LONGITUDINAL OSCILLATIONS OF VEHICLE/TRAILER COMBINATIONS INDUCED BY OVERRUN BRAKING

A mathematical model for the representation of longitudinal oscillations which can occur in car/trailer systems in braking, when the trailer brakes are applied through compression of the towing hitch, is described. The model is used to show how the trailer braking system parameters affect the steady deceleration performance of the vehicle combination, and the stability, in the linear system sense, of the steady motions. The sensitivity of the stability to other system design parameters is also examined. Digital simulation of the motions occurring in response to a step input of car braking torque is reported, with the results confirming the predictions of the linear stability analysis, and also showing the influence of backlash in the trailer brake actuating mechanism. The system is shown to be capable of self-excitation in a "shunting" mode, in which the car and trailer motions are in antiphase, with the stability/damping property critically dependent on drawbar damping, and only weakly dependent on other system parameters. The characteristic frequency of the "shunting" mode oscillations is shown to be controllable via the stiffness of the trailer brake linkage, but this frequency is closely related to the steady drawbar deflection which occurs in uniform deceleration. The model behaviour described provides a basis for the design of relevant systems whose longitudinal dynamic characteristics will be satisfactory. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00423114
• Corporate Authors:

  Swets & Zeitlinger

  Heereweg 347B
  2161 CA Lisse,   Netherlands 
• Authors:
  • SHARP, R S
• Publication Date: 1982-2

Media Info

• Features: Figures; References;
• Pagination: p. 43-61
• Serial:
  • Vehicle System Dynamics
  • Volume: 11
  • Issue Number: 1
  • Publisher: Taylor & Francis
  • ISSN: 0042-3114
  • EISSN: 1744-5159
  • Serial URL: https://www.tandfonline.com/toc/nvsd20/current

Subject/Index Terms

• TRT Terms: Automobiles; Braking; Cost overruns; Damping (Physics); Deceleration; Deflection; Drawbar pull; Dynamics; Mathematical models; Oscillation; Sensitivity; Simulation; Stability (Mechanics); Torque; Trailers; Vehicle dynamics; Vibration
• Uncontrolled Terms: Longitudinal
• Old TRIS Terms: Overruns
• ITRD Terms: 1874: Braking; 5416: Deceleration; 5473: Dynamics; 6473: Mathematical model; 9103: Simulation; 1203: Trailer; 5558: Vibration
• Subject Areas: Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00361652
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 30 1982 12:00AM