【作者】 张海涛；

【导师】 卢荡；

【作者基本信息】 吉林大学 ， 车辆工程（专业学位）， 2016， 硕士

【摘要】 汽车动力学仿真技术已广泛应用于平顺性、操纵稳定性和耐久性的研究。人们普遍认识到对汽车模型精度影响最大的组件是轮胎。最近研究车辆平顺性的轮胎模型成为热点,即中高频轮胎模型。中高频轮胎模型的精度直接影响整车动力学中平顺性的仿真精度。目前,中高频轮胎模型有SWIFT、FTire、RMOD-K、CDTire、Gim二自由度轮胎模型等,其中发展比较成熟并得到商业化应用的中高频轮胎模型有SWIFT和FTire。两种轮胎模型各有优缺点,CAE工程师对选择哪种轮胎模型很困惑。为此,本文分别研究两种轮胎模型的建模机理,对比两种轮胎模型的辨识精度、预测能力、试验需要、辨识费用和仿真速度等方面,主要开展了如下研究工作:1、研究了SWIFT轮胎模型建模机理,SWIFT轮胎模型由魔术公式、接地质量块滑移模型、串联椭圆等效路面模型和刚性环模型四部分组成。首先,介绍了魔术公式,包括魔术公式基本参数、具体公式、建模要点和特点。其次,由线性瞬态模型引入接地质量块滑移模型,基于Simulink搭建接地质量块滑移模型,并验证其准确性。再次,介绍了等效路面模型,包括轮胎包容特性、等效路面经验模型和串联椭圆凸轮模型的建模机理,基于MATLAB建立等效路面。最后,介绍了平面内三个方向的刚性环模型建模机理,基于Simulink建立了固定轮心高度轮胎高速过转鼓凸块模型。2、介绍了FTire轮胎模型建模机理,包括结构模型、胎面模型、热模型和磨损模型。首先,介绍了结构模型中带束单元的自由度、带束单元与轮辋之间和相邻带束单元之间的连接方式。其次,介绍了胎面模型中胎面块的数量、分布特点、胎面块与带束单元的连接方式和胎面与路面相互作用力的计算方式。再次,介绍了热模型,包括轮胎在滚动过程中产生热量的因素、FTire热模型的建模机理和结构。最后,介绍了磨损模型中胎面块的瞬时磨损率与胎面块能量损耗、胎面温度和胎面块法向力的计算公式,瞬时磨损率描述随时间变化的花纹深度,间接影响轮胎力学特性。3、介绍了本文需要的轮胎力学特性试验及试验台、建立SWIFT和FTire轮胎模型需要的试验数据与参数辨识方法。首先,介绍了各种轮胎力学特性试验,包括稳态特性试验、静态特性试验、瞬态特性试验、包容特性试验和动态特性试验的定义、试验方法和需要的试验台。其次,介绍了建立SWIFT轮胎模型需要的试验工况、试验方法、试验大纲和参数辨识方法,包括轮胎基本参数、轮胎稳态特性试验、轮胎基本特性试验、轮胎包容特性试验和轮胎动态特性试验。再次,介绍了建立FTire轮胎模型需要的试验数据、试验大纲,包括轮胎基本参数、轮胎接地印迹形状、轮胎静态特性试验、轮胎稳态特性试验、轮胎动态特性试验。最后,介绍了使用COSIN软件中的FTire/fit模块进行FTire参数辨识的具体流程。4、分别从辨识精度、仿真速度、越障仿真、模型复杂程度、辨识费用等方面对SWIFT和FTire轮胎模型进行了对比。但是由于本人能力有限,对比结果不是绝对的,仅供参考,如有问题欢迎指正。总之,SWIFT轮胎模型比较适合汽车操纵稳定性和平顺性仿真,FTire轮胎模型比较适用于汽车平顺性、舒适性、耐久性仿真。更多还原

【Abstract】 Vehicle dynamics simulation technology has been widely used to study riding comfort, handling stability and durability. More and more people think that The biggest impact of the model cars is tire model. Intermediate and high Frequency Tire Mode become a focus in the research of vehicle ride comfort. Intermediate and high Frequency Tire Mode directly influences the precision of vehicle dynamics in the study of riding comfort. At present, there are SWIFT, FTire, RMOD-K, CDTire, Gim 2-dof tire model, etc. SWIFT and FTire tire model are widely used. This two kinds of tire models each have advantages and disadvantages, CAE engineer don’t know how to choose which kind of tire model. So that this paper studies the mechanism of two kinds of tire model, compared to two kinds of tire identification precision, speed of simulation, test needs, identify cost and, etc. the main research work carried out as follows:1, The modeling mechanism of SWIFT tyre model is studied, and it is made by magic formula, grounding block sliding model, serial elliptic equivalent road model and rigid ring model. First of all, the magic formula is introduced, including basic parameters, the specific formula, the modeling points and features. Secondly, ground mass sliding model is introduced by linear transient model, to establish grounding quality block sliding model based on Simulink, and verify its accuracy. Again, this paper introduces the equivalent pavement model, including tyres inclusive characteristics, equivalent pavement experience model and serial elliptic model. Finally, this paper introduces the three directions of rigid ring plane model modeling mechanism, built the modle of tire high-speed drum pasing convex block based on Simulink.2, FTire tire model modeling mechanism is introduced, including the structure model, tread model and thermal model and wear model. First, this paper introduces the freedom of beam unit, the connection between rim and beam, the connection between adjacent beam unit. Secondly, this paper introduces the number of the tread blocks, distribution characteristics, connection between tread blocks and beam unit, the calculation of between tire and road surfaces. Again, this paper introduces the thermal model, including the factors to generate heat in the process of rolling tires, thermal modeling mechanism and structure of FTire. Finally, this paper introduces the wear model of tread instantaneous wear rate and tread blocks of energy loss, tread temperature and force calculation formula of tread blocks. The instantaneous wear rate describe the depth of tread pattern over time, the wear rate indirectly affect tyre mechanical characteristics.3, introduces tire mechanics characteristic test and test bench, the need of test data establish SWIFT and FTire tire model and the parameter identification method. First of all, this paper introduces various kinds of tire mechanics characteristic test, including the steady state characteristic test, static characteristic test, transient characteristic test, dynamic characteristic test. Secondly, this paper introduces the test condition test method, test outline and parameter identification methods of SWIFT tyre model, including basic parameters, tire steady state characteristic test, basic characteristic test tire, tire enveloping characteristics test and tire dynamic characteristics test. Again, this paper introduces the test data need to build FTire tire model, test outline, basic parameters, including Basic parameters of the tire, tire static grounding mark shape characteristic test, tire steady state characteristic test, tire dynamic characteristic test. Finally, this paper introduces the using of COSIN FTire/fit for FTire parameter identification and the Identification process.4, Compare respectively from the identification precision, the simulation speed, complexity of obstacle negotiation simulation, identify cost of SWIFT and FTire tire models. But because my ability is limited, the comparing result is not absolute, for reference only, welcome to correct me if you have any questions. In short, SWIFT tyre model is suitable for vehicle handling stability and ride comfort simulation. FTire tire model is more suitable for vehicle ride comfort simulation.更多还原