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

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