汽车排气系统的流场分析与优化

给出了某汽车排气系统一维非定常流动的气体动力学方程组和三维模拟数学模型.建立了该汽车排气系统与发动机的联合模型,并利用此模型得到了排气系统进口温度、质量流量、密度等参数.以此作为边界条件,利用三维CFD软件对该汽车排气系统流场进行了模拟,找到了影响排气系统背压的关键结构并进行了优化.结果表明,模拟结果与试验结果吻合性良好,优化后排气系统背压由40.5 kPa降至30 kPa.     

基于驾驶员在环的EPS试验台开发

汽车转向系统性能与汽车的操纵稳定性和舒适性有关,对汽车的行驶安全起着至关重要的作用。随着动力转向系统的发展,电动助力转向系统的优势逐渐突出。这里运用七自由度汽车模型,拟设计出一种基于驾驶员在环的转向测试试验台,将驾驶员操纵的油门踏板和转向信号实时采集,通过信号运算和汽车动力学模型实时仿真,实现转向力矩的模拟和车辆状态信息的输出,并可以快速进行EPS系统的开发验证。     

汽车电源电压标准提升的研究

随着电子、电器元件的发展,其在汽车上的应用日益广泛,以致汽车原有的电能供应出现了严重不足,提高汽车供电系统的电压,采用42V电压值,已成为一些国际论坛中的讨论热点。本文以陕汽牌SX2190越野车为例,并结合当前汽车行业的发展现状,对提高汽车供电系统电压进行研究。     

Viable combined cycle design for automotive applications

A relatively new approach for improving fuel economy and automotive engine performance involves the use of automotive combined cycle generation technologies. The combined cycle generation, a process widely used in existing power plants, has become a viable option for automotive applications due to advances in materials science, nanotechnology, and MEMS (Mico-Electro Mechanical Systems) devices. The waste heat generated from automotive engine exhaust and coolant is a feasible heat source for a combined cycle generation system, which is basically a Rankine cycle in the context of this study. However, there are still numerous technical issues that need to be solved before the technology can be implemented in automobiles. A simulation was performed to examine the amount of waste energy that could be recovered through the use of a combined cycle system. A simulation model of the Rankine cycle was developed using Cycle-Tempo software. The simulation model was ultimately used to evaluate the rate of waste heat recovery and the consequential increase in the overall thermal efficiency of the engine with the combined cycle generation system under typical engine operating conditions. The most effective automotive combined cycle system recovered 68% of the waste heat from the exhaust and coolant, resulting in a 6% improvement in engine efficiency. The results are expected to be beneficial for evaluating the feasibility of combined cycle generation systems in automotive applications.     

基于微分几何理论的汽车半主动悬架非线性振动控制

针对汽车悬架系统的非线性特性,采用1／4汽车二自由度悬架模型分析半主动悬架控制。应用微分几何理论得到输出-干扰解耦方法,再经适当的坐标变换将该模型由非线性系统简化成一线性系统,并对此系统进行最优控制,然后通过非线性状态反馈实现对原系统的半主动控制。与被动悬架的仿真结果进行了比较,表明这种针对具有非线性特征的半主动悬架的非线性控制方法是可行的。通过功率谱分析,控制后系统的能量比被动悬架更趋于平均,悬架动态性能更稳定。     

虚拟现实技术在汽车人机工程开发中的应用

在汽车研发项目中,人机工程相关的问题一般涉及系统比较多且更改成本很高,因此提早人机工程性能的验证时间可以有效缩短项目研发周期.文章介绍了虚拟现实技术在汽车人机工程开发中的具体应用方法,通过头戴显示器式虚拟现实设备结合人机台架来对整车环境进行模拟,利用光学追踪软件增加虚拟环境的真实性以及记录评价过程.     

