Several techniques of closed loop idle speed control have been evaluated within the Ford Motor Company that use both throttle-stop--stepper motor and air by-pass valves with microprocessor "feed forward" and "feed back" control strategies. This paper describes one such application that used an air by-pass valve and the Ford Motor Company's "Electronic Engine Control" (EEC IV) microprocessor. A prime requirement of an Idle Speed Control system is to provide speed stability during changes in load caused by the transition from neutral to drive on an automatic and by steps in load from electrical equipment such as air-conditioning. Although this can be achieved with "Pre-emption" input signals and feed forward, component and wiring loom cost can be reduced by Proportioned Integral feedback alone. This technique places greater emphasis on loop stability, gain and linearity control and the paper describes how the EEC IV development aids were used to optimise the calibration parameters associated with the control strategy. Results are presented in the form of graphic speed responses to step changes in engine load and target speeds together with a summary of microprocessor resources used to implement the control strategy.

Media Info

  • Features: References;
  • Pagination: p. 15-30

Subject/Index Terms

Filing Info

  • Accession Number: 00393088
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: Proceeding, HS-037 234, HS-037 235
  • Files: HSL, USDOT
  • Created Date: Mar 29 1985 12:00AM