主动后轮转向对车辆操纵稳定性的影响

Effect of active rear wheel steering on vehicle handling stability

基于经典线性二自由度数学模型的研究方法,通过分析建立了引入回正力矩的非线性数学模型。对比分析了不同工况下两种数学模型与TruckSim模型的接近程度,结果表明,引入回正力矩的非线性模型更为准确。在此基础上,提出了一种主动后轮转向控制策略,通过控制质心侧偏角来提升车辆的操纵稳定性和循迹性。利用TruckSim与MATLAB/Simulink进行联合仿真,通过方向盘转角阶跃试验来验证控制策略的有效性。仿真结果表明,在各车速区间,相比传统的前轮转向车辆,采用主动后轮转向控制的车辆在稳态时的质心侧偏角均处在理想范围。针对文中所采用的控制策略,与采用恒定侧偏刚度的策略相比,考虑侧偏刚度的非线性变化的控制效果提升不明显。但通过两者的对比分析,为如何调整后轮转角使车辆状态达到预期效果提供了一种研究的思路。

Based on the method of linear two degree of freedom mathematical model,a nonlinear model considering the aligning torque is established.The similarity between the two mathematical models and TruckSim model under different working conditions is compared and analyzed.The result shows that the nonlinear model is more accurate.On this basis,an active rear wheel steering control strategy is proposed to improve vehicle handling stability and tracking by controlling the sideslip angle of the mass center.The effectiveness of the control strategy is verified by steering wheel angle step test using TruckSim and MATLAB/Simulink.The simulation results show that in each speed range,compared with the traditional front wheel steering vehicle,the sideslip angle of the vehicle with active rear wheel steering control is ideal in the steady state.For the control strategy adopted in this paper,compared with the constant cornering stiffness,the control effect considering the nonlinear change of cornering stiffness is not significantly improved.However,through the comparative analysis of the two cases,it provides a kind of research idea for how to adjust the rear wheel angle to make the vehicle state achieve the desired effect for further study.