LIMITS AND RELIABILITY OF THEORETICAL EVALUATION OF VEHICLE LATERAL DYNAMICS. PROCEEDINGS ENTITLED "THE DYNAMICS OF VEHICLES ON ROADS AND ON RAILWAY TRACKS"
Limits of theoretically predicting a vehicle's dynamic reactions may match the total range of operations, up to the limits of road holding, cornering ability, breakaway, or even rollover. Research on preaccident dynamics may be the domain of simulation techniques, if it is possible to satisfy requirements of limit conditions by theoretical means. Limit conditions include an adequate theoretical model, mathematical stability beyond limits of system stability, vehicle data accuracy, and synchronous translation of computed results into the driver's customary sensory perception. A model, completed to evaluate vehicle lateral dynamics, has additional degrees of freedom for wheels, is compatible with a nonlinear kinematic and compliant chassis, and has an adequate concept to describe tire characteristics. The model has been used in steady-state circular path, step input to steering wheel, sine input to steering wheel (slalom), side wind, rapid deceleration during circular path, and rollover tests. These tests have been extended to maximum lateral accelerations, and most of the tests for both front- and rear-wheel drive vehicles. Results of model testing show that a vehicle's dynamic behavior is governed by many influences. Drift problems, caused by stepwise integration of differential equations, can be controlled by considering divergence effects in all steady-state solutions. The main barrier in obtaining reliable simulation results is the lack of comprehensive tire data compatible with modeling assumptions. The use of well-known testing vehicles, however, can minimize uncertainties in tire data. Theoretical vehicle models dedicated to real-time applications may be more simplified in their adaptation to the simulator capsule concept which requires the abandonment of limit-condition-dynamics.
- 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 110-8.
International Union of Theoretical and Applied MechanicsChalmers University of Technology, Sweden
S-412 96 Gothenburg, Sweden
- Sorgatz, U
- Publication Date: 1976
- Features: References;
- Pagination: 9 p.
- TRT Terms: Equations; Forecasting; Mathematical models; Motor vehicles; Reliability; Stability (Mechanics); Theory; Tires; Ultimate load design; Vehicle dynamics
- Old TRIS Terms: Limits
- Subject Areas: Safety and Human Factors; Vehicles and Equipment;
- Accession Number: 00394097
- Record Type: Publication
- Source Agency: National Highway Traffic Safety Administration
- Report/Paper Numbers: HS-026 987U
- Files: HSL, USDOT
- Created Date: May 31 1985 12:00AM