摘要:
A system and method for adjusting fuel vapor delivery from a fuel vapor recovery system in an internal combustion engine. A requested amount of fuel vapor delivery is determined based upon a desired fuel vapor delivery amount and various system constraints, which ensure continued optimal operation of the vehicle. Purge fuel ratios are calculated by comparing desired levels to actual levels of various operating parameters. The purge fuel ratios are compared to each other to determine the minimum value from among the various purge fuel ratios, which is indicative of the most limiting system constraint. The most limiting system constraint is used to calculate an amount of fuel vapor to be delivered from the vapor recovery system.
摘要:
An air/fuel control system (8) and method for an engine (28) having two engine banks coupled to a single catalytic converter (50) uses first and second exhaust gas oxygen sensors (44, 55) coupled to respective first and second exhaust manifolds (56, 57) and various engine operating parameters. During a first set of engine operating conditions, air/fuel control system (8) maintains the exhaust air/fuel ratio oscillations of the two bank in phase with one another. During a second set of engine operating conditions, air/fuel control system (8) maintains the exhaust air/fuel ratio oscillations of the two bank 180 degrees out of phase with one another. When transitioning, emission impacts are minimized.
摘要:
A method for enacting DFSO in a motor vehicle having an engine and a transmission. The method includes, during a condition of normal engine-braking efficiency, disabling the DFSO below a higher gear of the transmission. During a condition of reduced engine-braking efficiency, by contrast, the DFSO is disabled below a lower gear of the transmission.
摘要:
Systems and methods for supplying air to an engine are disclosed. In one example, an air inlet throttle is at least partially closed in response to a change in engine torque request. In another example, the air inlet throttle is adjusted in conjunction with adjusting an engine throttle. The approach can reduce compressor noise and may reduce the possibility of compressor surge.
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:
A method for determining degraded valve operation. According to the method, valve degradation can be determined from the duration of a spark event. This method allows for the determination of both intake and exhaust valve degradation.
摘要:
A method and system are disclosed for controlling a vehicle. The method includes adjusting a first actuator to increase vehicle stability during vehicle traveling conditions, the actuator adjusted in response to a vehicle acceleration sensor. The method also includes adjusting a second actuator to maintain vehicle position during stopped vehicle conditions on an inclined surface, the second actuator adjusted in response to the vehicle acceleration sensor.
摘要:
A system and method are disclosed for regulating engine idle speed by coordinating control of two actuators: a slow actuator and a fast actuator. The slow actuator is preferably a throttle valve and the fast actuator is preferably an ignition system affecting spark timing. The slow actuator is controlled based on an idle power requirement and the target idle speed; whereas the fast actuator is controlled based on the idle power requirement and the actual idle speed. Additionally, control of the two actuators is further based on a desired power reserve and an actual power reserve. Power reserve is related to the ratio of the power produced by the engine and the power that would be produced by the engine if the faster actuator were at its optimal setting.
摘要:
A method is presented for diagnosing a condition in the fuel vapor purge system. The engine, the fuel tank and the carbon canister are connected in a three-way connection. The engine can be selectively isolated by a purge control valve, and the fuel tank can be selectively isolated by a fuel tank control valve. The operation of both valves is coordinated by an electronic engine controller. By isolating the fuel tank, and comparing the actual rate of change of the internal tank pressure (from the tank pressure sensor) to the estimated rate of change (from engine operating conditions) it is possible to determine if a condition occurred, and whether it is in the tank or in the vapor purge lines.
摘要:
A method and system for controlling the fuel mass to be delivered to an individual cylinder of an internal combustion engine during engine transients caused by intake control device transitions. The method and system compensates for fuel transport dynamics and the actual fuel injected into the cylinder. A plurality of engine parameters are sensed, including cylinder air charge. An initial base desired fuel mass is determined based on the plurality of engine parameters. An initial transient fuel mass is also determined based on prior injection history which, in turn, is modified based on the transition of the intake control device for that cylinder. A desired injected fuel mass to be delivered to the cylinder is determined based on the initial base desired fuel mass and the initial transient fuel mass. These same calculations are then used to compensate for changes to the base desired fuel mass while the fuel injection is in progress, resulting in an updated desired injected fuel mass. Finally, the injection history for that cylinder is updated to account for the actual desired fuel mass delivered to the cylinder.