Concurrent design of machined products: a multivariate decisionapproach

In the traditional process of product design, a sequential approach treats each of the design steps individually without considering requirements of manufacturing, assembly and other downstream activities in the product life cycle. The lack of systematic and simultaneous consideration on the impact of design decisions on manufacturing and assembly leads to repeated and excessive changes in design and processes. To resolve this problem, the concurrent engineering approach to product design foresees and avoids potential design flaws by incorporating design requirements from downstream activities of the product development life cycle early in the design stage. This research develops a methodological framework for product life cycle design in concurrent engineering. Through a cohesive organization of semantics of high-level design features and relationships, this representation provides a means to evaluate the impact of design on subsequent activities in the product life cycle, including design for manufacture (DFM), design for assembly (DFA), and design for productivity (DFP). In the first stage of a two-level design, selection of design candidates is made based on multiple design criteria using utility theory taking into account imprecision of design information and user preference. The second stage of design further fine-tunes attribute values of the selected design by a genetic algorithm based parametric optimization procedure. An illustrative example of two alternative designs of a milling fixture demonstrates the effectiveness of the framework and its implementation methodology     

The Test Engineer's Assistant: a design environment for testableand diagnosable systems

The Test Engineer's Assistant (TEA) is a set of computer-aided design (CAD) tools that helps the system design engineer meet testability requirements by construction. TEA addresses system design for testability at all levels of the design hierarchy, the lowest level being the board level. The design is represented as a graph where each node indicates a hardware component (or chip on a board) and each arc represents intercomponent connections. Attributes associated with the graph nodes and a set of rules and testing techniques that are incorporated in the tool databases are used to determine the design features that have to be incorporated into the design to meet test and diagnostic requirements. The tool operates on a design using a combination of algorithmic and heuristic techniques. The authors present the design methodology supported by TEA, discuss the techniques used by the TEA tools to obtain solutions for different design for testability requirements, and present an example of the use of TEA with a real system     

A conceptual framework for ASIC design

An attempt is made to gain a better understanding of the nature of ASIC (application-specific integrated circuit) design. This is done from a decision-making perspective, in terms of three knowledge frames: the design process, the design hyperspace, and the design repertoire. The design process frame emphasizes the hierarchical design approach and presents the methodology as a formalization of the design process. The design hyperspace concept relates to the recognition of design alternatives. Analysis techniques for evaluating algorithmic and architectural alternatives are collected and classified to form the design repertoire. This conceptual framework is an effective instrument for bridging the widening gap between system designers and VLSI technology. It also provides a conceptual platform for the development of tools for high-level architectural designs     

基于SolidWorks管路在反应装置中的应用与实例

在反应装置装配体的机械设计中,存在着大量的管路零部件,对其各个零部件使用传统的三维设计方法,如拉伸、扫描等来绘制管路,不仅使工作强度增大,而且在装配过程中经常会出现干涉现象,同时存在设计效率低、设计周期过长等问题。本文采用solidworks routing为设计平台针对装配体中的管路进行三维设计,简短了设计开发时间,提高了设计的高效性和准确性,同时建立自定义零部件库文件,为今后设计使用提供了方便的辅助,并给出了反应装置部分设计实例。     

基于CPLD的数字系统设计

介绍了应用可编程逻辑器件CPLD及硬件描述语言VHDL设计数字系统的方法,说明基于CPLD器件进行数字系统设计的特点、VHDL设计流程,重点介绍了在数字系统设计中,采用CPLD设计是一种基于芯片的、层次化、自顶向下的方法。以数字频率计设计为例,说明基于可编程逻辑器件的数字系统设计的方法。     

Complexity management in system-level design

The system-level design problem spans a large design space. Typically, the designer needs to explore possible target architectures, experiment with different tools, and work with a range of constrains and optimization criteria. This design process is quite complex and involves considerable bookkeeping and management, in addition to sophisticated design tools. We believe that managing the design process is an important (although often neglected) part of system-level design. The contribution of this paper is in two parts. First, we present a framework for systematically managing the design process. Secondly, we illustrate how this framework can be used to manage a system-level design environment that consists of a suite of sophisticated hardware and software design tools.We begin by identifying some of the desirable features of system-level design methodology management. A candidate framework that manifests these features is presented. Complex design flows with iterative and conditional behavior can be specified within the framework. The framework also supports automated scheduling of tools in a well-defined design flow. It has been implemented as the DMM domain in Ptolemy.In the second part of the paper, we describe a case study that we have developed within this framework. The case study, called the Design Assistant, is a complete hardware-software codesign environment. It encapsulates various codesign tools for specification, partitioning, and synthesis; their interplay can be managed efficiently by the design methodology management framework.     

IP模块设计:实例研究

设计能力和硅芯片所能提供的集成能力增长差距的扩大阻碍了片上系统的有效开发 ,为此必须提高设计人员的设计能力 ,降低产品开发周期和成本。设计的重用是提高设计能力的有效方法。文中通过实际 IP模块的设计 ,分析研究了如何开发高质量的可重用 IP模块。     

雷达产品三防设计初探

军用电子设备的“三防”性能,已成为整机的重要技术指标之一。现代三防技术已不再单纯是一项工艺技术,而涉及到总体设计、电路设计、结构设计、工艺设计、技术管理等方方面面。本文通过对各种腐蚀因素的分析,结合我所三防设计现状,提出了自己的雷达产品三防设计思路。     

Design and development of optoelectronic mixed signal system-on-package (SOP)

This paper describes the design and development of a 2.5-Gb/s optical transceiver module as a mixed signal SOP for access networks. The module development consists of concurrent design of an optoelectronic package optimizing optical, electrical, thermal, mechanical functions and optical subassembly and RFICs housed in a chip-on-board package. The optical subassembly (OSA) consists of laser and photodiode assembled on a silicon substrate. The transmit and the receiver sections are combined into a single fiber through a polymer coupler on silicon. The splitter between the transmit and receive section is realized using a polymer waveguide. The electronic ICs are assembled on a multilayer organic substrate. The package design includes optical coupling design, impedance matched transmission line design for RF signals, electrical layout design for mixed signals and thermal design for the package. The module is housed in a plastic molded nonhermetic package to achieve low cost packaging. The assembly is completed using passive alignment of optical devices and attachment of electronic devices using adhesives. In this paper, we present the details of the component design and the development of packaging process methods to achieve the design specifications, test results and process guidelines for assembly and integration.     

