Extended Pacejka Tire Model for Enhanced Vehicle Stability Control

Despite their widespread use, current tire models have demonstrated a certain level of inaccuracy, primarily due to uncertainties related to unaccounted nonlinearity and disturbance effects resulting from tire operating conditions. Noteworthy factors such as tread depth, inflation pressure, tire temperature, and road surface condition significantly impact tire force and moment characteristics. These factors can vary considerably during tire operation and significantly affect both tire and vehicle performance. The improvement of tire models is crucial to enhance the effectiveness of advanced vehicle control systems, as accurate tire force characteristics are required for maintaining vehicle stability during demanding maneuvers. This paper investigates the impact of varying tire temperature, inflation pressure, and tread depth on steady-state tire force characteristics by analyzing the coefficients of the Pacejka 'magic formula' (MF) tire model. Based on this analysis, adaptation equations are proposed to compensate for the influence of these variables on the tire force curve. The advantages of using an adapted tire model are then demonstrated through simulation studies of a classical vehicle stability control system that can adapt to diverse operating conditions. A comparison is made between the adapted tire model-based controller and a controller based on a fixed reference model.