基于区间分析的汽车平顺性优化

Vehicle Ride Comfort Optimization Based on Interval Analysis

基于区间分析方法,建立了一种汽车悬架平顺性的不确定性优化模型。以悬架弹簧刚度和减振器阻尼为设计参数,车身加速度均方根值最小化为目标,悬架刚度和固有频率等为约束,并使用区间描述设计变量的制造和测量误差。利用公差指标和区间可能度,将该不确定性优化模型转化为确定性优化问题,并利用序列二次规划法和非支配排序遗传算法进行求解;在保证平顺性目标的前提下,使设计变量的对称公差最大化,以降低制造成本。最后,该方法被应用于两自由度1/4车身和7自由度整车车身悬架振动系统的平顺性优化。

An uncertainty optimization model for the ride comfort of vehicle suspension is built based on interval analysis technique. With suspension spring stiffness and shock absorber damping as design variables,minimizing the root mean square of car body acceleration as objective,and the stiffness and natural frequency of suspension as constraints,and by means of tolerance indicator and possibility degree of interval,the uncertainty optimization model is transformed into a certainty one,which is then solved with SQP and NSGA-Ⅱ. On the premise of assuring the objective of ride comfort,the symmetric tolerance of design variables is maximized with manufacturing cost reduced. Finally the scheme proposed is applied to the ride comfort optimization of suspension vibration system with both 2 DOF quarter car body model and 7 DOF whole car body model.