CLOSED LOOP CONTROL OF INTERNAL COMBUSTION ENGINE EXHAUST EMISSIONS

Automotive engine emissions have been shown to be sensitive to changes in engine control variables. One of the most important variables is the fuel-air ratio (f/a) which is initially maintained by today's carburetors to about 3-5% but degrades with time. This research investigated several different sensors to be used in the exhaust for measurements of the f/a and investigated closed-loop control techniques for maintaining better accuracies of the f/a. Of the three sensors tested, a zirconia device which measures oxygen in the exhaust was found to have the most desirable properties from a control standpoint and was used in the f/a controllers. A laboratory engine was equipped with a fuel injector and used to perform studies on the closed-loop controller. It was found that f/a accuracies of 1% or less were readily achievable in the presence of conceivable disturbances.

• Corporate Authors:

  Stanford University

  Department of Aeronautics and Astronautics
  Stanford, CA  United States  94305

  Department of Transportation

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Powell, J D
  • HUBBARD, M
• Publication Date: 1974-2

Media Info

• Pagination: 68 p.

Subject/Index Terms

• TRT Terms: Accuracy; Air quality management; Control; Detectors; Equipment; Feedback control; Flow control (Air traffic control); Fuel air mixtures; Fuel injection; Fuel injectors; Gas detectors; Internal combustion engines; Loops (Control systems); Measuring instruments; Oxygen; Pollutants; Sensors; Vehicle power plants; Zirconium
• Uncontrolled Terms: Air fuel ratio
• Old TRIS Terms: Air pollution control devices; Automobile engines; Flow control
• Subject Areas: Highways; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00090457
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: Final Rpt.
• Contract Numbers: DOT-OS-30111
• Files: NTIS, TRIS, USDOT
• Created Date: May 29 1975 12:00AM