A real-time Driver/Vehicle Model, incorporating analog electronics on an engine dynamometer, was developed to allow accurate transient calibration of an experimental engine/transmission and its digital controller. The engine spark advance control system, divorced from engine vacuum and fuel-driven by the Engine Air Control (EAC) system demonstrated significantly reduced interaction and coupling with engine air-fuel ratio. This hierarchial EAC-spark advance structure has been shown to be amenable to simultaneous controller/control law optimization for maximum vehicular fuel economy within specified emission constraints during the cold-start FTP driving schedule. The EAC structure was shown to enable the adaptive phasing of engine airflow to fuel flow. Significantly large and variable fuel delays were identified throughout cold-start, warmup and hot engine transients. The EAC air valve, adaptively delayed as a function of engine coolant temperature, transformed this engine (which at cold-start, 17:1 air-fuel ratio, would hesitate, sag and/or stall) to one which would perform relatively crisply under like FTP driving schedule conditions.

  • Supplemental Notes:
    • Prepared for the SAE meeting February 27-March 3, 1978.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Stivender, D L
  • Publication Date: 1978

Media Info

  • Features: References;
  • Pagination: 34 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00177341
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: SAE 780346 Proceeding
  • Files: TRIS
  • Created Date: Sep 27 1978 12:00AM