【作者】 孙丽；

【导师】 何仁；

【作者基本信息】 江苏大学 ， 车辆工程， 2012， 博士

【摘要】 人们对客车安全性和舒适性要求的逐渐提高,导致汽车设计者对平顺性和操纵稳定性提出了更高要求,尤其是人们对高品质生活的追求,导致客车的平顺性成为设计和优化的主要性能。随着全球“节能减排”号召的大力实施,汽车行业开始研究混合动力汽车(Hybrid Electrical Vehicle,简称HEV),本文提出针对混合动力客车平顺性的分析、评价和优化设计方法进行研究,由于车辆的平顺性与操纵稳定性相互关联,相互影响,因此本文的平顺性研究是在满足其操纵稳定性的前提下进行的。本课题结合某企业将某一款畅销客车改装成混合动力客车项目,在研究其结构布置引起质量参数改变的前提下,应用ADAMS整车模型仿真其平顺性和操纵稳定性,然后基于操纵稳定性构建混合动力客车平顺性评价体系,并对平顺性优化设计方法展开系统研究。(1)整车虚拟建模技术与平顺性、操纵稳定性分析模型是车辆性能分析的基础,因此需要研究车辆虚拟建模技术。首先,针对后悬架中最复杂的钢板弹簧元件,提出改进中性面法建立钢板弹簧模型,并对比分析了仿真与试验刚度值,模型建立速度较快,精度较高。其次,创建FTire轮胎模型,重构虚拟试验场路面,以建立精度较高的整车刚柔耦合模型,其性能均能满足要求。最后,将已建立的悬架、转向、轮胎、路面和车身子系统整合为整车模型,分别进行车辆的平顺性和操纵稳定性仿真分析,再分别进行实车试验,验证了仿真结果的准确性,说明建立的普通客车的整车模型是准确的,可以用来做仿真试验。为后续混合动力客车的模型建立提供了一种可行的建模方法。(2)混合动力客车结构布置及对平顺性和操纵稳定性的影响分析将普通客车改装成混合动力客车,为了满足混合动力客车的动力性、经济性和能量控制等要求,必须对普通客车结构进行以加装总成部件为主的改装设计。对于后加装的总成部件,尤其是电机、电机控制器、电池模块等重要总成部件,不仅作用大,而且其体积和质量均很大。因此,需要认真设计其布置位置,尽量使混合动力客车与原车的前、后轴荷相差不大,以保证车辆的各方面性能。尤其是7个电池模块需要分成3个部分分别安装,以保证整车性能。然后针对整车布置参数的变化,分别分析质量参数对整车平顺性和操纵稳定性的影响。(3)基于操纵稳定性的混合动力客车平顺性评价方法与系统开发因为平顺性与操纵稳定性的相互影响关系,针对混合动力客车的平顺性和操纵稳定性分析结果,将评价操纵稳定性的近30个指标进行降维处理,得出对操纵稳定性累计贡献率达99%的10个指标,将各指标的贡献率确定为指标权重,用圆心角度表示权重,提出操纵稳定性评价的改进网状图法。将加权加速度均方根值与最有代表性的4个操纵稳定性评价指标组合,提出一种基于操纵稳定性的混合动力客车平顺性评价方法。最后应用VS2008 C#语言开发了混合动力客车平顺性评价系统,方便了用户评价使用。(4)基于操纵稳定性的混合动力客车平顺性优化混合动力客车总质量的增加使该车平顺性略有提高,但是整车布置参数的变化又使车辆的轴荷分配发生改变、质心位置后移,进而导致车辆的操纵稳定性变差。针对上述情况,以保证操纵稳定性、优化平顺性为目的,深入分析混合动力客车改装设计对车辆平顺性产生的影响以及各因素的影响规律。为了同时保证车辆的操纵稳定性,对该车的前横向稳定杆进行改型设计。然后,采用遗传算法优化的神经网络对混合动力客车的平顺性优化,除了悬架的刚度和阻尼之外,还将加装的两组电池质心的纵坐标作为优化变量,在保证该车操纵稳定性的前提下,得出平顺性优化方案。最后通过仿真试验对优化后的车辆平顺性和操纵稳定性进行了分析与评价。本文的创新之处在于：(1)提出一种建立钢板弹簧仿真模型的新方法——改进中性面法,在仿真其刚度时,应用板——球式加载,能更快速、准确的仿真其刚度值,为整车虚拟试验奠定基础。(2)依据混合动力客车前、后轴荷与原车相一致原则,对于加装的电机、电机控制器、电池模块等体积和质量较大的部件进行布置,并提出将加装的电池模块分解,分别安装在车架中段和末段的左右两侧,以保证整车性能。(3)提出操纵稳定性评价的改进网状图法,用圆心角分别表示操纵稳定性的各指标权重,该方法可以方便、直观地看到操纵稳定性的计分状况。进而提出基于操纵稳定性的混合动力客车平顺性评价方法,可以同时对有关联性的平顺性和操纵稳定性进行综合评价,并应用VS2008 C#语言开发出面向用户的评价系统,方便用户使用。(4)应用遗传算法优化的神经网络法对混合动力客车平顺性进行优化,除了悬架刚度和阻尼以外,将加装的电池质心的纵坐标也作为优化变量,切实考虑了混合动力客车的结构特点。该优化方法考虑了操纵稳定性的要求,尽量优化混合动力客车的平顺性,以适应人们对乘坐舒适性的极大追求。本文为混合动力客车平顺性、操纵稳定性等主要使用性能分析提供重要的仿真建模方法参考,为混合动力客车的结构设计提供了一种布置方案,为平顺性和操纵稳定性评价方法的完善提供充分依据,为混合动力客车性能优化提供一种新的理论。更多还原

