Stereoscopic Camera-Sensor Model for the Development of Highly Automated Driving Functions within a Virtual Test Environment

The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.

5G technology requirements and related test environments for evaluation

To meet the considerably increase of mobile data traffic and wireless communication connections around 2020,the 5th generation(5G)mobile network will necessarily consider more frequency bands,enabling technologies and diversified key performance indicators and test environments comparing with existing network,for example Long Term Evolution.More specifically,the obvious difference between 5G and previous wireless communication system are not only included eMBB(enhance mobile broadband) usage scenario,but also introduced mMTC(massive machine type communications)and URLLC(ultra-reliable and low latency communications) usage scenarios.Hence,in order to evaluate 5G related technologies,some novel test environments will be widely discussed,as well as,certain new key performance indicators will be drawn into5 G evaluation methodology for satisfied new requirements.We will discuss characteristic of these 4 candidate test environments,such as indoor isolated environment,high speed train environment;and the definition of 15 keys performance indicator will be explained and clarified,for example,Throughput,Network Energy Efficiency,Device Connection Density and so on.Furthermore,high-level assessment method of each test environment also will be initially considered.It is notable that an initial evaluation of indoor isolated environment also can be found,which the results show that there are 3 times average cell spectral efficiency than IMT-advanced's in same test environment.

文献“Environmental Testing for Launch and Space Vehicles”点评

作者根据多年的实践经验,对该文献中重要部分进行了点评,指出:空间系统的结构设计要“严格”按照环境设计来进行考核,而环境试验的目的除了筛选工艺质量之外,更重要的是验证设计载荷是否合理。文章还分别对声、振动和冲击试验中的关键步骤和内容进行了解析和说明。

Tribological behaviors of hydrogenated diamond-like carbon films in different testing environments

Hydrogenated diamond-like carbon (DLC) films were deposited on Si substrate using plasma enhanced chemical vapor deposition(PECVD) technique with CH4 plus H2 as the feedstock. The tribological properties of the hydrogenated DLC films were measured on a ball-on-disk tribometer in different testing environments (humid air,dry air, dry O2, dry Ar and dry N2 ) sliding against Si3 N4 balls. The friction surfaces of the films and Si3 N4 balls were observed on a scanning electron microscope (SEM) and investigated by X-ray photoelectron spectroscopy (XPS). The results show that the tribological properties of the hydrogenated DLC films are strongly dependent on the testing environments. In dry Ar and dry N2 environments, the hydrogenated DLC films provide a superlow friction coefficient of about 0. 008 -0.01 and excellent wear resistance (wear life of above 56 km). In dry air and dry O2, the friction coefficient is increased to 0. 025 - 0.04 and the wear life is decreased to about 30 km. When sliding in moist air, the friction coefficient of the films is further increased to 0. 08 and the wear life is decreased to 10. 4 km. SEM and XPS analyses show that the tribological behaviors appear to rely on the transferred carbon-rich layer processes on the Si3 N4 balls and on the friction-induced oxidation of the films controlled by the nature of the testing environments.

The Application of GGE Biplot Analysis for Evaluating Test Locations and Mega-Environment Investigation of Cotton Regional Trials

In the process to the marketing of cultivars, identification of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction（GGE） biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley（YaRV）, China. Four traits（cotton lint yield, fiber length, lint breaking tenacity, micronaire） and two composite selection indices were considered. It was found that the assumption of a single mega-environment in the YaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments： a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identification of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, Sichuan Province, China, was found to be desirable for none.

Problems of Environmental Acceptance Tests on Power Transmission and Transformation Projects

Based on the experience of environmental acceptance tests for power transmission projects, the problems found in acceptance tests and the system shortcomings of acceptance test itself are analyzed. Recommendations are provided to improve the future work.

