基于正交试验工程车辆油气悬挂优化设计建模分析

Modeling and Optimization Design of Hydro-pneumatic Suspension in Construction Vehicle Based on Orthogonal Experiment Method

油气悬挂因为结构简单且具有良好的非线性变刚度和变阻尼特性,其应用非常广泛。根据单气室油气悬挂的结构特点对其进行参数化,利用四分之一车辆振动系统进行试验设计分析,确定对车辆振动性能影响最大的结构参数和结构参数之间的组合;进行结构性能参数优化分析,分析车辆振动性能达到最优时,结构参数的分布情况和分布规律。利用正交试验法对油气悬挂设计参数进行优化,同时结合油气悬挂数学模型,提出利用活塞和阻尼孔与活塞杆直径之比、单向阀当量直径与阻尼孔直径之比等3个参数来简化设计过程。分析油气悬挂参数对车辆行驶平顺性和操作安全性的影响趋势和以影响程度为衡量标准的影响顺序,从而确定主要因素和相对次要因素,对油气悬挂进行参数优化。从分析结果可知:悬架的初始位置对油气悬挂性能影响最大,其次为活塞与活塞杆直径之比;设计变量对目标的影响大小依次为:x_0>λ_1>τ_2>τ_1>d;在悬挂设计过程中,λ_1与τ_1能取值使得目标函数值达到最小,d与τ_2则需要在其对目标函数的影响趋势下根据实际约束条件选取;优化后,系统性能有较大改善。

For simple structure and good non-linear variable stiffness and damping characteristics, hydro-pneumatic suspension is widely used. According to the structure characteristics of the single chamber hydro-pneumatic suspension, it was parameter treated, and the experimental design analysis was performed using a quarter vehicle vibration system model, The structure parameters having largest influence on vehicle vibration performance and their combination were determined. Structural parameter optimization analysis was car- fled out to analyze the distribution of the structural parameters when the vehicle vibration performance was optimal. The parameters were optimized based on orthogonal experiment. And combining with the hydro pneumatic suspension mathematical model, ratio of piston diameter to piston rod diameter, ratio of damping hole diameter to piston rod diameter, ratio of one-way valve equivalent diameter to damping hole diameter were used to simplify the design process. The effects of hydro-pneumatic suspension parameters on vehicle running smooth and safe operation were analyzed, as well as the influence sequence measured by influence degree, then the main factors and secondary factors were determined. Through optimization analysis to the parameters of hydro-pneumatic suspension, it is known that ： the initial position of the suspension affects the performance of the hydro-pneumatic suspension, followed by the ratio of piston di- ameter to piston rod diameter; design variables influencing the target size is as following：x0〉λ1〉τ2〉τ1〉d; in design process, λ1 and τ1 can value that the objective function value reaches minimum; the d and τ2 need to be selected according to the actual constraint condition under the trend of impact on the target function. After optimization, the system performance is greatly improved.