基于Imageware和UG的某轿车车身侧围逆向设计研究

通过测量某实物轿车,得到车身点云图。应用Imageware的点云处理功能和UG的曲面造型方法,提出了利用逆向设计来快速构建侧围模型的方法。本文对用逆向工程方法进行车身建模进行了初步探讨,并最终建立了侧围的模型,得到了逆向工程的一般步骤和建模技巧,为其他车型的逆向设计提供了参考。     

攻击性驾驶行为选择模型及影响因素敏感度分析

基于行为学理论和非集计方法,以160名驾驶人为研究对象,确定了影响驾驶人攻击性驾驶行为选择的影响因素变量及取值方法,建立了攻击性驾驶行为选择模型（多项Logit模型）。运用弹性值理论进行各变量对攻击性驾驶选择行为的影响程度与过程敏感度分析;最后选取58名驾驶人的驾驶行为数据进行计算,验证模型的有效性。结果表明：驾驶人人格和其他车辆违法情况2个因素对驾驶人攻击性驾驶行为影响较大,起决定性作用;该模型计算值与量表判定值相对误差在10%左右,模型精度可满足实际使用要求。     

基于能量转移理论的行车风险量化建模方法研究

为建立一种简洁且适用的行车风险量化模型，提出了基于能量转移理论的行车风险量化建模方法，分析了换道避险场景和典型跟车场景的行车风险分布。模型从描述事故致因的能量转移理论出发，提出描述行车风险的风险作用力，通过考虑车辆的动力学约束，推导了车辆可行驶区域，明确了行车风险的影响范围，实现对风险分布的有效约束。仿真结果表明，模型能有效量化行车风险并与传统风险评估指标 THW的结果一致，同时，为缓解道路交通风险应当避免行车风险的大规模叠加造成的风险累积。     

Emission-robust operation of diesel HEV considering transient emissions

In this paper, we consider a method to create an engine emission simulation model for cycle and customer driving of a vehicle. The emission model results from an empiric approach, also taking into account the effects of engine dynamics on emissions. We analysed transient engine emissions in driving cycles and during representative customer driving profiles and created emission meta models. The analysis showed a significantly higher correlation in emissions when simulating realistic customer driving profiles using the created verified meta models (< 1 % model error) compared to static approaches, which are commonly used for vehicle simulation. Therefore, a transient modelling approach is conducted, which shows a great increase in accuracy in customer driving operation.     

eTS fuzzy driver model for simultaneous longitudinal and lateral vehicle control

In this paper, evolving Takagi-Sugeno (eTS) fuzzy driver model is proposed for simultaneous lateral and longitudinal control of a vehicle in a test track closed to traffic. The developed eTS fuzzy driver model can capture human operator’s driving expertise for generating desired steering angle, throttle angle and brake pedal command values by processing only information which can be supplied by the vehicle’s on-board control systems in real time. Apart from other fuzzy rule based (FRB) models requiring human expert knowledge or off-line clustering, the developed eTS driver model can adapt itself automatically, even ‘from scratch’, by an on-line learning process using eTS algorithm while human driver is supervising the vehicle. Proposed eTS fuzzy driver model’s on-line human driver identification capability and autonomous vehicle driving performance were evaluated on real road profiles created by digitizing two different intercity express ways of Turkey in IPG© CarMaker® software. The training and validation simulation results demonstrated that eTS fuzzy driver model can be used in product development phase to speed up different tests via realistic simulations. Furthermore eTS fuzzy driver model has an application potential in the field of autonomous driving.     

Matlab-based modeling,simulation and design package for Eletric,Hydraulic and Flywheel hybrid powertrains of a city bus

In this paper a package for designing, modelling and simulation of three hybrid powertrains are presented. These powertrains are Electric hybrid, Hydraulic hybrid and Flywheel hybrid. The differences among the proposed hybrid powertrains include the energy storage system components, the secondary power converter and also the powertrain configuration. The O457 city bus is considered as the benchmark vehicle. At first, the design process for each hybrid powertrain which is based on the power requirements of the bus in any driving condition is presented. Then, the powertrains modelling using MATLAB/Simulink as a powerful simulating tool is presented. The models are feed-forward and resemble the real world driving conditions. Each model has the blocks for the main components of the corresponding propulsion system. The most important stage in the modeling process is implementing of the components efficiency in each powertrain. Moreover, there is a block in each hybrid powertrain model for the energy management. Finally, the simulation results for comparing the usefulness of the hybrid powertrains are presented. The results indicate that the electric hybrid powertrain has the most effect on reducing the bus fuel consumption. But regarding the fabrication expenses and manufacturing complexity, the hydraulic hybrid powertrain is recommended.     