长三角地区集中式露地农业光伏方阵夏季光热环境试验研究

基于太阳照度和环境温度逐时变化,以长三角地区的集中式露地农业光伏方阵为研究对象,在跨度为6.8 m的单跨方阵中沿从南到北的跨度方向取0.65、3.40、6.15 m处的3个和长度方向共面的测试断面,即南区、中区、北区。基于此,进行夏季方阵内外的光热环境测试,分析并明确光伏组件下方区域的光热环境变化规律,为其太阳能资源合理利用、结构改进和夏季农业生产管理提供参考。结果表明,该地区光伏方阵夏季内部3个区域光热环境呈现规律性差异,整体表现为北区略优于南区,中区优于南、北两区。综合考虑作物生长的光热环境需求,一方面可通过结构改进、种植方式优化等方式改善或利用好内部光环境;另一方面基于热环境规律,分类做好内部3个区的夏季灌溉等田间管理,从而推动光伏农业发展升级。

空空导弹海洋大气自然环境试验研究

针对空空导弹随航母服役需求和海洋大气自然环境适应性风险,结合相关标准和研制经验,对空空导弹海洋大气自然环境试验方案设计流程、方法及要点进行了研究。提出了一套空空导弹海洋大气自然环境试验方案,可用于指导新研型号科学有效地开展自然环境试验,为回答空空导弹海洋大气自然环境适应性指标提供了支撑。空空导弹应系统策划海洋大气自然环境试验,以尽早暴露问题,实现产品设计改进,为上舰环境适应性的提高奠定基础。同时,还应大力开展自然加速环境试验技术和动态自然环境试验技术研究工作。

岩土工程勘察、测试与评价进展

文章全面总结了近5年岩土工程勘察测试与评价领域的技术进展,主要包括土工室内试验技术,原位测试技术、模型试验以及岩土工程勘察测试智能化技术。重点介绍了特殊环境(低温)试验技术、特殊材料(含气土、污染土等)、新型微观分析、技术原位测试新功能与新应用、水陆域超深原位测试技术、土工离心机技术、大型模型试验技术、智能勘察技术、智能监测技术、智能评价技术以及岩土工程智能管理平台建设等方面的进展。分析表明,重大工程建设、低碳绿色理念、智能技术、极端环境催生了一批岩土工程勘察测试新技术与新方法,智能化测试与评价是未来一段时期我国岩土工程勘察评价技术发展的方向。

Genotoxicity Tests and Their Contributions in Aquatic Environmental Research

As many chemicals with genotoxic potential are emitted to surface water, genotoxicity tests are gaining importance which led to the development of several techniques to detect directly DNA damage. The relevance of detecting the genotoxic risks associated with water pollution was firstly perceived in the late 1970s. Since that time several tests have been developed for evaluating DNA alterations in aquatic animals. These tests rely on the premise that any changes to DNA may have long-lasting and profound consequences. Sister chromatid test, chromosome aberrations, comet assay, and micronucleus test are currently the most widely employed methods to detect DNA lesions in ecotoxicology. Chromosomal aberration and sister chromatid exchanges are time consuming, resource intensive and require proliferating cell population. Hence, Comet assay and Micronucleus test as cost effective and more sensitive test systems have now been introduced for assessing the genotoxicity of chemicals. This review presents a synthesis of the state of the art in the methodologies of comet assay and micronucleus test and their contributions in aquatic environmental research. The text explores the latest knowledge and thinking on these very important approaches for the assessment of environmental health, management, and conservation. The primary concern of the present review is the measurement of genotoxic potential in aquatic organisms under field and laboratory conditions, where effects of chemicals at different levels of biological organization can be examined.

