Development of generic multibody road vehicle models for crashworthiness

The crashworthiness analysis of road vehicles requires detailed data of the vehicles that the automotive manufacturers are, generally, unable to release due to commercial or legal restrictions. In the development of passive safety subsystems or substructures, the overall crash response of a vehicle model used to support it, must mimic that of the real vehicle; if this exists, regardless of any particular constructive detail of its structure provided that it is not located in the vicinity of such subsystem. This work proposes a methodology for the development of multibody models of road vehicles, for passive safety analysis, which include all general structural and mechanical features of real vehicles and start by exhibiting impact dynamic responses similar to the top of line vehicles. These vehicle models, designated as generic, do not require the knowledge of most of the particular details of the design of the real vehicle, which the manufacturers are unable to release, but can be adjusted to have crash responses similar to those of the real vehicle. Based on an existing finite element model of a car, which has all constructive features of vehicles of the chosen class, a multibody model is built applying the plastic hinge approach. By using a selected number of crash scenarios, defined in international standards such as the EuroNCAP, selected parameters of the vehicle multibody model are adjusted to ensure a good correlation between its impact responses and those of the finite element model. The crash responses are measured in terms of structural deformations, velocities and accelerations, occupant injury measures and structural energy absorption capabilities. Assuming that the plastic hinge constitutive equations of the multibody model are not exactly known, their parameters are used here as the multibody vehicle model that are adjusted. The methodology proposed is demonstrated by its application to the identification of the vehicle multibody model of a large family car for which the reference vehicle is available as a detailed finite element model.     

三厢轿车侧面造型特征及发展趋势研究

汽车的侧面造型决定着整个车型的设计风格和车型定位,在整车的设计中具有十分重要的地位。文章通过对三厢车侧面造型六个主要造型特征的纵向和横向对比分析,探求三厢车侧面造型的发展变化规律,寻找不同档次车型的差异原因,指导以后的汽车设计。     

混合动力轿车的建模与仿真

该文介绍了应用电动汽车仿真软件ADVISOR 2 0 0 2对国内一汽车企业的混合动力轿车样车进行建模与仿真的研究工作。待仿真的轿车与日本本田公司的混合动力轿车Insight的动力系统结构相同 ,因此作者采用在ADVISOR中的Insight模型的基础上 ,修改其设备参数 ,重新设计其控制策略模块的模型的技术方案来进行仿真工作 ,最后给出了混合动力轿车的整车性能和工作过程的仿真结果。该研究可以帮助确定混合动力轿车动力系统的配置方案 ,为企业设计混合动力轿车提供参考。     

增强现实环境下的汽车A立柱视野评估方法

针对目前汽车造型设计过程中A立柱视野评估缺乏从设计师视角主动参与的使能工具,提出基于增强现实技术的汽车A立柱评估方法.首先建立了汽车内饰评估的增强现实软硬件环境,将虚拟汽车模型准确、实时地叠加到真实的驾驶环境中;其次建立了虚拟视锥体几何模型,设计了用户左右眼视锥的标定方法以及基于视线碰撞检测的A柱盲区角计算方法,并分析了标定误差对盲区角计算精度的影响,结果表明标定方法可靠.最后采用某型轿车模型进行应用验证,通过跟踪用户人眼位置驱动虚拟视锥体,实现不同驾姿下的A立柱盲区角的快速计算,主观地评估A立柱对前方视野的影响.结果表明,该方法操作简单有效,为汽车视野A立柱评估提供了一个新型工具.     

Automotive display innovation: 12.3‐inch automotive free‐form curved cluster

As the market share of automotive display increased, special used displays are required; BOE developed 12.3‐inch automotive free‐form curved cluster. For this product, free‐form and curved design can be matched in vehicle preferably. Meanwhile, it is designed in automotive class, which means that this product will perform excellently in severe environment.     