车用发动机动态排放测试系统及其应用

介绍了某汽车开发中心发动机动态排放测试系统的系统构成、系统集成方法及部分试验结果。提出了发动机动态排放测试系统的具体构成，比较分析了发动机／测功器控制子系统的各种类型。由此，得出动态排放测试系统的设备选型及实施方案，并通过图形给出系统安装调试完成后的试验结果。     

汽车试验场可靠性试验强化系数的研究

本文按疲劳等损伤寿命原则推导了计算汽车可靠性试验强化系数的数学模型,并在模型中引入损伤因子统计量和频率因子统计量的概念,使影响强化系数的各因素的物理意义更为清晰。本文编制了计算强化系数的软件,对CA141汽车在试验场可靠性试验道路上的载荷谱测试数据进行了处理,计算得到了各种路面组合的综合强化系数。本文提供的方法对各试验场可靠性试验强化系数的分析计算具有普遍参考价值。     

Optimized dynamic battery model suited for power based vehicle energy simulation

Ever increasing demand for the petroleum is causing faster than expected oil shortages in the supply and demand balance around the world and furthermore, many specialists in the field of oil production such as Association for the Study of Peak Oil and World Energy Outlook are claiming that the petroleum is around the peak of its production (Figure 1). Such shortage made the greatest impact on the gasoline price hikes at the gas pump and thus, this impact was felt by the consumers severely and became the greatest motivation for automotive industries to strive to pioneer the researches for the next generation vehicle configurations ranging from HEV, PHEV, Pure EV to FCHEV (collectively noted as xEV). While the great deal of researches has been carried over the last few decades, it is still far from mass productions for consumer use except for the HEV mainly due to the high cost involved with other types of xEV configurations. Therefore, it is critical to design the vehicle to maximize the use of each component at its highest point regardless of any cost scenarios and it is clear that this optimization can only be achieved through the accurate energy balance simulation for a specific target vehicle prior to the actual hardware implementation. In this paper, it is our intention to introduce modified dynamic battery modeling scheme that would provide a more accurate way of simulating the battery behavior when used in the vehicle energy simulation system. Starting from a typical battery dynamic model to predict the voltage given an imposed current request, we have introduced a new scheme to establish the relationship between the voltage and the power (rather than the current) requested by the vehicle simulation system. The proposed scheme handles the power request from the vehicle simulator considering the dynamic battery characteristics and in turn, contributes to the better estimation of the current integrated energy usage and battery SOC level in the given battery dynamic system used in the vehicle energy simulation system.     

影响汽车骨架类零件冲压成形数值模拟质量研究

以汽车落地骨架零件为具体研究对象,利用LS-DYNA的动态有限元显式算法,研究冲压成形有限元数值模拟技术中影响模拟质量的重要因素,如网格质量、时间步长控制、渗透控制、沙漏控制,对汽车骨架类零件冲压成形数值模拟质量的影响。这对于有限元数值模拟技术在实际生产中的应用能够起到有益的指导作用。     

汽车光纤多路传输控制系统

针对传统布线的缺陷，设计了汽车光纤多路传输（布线）控制系统。本文概述了它的发展，并重点介绍了基本设计原理、模块化结构及抗干扰试验。系统由控制开关、光发射模块、三根总线（电源线、光纤信号线、系统地线）、光接收功能模块、终端用电器或执行器组成。用电器地线为搭铁。以大功率场效应晶体管代替继电器作功率形状，信号由光纤按串委分时复用方式传递。它只用三根总线控制多个终端用电器。其优点是：用线数量大减，线束简单，便于安装、检修、与传统布线系统相比，它还具有质量轻、体积小、传输信息量大等特点，其原理适用于对发;支机实时控制、车辆状态监测和通－断负载的开关控制等要求。     

Advanced permanent magnet motor drive modeling for automotive application under matlab/simulink environment

This paper proposes an advanced permanent magnet (PM) motor drive modeling for dynamic analysis of automotive control systems with PM motor drives. To enhance the reusability of the proposed PM motor drive model, each component is modeled in an object-oriented manner according to the physical partitioning of a real drive system, and userfriendly and well-organized interfaces are also proposed. These characteristics enable this model to be used as a kind of a programming library. A multi-level modeling strategy is also proposed, which helps make a compromise between model accuracy and simulation speed without structural modification of the system model. The model and modeling strategy developed allow for a comprehensive analysis of each component and dynamic analysis of the total system. System simulation results show the practical effectiveness of the proposed modeling strategy.     

