基于Simulink轮胎跳动对重型车转向特性影响分析

Influence Analysis of the Tire Runout on the Heavy-Duty Steering Characteristics Based on Simulink

转向过程轮胎受地面载荷影响呈现跳动,而其对车辆稳定转向产生重要影响。车辆与地面间的接触是通过轮胎得以实现,轮胎受力直接影响到车辆转向稳定性。选用重型车辆轮胎外倾时的受力进行分析,基于此,对空载和满载工况下,高低速转向时的转角偏差进行分析;并对空载和满载工况下,转向时,车轮的摆动误差及滑移量进行分析,获取不同工况下各参数最优的数学模型;根据数学模型分析,基于Simulink搭建包含承载特性的转向系统模型,以此分析不同转速条件下轮胎的受力和轮胎跳动对转向的影响;应用实际车辆,选取双移线转向工况,对比分析运行轨迹和转角关系的差异,以此验证数学模型和仿真分析的可靠性。结果可知:在转向过程中,各轮胎的侧向力变化趋势基本一致;随着车速的增加,在转向过程中各轮胎所受的侧向力也呈现增加的趋势;随着速度的增加,前轴内侧轮胎受力先减小后增加;满载时,车轮跳动对车轮摆动误差的影响随着车轮转角增大而增大,而空载时,则影响更大,变化趋势也更复杂;实车测试与仿真轨迹基本保持一致,且外侧轮转向角曲线基本无较大变化,保持一致特性,误差小于3%,表明数学模型和仿真分析的准确性,为此类设计提供参考。

In the process of steering,the tire runout under the influence of the ground load,which has an important impact on the stable steering of the vehicle.The contact between the vehicle and the ground is realized through the tire,and the tire force directly affects the steering stability of the vehicle.Based on this,the angle deviation of high and low speed steering under no-load and full load conditions was analyzed.The wheel swing error and slip were analyzed under the condition of no-load and full load,and the optimal mathematical model of each parameter under different working conditions was obtained.According to the mathematical model analysis,a steering system model with load-bearing characteristics was built based on Simulink to analyze the influence of tire force and tire runout on steering under different speed conditions.In order to verify the reliability of the mathematical model and simulation analysis,the difference of the relationship between the running track and the turning angle was compared and ana⁃lyzed under the condition of double lane change steering.The results show that:during the steering process,the change trend of lat⁃eral force of each tire is basically the same.With the increase of vehicle speed,the lateral force on each tire also increases.With the increase of the speed,the force on the inner tire of the front axle first decreases and then increases.Under full load,the influence of wheel runout on wheel swing error increases with the increase of wheel angle,while under no load,the influence is greater and the change trend is more complex.The real vehicle test and simulation track are basically consistent,and the steering angle curve of the outer wheel basically has no big change,and the consistent characteristic is maintained,and the error is less than 3%,which shows the accuracy of the mathematical model and simulation analysis,and provides a reference for this kind of design.