液压参数对互联悬架动态响应的灵敏度分析及优化

发布时间：2019-05-13 10:09

【摘要】：本文的研究来源于国家自然科学基金项目(51275162)“车辆转向系统和互联悬架集成控制策略及智能优化方法研究”。悬架系统可以缓冲由不平路面传给车架或车身的冲击力,并衰减由此引起的震动,以保证汽车平顺行驶。液压互联悬架作为一种新型悬架系统,可以独立配置悬架系统的刚度和阻尼,在不影响乘坐舒适性的前提下,还可以改善车辆的操纵稳定性。从已有的研究侧重点和方法来看,国内外学者对互联悬架的研究主要集中在建模和对稳定性的考察,几乎没有对液压参数进行过单独的分析。因此,本文对液压互联悬架系统展开了一系列研究,运用Sobol全局灵敏度分析方法对液压参数进行了灵敏度分析,并选择关键液压参数进行了正交优化分析,主要内容如下:本文首先建立了四自由度半车防侧倾液压互联悬架模型,分析介绍了机械系统与液压系统的组成与工作原理,并基于该模型的机械液压耦合的边界条件建立了频域内的整个系统的动力学方程。其次,为了得到液压互联悬架的动态响应,首先根据频域的动力学模型得到四阶振动模态、传递函数等模型的固有特性,验证了模型的准确性和有效性。通过加入路面对半车模型的输入激励,得到不同工况下的垂直模态和侧倾模态下的车身加速度功率谱密度响应。然后,针对液压参数对液压互联悬架动态响应的灵敏度分析展开了研究。选用最优拉丁超立方抽样方法对液压参数进行试验设计。为了可以检验多个参数同时变化对模型结果产生的总影响,选取Sobol全局灵敏度分析方法计算液压参数的灵敏度值。将垂直和侧倾两种模态下的液压参数灵敏度值进行大小排序,得出影响车身垂直加速度输出谱密度和车身侧倾加速度输出谱密度的关键液压参数,并做出理论分析,验证了结果的合理性。最后,基于灵敏度分析的结果,对液压参数进行正交优化分析。选定优化变量和目标函数后,建立Isight与Matlab联合仿真平台对垂直和侧倾两个模态的车身加速度功率谱密度响应进行多目标优化,得到优化后的液压参数值和优化前后的液压互联悬架动态响应对比曲线。
[Abstract]:The research in this paper comes from the National Natural Science Foundation of China (51275162), "Research on Integrated Control Strategy and Intelligent Optimization method of vehicle steering system and connected suspension". The suspension system can buffer the impact force transmitted from the uneven road to the frame or body, and reduce the vibration caused by it to ensure the smooth running of the car. As a new type of suspension system, hydraulic interconnection suspension can independently configure the stiffness and damping of the suspension system, and can also improve the handling and stability of the vehicle without affecting the ride comfort. From the existing research focus and methods, scholars at home and abroad mainly focus on modeling and stability of interconnected suspension, and almost no separate analysis of hydraulic parameters has been carried out. Therefore, in this paper, a series of studies are carried out on the hydraulic interconnection suspension system, the sensitivity analysis of the hydraulic parameters is carried out by using the Sobol global sensitivity analysis method, and the orthogonal optimization analysis of the key hydraulic parameters is carried out. The main contents are as follows: in this paper, a four-degree-of-freedom and half-vehicle anti-roll hydraulic suspension model is established, and the composition and working principle of mechanical system and hydraulic system are analyzed and introduced. Based on the boundary conditions of mechanical and hydraulic coupling of the model, the dynamic equations of the whole system in frequency domain are established. Secondly, in order to obtain the dynamic response of hydraulic interconnection suspension, the inherent characteristics of fourth-order vibration mode, transfer function and other models are obtained according to the dynamic model in frequency domain, and the accuracy and effectiveness of the model are verified. By adding the input excitation of the pavement to the half-vehicle model, the acceleration power spectral density response of the car body under different working conditions is obtained under the vertical mode and the tilting mode. Then, the sensitivity analysis of hydraulic parameters to the dynamic response of hydraulic interconnection suspension is studied. The optimal Latin hypercubic sampling method is selected to design the hydraulic parameters. In order to test the total influence of multiple parameters on the results of the model, Sobol global sensitivity analysis method is selected to calculate the sensitivity of hydraulic parameters. The sensitivity values of hydraulic parameters in vertical and roll modes are sorted, and the key hydraulic parameters which affect the output spectral density of body vertical acceleration and the output spectral density of body tilting acceleration are obtained, and the theoretical analysis is made. The rationality of the result is verified. Finally, based on the results of sensitivity analysis, the hydraulic parameters are analyzed by orthogonal optimization. After the optimization variables and objective functions are selected, the joint simulation platform of Isight and Matlab is established to optimize the power spectral density response of vehicle body acceleration in vertical and roll modes. The optimized hydraulic parameters and the dynamic response curves of hydraulic interconnecting suspension before and after optimization are obtained.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.33

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