Quantitative analysis of tire lateral force and stability region boundary sensitivity in vehicle planar motion system based on energy deviation

For the first time, this paper introduces the energy deviation method for quantitative analysis of sensitivity between the stable region boundary and tire lateral force. The vehicle model adopts a three degree of freedom vehicle model and unified tire model suitable for large side-slip angle. Through comprehensive analysis from vehicle handling diagram, dissipation of energy, equilibrium points, and energy deviation, the results demonstrate that this method can not only reveal the sensitive areas on the stable region boundary but also quantitatively characterize the sensitivity. It is more intuitive, concise, and convenient compared to traditional methods. Additionally, this research for the first time quantitatively demonstrates the spiral phenomenon occurring at the boundary between stable and unstable region due to fluctuations in tire force from energy perspective. Furthermore, it explains that this method based on conserved quantity, making it applicable to higher-dimensional vehicle models and has a wide range of applications.