汽车正面碰撞中乘员约束系统对乘员的保护分析

根据汽车碰撞特性,文章系统地介绍了汽车安全带、安全气囊等乘员约束系统对乘员的保护.利用MADYMO软件建立HybridⅢ第50百分位男性假人模型、三点式多刚体一有限元复合式安全带和有限元安全气囊等乘员约束系统模型,在4种情况下进行正面碰撞的模拟,对比分析乘员的受伤程度.     

安全气囊对离位乘员的损伤及其改善措施的研究

详细介绍了基于计算流体力学的前排乘员安全气囊的建模方法;依据FMVSS 208法规,利用MADY-MO软件通过仿真模拟前排离位乘员和安全气囊的接触过程,对气囊造成伤害的机理进行分析;为减轻气囊对离位乘员的伤害,提出了可断裂式拉带安全气囊的改进方案,并对其改善效果进行仿真.结果表明该方案能较好地达到改善伤害的效果.     

汽车安全气囊起爆车速与乘员伤害关系的仿真研究

利用碰撞受害者模拟软件MADYMO建立了某客车乘员约束系统前碰撞计算机仿真模型,通过对不同碰撞车速下乘员伤害值的仿真计算,研究了保证乘员伤害指标达到一定要求的汽车安全气囊起爆车速。使用生物力学灰度区的概念描述和确定气体发生器的点火阈值,也就是从乘员保护的观点出发,确定不同结构汽车的气囊点火车速,从而为整车匹配安全气囊提供了良好的手段和依据,并能够大大降低匹配时间和周期。     

基于提高乘员保护效能的安全气囊折叠方法研究

提出了安全气囊展开特性的优化指标。使用LS-DYNA软件建立了不同折叠方式的气囊有限元模型,结合静态点爆试验和图像处理技术,对一种新型气囊在典型折叠方式下的展开特性进行了分析。以模拟计算结果为依据,设计了基于提高乘员保护效能的新折叠方法。经试验验证,新设计的折叠方法具有良好的展开特性。     

汽车正面碰撞乘员约束系统模型建立及乘员保护分析

利用MADYMO软件建立了乘员约束系统的模型,整个模型包括车体、安全带、安全气囊和假人.模型经过验证后与试验数据相比较符合要求,并利用验证后的模型对座椅坐垫倾角参数和集成安全带式座椅对正碰中乘员的保护效果进行了分析.     

主动膝部垫式安全气囊(Active Knee Bolster)

德尔福提供各种选用的的主动膝部垫式安全气囊,用于保护人体低部位肢体。主动膝部垫式安全气囊是配合前部安全气囊而设计的安全装置,用于降低对人体下部肢体的伤害,并改善乘员的乘坐安全性。除了对乘员提供更好的乘员保护以外,德尔福主动膝部     

正面碰撞条件下驾驶员安全气囊的匹配优化

为实现正面碰撞条件下驾驶员安全气囊的匹配优化，建立了某小型纯电动汽车的安全气囊有限元模型及其简化乘员约束系统模型，利用静态展开试验验证了模型的准确性，通过对安全气囊的气体质量流量缩放率、点火时刻等 7 个参数对乘员加权伤害指标（WIC）的灵敏度进行分析，确定了气囊主要优化参数。设计三因素七水平的正交试验，考察优化参数对 WIC、头部伤害指数（HIC）、胸部 3 ms 合成加速度及胸部压缩量的影响等级，利用极差分析确定气囊初步及局部匹配时参数调整优先顺序。构建气囊变量与 WIC 的高阶多项式代理模型，确定了气囊最优参数组合。结果表明，优化后 WIC 下降14.92%，乘员保护效果明显提高。     

现代汽车安全气囊技术

安全气囊作为辅助的乘员约束系统,主要用来防止乘员在前碰撞事故中与驾驶室内饰件的二次碰撞。本文根据安全气囊对乘员不同身体部位进行的保护,详述了不同位置汽车安全气囊的功能、结构和ECU对安全气囊的时间控制,并对汽车安全气囊技术的发展趋势进行了简要阐述。     

顶棚安全气囊增加驾驶室选择

TRW推出了一种新型的前排乘员安全气囊,安装在前挡风玻璃上方的车顶,提高了内饰设计美感、改善人体工程学功能,同时节省仪表板空间。从此乘员安全气囊可以不用再安装在仪表板内,顶棚安全气囊可以沿着前挡风玻璃展开,然后向下伸展。     

安全气囊技术的新进展

安全气囊是一种在汽车碰撞事故中自动充气膨胀,在二次碰撞中保护乘员、减轻伤害的安全保护装置。目前,世界汽车市场上,安全气囊日益普及,安全气囊技术也日臻成熟。本文介绍了安全气囊技术,指出现存问题,并对智能气囊技术进行介绍。     

基于任意拉格朗日-欧拉算法的气帘展开数值模拟

大多数气囊展开模拟采用均匀压力算法,为了更有效地模拟充气气体与袋体的相互作用,建立了基于任意拉格朗日-欧拉算法(ALE)的气帘仿真模型,详细介绍了ALE模型相关组成部件、参数设置和接触定义方法,并利用LS-DYNA软件对该模型进行了仿真验证,最后将所建的气帘ALE模型初步应用到某车侧面碰撞仿真中,以考察气帘对乘员的保护作用.     

