Methods and systems for an exhaust oxygen sensor operation
AssigneeFord Global Technologies, LLC
InventorChris Paul Glugla
Life of this patent
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Abstract
Methods and systems are provided for activating a universal exhaust gas oxygen (UEGO) sensor activation during each of a pre-delivery phase and a post-delivery phase of a vehicle. In one example, a method may include during the pre-delivery phase, following an engine start, using a lower current flowing via a heater coupled to the UEGO sensor to heat the UEGO sensor and during the post-delivery phase, following an engine start, once exhaust temperature reaches a threshold temperature, using a higher current flowing via the heater coupled to the UEGO sensor to heat the UEGO sensor.
Claims18
A method, comprising:
- during a vehicle pre-delivery phase,
- feed-back controlling an oxygen sensor heater element to a set-point temperature with a first, lower gain, and maintaining spark timing independent of exhaust temperature;
- and
- during a vehicle post-delivery phase,
- feed-back controlling the oxygen sensor heater element to the set-point temperature with a second, higher gain, and responsive to a lower than threshold exhaust temperature, retarding spark timing from maximum brake torque.
A method, comprising:
- during a first engine start while a vehicle is operated in an assembly plant,
- operating an engine with spark at a nominal timing independent of an exhaust temperature, applying a first, lower gain to feedback control of a temperature of an oxygen sensor heater to a set-point temperature, and flowing a first, lower electric current through the oxygen sensor heater until a temperature of the oxygen sensor reaches a threshold-temperature, wherein the first engine start includes one of a hot-start and a cold-start of the engine;
- and
- during a second engine cold-start while the vehicle is operated outside the assembly plant,
- operating the engine with spark timing retarded from the nominal timing until the exhaust temperature exceeds a threshold exhaust temperature, and then applying a second, higher gain to feedback control the temperature of the oxygen sensor heater to the set-point temperature and flowing a second, higher electric current through the oxygen sensor heater until the oxygen sensor temperature reaches the threshold-temperature.
A vehicle system, comprising:
- a vehicle;
- an engine including a cylinder;
- an exhaust system including an exhaust catalyst, an exhaust temperature sensor, an oxygen sensor, and a heater including an electric circuit with a power source and a switch coupled to the oxygen sensor;
- a spark plug coupled to the cylinder;
- a controller with computer readable instructions stored on non-transitory memory for:
- in response to a vehicle key-on event during a vehicle pre-delivery phase at an assembly plant,
- applying a first calibration for heating the oxygen sensor to an activation temperature by applying a first, lower voltage to the electric circuit of the heater to flow a first, lower current through the electric circuit of the heater and by setting a first, lower gain for feedback control of an inferred heater temperature to a set-point temperature;
- and
- in response to a vehicle key-on event during a vehicle post-delivery phase outside the assembly plant,
- applying a second calibration for heating the oxygen sensor to an activation temperature applying a second, higher voltage to the electric circuit of the heater to flow a second, higher current through the electric circuit of the heater and by setting a second, higher gain for feedback control of the inferred heater temperature to the set-point temperature.
Dependencies are inferred from the claim text.