System for air-fuel ratio control
AssigneeFord Global Technologies, LLC
InventorsGopichandra Surnilla, Salomone Castro
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Abstract
A system and a method of controlling an engine during and after a temporary fueling shut-off during idling, deceleration or a switch to auxiliary power generating device is presented. According to this method, maintaining power to the heater of an exhaust gas sensor during the temporary shut-off, and thus keeping the sensor operational shortly following resumption of fueling can eliminate a delay in closed loop air-fuel ratio control. This method provides improvements to fuel economy and emission control.
Claims25
A method of controlling an internal combustion engine having a sensor disposed in an exhaust manifold connecting the engine and an exhaust gas aftertreatment device, the method comprising:
- starting the engine;
- performing closed loop air-fuel ratio control after a first set of operating conditions has been met;
- stopping the engine;
- subsequently restarting the engine;
- and
- performing closed loop air-fuel ratio control after a second set of operating conditions different from said first set of operating conditions has been met.
A system for controlling an engine in a vehicle, the engine having an exhaust gas aftertreatment device coupled downstream of it, the system comprising:
- a sensor, comprising a heater, providing a signal indicative of an air-fuel ratio of an exhaust gas mixture entering the device;
- a controller supplying power to said heater, providing a first indication that a first set of operating conditions has been met, and in response to said first indication adjusting an amount of fuel into the engine based on said sensor signal, discontinuing supply of fuel to the engine, maintaining power to said heater, resuming supply of fuel to the engine, providing a second indication that a second set of operating conditions different from said first set of operating conditions has been met, and in response to said second indication adjusting said amount of fuel of fuel into the engine based on said sensor signal.
Dependencies are inferred from the claim text.