Technical Paper
Tire Modeling for Low-Speed and High-Speed Calculations
1995-02-01
950311
Vehicle dynamics simulations typically use semi-empirical tire models. The input to these models are normal load, sideslip angle and longitudinal slip, and the output are shear forces, aligning moment, and overturning moment. Since the longitudinal speed is in the denominator of both sideslip angle and longitudinal slip, the calculation of sideslip angle and longitudinal slip at very low longitudinal velocities leads to numerical problems. This has not been a particular stumbling point in the past because vehicle dynamics calculations were largely concerned with high speed analysis. In situations wherein the vehicle was braked to a stop, patchwork techniques sufficed for calculations at low speeds. Now, however, with the advent of serious attention to driving simulators, low speed tire modelling has become more important.