为了提高电动汽车在复杂路面情况下的加速能力和稳定性,提出了一种基于动态路面最优滑转率估计的驱动防滑控制策略并进行了仿真研究。首先从车辆-地面系统模型入手,分析了路面参数估计的数学原理并给出了单一路面下的最优滑转率判别条件,进而将多种路面交叠的情况下的最优滑转率参数估计问题转化为高、低附着路面相互切换的统一问题进行了深入分析,引入高估门限λmax 与低估门限λmin 设计了最优滑转率的动态估计方法。基于动态路面的参数估计建立了相应的驱动防滑控制策略。仿真结果表明:所提出的参数估计方法和控制策略显著提高了电动汽车的加速能力,且在路面条件突变的情况下也能有效抑制驱动轮的过度滑转,改善了整车的行驶稳定性。
An acceleration slip regulation strategy based on optimal slip ratio dynamic estimation and its simulation study were presented to improve the accelerating ability and stability for electric vehicles under complicated road conditions. Firstly, the mathematical principle of road parameter estimation was analyzed using the vehicle-road sys- tem model, through which the judgment condition of optimal slip ratio under a single road condition was proposed. Then the estimation problem of optimal slip ratio under complicated road conditions was analyzed by transforming it into a uniform problem of the switch between high and low ground adhesion coefficients. Furthermore, the dynamic estimation method of optimal slip ratio is acquired by introducing overestimated threshold λmax and underestimated threshold λmin Finally, the corresponding acceleration slip regulation strategy is established based on estimating dynamic road parameters. Simulation results indicate that the proposed estimation method and control strategy can im- prove the accelerating ability of extended range electric vehicles observably and can also prevent the excessive slip of dfiving wheel effectively and improve vehicle's stability while the road condition changes suddenly.