Rapid design exploration of safety-critical distributed automotive applications via virtual integration platforms

Modern automotive applications such as Drive-by-Wire are implemented over distributed architectures where electronic control units (ECU’s) communicate via broadcast buses. In this paper, we present the concept of virtual integration platform for automotive applications. The platform provides the basis for early analysis and validation of distributed applications, therefore enhancing the current model based development process techniques that are applied to one ECU at a time. The virtual prototype includes both functional and performance (time) models of the application software, scheduling policies, and the bus communication protocols. As a result, since design errors can be found earlier in the design process before the different sub-systems are integrated in the car, savings in both production and development costs can be achieved. The virtual integration platform concept is supported by an integrated IP-based tool environment for authoring, integration, and validation. First, a model of the distributed application is built by composing models of HW and SW components. The models can be either authored or imported from different tools. Functional simulation of the overall distributed control algorithm can be carried out first. Then, the mapping phase can take place: sub-functions of the control algorithm are mapped to architectural resources (CPUs), and zero-time communication links between the sub-functions are mapped to bus protocol delay models. Changing mappings, parameters such as task priorities, and bus schedule enables the exploration of alternative implementations. The validation is carried out by simulating the resulted virtual prototype of the distributed control algorithm running on the ECU network. The design environment shortens design turn-around time by supporting (semi)-automatic configuration of the architecture model (e.g. frame packaging, redundancy level, communication matrix, bus and RTOS scheduling, etc.).     

Universal model of a ground vehicle for realization of integrated inertial-satellite navigation systems

Tight integration of satellite and strapdown inertial navigation systems is used for automotive vehicles and complicated by the necessity to design adequate models of the object of research. A universal stochastic model adequately reflecting the processes of arbitrary motion of a ground vehicle is synthesized in a canonical form. The model can be used for realization of tightly coupled inertialsatellite navigation systems. The results of simulation modelling are given, which confirm the efficiency of the synthesized model.     

基于CAN总线的汽车智能网关/节点的设计

研究汽车局域网C A N总线在汽车中的具体应用。针对汽车总线技术网关、节点的开发设计,结合现行汽车厂家提出的实际需求,即不改变原汽车电气系统的结构,从实用性和经济性两方面提出了解决方案。本设计采用飞思卡尔微处理器MC9S08DZ作为网关/节点的核心,除了完成网关的CAN数据发送接收功能,还设计出数据采集系统,能完成数据采集和实时数据的输出驱动等功能。因为所有输入信号都严格执行SAEJ1939规程,这更适应于目前的分块开发方式。     

Optical information for car following: the driving by visual angle (DVA) model

OBJECTIVE: The present study developed and tested a model of car following by human drivers. BACKGROUND: Previous models of car following are based on 3-D parameters such as lead vehicle speed and distance information, which are not directly available to a driver. In the present paper we present the driving by visual angle (DVA) model, which is based on the visual information (visual angle and rate of change of visual angle) available to the driver. METHOD: Two experiments in a driving simulator examined car-following performance in response to speed variations of a lead vehicle defined by a sum of sine wave oscillations and ramp acceleration functions. In addition, the model was applied to six driving events using real world-driving data. RESULTS: The model provided a good fit to car-following performance in the driving simulation studies as well as in real-world driving performance. A comparison with the advanced interactive microscopic simulator for urban and nonurban networks (AIMSUN) model, which is based on 3-D parameters, suggests that the DVA was more predictive of driver behavior in matching lead vehicle speed and distance headway. CONCLUSION: Car-following behavior can be modeled using only visual information to the driver and can produce performance more predictive of driver performance than models based on 3-D (speed or distance) information. APPLICATION: The DVA model has applications to several traffic safety issues, including automated driving systems and traffic flow models.     

