摘要:
A vapor canister of an evaporative emissions (EVAP) system is configured to store fuel vapor evaporated from a liquid fuel housed in a fuel tank of a vehicle. A boost line is connected between a high-pressure side of a boost system of an engine and the vapor canister, a boost pressure control valve is disposed in-line along the boost line and configured to control an amount of boost pressure provided to the vapor canister, and a set of purge lines are connected between the vapor canister and at least one of the engine, an induction system of the engine, and an exhaust treatment system of the engine. A controller is configured to control the boost pressure control valve to control the boost pressure provided to the vapor canister to control an amount of fuel vapor forced from the vapor canister through at least one of the set of purge lines.
摘要:
An evaporative emissions (EVAP) control system for a vehicle includes a purge pump configured to pump fuel vapor trapped in a vapor canister to an engine of the vehicle via a vapor line when engine vacuum is less than an appropriate level for delivering fuel vapor to the engine, the fuel vapor resulting from evaporation of a liquid fuel stored in a fuel tank of the engine. The EVAP control system includes a hydrocarbon (HC) sensor disposed in the vapor line and configured to measure an amount of HC in the fuel vapor pumped by the purge pump to the engine via the vapor line. The EVAP control system also includes a controller configured to, based on the measured amount of MC, control at least one of the purge pump and a purge valve to deliver a desired amount of fuel vapor to the engine.
摘要:
A diagnostic system and method for diagnosing the performance of a particulate matter (PM) filter of an exhaust system each involve receiving, by a controller from at least one sensor, a gas component measurement of exhaust gas flowing through the exhaust system and the PM filter. The controller calculates a conversion efficiency of the gas component by the PM filter and compares the calculated conversion efficiency to a predetermined conversion efficiency threshold indicative of an expected conversion efficiency of a flow-through catalyst. The controller then determines whether the PM filter is cracked or damaged based on the comparison between the calculated conversion efficiency and the predetermined conversion efficiency threshold.
摘要:
A catalyst degradation detection method for use with a zero ceria catalyst. The method uses techniques to measure transient responses to engine control events of upstream and downstream sensors to determine catalyst degradation and performance. By measuring transient behavior, the method can determine catalyst degradation and performance based on the limited oxygen storage of precious metal catalysts that do not include added ceria or other materials with high oxygen capture rates.
摘要:
Ignition timing for a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the ignition timing in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the ignition timing is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the ignition timing.
摘要:
A vapor canister of an evaporative emissions (EVAP) system is configured to store fuel vapor evaporated from a liquid fuel housed in a fuel tank of a vehicle. A boost line is connected between a high-pressure side of a boost system of an engine and the vapor canister, a boost pressure control valve is disposed in-line along the boost line and configured to control an amount of boost pressure provided to the vapor canister, and a set of purge lines are connected between the vapor canister and at least one of the engine, an induction system of the engine, and an exhaust treatment system of the engine. A controller is configured to control the boost pressure control valve to control the boost pressure provided to the vapor canister to control an amount of fuel vapor forced from the vapor canister through at least one of the set of purge lines.
摘要:
An evaporative emissions (EVAP) control system for a vehicle includes a purge pump configured to pump fuel vapor trapped in a vapor canister to an engine of the vehicle via a vapor line when engine vacuum is less than an appropriate level for delivering fuel vapor to the engine, the fuel vapor resulting from evaporation of a liquid fuel stored in a fuel tank of the engine. The EVAP control system includes a hydrocarbon (HC) sensor disposed in the vapor line and configured to measure an amount of HC in the fuel vapor pumped by the purge pump to the engine via the vapor line. The EVAP control system also includes a controller configured to, based on the measured amount of HC, control at least one of the purge pump and a purge valve to deliver a desired amount of fuel vapor to the engine.
摘要:
A system and method for utilizing fuel as an on-board reductant for selective catalytic reduction of NOx is provided and includes a controller for controlling an engine to produce a lean first exhaust stream and a rich second exhaust stream that are received in respective first and second passageways of a dual path aftertreatment system. The rich second exhaust stream reacts with NOx stored in a NOx storage and reduction catalyst of the second passageway to regenerate this catalyst and generate ammonia. The first exhaust stream and the second exhaust stream having the generated ammonia are combined in a downstream common passageway to form a combined lean exhaust gas stream where the ammonia carried therein is stored or used by an SCR catalyst of the common passageway for NOx reduction. The engine is subsequently controlled to produce a rich first exhaust stream and a lean second exhaust stream.
摘要:
A diagnostic system and method for diagnosing the performance of a particulate matter (PM) filter of an exhaust system each involve receiving, by a controller from at least one sensor, a gas component measurement of exhaust gas flowing through the exhaust system and the PM filter. The controller calculates a conversion efficiency of the gas component by the PM filter and compares the calculated conversion efficiency to a predetermined conversion efficiency threshold indicative of an expected conversion efficiency of a flow-through catalyst. The controller then determines whether the PM filter is cracked or damaged based on the comparison between the calculated conversion efficiency and the predetermined conversion efficiency threshold.
摘要:
Ignition timing for a combustion engine may be controlled by determining the roughness of current engine operation, comparing the determined roughness with a control roughness to determine if the determined roughness is within a threshold limit of the control roughness, and changing the ignition timing in a subsequent fuel delivery event as a function of the difference between the determined roughness and the control roughness. Preferably, the ignition timing is changed at least when the determined roughness is not within the threshold limit, although other factors may be taken into account when changing the ignition timing.