Assessing the operational design domain of lane support system for automated vehicles in different weather and road conditions

With the growing rate of automated vehicles(AVs)at the lower level of automation,the experimental tests are also in progress with vehicles at higher levels.In the absence of extended digital infrastructures and deployment of level 5 full automated vehicles,the physical infrastructure is required to maintain a fundamental role to enable their introduction in public roads.This paper focuses on lane support system(LSS)whose operational design domain(ODD)is strongly connected to the road characteristics and conditions.An experimental test was carried out with a state of the art,and LSS and advanced technologies were used for road monitoring on different roads under various environmental conditions including dry,wet pavements and rain.We applied the generalized estimation equation for logistic regression to account within-cluster homogeneity which is induced by repeated measures on the same road sections.Statistical models allow the identification of variables that are significant for the LSS fault probability among various effects of road features including marking,pavement distress,weather conditions,horizontal curvature,and cross section.Results pointed out the relevance of the wet retro-reflection of marking(RLw)and the horizontal curvature in the definition of ODD for LSS.Threshold values have been proposed for the tested LSS.Wet pavement doesn’t affect the LSS performance when compared to the dry condition.Rain was shown to be critical even with very good road characteristics.

Multi Domain Design of Fluid Machinery

The scope of the paper is the design of a fluid machinery with a multiphysics procedure, through CAD （computer-aided design）-CAE （computer-aided engineering）-CAx （computer-aided technologies） tools. The study of a wind turbine is a perfect example of a project that requires an interdisciplinary team design, in fact for such a project mechanical structure, and CFD （computational fluid dynamics） designers are necessary. In addition, in the last years, the multi domain design has been supported by the continuous development of software for computer-aided design and the unceasing increase of the connection between performances and computer costs： the final aim is to propose the instruments that assist the designer throughout all the steps of the project. The multi domain design, illustrated in this article, is based on how to design the wind turbine, and it is not about process management and manufacturability. In particular, in the article, the emphasis will be placed on the integration between CAD and mathematical software of general type and on the CAD-CAE integration.

Aerodynamic Design of Airfoils Based on Variable-Domain Variational Finite Element Method

Designing airfoils according to given pressure (or velocity) distribution is one kind of free boundary problems. Free boundary condition can be coupled with the flow governing equations by variable-domain variational calculus, which makes it possible to calculate simultaneously the flow field and the free boundary. An accurate deduction of the variable-domain variational principles is taken herein to design airfoils in compressible and incompressible flows. Furthermore, two grid types (H and O) are used in the calculation with better results for the O-type grid. It is shown that convergence is accelerated and good results can be obtained even if the initial guessed airfoil shape is a triangle, demonstrating the strong adaptability of this method.

高架桥车辆行驶引起的环境振动研究

随着高科技产业的快速发展,对精密工程结构中产品质量的要求日益提高,其中微振动控制成为关键因素。针对西安某微电子厂房建设项目,考虑到周边高速公路高架桥对拟建场地可能产生的微振动影响,进行了详细的现场测试与分析。通过布置测点,采用高灵敏度振动传感器和数据采集系统,记录了南北、东西和垂直方向的振动速度。测试结果表明,高速公路高架桥的微振动水平处于VC-D—VC-C之间,可为芯片厂房的选址和隔振设计提供科学依据,对类似精密工程结构的防微振设计具有参考意义。

Influence of Software Modeling and Design on Domain-Specific Abstract Thinking: Student’s Perspective

Software engineering has been taught at many institutions as individual course for many years. Recently, many higher education institutions offer a BSc degree in Software Engineering. Software engineers are required, especially at the small enterprises, to play many roles, and sometimes simultaneously. Beside the technical and managerial skills, software engineers should have additional intellectual skills such as domain-specific abstract thinking. Therefore, software engineering curriculum should help the students to build and improve their skills to meet the labor market needs. This study aims to explore the perceptions of software engineering students on the influence of learning software modeling and design on their domain-specific abstract thinking. Also, we explore the role of the course project in improving their domain-specific abstract thinking. The study results have shown that, most of the surveyed students believe that learning and practicing modeling and design concepts contribute to their ability to think abstractly on specific domain. However, this finding is influenced by the students’ lack of the comprehension of some modeling and design aspects (e.g., generalization). We believe that, such aspects should be introduced to the students at early levels of software engineering curriculum, which certainly will improve their ability to think abstractly on specific domain.

