1 / 21

Active Steering Project

Active Steering Project. Andrew Odhams Richard Roebuck David Cebon 2 nd April 2009. Contents. Control concept Low speed testing High speed testing Conclusions. ACTIVE STEERING. Lead Point. Follow Point. Controller Low speed High speed Conclusions.

gretel
Download Presentation

Active Steering Project

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Active Steering Project Andrew Odhams Richard Roebuck David Cebon 2nd April 2009

  2. Contents • Control concept • Low speed testing • High speed testing • Conclusions

  3. ACTIVE STEERING Lead Point Follow Point • Controller • Low speed • High speed • Conclusions • Define Lead point and follow point • Calculate articulation angle of a perfect tracking trailer • Steer in relation to difference between real and ideal articulation angle • Set individual wheel angles to equalise tyre forces

  4. PATH FOLLOWING TESTS 11.25m 8.9m 12.5m 5.3m • Controller • Low speed • High speed • Conclusions UK Roundabout Test

  5. LOW SPEED ROUNDABOUT • Controller • Low speed • High speed • Conclusions • Unsteered:

  6. LOW SPEED ROUNDABOUT • Controller • Low speed • High speed • Conclusions • Command Steer:

  7. LOW SPEED ROUNDABOUT Locked Command CVDC • Controller • Low speed • High speed • Conclusions • Offtracking of 5th Wheel:

  8. LOW SPEED ROUNDABOUT CVDC Command Locked • Controller • Low speed • High speed • Conclusions • Offtracking of Trailer Rear:

  9. LOW SPEED ROUNDABOUT • Controller • Low speed • High speed • Conclusions • Tail Swing: Command Locked Path Following • Tail swings into blind spot

  10. LATERAL TYRE FORCES Unsteered: • Controller • Low speed • High speed • Conclusions

  11. LATERAL TYRE FORCES • Controller • Low speed • High speed • Conclusions • Unsteered: • FIXED TRAILER: 36.6 kN

  12. LATERAL TYRE FORCES • Controller • Low speed • High speed • Conclusions • Path following Strategy: • CT-AT TRAILER: 6.1 kN

  13. Rollover Prevention • Controller • Low speed • High speed • Conclusions • Rationale • Reduce the risk of rollover by controlling the path of the trailer • Optimal linear control strategy • Minimise lateral acceleration • Maintain acceptable path error • Virtual Driver Model • Original path following controller is nonlinear • ‘Virtual driver model’ performs same function using linear control

  14. Virtual Driver Modelof Trailer Steering Y Current position of 5th wheel Semi-trailer Tractor X O uT Snapshot of tractor semi-trailer and path of 5th wheel at time instant k • Controller • Low speed • High speed • Conclusions

  15. Optimal Control Strategy Discrete-time equations for vehicle and path of 5th wheel The control objectives The cost function where and Path error Lateral Accel’n Steering effort • Controller • Low speed • High speed • Conclusions

  16. Results continued Manoeuvre: Lane change Vehicle speed: 88km/h Fixed value of Q1/R=0.05 • Controller • Low speed • High speed • Conclusions

  17. Selection of weighting value 25% reduction Conventional Q2/R=0.005 Manoeuvre: Lane change Vehicle speed: 88km/h Fixed value of Q1/R=0.05 • Controller • Low speed • High speed • Conclusions

  18. Path errors in lane change • Controller • Low speed • High speed • Conclusions

  19. After lane change • Controller • Low speed • High speed • Conclusions V=88km/h Locked Path Following Control

  20. PERFORMANCE MEASURES • Controller • Low speed • High speed • Conclusions

  21. Conclusions Improved low-speed manoeuvrability Improved productivity (LCV) Improved safety Reduced tyre scrub Reduced tyre wear Reduced vehicle wear Improved high-speed stability 25% LTR reduction with no increase of PE Important for LCV

More Related