Online Detection of Toe Angle Misalignment Based on Lateral Tire Force and Tire Aligning Moment

Abstract

Wheel alignment of a vehicle composed of toe, camber and caster is essential for stable driving. Among them, the toe angle can be easily adjusted in many commercial vehicles when misaligned. However, there have been many difficulties for a driver to directly detect the misalignment of the toe angle. To solve this problem, this paper proposes a novel system that detects misaligned toe angle in real-time by utilizing the lateral tire force and tire aligning moment. The system is largely divided into the lateral tire force model construction, tire aligning moment model construction, and misalignment detection. During the lateral tire force model and the tire aligning moment model construction, linearized recursive least squares are used to identify parameters necessary for the building of the models. Afterwards, during the misalignment detection, the misaligned toe angle is detected in real-time without additional sensors by estimating the slip angle of each wheel reflecting the toe angle effect based on these two models. The proposed system is verified by the vehicle dynamics software CarSim, and the simulation results show that misaligned toe angle can be successfully detected in real-time while driving.