基于Design X软件的复杂曲面逆向设计应用

本文以逆向工程软件Geomagic Design X为基础,以复杂自由曲面塑料瓶的逆向造型为例,重点介绍了基于领域组划分与特征识别的快速高效数字化建模技术一般流程。最后,通过点云数据与数字化模型的偏差分析,验证了该建模方法具有快速、高效、准确度高等优点。

Domain-Service信息系统框架分析与设计

分析和设计了一个Domain-Service信息系统框架,并对系统框架运用模式设计、SOA和Domain-driven Design等思想进行分析和介绍,阐述了该框架在构建信息系统的灵活性。

Dynamic Accuracy Design Method of Ultra-precision Machine Tool

Ultra-precision machine tool is the most important physical tool to machining the workpiece with the frequency domain error requirement, in the design process of which the dynamic accuracy design(DAD) is indispensable and the related research is rarely available. In light of above reasons, a DAD method of ultra-precision machine tool is proposed in this paper, which is based on the frequency domain error allocation.The basic procedure and enabling knowledge of the DAD method is introduced. The application case of DAD method in the ultra-precision flycutting machine tool for KDP crystal machining is described to show the procedure detailedly. In this case, the KDP workpiece surface has the requirements in four different spatial frequency bands, and the emphasis for this study is put on the middle-frequency band with the PSD specifications. The results of the application case basically show the feasibility of the proposed DAD method. The DAD method of ultra-precision machine tool can effectively minimize the technical risk and improve the machining reliability of the designed machine tool. This paper will play an important role in the design and manufacture of new ultra-precision machine tool.

Geometry Services Construction Based on Ontology towards Cooperative Design in Cloud Environment

APIs of CAD system could be encapsulated to construct web services so as to provide standard access interfaces for web-based cooperative design. However, lack of semantic supporting make integration of heterogeneous modelling system limited to operational level. On the purpose of carrying out cooperative design in a flexible cloud environment, an intelligent and effective support mechanism is needed for mass and complex interaction in cooperative work. Therefore, Ontology-based Geometry Modeling Services Environment （OGMSE） is provided to realize a knowledge-level geometry modeling so as to supported semantic 3D model management and intelligent operation support. First, CAD APIs are encapsulated into web service for web invocation. Then, ontology contained structural semantic and operational semantic is built for management of models and modeling process. Lastly, conception-driven modeling mechanism is built to invocate service according to interaction requirement, thus to realize conception-level cooperative design. Based on an open geometry engine, a prototype system has been developed. The result shows that the approach provides a reference direction for large-scale application on the network.

学科交叉背景下2023年产品设计研究进展及反思

为进一步推动产品设计研究向着更深、更广的跨领域融合方向发展,通过文献研究法、Cite Space关键词共现分析及可视化呈现,系统梳理和深度剖析2023年度涵盖国家政策导向、教育体系改革、学术期刊论文发表概况、学位论文热点主题、国家级基金获批项目、高校与学术机构的论坛会议等多维度资料,揭示产品设计研究领域在学科交叉背景下的发展现状和特点,总结当前产品设计研究在跨学科交融过程中所面临的问题,展望了产品设计研究面向未来社会发展与产业需求、立足本土文化、跨领域创新理论与实践成果的高度融合等核心趋势,对未来研究方向做出了前瞻性的预测与建议。