荒漠草原不同植物群落蒸散组分特征及其环境因子影响分析

蒸散发是生态水文过程的关键环节,掌握蒸散组分的变化特征及其影响因子,对干旱半干旱地区的可持续发展至关重要。以荒漠草原多年生植物针茅群落和一年生植物猪毛蒿群落为研究对象,利用小型蒸渗仪开展了连续3年监测,分析了蒸散组分的日、月和年变化规律,探讨了影响蒸散组分的主要环境因子。结果表明:晴天时,多年生和一年生植物群落蒸散组分呈先增加后减小的抛物线型,夜间蒸散活动较弱,累积蒸散量较低,不足全天总累积蒸散量的20%;阴天时各蒸散组分无明显峰值,且日累积量均较小,一年生和多年生植物群落的蒸散量、蒸发量和蒸腾量无显著差异;10.64 mm/d及以上降雨对蒸散和蒸发的日变化具有明显影响,随着降雨量的增多,蒸散量和蒸发量也呈增大趋势,但蒸腾量则相对较小。从月动态来看,7—9月占全年蒸散量和蒸发量的一半左右,冬春季蒸散量和蒸发量维持在全年最低水平。年蒸散量与年降雨量接近,而蒸腾量占蒸散量的比例低于10%。总体来看,多年生植物群落蒸散量较一年生植物群落多。采用Mantel检验方法分析不同时间尺度影响蒸散组分的主要气候因素,在小时尺度上太阳辐射与蒸发量和蒸腾量显著性水平较高(P<0.01),但相关性较低(r<0.2);在日尺度上,蒸散量、蒸发量和蒸腾量与降雨量的显著性(P<0.01)和相关性(r≥0.4)均最高;而月尺度上,降雨量和降雨速率与蒸散量、蒸发量的相关性较高(0.2≤r<0.4),但显著性较低(P≥0.05)。因此,蒸散组分受环境因子的影响在不同时间尺度上具有较大差异,说明蒸散组分受多种因子共同影响。

新型Bell实验法环境应力开裂测试装置

自主设计并搭建了自动刻痕装置和压弯装置,提高了刻痕质量和测试结果的可重复性,同时采用改进的Bell实验方法对高密度聚乙烯材料的环境应力开裂行为进行了系统实验研究。结果表明,试剂浓度、刻痕偏移量、刻痕倾斜角度、刻痕刀片厚度的改变均会对环境应力开裂时间产生较大的影响;裂纹起裂位置既不在试样弯曲变形最大的中间位置,也不在刻痕边缘,而是在距离刻痕边缘约6.38 mm的位置。

船用柴油机排放耐久性试验方案及分析

为了改善我国内河及沿海船机的污染物排放现状,我国颁布了GB 15097-2016,并提出了船机及其后处理装置的耐久性试验要求。根据前期完成的几组耐久性试验的特点,对试验方案的制定和实施过程进行梳理。并结合某型中速船机的耐久性试验数据,分析环境因素变化对排放特性的影响。分析结果表明,NO_(X)比排放量和劣化趋势受环境因素变化的影响较严重,尤其是在温湿度变化剧烈的节点;PM比排放量的变化规律不明显。为了减少耐久性试验过程中环境因素不确定性的影响,试验方案的实施过程控制尤为重要。

新形势下航天装备环境试验技术的未来发展趋势

从航天装备面临的实战化考核、数字化建设和低成本控制等新形势与新要求出发,梳理了环境试验技术在航天装备试验鉴定中存在的实战化考核能力不足、全寿命周期环境效应考核不充分等技术难题,结合航天装备环境试验的国内外发展现状,系统分析了航天装备环境试验技术的未来发展趋势,试验环境综合化、试验设计一体化、试验手段数字化在提升航天装备环境试验水平、缩短装备试验周期、降低试验成本方面具有显著优势,也是航天装备环境试验未来发展的重要方向。

装备环境适应性研究进展及展望

首先分析了装备环境适应性的基本概念及其与装备环境工程的关系,论述了装备环境适应性研究工作内涵。其次,综述了装备环境适应性研究“六化”特征:自然环境试验站网建设全球化、装备环境适应性试验考核实战化、表征评估精细化、设计迭代化、资源积累数据化、综合管理体系化等,讨论了各方向的国内外发展现状以及研究重点、难点、不足,梳理了装备环境适应性在环境试验、环境分析等方面相关标准及其发展特点,并指出现有标准的局限性。最后,根据现阶段国家关于装备环境适应性的工作定位,展望了装备环境适应性研究领域重要发展方向。

新时期航天器环境工程面临的挑战与机遇

空间事业的发展对航天器环境工程提出了新挑战,同时也为该专业技术进步和领域延展提供了难得的机遇。近10年来,伴随着载人航天、深空探测等一系列重大航天工程的顺利实施,中国航天器环境工程领域在诸多方面取得了长足进步。文章回顾了中国航天器环境工程的发展历程,围绕中国空间站长期运行、深空探测新任务、低轨巨型星座建设等提出的新需求,分析了航天器环境工程将面对的挑战和必须突破的关键技术。结合具体工作内容介绍了北京卫星环境工程研究所在LEO辐射环境在轨探测与数据应用、特殊空间环境效应与防护、火星探测器特殊力热环境试验技术和航天器产品环境试验ISO标准等方面取得的最新进展。在建设航天强国的过程中,航天器环境工程必将伴随着航天器整体技术的升级实现更高水平的跃迁。

