STABILITY OF SINGLE TRACK VEHICLES. PROCEEDINGS ENTITLED "THE DYNAMICS OF VEHICLES ON ROADS AND ON RAILWAY TRACKS"

A 12th order mathematical model of single-track vehicles, which considers tire crown and other factors not included in previous studies, has been developed. The vehicle is assumed to consist of two rigid systems hinged at the steering axis, with freedom of the front system to rotate relative to the rear system. Four assumptions are made in formulating the mathematical model of the vehicle: the vehicle moves at a constant forward speed with no longitudinal slip in tires; the pneumatic trail of tires is not considered since it is small compared with caster trail and wheel base; the vehicle is an unsprung system; and the damping to steering rotation is linear. Equations of motion are established using the Lagrangian formulation. Tire forces and moments, wind force, and vehicle parameters are measured, and equations of motion are solved. It is shown that optimum value to rake angle, caster trail, and steering damping can be found for a particular vehicle for optimum performance. A small moment of inertia for the front system about the steering axis is desirable. The rear mass center should be brought as forward as possible, while front and rear wheel planes and front and rear mass centers should be brought close to the longitudinal plane. A small value of tire relaxation length is advantageous. A front tire with high cornering and camber rate is beneficial, and the front wheel moment of inertia can be made large.

• Supplemental Notes:
  • Also published in HS-026 982U, "The Dynamics of Vehicles on Roads and on Railway Tracks. Proceedings of International Union of Theoretical and Applied Mechanics Symposium, Delft, The Netherlands, 1975 August 18-22," Amsterdam, 1976 p 187-96.
• Corporate Authors:

  International Union of Theoretical and Applied Mechanics

  Chalmers University of Technology, Sweden
  S-412 96 Gothenburg,   Sweden 
• Authors:
  • SINGH, D V
  • GOEL, V K
• Publication Date: 1976

Media Info

• Features: References;
• Pagination: 10 p.

Subject/Index Terms

• TRT Terms: Equations; Lagrangian functions; Mathematical models; Mechanical stability; Moments of inertia; Motion; Motor vehicles; Motorcycles; Tires; Vehicle dynamics
• Old TRIS Terms: Moment of inertia
• Subject Areas: Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00394102
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: HS-026 992U
• Files: HSL, USDOT
• Created Date: May 31 1985 12:00AM