基于模糊灰色关联的三轴汽车操纵稳定性分析

Analysis on handing stability of three-axle vehicle based on fuzzy grey correlation

为研究三轴汽车各轴主要悬架K&C特性对操纵稳定性的影响程度,在考虑三轴汽车轴荷分配和侧倾力矩作用下左、右车轮垂直载荷重新分配的基础上,建立了基于悬架K&C特性参数的三轴汽车三自由度动力学模型.并以该模型为基础,采用模糊隶属度余弦值和欧氏距离公式建立三轴汽车悬架K&C特性模糊灰色关联分析模型,对影响三轴汽车稳态响应特性的主要悬架K&C特性的重要性程度进行了模糊灰色关联度分析.结果表明:车速为15km/h时,对于稳态响应阶段的侧倾角、横摆角速度和侧向加速度,各影响因素模糊灰色关联度排序皆为R4>R2>R3>R1>R6>R5;对于质心侧偏角,R5(β)>R6(β)>R1(β)>R2(β)>R3(β)>R4(β).同理可得车速为35km/h和55km/h时各个影响因素模糊灰色关联度排序.从而可以得出:三轴汽车各轴悬架K&C特性参数中,前桥侧倾转向特性对稳态响应阶段的侧倾角、横摆角速度、侧向加速度影响最大;中、后桥侧倾转向特性对质心侧偏角影响较大,且两者相差不大.

In order to study the influencing degree of main suspension K C characteristic parameters on handling stability,a 3-DOF dynamic model of three-axle vehicle based on its suspension K C characteristic parameters was established with considering of the axle load distribution of three-axle vehicle and reallocation of vertical load on both sides of wheels under roll torque.Moreover,on the basis of the 3-DOF model,fuzzy grey correlation analysis model based on main suspension K C characteristic parameters of three-axle vehicle was established using the cosine value of fuzzy membership and Euclidean distance formula to make fuzzy grey correlation analysis on the influencing degree of main suspension K C characteristic parameters on steady-state response of three-axle vehicle.The results showed that,for the roll angle,yaw rate and lateral acceleration in the stage of steady-state response,the order of fuzzy-grey correlation degree of influencing factors was all R4R2R3R1R6R5 when the speed was 15km/h;and for the side slip angle,R5（β）R6（β）R1（β）R2（β）R3（β）R4（β）.The order of fuzzy-grey correlation degree of influencing factors at 35km/h and 55km/h was obtained in the same way.Thus,thefront axle roll steering characteristics had the greatest influence on roll angle,yaw rate and lateral acceleration while intermediate and rear axle roll steering characteristics had greater influence on side-slip angle,with no statistics difference.