhaust gas pressure to achieve a first desired level of a second emission parameter during the first combustion event.

An internal combustion engine, comprising:

• a plurality of combustion chambers;
• at least one exhaust manifold and at least one exhaust valve for each of the plurality of combustion chambers configured to selectively fluidly connect each of the plurality of combustion chambers with the at least one exhaust manifold;
• a fuel arrangement;
• and
• at least one controller configured to:
• run a first cycle, the first cycle including:
• injecting fuel into at least one of the plurality of combustion chambers in accordance with at least one first injection parameter;
• combusting the fuel thereby creating exhaust gas;
• opening at least one exhaust valve to transfer exhaust gas from at least one of the plurality of combustion chambers to the at least one exhaust manifold, thereby influencing a first exhaust gas pressure in the exhaust manifold;
• and
• enabling a transfer of exhaust gas from the exhaust manifold to at least one of the plurality of combustion chambers, using the first exhaust gas pressure to achieve a first desired level of at least one emission parameter during a combustion event;
• and configured to
• run a second cycle, the second cycle including:
• injecting fuel into at least one of the plurality of combustion chambers in accordance with at least one second injection parameter different from the at least one first injection parameter;
• combusting the fuel thereby creating exhaust gas;
• opening at least one exhaust valve to transfer exhaust gas from at least one of the plurality of combustion chambers to the at least one exhaust manifold, thereby influencing a second exhaust gas pressure in the exhaust manifold different from the first exhaust gas pressure;
• and
• enabling a transfer of exhaust gas from the exhaust manifold to at least one of the plurality of combustion chambers, using the second exhaust gas pressure to achieve a second desired level of at least one emission parameter during a combustion event;
• and configured to
• repeat the first and second cycles, while repeatedly modifying an amount of exhaust gas transferred into the at least one combustion chamber by changing to the respective at least one first or second injection parameter.

An internal combustion engine, comprising:

• a plurality of combustion chambers;
• at least one exhaust manifold and at least one exhaust valve for each of the plurality of combustion chambers configured to selectively fluidly connect each of the plurality of combustion chambers with the at least one exhaust manifold;
• a fuel arrangement;
• and
• at least one controller configured to:
• cause a first combustion event in at least one cylinder, the first combustion event having at least one combustion characteristic;
• actuate at least one exhaust valve to provide a first exhaust gas pressure in the exhaust manifold by transferring exhaust gas from the at least one cylinder to the exhaust manifold;
• use the first exhaust gas pressure to achieve a first desired level of a first emission parameter during a second combustion event, the second combustion event having the at least one combustion characteristic;
• adjust the at least one combustion characteristic between the first and second combustion events;
• cause the second combustion event in the at least one cylinder;
• actuate the at least one exhaust valve to transfer exhaust gas from the at least one cylinder to the exhaust manifold to change the first exhaust gas pressure to a second exhaust gas pressure in the exhaust manifold;
• repeat the first combustion event and the second combustion event, while repeatedly modifying an amount of exhaust gas transferred into the at least one cylinder using the first or second exhaust pressure by changing the at least one combustion characteristic;
• and
• use the second exhaust gas pressure to achieve a first desired level of a second emission parameter during the first combustion event.

A method of controlling an internal combustion engine, the internal combustion engine having a plurality of combustion chambers, and at least one exhaust valve for each of said plurality of combustion chambers, the method comprising:

• running a first cycle, the first cycle including:
• injecting fuel into at least one of the plurality of combustion chambers in accordance with at least one first injection parameter,
• combusting the fuel thereby creating exhaust gas, and
• enabling a transfer of exhaust gas having a first exhaust gas pressure to at least one of the plurality of combustion chambers to achieve a first desired level of at least one emission parameter during a combustion event;
• running a second cycle, the second cycle including:
• injecting fuel into at least one of the plurality of combustion chambers in accordance with at least one second injection parameter different from the at least one first injection parameter,
• combusting the fuel thereby creating exhaust gas, and
• enabling a transfer of exhaust gas having a second exhaust gas pressure to at least one of the plurality of combustion chambers to achieve a second desired level of the at least one emission parameter during a combustion event, the first exhaust gas pressure being different from the second exhaust gas pressure;
• and
• repeating the first and second cycles in an alternating manner, wherein repeating the first and second cycles includes repeatedly modifying an amount of exhaust gas transferred into the at least one combustion chamber by changing to the respective at least one first or second injection parameter.