The Use of Random Steer Test Data for Vehicle Parameter Estimation

This paper describes a methodology for simple mathematical models to capture the handling behaviors of automobiles. The frequency response data obtained from random steer tests are assumed to fully represent the handling quality of a vehicle. The methodology calls for estimation of the values of some parameters in simple mathematical models. These models are developed from comprehensive understanding of vehicle handling dynamics. The parameter estimation process involves fit ting of the frequency response data numerically with a nonlinear optimization algorithm. Data of one sedan and three minivans are available to demonstrate the application of methodology. From the perspective of data fit, it can be concluded that roll motion does not play significant role in the handling dynamics of the sedan while it contributes more significantly to the handling dynamics of the three minivans.