基于不同风格行驶模型的自动驾驶仿真测试自演绎场景研究

为了验证自动驾驶汽车决策结果的安全性,提出一种具有自主决策和交互能力的行驶模型生成方法,该行驶模型作为背景车被用于构建自演绎仿真场景来测试自动驾驶汽车的连续决策能力。首先,以强化学习为基础、结合遗传与进化思想,创新地设计并生成了具有自主决策和交互能力的不同风格行驶模型;然后,在模型构建阶段分别训练生成了保守、普通和激进3种风格的行驶模型,其中普通风格行驶模型的训练参数来源于自然驾驶数据集highD的车辆参数分布,保证了该行驶模型的真实性;最后,在普通风格行驶模型的基础上设计并训练出了具有显著激进特征的激进风格行驶模型,以增强自演绎场景的复杂性和测试效果。结果表明：在模型真实性方面,以highD数据集中的跟车速度、车头间距、换道时刻下碰撞时间等参数的分布为真值,研究所生成的普通风格行驶模型的参数分布与真值的平均相似程度为88%,相较于基于规则的智能驾驶人模型（IDM）提升了20.3%;在场景测试性方面,以被测系统为主要责任方的碰撞次数为评估指标,研究生成的不同风格行驶模型所构成的自演绎场景的测试性约是由IDM构成的基线场景的7倍。因此,设计和生成的行驶模型所构成的自演绎场景可以有效支撑面向自动驾驶决策系统的仿真测试。     

两自由度系统的自由振动实验

汽车行驶过程中会因为地面不平引起的冲击载荷、发动机工作的振动等原因而产生振动,当汽车振动的频率与车身固有频率相接近时,车身会产生很大的垂向加速度,不仅会使驾乘人员感到不适,还会造成车身结构的损坏。因此,对于汽车振动模型的研究就显得尤其重要。以搭建的两自由度系统的试验模型为研究对象,求得其在不同初始条件下实验的自由振动响应,来验证理论求解模型的正确性,为汽车平顺性的改善提供理论依据。     

A Modular Computer Model for the Design of Vehicle Dynamics Control Systems1

SUMMARY

This paper describes a multiport approach to computer-aided modeling of vehicle dynamics. The modeling approach produces models that are suitable for the interactive design and evaluation of complex control strategies. The vehicle model which can be used for ride and handling analysis, is built from modular components. The components are programmed using the syntax of the computer aided control system design (CACSD) program EASYS. Seven modeling components are used to create a three-dimensional vehicle dvnamics model. The model is flexible enoug-h to simulate any suspension design with revolute joints.

Each component of the model consists of a FORTRAN subroutine and a main calling module called a macro. To simplify the process of model building, the modeling components in the car model are designed to represent physical elements, such as the spring, damper, link or tire. To create a model, the components, which are represented by blocks, are interconnected through points, located on the blocks, called pons. These ports have been designed to simulate the location of the connection points between the physical elements, as observed in real systems. The construction of multibody models within a CACSD program offers the flexibility of simultaneous interactive simulation of the three-dimensional dvnamics and evaluation of the desien of the controls.

Although modeling of multibody systems using FORTRAN components has been pioneered by Chace, Haug and Orlandea; and bond graph modeling of multibody systems has been investigated by Bos, this approach is novel because:-

The model is included in the control system design program (EASYS). This arrangement allows the designer to exploit the advanced control design tools available in the program. Furthermore, this approach significantly reduces the computation time required for running the model after parameters modification.

The model is built from components that are interconnected by ports which represent the actual physical location of the connection points between the elements. The multiport approach simplifies the model building process for multibody systems. This simplification is achieved by reducing the model of a multibody system to a block diagram form.     

Modeling and control of engine starting for a full hybrid electric vehicle based on system dynamic characteristics

This paper focuses on the dynamic modeling and control of engine starting for a Full Hybrid Electric Vehicle (FHEV) consisting of an Integrated Starter Generator (ISG) and Dual Clutch Transmissions (DCTs). The dynamic characteristics of the engine, the ISG motor and the main clutch are analyzed respectively. The dynamic models of the main components of the powertrain system are also established taking the system dynamic characteristics into consideration. The FHEV dynamic model of engine starting during electric driving mode has been investigated in detail. The coordinated control strategy of engine starting has been proposed based on the powertrain system dynamic characteristics. The simulation for the engine starting control during electric driving mode has been performed based on the Matlab/Simulink platform. The simulation results show that the proposed control strategy satisfies the requirements of response and smoothness during engine starting process. Furthermore, a bench test has been carried out to analyze the system characteristics during engine starting process. The test data is highly agreeable to the simulation data and the effectiveness of engine starting control strategy is validated by the comparison between simulation results and the test data.     

