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US 2022/0298979 A1Published application
Valve timing modulation for egr balancing
AssigneeFord Global Technologies, LLC
InventorsBrien Lloyd Fulton, Michiel J. Van Nieuwstadt
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for increasing EGR delivered to an engine. In one example, a method may include determining an EVO timing set point and an external EGR setpoint in parallel, based on an inverse model. The EVO timing may be adjusted based on a combination of the EVO timing setpoint and an EGR cylinder balancing feedback loop, thereby varying internal EGR to the engine to supplement external EGR.
Claims20
A method comprising:
- determining an exhaust valve opening (EVO) timing setpoint at an engine based on an inverse model, the inverse model continuously updated based on an exhaust gas NOx measurement;
- determining an external exhaust gas recirculation (EGR) setpoint based on the inverse model, the external EGR setpoint determined in parallel with the EVO timing setpoint;
- and
- adjusting an EVO timing based on a combination of the EVO timing setpoint and an EGR cylinder balancing feedback loop.
1 more element
A method for an engine, comprising:
- responsive to an increased demand for EGR at the engine;
- collecting information from engine sensors to determine an amount of EGR delivered to the engine;
- estimating a target EGR setpoint based on the information from the engine sensors via an outer loop of an EGR control system;
- and
- responsive to determination of an EGR shortfall;
- increasing internal EGR via a first closed inner loop of the EGR control system.
3 more elements
An engine, comprising:
- a plurality of cylinders, each cylinder having one or more exhaust valves controlling exhaust flow out of the plurality of cylinders;
- a continuously variable valve lift (CVVL) system configured to adjust an exhaust valve opening (EVO) timing of the one or more exhaust valves, wherein the EVO timing is adjusted based on a combination of an EVO timing setpoint determined from an inverse model and an EGR cylinder balancing feedback loop;
- one or more throttles controlling air flow to the plurality of cylinders;
- one or more of a low pressure (LP)-EGR system and a high pressure (HP)-EGR system, each of the LP-EGR system and the HP-EGR system configured to return exhaust gases to the plurality of cylinders through external passages of the engine;
- a compressor arranged in a path of the air flow to the plurality of cylinders;
- and
- a controller configured with executable instructions stored in non-transitory memory which, when executed, cause the controller to:
- balance EGR delivery amongst one or more of adjustment of the EVO timing via the CVVL system, adjustment of a LP-EGR valve position, adjustment of a HP-EGR valve position, and adjustment of a position of the one or more throttles when an EGR shortfall is detected by a nested control system configured to control EGR delivery to the engine.
5 more elements
Dependencies are inferred from the claim text.