舰船环境试验国家军用标准现状研究

舰船国军标是确保国家海防安全和军事效能的重要组成部分,通过设定科学合理的技术标准,可以确保舰船在海洋极端环境下保持最佳的性能。通过实施这些严格的标准,不仅能够提升装备的质量和性能,还能推动相关领域科技的快速发展,为国家的安全提供坚实的技术支撑。

某高导热绝缘胶在星载端机可靠性应用评价

针对星载端机对高导热绝缘底填胶可靠性应用需求,开展双组分高导热绝缘胶可靠性及环境适应性综合影响评估。通过导热绝缘胶性能测试标准样件,测试验证本征性能指标及工艺性指标,并分析评估其合格性;设计制作典型BGA菊花链网络结构样件,采用导热胶填充工艺技术,验证导热绝缘胶空洞率对BGA器件焊点的影响,评价其工艺适应性;设计制作星载端机载荷,开展星载产品验收级环境与可靠性试验,验证端机载荷具有经受工作应力和环境应力的能力。该高导热绝缘胶满足星载产品散热及抗高载荷的需求,实现可靠性应用。

复合材料复杂环境效应加速试验设计及评估方法

目的指导复合材料在复杂湿热环境下环境适应性摸底与评价试验的开展,分析评估复合材料在复杂综合应力下的激活能参数。方法分析装备全寿命周期复杂自然环境剖面及各环境因素影响效应,确定复合材料各工作阶段敏感应力类型及条件,基于应力加速模型及累积损伤等原理,制定复合材料复杂环境效应综合加速试验剖面。构建复合材料复杂环境条件下的动力学模型,并提出相应参数估计方法。开展复合材料加速试验,并基于实测数据开展复合材料性能退化建模与评估。结果分析了复合材料全寿命周期环境影响因素及环境效应,明确了各工作阶段敏感应力主要有温度、湿度、太阳辐照、温度交变、振动以及冲击等。依据实际环境数据,设计并开展了3组不同湿热条件(80℃/75%RH、80℃/85%RH、80℃/95%RH)的综合试验,收集得到复合材料拉伸强度、拉剪强度、径向弯曲强度以及纬向弯曲强度等4种性能指标的试验数据。试验数据表明,拉剪强度(最大相对退化速率为0.1773/循环)、径向弯曲强度(最大相对退化速率为0.1292/循环)以及纬向弯曲强度(最大相对退化速率为0.2610/循环)等性能参数可用于产品退化建模与评估。通过参数估计,进一步确定了退化速率与湿热应力的关系,并针对当前试验提供了改进依据。结论复杂环境效应综合加速试验对装备复合材料产品经历复杂环境条件的模拟效果和加速效果较好,试验可实施性较强。提出的改进广义Eyring模型可涵盖温度应力与湿热应力的加速效应,并综合考虑多种应力的相互作用,通过少量组合试验便可量化评估激活能等参数。所建模型指出当前基于激活能参考值(Ea=0.7eV)试验方案可由不同温度应力的综合试验数据进一步修正与优化,且所提试验与分析方法主要针对大部分树脂基复合材料产品,并可依据需要推广至电子产品、机电产品等试验对象。

建筑节能检测中的常用保温材料分析

近年来,我国经济由高速发展阶段转向高质量发展阶段,建筑领域也在追求发展质量的同时积极响应国家号召,注重节能环保,实现建筑材料的生态化,更加符合当代人们对建筑的需求。随着社会不断进步,建筑节能检测中常用的环保材料在升级革新,种类繁多,保温材料的运用使得建筑功能更加健全,而如何选择最佳环保材料是建筑行业在节能检测中的重要一环。本文着重研究几类市面上常见的保温材料的性能、适用环境等,以期为建筑行业提供参考。