Development of Real-Time Estimator on Maximum and Present Tire Grip for Direct Yaw Moment Control

This study proposes a method for estimating the maximum and present tire grips of a driving vehicle in real time. Direct yaw moment control (DYC) based on detecting wheel slip does not significantly affect general driving due to wheel slip at medium and low speeds. However, during the high-speed driving of a high-performance vehicle or driving within a racing track, frequent wheel slips have a significant adverse effect on the driving performance. This is because a tire that loses grip cannot generate additional driving and steering forces. Therefore, if the tire operating force of each wheel can be estimated in real time and the tire friction saturation limit can be precisely calculated, the driving performance can be significantly improved compared to control for wheel slip regulation. In this study, a precise tire friction limit model was developed to improve the limit driving handling performance through DYC, and the reliability of the estimation of the present tire grip was verified through actual vehicle measurements.