Occupant position detection system (OPDS) for side airbag system

In order to prevent injury of the occupant of the passenger seat when a side airbag deploys, we have developed an occupant position detection system. It detects the occupant's head entering the side airbag deployment zone. If so, the side airbag operation is inhibited and an indicator light on the side airbag alerts the occupant to the improper sitting position. It detects accurately the occupant's size and the head entering the side airbag deployment zone, using an occupant identification algorithm and electrostatic capacity sensors under the seat trim cover which determine the dielectric around the seat surface.     

Feature-Based Cad System Buildup for Passenger Airbag Design

The passenger airbag (PAB) requires a large volume and fast deployment because of the large distance between the dashboard and the passenger. And various shapes and sizes of the PAB are required depending on the type of vehicle. However, since the PAB modeling process for each design change is complicated and time consuming, the design parameters of the PAB could not be well investigated. In this study, a unique feature-based CAD system has been proposed that easily constructs PAB CAD model and then generates PAB FE model for collision analysis. Main keypoints and widths of PAB that determine the shape and size have been extracted by analyzing the geometric-feature of airbag. The PAB CAD model can be easily constructed by inputting keypoints and widths information. Then, from the constructed PAB CAD model, the PAB FE model is automatically generated. Finally, the generated PAB FE model can be directly employed for collision analysis, thereby reducing the modeling time of the PAB and enabling efficient parametric studies on design.     

Stereovision-based real-time occupant classification system for advanced airbag systems

Occupant classification in a passenger seat is one of the critical components for any advanced airbag system. Many automotive electronic suppliers and engineers predict that the camera will be the next generation sensor for active and passive safety systems because it has several advantages compared to other sensors. The present paper describes a stereovision-based occupant classification system (OCS) and intelligent algorithm with embedded system by which triggering of the airbag deployment can be controlled. The system consists of a pair of stereo cameras and dual Digital Signal Processor (DSP): the first DSP is for the stereo matching processing, and the second is for occupant classification. The results show that the reaches 97%, and the processing time is 960 ms. Such performance indicates that the feasibility of the system as an embedded OCS is high.     

基于CAB气囊展开问题的研究

实车试验出现CAB气囊后腔展开后飘动,扫到假人头部,且气囊后腔展开速度比前腔慢等问题,本文以此为切入点,简述如何通过改变气囊折叠方式、改变气囊花型的方法,改善CAB气囊展开状态的问题。通过此问题的改善,为后续CAB气囊开发提供经验积累。     

侧气帘展开对内饰影响的仿真研究

应用Hypermesh和LS—DYNA软件基于粒子法对复杂侧气帘经行了仿真建模，设计了静态起爆滑块冲击试验以验证仿真模型的有效性，重点研究了侧气帘展开过程对周边内饰的影响。研究结果为侧气帘及内饰系统的设计提供了有效的参考。     

Simulation of an airbag deployment in out-of-position situations

The commonly used 'uniform pressure method' (UP) is a well-tried method to simulate an airbag deployment in accident cases. Nevertheless, this method indicates rather heavy inadequacies at the examination of the airbag deployment in the first milliseconds. A solution is the airbag deployment calculation by using computational fluid dynamics (CFD) methods, wherein the calculated gas flow pressure may be applied 'correctly' to the airbag shell elements.

This CFD simulation is integrated in LS-Dyna with the so-called Arbitrary Lagrangian Eulerian (ALE) method and in this review the result's accuracy will be discussed. According to the FMVSS 208, an OoP model will be built-on and comparisons with simulations and tests are done. Another important detail in this labour is the airbag cover examination and the tear seam modelling, as a trivial FE modelling cannot be done due to the very fine mesh. So two possible solutions for tear seam modelling are introduced and discussed. Furthermore considerations concerning the gas generator combustion will also be revealed and an analysis about the impossibility of the direct comparison between gas generator tank test and airbag deployment will be done. At least some parameters, which take effects in the simulation, are researched and evaluated, so finally an optimised simulation model can be made available for further examinations.     

Performance evaluation of slim low-risk-deployment dual-type passenger airbag system with dispersed inflation pressure

Motor vehicle passenger airbags have been proven to be effective for reducing the possibility of passenger injury during a crash. However, the inflation of the airbag sometimes causes serious injury when a passenger is positioned close to the airbag. The United States Federal Motor Vehicle Safety Standard (FMVSS) 208 requires the use of a low-riskdeployment (LRD) passenger airbag system. This paper proposes a newly developed airbag system comprising two slim airbags mounted on the instrument panel. A series of tests were conducted using the FMVSS 208 test procedures to demonstrate the effectiveness of the proposed system. It was found that the system not only satisfied the injury criteria of FMVSS 208, but was also effective for protecting passengers of all sizes.