{
  "$type": "site.standard.document",
  "description": "A method and system for controlling the air/fuel ratio in an internal combustion engine (12) having a first group of cylinders and a second group of cylinders. The first group of cylinders is coupled to a catalyst (20) and at least one oxygen sensor (18,22), which provides a first feedback signal…",
  "path": "/patents/1111414",
  "publishedAt": "2001-07-25T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02D41/1443",
    "FORD GLOBAL TECH INC [US]"
  ],
  "textContent": "A method and system for controlling the air/fuel ratio in an internal combustion engine (12) having a first group of cylinders and a second group of cylinders. The first group of cylinders is coupled to a catalyst (20) and at least one oxygen sensor (18,22), which provides a first feedback signal. The second group of cylinders is coupled to a catalyst (24) and a post-catalyst oxygen sensor (26), which provides a second feedback signal. A controller (202) uses the first and second feedback signals to calculate a short-term air/fuel bias value for the second group of cylinders. The controller (202) also calculates a new long-term air/fuel bias value corresponding to the current engine speed and engine. The new long-term air/fuel bias value is based on a previously-calculated long-term air/fuel bias value calculated for the same engine load and speed. A total air/fuel bias value is calculated based on the short-term air/fuel bias value and the long-term air/fuel bias value. The new long-term air/fuel bias value is stored for future calculations.",
  "title": "Method for controlling air/fuel mixture in an internal combustion engine"
}