单元感知测试的优化方案

越来越多的半导体公司采用新型故障模型——单元感知测试(Cell Aware Test,CAT)来提高库单元内部覆盖率和低缺陷率,但CAT在自动测试向量生成(Auto Test Pattern Generation,ATPG)过程中使用的测试向量数量多,运行时间长,显著地增加测试成本。为了优化CAT,在ATPG流程中加入了总临界区域(Total Critical Area,TCA)和合并时钟域命名捕获过程(Named Capture Procedure,NCP)方法。TCA根据故障类型和最有可能出现故障的位置进行排序,合并时钟域NCP方法为被测知识产权(Intellectual Property,IP)管理时钟域、控制时钟、定义捕获方案。结果表明,结合TCA和合并时钟域NCP方法的CAT达到了提高覆盖率、降低测试向量数量、减少运行时间的优化目标。与以往的CAT优化研究相比,结合了TCA和合并时钟域NCP的CAT优化流程在优化覆盖率和测试向量方面达到了更好的效果。

Canny-Gauss通用域图像隐写算法

自适应图像隐写算法是一种以图像为载体,通过手工设计嵌入失真代价,指导隐写码在图像载体中嵌入秘密消息的信息隐藏算法.长期以来,这类算法将秘密消息尽可能隐藏在图像纹理更深更复杂的位置以对抗基于富特征的隐写分析检测.然而,伴随着深度学习在隐写分析领域的快速发展,人工设计的自适应算法受到严重挑战.此外,基于加性失真的隐写编码在嵌入消息时,复杂纹理向边界聚集所产生的统计异常问题也亟待解决.因此,本文总结了各类人工失真代价的优势和不足,归纳出当前自适应算法在空域的设计范式,并结合UNIWARD在各嵌入域的转换规则,提出基于嵌入失真代价ρ的通用域隐写转换公式.然后,从隐写嵌入失真代价与图像纹理稀疏关系的角度出发,以Canny算子划分纹理、Gauss模糊缩放轮廓、AutoML搜索阈值的方式,提出了一种通用域隐写算法Canny Gauss.实验结果表明,本文所提通用域隐写转换公式能够有效应用于现有主流算法.同时,在UNIWARD所有可行嵌入域中,本文所提算法表达出更高嵌入失真代价稳定性和隐写隐蔽性,在第三方权重加持下的深度隐写分析表现与UNIWARD相比至少提升2.6%、最高提升14.6%.这为自适应隐写算法的通用域设计,以及抵抗基于纹理特征的深度隐写分析检测提供了新思路.

基于时域模型的CLLC谐振变换器参数优化设计方法

CLLC谐振变换器能够实现双向功率传输,具有高功率密度、高效率的特点,但传统的参数设计方法步骤繁琐且求解困难。为此,深入分析CLLC谐振变换器的工作原理和工作特性,综合考虑参数对CLLC谐振变换器增益、模式切换条件、软开关和功率损耗的影响,提出一种基于时域模型的参数优化设计方法,以实现宽电压输出范围和窄频带范围。在2 kW的实验中,所提出的参数设计方法在一定频带范围内效率达到98.3%,证明了时域分析的准确性以及参数优化方法的有效性。

基于延迟校正扩张状态观测器的内置式永磁同步电机电流控制策略

高速电驱动场合会受到开关频率的限制,低载波比特性凸显,由此引起的控制延迟问题影响了内置式永磁同步电机(IPMSM)矢量控制系统性能。基于扩展电动势的建模方案能够获得IPMSM的对称化模型,有利于离散化分析和设计,以提升低载波比运行性能。扩张状态观测器(ESO)能够实现扩展电动势和扰动的集总观测,然而低载波比延迟问题影响了估算性能。该文在离散域中分析延迟影响,设计和对比研究了几种延迟影响抑制方案,即延迟校正扩张状态观测器,提升了估计精度。基于此,设计了IPMSM离散域电流控制方案,显著提升了电流响应特性。通过电动汽车驱动实验平台验证了该文的分析和设计。