驾驶人驾驶决策机制遵循最小作用量原理

为提升智能汽车的自主决策能力，使其能够学习人的决策智慧以适应复杂多变的道路交通环境，需要揭示驾驶人决策机制。首先通过对自然驾驶数据的分析，发现在车辆行驶过程中能够反映驾驶人决策行为的主要运动特征参数存在极值现象，而产生极值现象的内在动因是驾驶人遵循“趋利避害”的基本决策机制，即驾驶过程中驾驶人力图实现机动性和安全性综合性能最优。受自然界包括物理和生物行为上的众多极值现象遵循最小作用量原理的启发，提出驾驶人决策机制遵循最小作用量原理的假设。随后建立抽象描述驾驶过程的物理模型，并提出最小作用量决策模型（Least Action Decision-making Model，LADM），通过与传统驾驶决策模型（经典跟车模型和换道模型）对比，分析结果显示LADM模型更具通用性。最后开展了实车试验，采集20名驾驶人在自由行驶、跟车行驶和邻车切入3种工况下的试验数据，分析计算并检验了不同驾驶人行车过程的理论最小作用量和实际作用量。试验结果表明：驾驶人在驾驶过程中的实际作用量与最小作用量之间无显著性差异，体现出驾驶人在行车过程中对安全和高效具有共性追求，验证了驾驶人决策机制遵循最小作用量原理。     

电动汽车全参数化车身平台化与模块化建模及性能带宽研究

为解决概念设计阶段电动汽车开发周期长等问题,基于隐式参数化方法提出一种电动汽车全参数化车身的平台化与模块化建模策略。首先将车身结构分解为上车体结构与下车体结构,根据设计要求对上下车体各自进行区域划分,定义各区域关键平台化衍生尺寸并进行基线总布置,形成平台化建模策略;然后基于平台化建模对下车体进行功能性模块划分,对上车体进行匹配性模块划分,分别进行参数化建模,形成模块化建模策略;最终建立了某款电动汽车车身的全参数化模型。结果表明,建模策略可实现不同车型的快速衍生,并且根据性能带宽规律,探究了轮距、轴距、车高、前端长度以及后端长度变化对刚度和模态性能的影响,有助于实现基于性能驱动的电动汽车车身与电池包的短周期开发。     

A Modular Computer Model for the Design of Vehicle Dynamics Control Systems1

This paper describes a multiport approach to computer-aided modeling of vehicle dynamics. The modeling approach produces models that are suitable for the interactive design and evaluation of complex control strategies. The vehicle model which can be used for ride and handling analysis, is built from modular components. The components are programmed using the syntax of the computer aided control system design (CACSD) program EASYS. Seven modeling components are used to create a three-dimensional vehicle dvnamics model. The model is flexible enoug-h to simulate any suspension design with revolute joints.

Each component of the model consists of a FORTRAN subroutine and a main calling module called a macro. To simplify the process of model building, the modeling components in the car model are designed to represent physical elements, such as the spring, damper, link or tire. To create a model, the components, which are represented by blocks, are interconnected through points, located on the blocks, called pons. These ports have been designed to simulate the location of the connection points between the physical elements, as observed in real systems. The construction of multibody models within a CACSD program offers the flexibility of simultaneous interactive simulation of the three-dimensional dvnamics and evaluation of the desien of the controls.

Although modeling of multibody systems using FORTRAN components has been pioneered by Chace, Haug and Orlandea; and bond graph modeling of multibody systems has been investigated by Bos, this approach is novel because:-

The model is included in the control system design program (EASYS). This arrangement allows the designer to exploit the advanced control design tools available in the program. Furthermore, this approach significantly reduces the computation time required for running the model after parameters modification.

The model is built from components that are interconnected by ports which represent the actual physical location of the connection points between the elements. The multiport approach simplifies the model building process for multibody systems. This simplification is achieved by reducing the model of a multibody system to a block diagram form.     

低地板发动机后置式铰接客车急转弯特性有限元分析

对于客车车身来说,整体结构的有限元模型部分已经很成熟了。但是对于发动机后置式铰接客车在急转弯工况下的结构有限元分析,尚不多见。文章基于有限元理论,对某型低地板发动机后置式城市铰接客车结构进行建模和静态特性分析。在分析中以汽车各部件的实际连接关系的精确模拟为出发点,考虑了铰接盘处的转动,建立车身有限元模型,并结合国外大汽车公司的FEM行业分析经验,着重考虑了汽车行驶时的急转弯工况,建立了数学模型且对车身强度进行了分析,其结果可作为车身骨架结构优化的参考。     

