A PRELIMINARY STUDY OF ACTIVELY CONTROLLED AIR CUSHION VEHICLE SUSPENSIONS

The primitive vehicle suspension system coupling a simple vehicle model in point contact with a two-dimensional guideway having random irregularities is defined. The optimum linear suspension which minimizes a linear combination of vehicle heave acceleration (passenger comfort) and suspension-guideway displacement (suspension excursion) is synthesized using Weiner-Hopf filter theory. The mechanics of flexible base externally pressurized air cushion vehicle suspensions are discussed, including the use of a feedback control flow into the cushion region. The required form of control law to make the fluid suspension dynamically identical to the primitive optimum suspension is determined and the corresponding mean square control flow calculated. By properly selecting the suspension capacitance the control flow can be limited to a moderate fraction of the suspension equilibrium flow. Compared with optimized flexible base suspensions, heave accelerations are lowered by about 2.7 times through the use of optimum feedback control. An exploratory experimental program using a small scale rigid plenum suspension with electropneumatic valve modulated control flow is described. The results show that significant improvements in system dynamic response are possible with control flows of only 15 per cent of the equilibrium suspension flow. In a design example several suspension systems are designed for a full-scale hypothetical vehicle for 300 mph operation and comparison made between rigid plenum and flexible base suspensions with and without active control. (Author)

  • Corporate Authors:

    Massachusetts Institute of Technology

    Engineering Projects Laboratory
    Cambridge, MA  USA 
  • Authors:
    • Hullender, D A
    • Wormley, D N
    • Richardson, H H
  • Publication Date: 1970-6-15

Media Info

  • Pagination: 161 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00039209
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: EPL-70-76110-11 Tech Rpt, DSR-76110-11
  • Contract Numbers: C-85-65t
  • Files: TRIS
  • Created Date: Nov 24 1973 12:00AM