System and method for controlling catalyst storage capacity
AssigneeFord Global Technologies, LLC
InventorsDonald James Lewis, Kevin Ronald Carlstrom, Stanley Larue Bower, Stephen Hahn
Life of this patent
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Abstract
The invention relates to a new method and system for optimizing the efficiency of an automotive catalytic converter by adjusting the engine air/fuel ratio based on estimates of the actual amount of oxidants stored in the catalyst. The oxidant storage capacity of the catalyst is adjusted by controlling engine spark in response to an estimate of a current amount of oxidants stored in the catalyst and an estimate of the total available oxidant storage capacity of the catalyst. To maintain engine speed in spite of adjustments to the engine spark, the engine air mass is also adjusted.
Claims14
In an internal combustion engine coupled to an exhaust system having a catalyst, a method of adjusting an oxidant storage capacity of the catalyst, comprising:
- estimating a current amount of oxidants stored in the catalyst;
- estimating an amount of oxidant storage available in the catalyst;
- comparing said estimated amount of oxidants stored in the catalyst to said estimated amount of oxidant storage available;
- adjusting an engine operating parameter in response to said comparison to affect a temperature of the catalyst and obtain a desired temperature.
6-12. (canceled)
A system for adjusting an air/fuel ratio in the cylinders of an internal combustion engine coupled to an exhaust system, comprising:
- a catalyst positioned in the exhaust stream;
- and
- a controller for estimating an actual amount of oxidants stored in said catalyst, comparing said actual oxidant amount to a target amount of oxidants stored in the catalyst, adjusting an amount of fuel provided to the cylinders based on said comparision, and adjusting an engine operating parameter in response to said comparison to obtain a desired temperature of the catalyst and thereby adjust an oxidant storage capacity of the catalyst.
In an internal combustion engine coupled to an exhaust system having a catalyst, a method of adjusting an oxidant storage capacity of the catalyst, comprising:
- adjusting a fuel injection amount in response to maintain an desired amount of oxidants actually stored in the catalyst relative to the oxidant storage capacity of the catalyst and thereby providing an available oxidant storage;
- and
- adjusting an engine operating parameter other than said fuel injection in response to said available oxidant storage to affect a temperature of the catalyst and obtain a desired temperature, thereby adjusting the oxidant storage capacity of the catalyst.
In an internal combustion engine coupled to an exhaust system having a catalyst, a method of adjusting an oxidant storage capacity of the catalyst, comprising:
- estimating a current amount of oxidants stored in the catalyst;
- estimating an amount of oxidant storage available in the catalyst;
- comparing said estimated amount of oxidants stored in the catalyst to said estimated amount of oxidant storage available;
- adjusting a fuel injection amount in response to said comparison;
- and
- adjusting an engine operating parameter in response to said comparison to obtain a desired temperature of the catalyst and thereby adjust the oxidant storage capacity of the catalyst.
Dependencies are inferred from the claim text.