HYBRID COMPUTER SIMULATES FTP

This article describes a method devised by General Motors (GM) engineers to simulate a complete Federal Test Procedure test for automobile exhaust emission and fuel economy in 8 min. The GM computer model exploits hybrid programming: an analog computer handles continuous simulation chores at four times normal speed, while a digital device takes care of computational work, storage, and control. The system gives an efficient simulation of emissions and fuel economy testing sufficiently robust to study effects of varying test procedures, vehicle calibrations, and product mix. It is a simulation of vehicle/driver/dyanmometer interactions in a macroscopic sense, with enough details incorporated to allow reasonable confidence in the model's predictions of absolute values and trends. Comparison of computer simulations and vehicle tests gave an indication of the model's robustness. Vehicle tests, of course, involved the same engine/emission-control configuration used to generate the model's performance maps.

Media Info

  • Pagination: p. 49-53
  • Serial:
    • Automotive Engineering
    • Volume: 86
    • Issue Number: 5
    • Publisher: Society of Automotive Engineers
    • ISSN: 0098-2571

Subject/Index Terms

Filing Info

  • Accession Number: 00183847
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Dec 29 1978 12:00AM