NVH

  • 文章类型: Journal Article
    髓磷脂少突胶质细胞糖蛋白-IgG相关病症(MOGAD)和视神经脊髓炎谱系病症(NMOSD)都是中枢神经系统的脱髓鞘疾病。他们表现出相似的临床表现,如视神经炎,脊髓炎和后区综合征(APS)。视神经神经炎(ON)和脊髓炎之间的区别已被详细阐述,而它们在APS中的差异仍有待阐明。我们的目的是报告APS在MOGAD患者以及NNOSD患者中的频率。并比较MOGAD患者和NMOSD患者的APS特征。
    在2017年至2022年之间回顾性确定了7例MOG-IgG阳性APS患者。先前已经描述了APS表型。比较MOGAD和NMOSD患者APS的异同,包括APS在两种疾病之间的频率和持续时间,并对其伴发幕下病变的发生率进行了描述和比较。
    我们回顾了218名MOG-IgG阳性患者的队列,396例NMOSD患者。本研究包括200名MOGAD患者和332名NMOSD患者。在队列中,分析了7例出现APS的MOG-IgG抗体阳性患者,其中4人因APS发病。在332名NMOSD患者中,47人患有APS发作,而31人在疾病发作时患有APS。在MOGAD患者中,2有恶心,3有呕吐,5打嗝,1例患者出现上述三种症状。在NMOSD患者中,70.2%有恶心,在APS发作期间同时呕吐和打嗝。除了延髓,6/7MOGAD患者的其他幕下区域也受到影响,而14/47NMOSD患者的其他幕下区域也受到影响。在APS攻击期间,MOGAD中脑干和其他区域伴随病变的发生率明显高于NMOSD队列(P=0.008*).
    APS是一种罕见的,但不是MOGAD的孤立临床表现。MOGAD中其他幕上和幕下病变发生APS的频率更高。NVH的症状(恶心,呕吐,打嗝)与NMOSD相比,在MOGAD中倾向于分别发生。APS在MOGAD中的表型或机制可能与NMOSD中的表型或机制不同。
    UNASSIGNED: Both myelin oligodendrocyte glycoprotein-IgG associated disorders (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD) are demyelinating diseases of the central nervous system. They present similar clinical manifestations such as optica neuritis, myelitis and area postrema syndrome (APS). The distinctions of optica neuritis (ON) and myelitis between them have been elaborated to great length while their differences in APS remain to be elucidated. We aim to report the frequency of APS in patients with MOGAD as well as NNOSD patients, and to compare the characteristics of APS between patients with MOGAD and those with NMOSD.
    UNASSIGNED: Seven MOG-IgG positive APS patients were retrospectively identified between 2017 and 2022. APS phenotypes have been previously described. The similarities and differences between MOGAD and NMOSD patients with APS was compared, including the frequency and duration of APS between the two diseases, and their incidences of accompanied subtentorial lesions have also been described and compared.
    UNASSIGNED: We reviewed a cohort of 218 MOG-IgG-positive patients, and 396 patients with NMOSD. 200 MOGAD patients and 332 NMOSD patients were included in this study. In the cohort, seven patients with MOG-IgG-positive antibody presented with APS were analyzed, four of whom had disease onset with APS. Of the 332 patients with NMOSD, 47 had APS attacks while 31 had APS at disease onset. In patients with MOGAD, 2 had nausea, 3 had vomiting, 5 had hiccups, and 1 patient presented with all three symptoms above. In patients with NMOSD, 70.2 % had nausea, vomiting and hiccups at the same time during APS attacks. Apart from the medulla oblongata, other subtentorial regions were also affected in 6/7 MOGAD patients while 14/47 NMOSD patients had other subtentorial regions involved. During an APS attack, the incidence of concomitant lesions in the brainstem and other regions was significantly greater in MOGAD than in the NMOSD cohort (P = 0.008*).
    UNASSIGNED: APS is a rare, but not isolated clinical manifestation of MOGAD. APS happened more frequently with other supratentorial and subtentorial lesions in MOGAD. The symptoms of NVH (nausea, vomiting, hiccups) tended to happen respectively in MOGAD compared with NMOSD. The phenotype or mechanism of APS in MOGAD may differ from that in NMOSD.
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  • 文章类型: Journal Article
    向混合动力和电动汽车的持续转变对噪声和振动工程产生了强烈影响。新,由于内燃机的缺失以及在车辆和驾驶感觉感知中的重要作用,复杂的动态现象引起了车辆用户的注意。本文提出了一种汽车电动助力转向总成的有限元动态仿真模型。实施了初步的模态仿真和实验以及现场数据复制技术,以识别现象并准备和验证模型组件。建立了电动助力转向系统的全动力学模型,和微调,包括润滑在齿轮啮合界面的存在。与FEM模拟一起进行了各种模型设置的实验研究。实现了线性和非线性接触刚度模型,以及接触阻尼,并在选定的装配界面进行模拟。结果表明,在NVH(噪声振动和不平顺性)分析的情况下,冲击/冲击起源问题,用于静态的接触参数,准静态,低速分析不适用。非线性和阻尼接触刚度在这种情况下提供了更好的结果。
    The ongoing shift towards hybrid and electric vehicles has a strong impact on noise and vibration engineering. New, complex dynamic phenomena are brought to vehicle user attention due to the absence of internal combustion engines and the significant role in vehicle and drive feel perception. This paper presents an FEM (Finite Element Method) dynamic simulation model of an automotive Electric Power Steering assembly. Preliminary modal simulations and experiments as well as field data replication techniques were implemented to identify the phenomena and prepare and validate model components. A full dynamic model of an Electric Power Steering was presented, and fine-tuned including the presence of lubrication at the gear mesh interface. Experimental investigations were conducted alongside FEM simulations for various model setups. Linear and nonlinear contact stiffness models were implemented, as well as contact damping, and simulated at chosen assembly interfaces. The results indicated that in the case of NVH (Noise Vibration and Harshness) analysis of shock/impact originating problems, contact parameters used for static, quasi-static, and low velocity analyses were not applicable. Nonlinear and damped contact stiffness provided better results in such a case.
