A closed-loop digital system for the control of diesel engine timing has been investigated both experimentally and theoretically. The optimizing control system continuously searches for maximum brake torque (MBT) fuel injection timing, or a timing advanced or retarded a pre-determined amount from MBT. It utilizes peak seeking logic in which the injection timing is continuously dithered (alternately advanced and retarded by small amounts) and corrected in accordance with engine speed changes resulting from the dithering. Two types of optimizing control are discussed: time-based and crankangle-based. The time-based control operates at fixed dither frequency. The system used in the experimental tests was a time-based control system. With the crankangle-based control, dithering is synchronized to engine rotation. Thus, the dither frequency varies with engine speed.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 245-272

Subject/Index Terms

Filing Info

  • Accession Number: 00393100
  • 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