System and method for controlling catalyst storage capacity

• US 6,964,160 B2
• Filed: 03/09/2004
• Issued: 11/15/2005
• Est. Priority Date: 06/20/2001
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Hahn, Stephen L., Lewis, Donald James, Bower, Stanley Larue Jr., Carlstrom, Kevin Ronald
• Primary Examiner(s): NGUYEN, TU MINH
• Application Number:
  US10/797,845
• Publication Number:
  US 20040154286A1
• Time in Patent Office: 616 Days
• Field of Search: 602/74, 602/76, 602/77, 602/85, 123/198.F, 123/481, 701/103, 701/109
• US Class Current: 60/285
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2430/00 Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
• CPC Class Codes: F01N 2430/06 by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 2570/16 Oxygen
• CPC Class Codes: F01N 3/0814 combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• CPC Class Codes: F01N 3/0842 Nitrogen oxides
• CPC Class Codes: F01N 3/20 specially adapted for catalytic conversion F01N3/22 takes precedence; Methods of operation or control of catalytic converters
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/0814 Oxygen storage amount
• CPC Class Codes: F02D 2200/0816 Oxygen storage capacity
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0275 the exhaust gas treating apparatus being a NOx trap or adsorbent
• CPC Class Codes: F02D 41/0295 Control according to the amount of oxygen that is stored on the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/126 transitional corrections at the end of the cut-off period
• CPC Class Codes: F02D 41/1441 Plural sensors
• CPC Class Codes: F02D 41/1446 : the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/1479 : Using a comparator with variable reference
• CPC Class Codes: F02D 41/1487 : Correcting the instantaneous control value
• CPC Class Codes: F02D 41/187 : using a hot wire flow sensor
• CPC Class Codes: F02D 41/2422 : Selective use of one or more tables
• CPC Class Codes: F02M 25/08 : adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003
• CPC Class Codes: F02P 5/1502 : using one central computing unit
• CPC Class Codes: F02P 5/151 : with means for compensating the variation of the characteristics of the engine or of a sensor, e.g. by ageing
• CPC Class Codes: F02P 5/1514 : with means for optimising the use of registers or of memories, e.g. interpolation
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/40 : Engine management systems

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.

Claims

1. An emission control system of an internal combustion engine, comprising:

an emission control device disposed in an exhaust passage of the internal combustion engine; and

a controller determining an initial oxidant state of said emission control device, said initial oxidant state based on an oxidant state before a previous vehicle shut down; and

adjusting a fuel injection amount into the internal combustion engine based on said initial oxidant state during engine starting.

2. The system of claim 1 wherein said determined initial oxidant storage is based on a shut down time.

3. The system of claim 1 wherein said determined initial oxidant storage is based on temperature of said emission control device.

4. The system of claim 1 wherein said determined initial oxidant storage amount is based on a time constant.