基于车载CAN总线的倒车雷达智能节点设计

现今倒车雷达在汽车电子领域中得到广泛应用,但其大部分产品仅仅是独立的电气控制单元,无法与车载CAN网络接轨。该文应用MCP2510 CAN控制器和TJA1050 CAN收发器设计一种倒车雷达的CAN总线智能节点。给出倒车雷达的总体硬件结构、CAN总线接口电路以及通讯报文和软件设计,结合插值运算提高报文精度,并通过实验验证了本设计的可行性。使倒车雷达能够被车载网络识别,实现与CAN总线的数据通讯和资源共享。     

夜航探照灯车控制系统设计

设计了一种夜航探照灯车控制系统,包括主控器、数据采集/驱动板、遥控装置三部分,其中主控器用于灯车监控视频和工作参数的显示,同时接收塔台遥控装置发送的无线指令控制灯车.数据采集/驱动板包含两部分:数据采集板,用于对探照灯的工作参数进行采集,包括探照角度、工作电流和电压,且利用传感器并通过电气隔离的方法实现直流信号的高精度测量;电气驱动板,用于实现灯光和探照角度控制,采用汽车电子行业成熟稳定的控制器局域网(CAN)总线进行通信.塔台遥控装置通过2.4 GHz频段与主控器进行通信,组成星状网络控制任意一台灯车.测试表明:灯车控制系统参数测量精度保持在1％以内、通信稳定可靠、功能和性能均符合系统设计要求.     

High performance automotive chassis design: a topology optimization based approach

Automotive chassis design in view of car weight reduction is a challenging task due to the many performance targets that must be satisfied, in particular in terms of vehicle safety. In this paper a methodology for automotive chassis design in involving optimization techniques is presented. In particular, topology, topometry and size optimizations are coupled with fem analyses and adopted in cascade for reaching an optimum chassis configuration. The methodology is applied to the design process of a rear-central engine high performance vehicle chassis. The objective of the optimization process is the chassis weight reduction, yet in fulfilment of structural performance constraints as required by Ferrari standards. The results demonstrate the general applicability of the methodology presented for obtaining the general trusses layout and thicknesses distribution of the structure. The numerical model at this stage shows a significant weight reduction when compared to the chassis of the Ferrari F458 Italia.     

SplineLearner: Generative learning system of design constraints for models represented using B-spline surfaces

Product design involves a computer-aided design (CAD) model with its design (dimensional) parameters. A generative design (GD) system can then be utilized to generate new designs by modifying these parameters. There is a need for a GD system to determine the visual validity of a design that is obtained after parametric modification. In this context, this paper introduces an approach to learn visual (i.e., design) constraints of a CAD model (represented using B-spline surfaces) by means of user feedbacks. A deformation technique (utilizing modification and limit curves) for B-spline surfaces is first introduced, which involves a few design (deformation) parameters. Via a generative learning process, the proposed system, SplineLearner, generates random designs, which are shown to user(s) for visual validity classifications. In a machine learning step, a mathematical model is computed that can perform prediction for a design to be valid or not. The mathematical model is also integrated into SplineLearner (after some user interactions) to prevent imbalances between the numbers of valid and invalid designs. As a proof of concept, B-spline surface models of a car body parts (hood, roof, side and trunk) are utilized, and two user studies are conducted to demonstrate the efficacy of the proposed method.     

A method for selecting surrogate models in crashworthiness optimization

Surrogate model or response surface based design optimization has been widely adopted as a common process in automotive industry, as large-scale, high fidelity models are often required. However, most surrogate models are built by using a limited number of design points without considering data uncertainty. In addition, the selection of surrogate model in the literature is often arbitrary. This paper presents a Bayesian metric to complement root mean square error for selecting the best surrogate model among several candidates in a library under data uncertainty. A strategy for automatically selecting the best surrogate model and determining a reasonable sample size was proposed for design optimization of large-scale complex problems. Lastly, a vehicle example with full-frontal and offset-frontal impacts was presented to demonstrate the proposed methodology.     

