A Methodology for Validating Vehicle Dynamics Simulations

This paper presents a methodology for validating vehicle stability and control computer simulations. Validation is defined as showing that, within some specified operating range of the vehicle, a simulation's predictions of a vehicle's responses agree with the actual measured vehicle's responses to within some specified level of accuracy. The method uses repeated experimental runs at each test condition to generate sufficient data for statistical analyses. The acquisition and reduction of experimental data, and the processing path for simulation data, are described. The usefulness of time domain validation for steady state and slowly varying transients is discussed. The importance of frequency domain validation for thoroughly validating a simulation is shown. Both qualitative and quantitative methods for the comparison of the simulation predictions with the actual test measurements are developed.

To illustrate the validation methodology, experimental testing of four different vehicles was performed; with the results being compared with predictions made by two existing vehicle stability and control simulations. Constant steer, braking in a turn, straight line braking, double lane change, and sinusoidal sweep steering maneuvers of varying severity were performed to study simulation validity for a wide range of vehicle operating conditions. Comparisons between the actual test measurements and the simulation predictions are shown.