A semi-physical tire model for a vehicle dynamics analysis of handling and braking

Abstract

For a semi-physical model, this paper first presents its basic concept, transient steer effect and driving conditions. The model experimentally formulates vertical force as a function of tire deflection, camber angle and lateral force. In order to describe longitudinal and lateral forces as functions of tire characteristic parameters such as stiffness and friction, the basic formulations of the UA tire model are re-used. For self-aligning and overturning moments, the application points of three forces are first experimentally formulated, and then the moments are expressed as functions of the three forces and their application points. All characteristic parameters are experimentally determined as functions of load, camber angle, slip angle, slip angle sweep rate and/or slip ratio for cornering and/or driving/braking. For the purpose of validation, the model is implemented into ADAMS and then its simulation results are compared with measurement data for various test conditions.

Keywords:

• Tire model
• Tire characteristic parameters
• Transient steer
• Time delay
• Stress relaxation
• Heat generation
• Loaded radius
• Vertical stiffness