某城市综合体电气设计综合布线系统设计

某大型城市综合体项目的电气设计是整个项目设计的一部分。电气设计包括强电设计和弱电设计,综合布线系统是建筑智能化系统(弱电系统)的重要组成部分。针对此项目的特点,分析了项目综合布线系统整体设计思想,然后介绍了各子系统的设计要求和设计内容,最后通过部分综合布线系统图,进一步阐述了各个子系统之间的关联方式和配置。     

卫通扩频收发终端的电磁兼容设计

电磁兼容设计是产品可靠性设计中的重要内容之一。本文以导航系统卫通扩频收发终端设备为例,从电磁屏蔽、印制板设计、机箱设计、接地、滤波方法等方面分析其电磁兼容设计方法和相关措施,提出了产品电磁兼容设计要统筹规划、结合具体电路灵活设计的理念,采用屏蔽、滤波接地等必要措施,其理念和方法对电子产品或电子工程系统的电磁兼容性设计有很好的参考和借鉴作用。     

流水线式通信勘察设计平台研究

本文通过对通信设计院传统勘察设计模式和生产工具的分析,以实现勘察设计整个过程的信息化和集中化为主线,提出并搭建了流水线式勘察设计平台,能够帮助通信行业设计院完成勘察设计的标准化、集中化和信息化,从而提高设计院生产效率和设计质量.     

高功率速调管发射机的防护设计

雷达装备的防护设计直接与系统设计、电讯设计、结构设计、工艺设计、计划与生产管理等相关联,是一门复杂的涉及多专业的系统工程。针对海洋大气环境的具体特点,详细阐述了高功率速调管发射机的环境适应性防护设计方法,从电讯设计、结构设计、工艺设计等方面给出了具体而有效的防护设计措施,具有广阔的应用和参考价值。     

探析协同设计在工程机械设计中的应用

目前在设计方面更新技术的重要工具就是协同设计,协同设计是在统一的平台进行,其能够使得行业间的沟通得到加强.在工程机械设计中应用协同设计,能够使得设计的质量以及效率都得到显著的提升.本文围绕着协同设计在工程机械设计中的应用这一主题展开了讨论,首先介绍了我国工程机械设计的现状,随后提出了工程机械设计的CSCD体系.     

Design of CMOS circuits for stuck-open fault testability

A CMOS design that offers highly testable CMOS circuits is presented. The design requires a minimal amount of extra hardware for testing. The test phase for the proposed design is simple and uses a single test vector to detect a fault. The design offers the detection of transistor stuck-open faults deterministically. In this design, the tests are not invalidated due to timing skews/delays, glitches, or charge redistribution among the internal nodes     

Rapid design space exploration using legacy design data and technology scaling trend

Rapid and effective design space exploration at all stages of a design process enables faster design convergence and shorter time-to-market. This is particularly important during the early stage of a design where design decisions can have a significant impact on design convergence. This paper describes a methodology for design space exploration using design target prediction models. These models are driven by legacy design data, technology scaling trends and, an in situ model-fitting process. Experiments on ISCAS benchmark circuits validate the feasibility of the proposed approach and yielded power centric designs that improved power by 7-32% for a corresponding 0-9% performance impact; or performance centric designs with improved performance of 10.31-17% for a corresponding 2-3.85% power penalty. Evolutionary algorithm based Pareto analysis on an industrial 65 nm design uncovered design tradeoffs which are not obvious to designers and optimize both power and performance. The high performance design option of the industrial design improved the straight-ported design's performance by 29% with a 2.5% power penalty, whereas the low power design option reduced the straight-ported design's power consumption by 40% for a 9% performance penalty.     

A practical approach to radio propagation measurements—As used in the design of mobile radio communications systems

The design of a mobile or portable radio communications system requires the consideration of a number of unique engineering factors which do not necessarily apply to the design of a fixed, or point-to-point system. The design procedure is a combination of theoretical and empirical methods, which when taken with measured data, produce a system design meeting the required specifications. This paper will treat that portion of the system design pertaining to radio frequency propagation and system coverage. It stresses a realistic measurement program which will provide coverage data in support of the system design.     

基于Protel DXP的印刷电路板设计

论述利用Protel DXP软件设计印刷电路板的技术,其中包括电路原理图设计、印刷电路板PCB的生成以及CAM文件输出。指出了Protel DXP作为Protel软件最新版本所具有的一些优点。分析了在原理图设计和印刷电路板设计过程中会出现的问题,根据实际电路设计给出了如何避免和解决这些问题的方法,为正确高效率设计印刷电路板提供了有效的途径。     

嵌入式系统PCB的可信性设计

嵌入式系统具有独特的电路结构和电气特性,在产品设计阶段进行合理的可信性设计是保证产品质量,降低成本的基本手段。可信性设计的内容包括可测试性设计、可维修性设计、可靠性设计。产品设计过程中这三部分是相互交叉,相互影响的。