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  • 文章类型: Journal Article
    噪音的新发展过程,振动,使用具有长期NVH驾驶数据的数据分析和机器学习来呈现车辆的不平顺性(NVH)。该过程包括探索性数据分析(EDA),变量重要性分析,相关分析,敏感性分析,和发展目标选择。在本文中,大幅缩短与车辆NVH相关的开发周期和成本,我们提出了一种技术,可以准确地识别车辆系统和NVH因素之间的精确连接和关系。这种新技术利用了整个大数据,反映了动态特性的非线性,这在现有方法中没有考虑,并且没有数据被丢弃。通过所提出的方法,通过相关性分析和变量重要性分析,可以快速找到需要改进的地方,通过灵敏度分析了解当系统的NVH水平变化时房间噪声增加了多少,并通过提高效率来减少车辆开发时间。该方法可用于开发过程以及其他深度学习和机器学习模型的验证。这可能是应用人工智能的重要一步,大数据,以及车辆和出行行业的数据分析作为未来车辆的发展过程。
    A new development process for the noise, vibration, and harshness (NVH) of a vehicle is presented using data analysis and machine learning with long-term NVH driving data. The process includes exploratory data analysis (EDA), variable importance analysis, correlation analysis, sensitivity analysis, and development target selection. In this paper, to dramatically reduce the development period and cost related to vehicle NVH, we propose a technique that can accurately identify the precise connectivity and relationship between vehicle systems and NVH factors. This new technique uses whole big data and reflects the nonlinearity of dynamic characteristics, which was not considered in existing methods, and no data are discarded. Through the proposed method, it is possible to quickly find areas that need improvement through correlation analysis and variable importance analysis, understand how much room noise increases when the NVH level of the system changes through sensitivity analysis, and reduce vehicle development time by improving efficiency. The method could be used in the development process and the validation of other deep learning and machine learning models. It could be an essential step in applying artificial intelligence, big data, and data analysis in the vehicle and mobility industry as a future vehicle development process.
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  • 文章类型: Journal Article
    随着电池电动汽车(BEV)市场份额的增长,我们必须了解噪音,振动,以及在BEV内部发现的粗糙性(NVH)现象使这种技术革命成为可能。类似于传统车辆,直到今天遇到了许多NVH问题,BEV必须面对许多新的和棘手的NVH问题。例如,传统的车辆由内燃机(ICE)提供动力,内燃机是主要的噪声源。来自其他来源的噪音通常被内燃机掩盖,因此,研究重点是减少燃烧发动机,而较少关注其他来源的噪声。BEV没有冰,自动变速器,分动箱,燃油箱,进气口,或排气系统。在他们的地方,有足够的空间来容纳电驱动单元和电池组。BEV在没有内燃机的情况下更安静,然而,对车辆NVH的研究甚至更重要,因为消除内燃机会暴露BEV的许多噪声行为,这些行为以前被忽略,但现在看起来很明显和恼人。最近对BEV的NVH进行了研究,主要集中在降低动力总成引起的噪声上,轮胎,风和辅助系统以及音质的改善。本文将重点介绍BEVNVH研究的最新进展,以促进BEV系统的未来发展。这是对理论的回顾,计算,以及过去几年学术界和工业界进行的实验工作。
    As battery electric vehicle (BEV) market share grows so must our understanding of the noise, vibration, and harshness (NVH) phenomenon found inside the BEVs which makes this technological revolution possible. Similar to the conventional vehicle having encountered numerous NVH issues until today, BEV has to face many new and tough NVH issues. For example, conventional vehicles are powered by the internal combustion engine (ICE) which is the dominant noise source. The noises from other sources were generally masked by the combustion engine, thus the research focus was on the reduction of combustion engine while less attention was paid to noises from other sources. A BEV does not have ICE, automatic transmission, transfer case, fuel tank, air intake, or exhaust systems. In their place, there is more than enough space to accommodate the electric drive unit and battery pack. BEV is quieter without a combustion engine, however, the research on vehicle NVH is even more significant since the elimination of the combustion engine would expose many noise behaviors of BEV that were previously ignored but would now seem clearly audible and annoying. Researches have recently been conducted on the NVH of BEV mainly emphasis on the reduction of noise induced by powertrain, tire, wind and ancillary system and the improvement of sound quality. This review paper will focus on recent progress in BEV NVH research to advance the BEV systems in the future. It is a review for theoretical, computational, and experimental work conducted by both academia and industry in the past few years.
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