基于DSP的车道偏离检测与车辆前向车距检测

基于智能交通的快速发展,研究了在高速路段下基于机器视觉的车道偏离检测与车辆前向安全车距检测技术.首先固定车载相机,通过相机标定获取相机的内参数和外参数,进而设计车距检测模型.该模型不但能够检测出前方车辆与无人车的距离,还能计算出前方车辆相对于摄像机光轴的偏转角度.接着在CCP偏离检测算法的基础上,设定安全和报警区来建立车道偏离模型,并对当前车辆的偏离结果作出正常行驶的评判.最后借助TI的DVSDK组件包将算法移植到嵌入式平台DSP-DM3730上测试.实验表明,本文设计的车距检测模型和车道偏离模型在解决无人车的前向防撞检测和车道偏离检测等问题上具有较好的参考价值.     

汽车信息安全攻防关键技术研究进展

汽车技术的迅猛发展,车载信息系统的智能化、电子化水平不断提高,促使了车辆信息安全问题已经成为近年来最热门的研究领域之一。为提高车载信息系统抗攻击能力、实现汽车的安全平稳运行,从信息安全的角度,综述了汽车入侵式攻击与车辆信息安全防护保障措施理论与关键技术：对现代汽车的车载信息系统概念、结构、软件标准化等进行了详细的论述;对汽车的功能性安全、信息系统安全的区别进行了详细对比;对现代汽车入侵式攻击的方法与种类,及安全防护保障策略等进行了深入剖析;对汽车信息安全领域的国内外研究进展情况作了概括性总结;最后给出了汽车信息安全领域的发展趋势及展望。     

Car make and model recognition under limited lighting conditions at night

Car make and model recognition (CMMR) has become an important part of intelligent transport systems. Information provided by CMMR can be utilized when license plate numbers cannot be identified or fake number plates are used. CMMR can also be used when a certain model of a vehicle is required to be automatically identified by cameras. The majority of existing CMMR methods are designed to be used only in daytime when most of the car features can be easily seen. Few methods have been developed to cope with limited lighting conditions at night where many vehicle features cannot be detected. The aim of this work was to identify car make and model at night by using available rear view features. This paper presents a one-class classifier ensemble designed to identify a particular car model of interest from other models. The combination of salient geographical and shape features of taillights and license plates from the rear view is extracted and used in the recognition process. The majority vote from support vector machine, decision tree, and k-nearest neighbors is applied to verify a target model in the classification process. The experiments on 421 car makes and models captured under limited lighting conditions at night show the classification accuracy rate at about 93 %.     

Dynamic modeling of a wave glider

We propose a method to establish a dynamic model for a wave glider, a wave-propelled sea surface vehicle that can make use of wave energy to obtain thrust. The vehicle, composed of a surface float and a submerged glider in sea water, is regarded as a two-particle system. Kane’s equations are used to establish the dynamic model. To verify the model, the design of a testing prototype is proposed and pool trials are conducted. The speeds of the vehicle under different sea conditions can be computed using the model, which is verified by pool trials. The optimal structure parameters useful for vehicle designs can also be obtained from the model. We illustrate how to build an analytical dynamics model for the wave glider, which is a crucial basis for the vehicle’s motion control. The dynamics model also provides foundations for an off-line simulation of vehicle performance and the optimization of its mechanical designs.     

Multiobjective optimization for crash safety design of vehicles using stepwise regression model

In automotive industry, structural optimization for crashworthiness criteria is of special importance. Due to the high nonlinearities, however, there exists substantial difficulty to obtain accurate continuum or discrete sensitivities. For this reason, metamodel or surrogate model methods have been extensively employed in vehicle design with industry interest. This paper presents a multiobjective optimization procedure for the vehicle design, where the weight, acceleration characteristics and toe-board intrusion are considered as the design objectives. The response surface method with linear and quadratic basis functions is employed to formulate these objectives, in which optimal Latin hypercube sampling and stepwise regression techniques are implemented. In this study, a nondominated sorting genetic algorithm is employed to search for Pareto solution to a full-scale vehicle design problem that undergoes both the full frontal and 40% offset-frontal crashes. The results demonstrate the capability and potential of this procedure in solving the crashworthiness design of vehicles.