液阻悬置动特性建模及汽车动力总成悬置系统振动控制优化

MODELING OF DYNAMIC PROPERTIES FOR HYDRAULIC ENGINE MOUNTS AND OPTIMIZED VIBRATION CONTROL METHOD OF POWERTRAIN MOUNTING SYSTEMS

给出了表征液阻悬置动态特性与激振频率相关性的五参数分数导数模型,模型中的五个参数具有明确的物理意义。建立了含有液阻悬置的六自由度动力总成悬置系统振动分析模型,在路面垂直位移激励下,给出了动力总成质心位移和悬置支承点动反力频响特性的计算公式。为降低动力总成质心位移和悬置支承点动反力的振动幅值,给出了基于遗传算法和序列二次规划算法的优化设计方法,对一轿车动力总成中含有的两个液阻悬置的动态特性进行了优化设计。优化结果表明,利用该优化方法得到的液阻悬置的动态特性,可以有效地降低动力总成在垂直方向振动以及悬置支承点动反力的振动幅值。

A version of fractional derivative model characterized by five parameters is used to describe the dynamic properties of a hydraulic engine mount (HEM). The physical meanings of the model parameters are defined and constraints on the parameter values are assigned. A six-degrees-of-freedom model of powertrain mounting system (PMS) is presented, and the formulae for estimating the dynamic displacement of the powertrain mass center and the reaction forces at the mounts under unit displacement excitation from ground are presented. An optimization procedure based on genetic and SQP algorithm is developed for reducing the resonant peaks of powertrain mass center and the reaction forces at mounts of the PMS with HEMs. A generic PMS with two rubber mounts and two HEMs are used to validate the optimization method. Optimization results show that resonant peaks of the powertrain displacements and reaction forces at mounts under the load can be effectively reduced with the proposed optimization method.