汽车空调系统与发动机冷却系统的耦合分析

建立汽车空调系统与发动机冷却系统数学模型,对两系统进行耦合计算,与实验结果对比表明:仿真与实验结果吻合较好,能够满足工程设计的需要。     

An Iterative Approach to Road/Profile Identification Utilizing Wavelet Parameterization

A time domain simulation error method is presented in the following article for estimating the excitation of structural systems from local operational responses. The present study focuses on the case in which the location of the excitation is known a priori, as it is for the interaction of the road profile and the tyre patch for an automotive vehicle. The road profile is parameterized into coefficients using truncated sets of base functions which greatly reduce the number of unknowns in the resulting non-linear optimization problem. A complex non-linear model of a ground excited vehicle is utilized to illustrate the applicability and performance of the method.     

Hybrid neural network model for history-dependent automotive shock absorbers

The method of numerical multi-body simulation is an often used and well-understood development tool in the automotive industry. In order to reproduce the ride comfort or handling behaviour of vehicles, mathematical models have to be built up. To achieve accurate simulation results, highly detailed component models are required. However, the formulation of appropriate physically-based model equations of complex automotive components (e.g. air springs, shock absorbers, rubber bearings, tyres, etc.) can be very difficult. To handle this, empirical modelling methods have been developed. Simple algebraic equations are used to describe complex system behaviour. This simplification is very effective, although it largely ignores the natural laws of mechanics and thermodynamics but is still capable to predict the component response. This article illustrates how to take advantage of this approach in numerical simulations. We describe the development of a hybrid automotive shock absorber model based on both spline and neural network (NN) approaches. By combining these different approaches, an accurate model is achieved without loss of variability. Non-isothermal laboratory force-displacement measurements of an automotive shock absorber are being used to estimate the parameters of the NN. As shown, the model replicates the measured data with sufficient accuracy, especially the hysteresis. Finally, we present a set of quarter-car simulations with a built-in hybrid NN shock absorber.     

汽车空调整车环境模拟试验室热湿负荷及主要参数的计算

利用状态空间法对环境模拟试验室各围护结构的热负荷进行了精确的计算，同时对空调机组的制冷量、风量及加湿设备的加湿量进行了计算。通过所建立的汽车空调环境模拟试验室进行了长安汽车2种工况的实车测试．结果表明该环境模拟试验室的设备选型是合理的。     

汽车空调整车环境模拟系统的仿真

建立了汽车空调整车环境模拟系统的数学模型,并在M ATLAB S/IM ULIN K软件平台上开发了汽车空调整车环境模拟系统的仿真模块库。简单介绍了所开发的仿真模块库,并用此仿真模块库对某汽车空调整车环模系统进行了仿真研究。与试验结果对比表明,所开发的仿真模块库具有很高的仿真精度。     

在汽车装备企业联合共建工程中心的意义

为了落实我国智能制造发展规划(2015-2025年)指导精神,以我国汽车产业链智能制造需求为导向,加快提升新能源汽车智能装备系统研发与集成工程技术能力,全面实现我国汽车智能制造自主创新体系和国产化水平,在机器人应用最为广泛的汽车及其零部件行业大力发展智能装备与系统、培育发展系统集成及其应用,成为了当前我国智能制造202...     

虚拟激励法及其在汽车随机振动应用中的探讨

论述了虚拟激励法,为探讨其应用于汽车随机振动的可行性,构造了虚拟路面激励。以1/4汽车单自由度振动系统为对象,由虚拟激励法推导出系统和振动响应量的频率响应特性,提出了求取系统振动响应量功率谱密度的新方法,给出了应用虚拟激励法求解汽车随机振动的计算实例。结果表明,虚拟激励法是比傅里叶分析方法更为简便的时频研究方法。     

选择性输出双离合自动变速器换挡仿真

为提高我国车企的竞争优势,文章介绍一种具有自主发明专利技术的双离合自动变速器(DCT)的结构及工作原理。并利用Matlab/Simulink仿真软件,建立了整车系统动力学模型,包括发动机、双离合自动变速器、车体及其他负载。在此基础上进行DCT的换挡过程仿真分析,研究其控制策略。仿真实验结果验证了所建立数学模型的合理性和可行性,提高了DCT动力系统设计的效率。仿真结果表明该方法正确可行。