汽车操纵稳定性客观评价指标挖掘及主客观评价一致性研究

发布时间：2019-06-08 19:11

【摘要】：相较于其他载具,汽车的应用最为广泛,人—车之间的交互作用最为直接,任何用户都有评价和选择汽车的权利。在满足安全、舒适、节能、环保的前提下,个性化和人性化必将成为未来汽车的发展方向,这种趋势要求设计人员在设计阶段就能准确定位车辆性能,实现汽车模块化、数字化、智能化的正向开发。操纵稳定性作为影响汽车主动安全的重要因素之一,不仅影响汽车驾驶的操纵方便程度,而且也是决定高速汽车安全行驶的一个主要性能。然而,受研究内容、驾驶条件、主观感受以及周边环境等多方面的限制影响,时至今日仍然没有形成公认的汽车操纵稳定性客观评价体系。汽车操纵稳定性客观评价体系的建立本质上是一个大数据、多对多、强耦合、非线性分类问题,其核心是操稳性客观评价指标的提取及主客观评价一致性的数学描述。本文采用系统与综合、理论分析、数值模拟与试验相结合的方式对操纵稳定性的主客观评价展开研究,探索一种简洁准确的客观指标提取途径;建立一套具有良好一致性的操纵稳定性客观评价方法;并在此基础上设计一种考虑车辆主观性能的悬架特性优化方案。其主要研究内容和结论如下:1.汽车操稳客观指标的约简提取;首先,根据信息熵算法对连续型操稳客观评价指标离散化处理,形成离散化指标;然后,建立基于粗糙集理论的区分矩阵指标提取模型,并通过改进限制容差关系,对汽车操纵稳定性客观评价体系属性约简,剔除冗余项,提取12项核心客观指标。2.汽车操稳客观指标的权重决策;首先,建立集成操稳客观与主观指标权重的经验因子模型;然后,融合信息熵和粗糙集理论,建立多属性决策分析方法,应用CWAA算子解算操稳4级主观评价指标的重要度,并求取12项操稳核心客观指标的权重及其在整个指标体系中的相对排序。3.综合主观性能的操稳客观评价方法;首先,选取高斯径向基核函数作为隶属函数,集成评价指标及其权重,建立综合主观性能的操稳客观评价方法,其精度达到80%,具有较强的泛化能力;然后,通过归一化和保结构方法对评价模型进行耦合降阶处理,在保持系统稳定性的前提下降低系统维度并优化系统结构,利用粗糙集可拓分析方法挖掘4项综合评价指标,约简基础属性数量,减小运算量,实现评价模型结构的优化,其评价精度可达70%并能大幅提高运算效率。4.面向操稳主客观性能的悬架特性优化方法。首先,应用二次函数对各项悬架特性进行参数化,综合车辆操纵稳定性的12个无量纲客观评价指标以及13项主观评价项目,设计了整车操纵稳定性的优化目标;然后,建立了以悬架初始定位参数、运动学特性和弹性运动学特性为优化变量、基于Car Sim、Matlab与i SIGHT联合仿真的优化平台;最后,应用改进的多目标优化遗传算法将整车操稳的主客观性能要求分解到悬架的KC特性。本文为汽车操纵稳定性主客观一致性研究提供可行方法,为面向特性的悬架优化提供理论依据,为汽车的模块化、数字化和智能化开发奠定基础。
[Abstract]:Compared with other vehicles, the application of the automobile is the most extensive, and the interaction among the people is the most direct, and any user has the right to evaluate and select the automobile. Under the premise of meeting the safety, comfort, energy saving and environmental protection, the individuation and humanity will be the development direction of the future automobile, which requires the designer to accurately position the performance of the vehicle in the design stage, and realize the forward development of the automobile modularization, the digital and the intelligent. The operation stability is one of the important factors that affect the vehicle's active safety. It not only affects the driving convenience of the automobile, but also the main performance of the safe driving of the high-speed car. However, because of the limitations of the research, driving conditions, subjective feeling and the surrounding environment, there is still no objective evaluation system for the stability of the automobile steering. The establishment of objective evaluation system for vehicle operation stability is a large data, multi-to-many, strong coupling and non-linear classification. The core of the objective evaluation system is the extraction of the objective evaluation index of the stability and the mathematical description of the consistency of the subjective and objective evaluation. In this paper, the main objective evaluation of the operation stability is studied by means of the combination of system and synthesis, theoretical analysis, numerical simulation and test, a concise and accurate objective index extraction method is explored, and a set of objective evaluation methods with good consistency are established. On this basis, a suspension characteristic optimization scheme considering the subjective performance of the vehicle is designed. The main research contents and conclusions are as follows:1. The method comprises the following steps of: firstly, discretizing a continuous operation stability objective evaluation index according to an information entropy algorithm to form a discretization index; then, establishing a discrimination matrix index extraction model based on the rough set theory and improving the limiting tolerance relation, The attribute reduction of the objective evaluation system of the vehicle operation stability is reduced, the redundant items are removed, and the 12 core objective indexes are extracted. The weight decision of the objective index of automobile operation stability is established. First, an empirical factor model for integrating the objective and subjective index weights is established; then, the information entropy and the rough set theory are used to set up a multi-attribute decision analysis method, and the CWAA operator is used to solve the importance of the subjective evaluation index of the operation stability 4 level, The weight of the objective index of 12 stable core and its relative ranking in the whole index system are also obtained. the objective evaluation method of the operation stability of the comprehensive subjective performance is as follows: firstly, a Gaussian radial basis kernel function is selected as a membership function, an evaluation index and a weight thereof are integrated, an objective evaluation method for the operation stability of the comprehensive subjective performance is established, the accuracy of the objective evaluation method is 80 percent, and the method has strong generalization capability; and then, the system dimension is reduced and the system structure is optimized under the premise of keeping the stability of the system, the system structure is optimized, the four comprehensive evaluation indexes are mined by the rough set extension analysis method, the number of the basic attributes is reduced, the calculation amount is reduced, The evaluation model structure is optimized, the evaluation precision can reach 70 percent and the operation efficiency can be greatly improved. The method of suspension characteristic optimization for the objective performance of operation stability. First, the second function is used to parameterize the suspension characteristics, the 12 non-dimensional objective evaluation indexes of the vehicle control stability and the 13 subjective evaluation items are applied, and the optimization goal of the overall vehicle operating stability is designed; then, the initial positioning parameters of the suspension are established, The kinematics characteristic and the elastic kinematics characteristic are the optimization variables, based on the optimization platform of the Car Sim, Matlab and i SIGHT combined simulation; and finally, the improved multi-objective optimization genetic algorithm is used to decompose the main objective performance requirements of the whole vehicle to the KC characteristic of the suspension. This paper provides a feasible method for the objective and objective consistency study of automobile steering stability, and provides a theoretical basis for the characteristic-oriented suspension optimization, which lays the foundation for the modularization, digitization and intelligent development of the automobile.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U461.6

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