Conclusions

• TFS-based pneumatics library:
  • usually works directly
    • in case of instability add auxiliary pipes
  • more accurate results
    • dynamic pressure changes missing in crude MFL version
  • more detailed tee branch components
    • change results only marginally
    • generally reduce stability
• Using OpenModelica:
  • introduced additional problems with MFL version
  • with PneuBibTFS no differences to Dymola
    • enhanced OpenModelica simulator
    • TFS models much simpler for simulator
• Enhancement of tank model:
  • more realistic: use one tank port in both flow directions
  • possible due to TFS enhancement for bidirectional flows
  • open questions
    • significantly better results?
    • stability?
• Problem of stability:
  • cause
    • MFL: nonlinear equations
    • TFS: unstable differential equations
  • probably related
  • open questions
    • mathematical analysis of instability
    • mechanism of stabilization through pipes
• Initialization problem:
  • in MFL still open (Drente, Junglas 2015)
  • in TFS solved (at least for pneumatics networks)