时频电磁法频率域视电阻率求取方法研究

时频电磁法(TFEM)是一种应用于油气勘探领域,可同时实现时间域和频率域电磁一体化勘探的可控源电磁方法。本文引入水平电流场源定义的广义视电阻率,结合TFEM的发射源特征,实现TFEM频率域视电阻率的求取;分析不同偏移距、发设距水平电场振幅和视电阻率特征,验证了方法的可行性。TFEM频率域视电阻率的求取和基于模型的研究,为TFEM勘探采集参数的设计和采集数据的处理提供科学的借鉴和参考。

高超声速变体飞行器关键技术研究综述

高超声速变体飞行器有潜力通过变形提升飞行器在宽速域、大空域飞行全包线下的适用性,在未来的民用与军事领域都具有极大的战略意义。本文主要对高超声速变体飞行器的研究进展进行综述,阐述了国内外高超声速和变体飞行器项目的研究进展和现状,并且对现有的高超声速变体飞行器的主要变形方式进行了分类与介绍。同时,总结了高超声速变体飞行器在变构型机构设计方法与理论、高功重比与快速响应的驱动设计、可承载大变形蒙皮、承载/热防护一体化结构设计等方面的技术难点,提出了高超声速变体飞行器的后续研究发展方向,以期对后续高超声速变体飞行器的相关研究提供一定的参考。

基于合并时钟域的片上时钟描述优化方法

多时钟域的可测试性设计有两种描述片上时钟(On Chip Clock,OCC)行为的方法:时钟控制定义(Clock Control Definition,CCD)和命名捕获过程(Named Capture Procedure,NCP)。但这两种方法都存在不足:CCD无法定义复杂的时钟方案和捕获方案;NCP所需的测试向量数目多,运行时间久。有鉴于此,提出了一种合并时钟域NCP方法。合并时钟域NCP提高了对时钟、捕获方案、流程的可控性,弥补了CCD不可控的不足。实验数据表明,合并时钟域NCP在不影响覆盖率的情况下,为固定型故障(Stuck At Fault,SAF)节省约28%的测试向量数量和22%的运行时间,为跳变延迟型故障(Transition Delay Fault,TDF)节省约18%的测试向量数量和13%的运行时间,提升了测试向量的效率,弥补了NCP的不足。

航空发动机燃油伺服系统定压活门正向频域设计方法

定压活门是为航空发动机燃油伺服系统提供伺服参考压力的关键部件,其性能直接影响燃油伺服系统的性能。本文提出一种定压活门的正向频域设计方法,内容包括:基于线性系统理论,推导了定压活门系统的状态空间模型;基于频域设计理论,提出了一种定压活门的动态设计方法,完成了镇定控制增益的设计;为了便于工程应用,提出了基于图谱的型孔设计、组合设计方法,指导规则型孔、组合型孔结构参数的设计。仿真结果表明,在幅值为1 MPa的进口油源压力阶跃扰动和大幅值的变负载出口型孔流通面积阶跃扰动下,设计的定压活门稳态特性满足1.5±0.01 MPa,稳态误差小于0.7%,动态调节时间小于5 ms,相角裕度基本大于45°。

声学释放器机械释放单元多域物理建模与试验研究

声学释放器机械释放单元的释放过程决定着声学释放器的释放成功率。为验证研制的声学释放器机械释放单元样机的释放过程和使用性能,采用基于模型设计的方法,建立声学释放器机械释放单元的多域物理模型,通过仿真试验验证声学释放器机械释放单元的结构性能,并对声学释放器机械释放单元样机进行压力釜、抗负载拉力试验和万米海试。结果表明,通过仿真试验、压力釜试验、抗负载拉力试验和万米海试,证实了研制的声学释放器机械释放单元样机可以在最大工作深度11 km和最大有效载荷10 t的工作条件下实现释放功能。

应急导向标识国外研究进展

对应急导向标识领域的关键问题进行了详细概述,从应急导向标识的特征以及人类疏散行为的角度出发,探究了目前研究的现状.通过科学知识图谱展示了当前研究的发展进程和结构关系.总结了现有研究的不足之处,梳理并展望了未来应急导向标识领域的相关研究方向,为未来应急导向标识的设计优化提供参考.