摘要:
Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.
摘要:
Methods and systems are provided for improving engine exhaust emissions while enabling exhaust catalyst regeneration following an engine lean event. Prior to a VDE event, or prior to an engine idle-stop, ammonia is produced and stored on an exhaust underbody SCR catalyst. Then, during the engine restart after the VDE mode or the idle-stop, the stored ammonia is used to treat exhaust NOx species while an upstream exhaust underbody three-way catalyst is regenerated.
摘要:
Methods and systems are provided for improving engine exhaust emissions while enabling exhaust catalyst regeneration following an engine lean event. Prior to a VDE event, or prior to an engine idle-stop, ammonia is produced and stored on an exhaust underbody SCR catalyst. Then, during the engine restart after the VDE mode or the idle-stop, the stored ammonia is used to treat exhaust NOx species while an upstream exhaust underbody three-way catalyst is regenerated.
摘要:
Methods and systems are provided for selecting a group of cylinders for selective deactivation, in a variable displacement engine system, based at least on a regeneration state of an exhaust catalyst. The position of one or more valves and throttles may be adjusted based on the selective deactivation to reduce back-flow through the disabled cylinders while also maintaining conditions of a downstream exhaust catalyst. Pre-ignition and knock detection windows and thresholds may also be adjusted based on the deactivation to improve the efficiency of knock and pre-ignition detection.
摘要:
A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on a time delay and line length of each sample of a set of exhaust gas sensor responses collected during a commanded change in air-fuel ratio. In this way, the exhaust gas sensor may be monitored utilizing robust parameters in a non-intrusive manner.
摘要:
Methods and systems are provided for controlling the automatic shutdown of an idling vehicle engine. When the vehicle is parked in an enclosed space, the idling engine may be automatically shutdown, while when the vehicle is parked in an open space, the automatic shutdown may be delayed based on an ambient temperature. In this way, the vehicle cabin may be maintained at a temperature that provides enhanced driver comfort while allowing wasteful engine idling to be reduced.
摘要:
A system for filtering and oxidizing particulate matter produced by a gasoline direct injection engine is disclosed. In one embodiment, engine cylinder air-fuel is adjusted to allow soot to oxidize at an upstream particulate filter while exhaust gases are efficiently processed in a downstream catalyst.
摘要:
A method for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one embodiment, the method comprises indicating exhaust gas sensor degradation based on characteristics of a distribution of extreme values of a plurality of sets of lambda differentials collected during selected operating conditions. In this way, the exhaust gas sensor may be monitored in a non-intrusive manner.
摘要:
A method of monitoring an exhaust gas sensor coupled in an engine exhaust in an engine is provided. The method includes adjusting engine operation responsive to exhaust gas sensor degradation, the degradation identified during deceleration fuel shut-off (DFSO) and compensated based on whether vapor purge operation is occurring in the engine during DFSO.
摘要:
A method and system for fuel vapor control in a hybrid vehicle (HEV). The HEV fuel vapor recovery system includes a fuel tank isolation valve, which is normally closed to isolate storage of refueling from storage of diurnal vapors. The method for fuel vapor control includes selectively actuating the fuel tank isolation valve during interrelated routines for refueling, fuel vapor purging, and emission system leak detection diagnostics to improve regulation of pressure and vacuum the HEV fuel vapor recovery system.