基于主动转向和差动制动的车辆防侧翻控制

摘要

Nowadays, active steering and differential braking are the main techniques for vehicle's rollover prevention. But the single use of active steering may modulate more wheel angle and differential braking may lead to wheel lock because of big braking force. The early warning system is also too slow based on the lateral acceleration signal. In this paper, a vehicle model for rollover was established. A new early warning method called LTR was proposed to predict vehicle's rollover early. A combination control strategy of active steering and differential braking was illustrated. In Matlab/simulink, the program was compiled. It can maintain vehicle's lane and decrease speed slowly during a certain period by changing the parameters PI and K. The result showed that the optimal control strategy can not only prevent vehicle's rollover effectively but also keep lane and avoid excessive braking force.%目前车辆防侧翻技术主要有主动转向或差动制动,但单独的主动转向会导致车轮转角调整过大,差动制动会导致制动力过大出现轮胎抱死,而且预警是依据侧向加速度信号,预警时间过慢,导致不安全.为了提高控制能力,通过建立车辆侧翻模型提出了LTR预警方法,能准确快速地计算车辆侧翻概率.并采用了主动转向和差动制动联合的防侧翻控制,在Mat-lab/simulink中设计出了联合控制算法.算法通过改变PI参数值和制动力增益系数K,既保证了不破坏车辆的车道保持功能,又减小了速度在-定时间内的下降率.仿真结果表明,优化控制防止了车辆侧翻,避免制动力过大,保证了系统安全性,确实为防侧翻控制设计提供了参考.