关键词: 车辆失速；侧倾加速度阈值；稳态转向半径；弯道防护

Abstract: The instability condition is calculated and analyzed when the rubber tire vehicle enters the curve to provide the basis for the sliding vehicle protection in curves in this paper. The roll acceleration threshold of vehicle rollover is derived by analyzing the force of the sliding vehicle in the roll plane. The formula for calculating steady-state steering radius of vehicle is obtained by establishing a two-degree-of-freedom model of vehicle, calculating the entry speed of sliding vehicle and deriving the entry steering angle under Ackermann steering conditions. The parameters of the instability calculation of the sliding vehicle are given. MATLAB/Simulink is used to simulate the instability of the vehicle entering the corner with the sliding distance from 25 m to 200 m. The results show that when the sliding distance is 0~100 m, the operating margin of the steering wheel is 2.85°, and the vehicle has the risk of scratch collision. When the sliding distance is greater than 100 m, the lateral acceleration of the vehicle is greater than 5.16 m/s2 , and the vehicle will roll over.

Key words: vehicle sliding; roll acceleration threshold; steady turning radius; curve protection