【Abstract】 The gradual increase in passenger safety and comfort requirements, leading automotive designers have put forward higher requirements for the ride comfort and handling stability. With implementing strongly the call of "saving energy and reducing emission" in the global, the automotive industry began to study hybrid vehicles (Hybrid Electrical Vehicle, referred to as HEV). The analysis, evaluation and optimization on ride comfort and handling stability of hybrid bus become research focus at present. In this paper, combining with a bus improvement to a hybrid bus, the changes of the structural arrangement and quality parameters were studied, and simulated its ride comfort and handling stability by modeling with ADAMS, and then, the ride comfort evaluation system of hybrid bus based on handling stability was built, at the same time, and the corresponding optimal design theory research were done in depth.(1) Vehicle virtual modeling techniques for ride comfort and handling stability analysisFirstly, for the most complex leaf springs in rear suspension, an improved neutral face method was proposed to build the model, and simulation values was comparatively analyzed with the test stiffness. The modeling method was more high speed and high precision.Secondly, FTire tire model was built and virtual proving ground road was reconstructed. The road roughness measurement test was completed by application of multi-function laser detector. The data was processed by interpolation method. The grid combination road model was reconstructed to provide a realistic testing ground model for bus ride comfort simulation analysis.Thirdly, the high precision rigid-flexible coupling model was established, by which the prototype bus ride comfort and handling stability were simulated respectively, and the performance met requirements.Finally, the simulation results of ride comfort and handling stability of the bus were verified by real vehicle tests that were accurate. So, it is that the vehicle model was accurate, and which provided a biable modeling method and basic reference for the subsequent hybrid bus modeling. (2) Hybrid bus structural arrangement and its effects on ride comfort and handling stabilityWhen the ordinary bus was converted to the hybrid bus, the requirements of the power, economy and energy control should be meet firstly. For the added installation parts, their size and quality were great, especially motor, motor controller, battery modules and other important components. Because of their important roles, their layout position must be designed carefully, so as to change as little as possible the hybrid bus front and rear axle load compared with the original bus, to ensure all of the vehicle performance. Particularly, seven battery modules were divided into three parts and installed respectively, by which ensured hybrid bus performance. Then based on the changes of the vehicle layout parameters, the effect on ride comfort and handling stability of the hybrid bus were analyzed respectively.(3) Ride comfort evaluation method and system development of hybrid bus based on handling stabilityThere was the impact each other between ride comfort and handling stability. Taking into account the analysis results of ride comfort and handling stability of hybrid bus, nearly 30 handling stability evaluation indexes were reduced the dimension, the 10 indexes of the cumulative contribution reached 99% were obtained, and the contribution rate of each index was as the index weight that represent in central angles, the improved handling stability evaluation network map method was proposed. The ride comfort evaluation method on hybrid bus based on handling stability was proposed by combining the weighted RMS values with the most representative of four handling stability evaluation indexes. Finally, the evaluation program was developed by VS2008 C# language, to facilitate the user evaluation.(4) Ride comfort optimization on the hybrid bus based on handling stabilityThe increase of the hybrid bus total mass mad the bus’s ride to increase slightly, but the change of layout parameters mad the axle load distribution change, the mass center changing, which led to deterioration of the handling and stability. Aimed to ensure handling stability, optimize ride comfort, analyzed deeply the impact by hybrid bus improved designing and the law of the various factors. To improve the handling stability simultaneously, the front horizontal stabilizer was designed improved, and ride comfort optimization on the hybrid bus based on handling stability was implemented by using the genetic algorithm optimizing neural network method. In addition to stiffness and damper of the suspensions, two body vertical coordinals of the installationed batteries were as the optimization variables, in the premise of ensuring handling and stability of hybrid bus, ride comfort optimization program on hybrid bus was obtained. Finally, the analysis and evaluation on the hybrid bus ride comfort and handling stability after optimization were completed by simulation experiments.The innovations of this paper were,1, improved neutral surface method was proposed to build leaf spring model. When simulating leaf spring stiffness, by board-ball loading way, the stiffness could be simulated more quickly and accurately. It is the foundation of the bus virtual test.2, under the principle of ensuring front and rear axle load little difference from the hybrid bus to the original layout, the important parts added installation, such as the motor, motor controller, battery modules and so on were arranged. A program that battery modules were divided into three parts and installed in the middle frame and the right and left sides of the last paragraph was proposed to ensure hybrid bus performance.3, the improved handling stability evaluation network map method was proposed, the central angels was used to denote respectively the index weights of the handling stability, which could make the scoring of handling stability be saw more easily and intuitively. Then, the ride comfort evaluation method was proposed of hybrid bus based on handling stability. The method could simultaneously evaluate the ride comfort and handling stability easily and intuitively. By using VS2008 C#, the evaluation program of hybrid bus was developed to facilitate to the user.4, Ride comfort optimization method on hybrid bus based on handling stability was proposed by applying genetic algorithm optimizing neural network. In addition to stiffness and damper of the suspensions, two body vertical coordinals of the installationed batteries were as the optimization variables, which effectively taking into account the structure characteristics of the hybrid buses. The method considering the requirements of handling stability, try to optimize the ride comfort of the hybrid bus to accommodate the great pursuit of people’s comfort.The paper provides the important simulation modeling method for hybrid bus performances analysis,for example the ride comfort and handling stability, provides a arrangement project for structural design, provides sufficient basis for improved hybrid bus ride comfort evaluation method, and provides new theory to optimize ride comfort of hybrid bus.更多还原