车身结构耐撞性的概念设计仿真

车身结构耐撞性的概念设计是由车辆乘员伤害指标确定出整车碰撞波形（正面碰撞），根据波形将车身结构性能分解参数化设计，文章从CAE建模角度。探讨比较了建立车身概念设计模型的各种主要方法工具，包括LMS模型、有限元Beam—element模型和多体MadymoFrame模型。表明各模型的建模特点和基本方法主要取决于结构刚度特性和惯性特性的提取与参数化。指出三维模型在概念设计阶段具有适用性和局限性。     

Influence of segment length on the fitness of multivariate crash prediction models applied to a Brazilian multilane highway

Road safety modeling enables the development of crash prediction models and the investigation of which factors contribute to crash occurrence. Developing multivariate response models is also valuable, but such models are currently under-exploited. Machine learning techniques, especially artificial neural networks (ANN), have been presented as possible alternatives. Furthermore, selecting a proper roadway segmentation is one of the first tasks in the standard crash modeling workflow. However, this is a challenging task, especially in terms of choosing a segment length. This article presents a study of the influence of segment length on the development of multivariate response models (i.e., three response variables: property damage only crashes, injured victims crashes, and fatal crashes). The models use ANN for a road segment of a Brazilian divided multilane highway. The highway to be modeled was divided into segments with 10 different fixed lengths. The model characterization included geometric and operational data available for the years from 2011 to 2017. The models were evaluated in terms of errors and by residual plot analysis. The 5-km segment of the northbound carriageway and the 4.5-km segment of the southbound carriageway presented the smallest errors and the highest values of R². The residual analyses confirmed the trend to improve the model with the greater segment lengths. This was clear by the residues' distribution around zero, except for the output “Fatal crashes”. The better performance of the longer segments models was expected because these models aggregate more crashes into one segment. The reduction of no crash observations also facilitated the improvement of the models' goodness-of-fit. The use of ANNs also revealed its potential value. However, it is still important to seek strategies to deal with the excess of zeros in fatal crashes; a problem that also occurs in the traditional statistical modeling process.     

基于中国人体数据的汽车总布置用2D模板开发与应用

人体2D模板作为整车总布置的基础,影响到整车驾驶和乘坐的舒适性、方便性以及行车安全性。本文应用最新的权威中国人体数据,提取人体各项关键尺寸,进行数据建模,并进行软件封装,开发人体2D模板。模板更符合中国人实际的乘坐姿态,基于模板可进行乘坐空间、视野等相关测试,切实提高车辆的安全性、舒适性。     

Neural-network multiple models filter (NMM)-based position estimation system for autonomous vehicles

A highly accurate and reliable vehicle position estimation system is an important component of an autonomous driving system. In generally, a global positioning system (GPS) receiver is employed for the vehicle position estimation of autonomous vehicles. However, a stand-alone GPS does not always provide accurate and reliable information of the vehicle position due to frequent GPS blockages and multipath errors. In order to overcome these problems, a sensor fusion scheme that combines the data from the GPS receiver and several on-board sensors has been studied. In previous researches, a single model filter-based sensor fusion algorithm was used to integrate information from the GPS and on-board sensors. However, an estimate obtained from a single model is difficult to cover the various driving environments, including urban areas, off-road areas, and highways. Thus, a multiple models filter (MMF) has been introduced to address this limitation by adapting multiple models to a wide range of driving conditions. An adaptation of the multiple model is achieved through the use of the model probability. The MMF combines several vehicle models using the model probabilities, which indicate the suitability of the current driving condition. In this paper, we propose a vehicle position estimation algorithm for an autonomous vehicle that is based on a neural network (NN)-based MMF. The model probabilities are determined through the NN. The proposed position estimation system was evaluated through simulations and experiments. The experimental results show that the proposed position estimation algorithm is suitable for application in an autonomous driving system over a wide range of driving conditions.     

基于关联图的车身零件装配序列规划

对车身零件装配优先关系应用装配关联图及矩阵建模,分析了装配不同构形下的分总成数学模型,根据识别出的分总成采取不同的选择方案以自动生成车身装配序列,该方法应用某车身前围进行了装配顺序规划的实例验证。     

轮毂电机式纯电动汽车平台的建立

为了顺利地进行轮毂电机式纯电动汽车的性能研究,文章具体描述了其样车实体平台的建立过程。表明该平台选取了内转子电动机减速驱动型电动轮,采用锂电池作为动力源。在传统内燃机式的沙滩车基础上,完成了底盘和车身部分的改造和重布置,并进行了虚拟样机的整车建模。该平台的设计思路符合未来发展的趋势并具有质量轻、结构简单以及成本低的优点,能很好地完成电动汽车控制策略和其他性能的研究任务。