虚拟产品设计方案神经网络决策模型研究

虚拟原型逼真设计作为虚拟产品开发研究的一个方面,是近几年发展起来的新技术,主要研究虚拟环境下的产品建模问题以及基于仿真的集成产品和过程设计问题。生命周期虚拟产品设计方案评价模型是虚拟原型逼真设计模型实现的重要模块之一,论文在设计方案多目标多级模糊综合决策模型的基础上,研究并建立了设计方案ANN多目标决策模型,该模型已应用于仪表新产品开发决策支持系统中。     

基于局部细分构造产品原型的PD-LS算法

将Loop细分原则引入产品设计系统中,提出并设计了一种基于局部细分模型构造产品原型的PD-LS算法。算法利用局部细分原则在产品图形的局部区域上进行迭代插值,经插值细分后,在降低整体网格密度的前提下,致使不同区域特征点密度不同,使重要区域具有较高密度,以此降低产品原型的褶皱度。最后通过仿真实验验证该算法具有较好的性能。     

LabVIEW与PSpice相结合用于分析和设计电子电路

阐述了将LabVIEW与PSpice相结合用于分析和设计电子电路的方法.并通过一个高通滤波器的设计作为实例,着重说明了如何用Labview语言读取PSpice仿真所得数据.这样就可将PSpice的仿真结果和设计原型通过LabVIEW获得的真实测量值相结合,设计工程师们可以更快速见到仿真结果与实际测量值的差异,从而在产品研发过程中快速诊断误差所在,并进行相应性能调整.     

LabVIEW与PSpice相结合用于分析和设计电子电路

阐述了将LabVIEW与PSpice相结合用于分析和设计电子电路的方法,并通过一个高通滤波器的设计作为实例,着重说明了如何用Labview语言读取PSpice仿真所得数据。这样就可将PSpice的仿真结果和设计原型通过LabVIEW获得的真实测量值相结合,设计工程师们可以更快速见到仿真结果与实际测量值的差异,从而在产品研发过程中快速诊断误差所在,并进行相应性能调整。     

基于逆向理论的电脑机箱创新设计研究

对市场上现有的电脑机箱产品进行调研,在逆向设计理论的指导下,提出创新的设计思想。以两款电脑机箱设计为例说明通过逆向设计方法可以快速得到原有机箱结构的不足之处,并在此基础上展开快速再设计创新,设计周期短,提出该理论应用于工业产品设计的重要意义,提高了产品设计的可用性与可实现性,减少了设计的重复性。     

数字化设计与虚拟样机技术

产品设计的数字化是企业信息化的重要内容。近年来,随着产品复杂性的不断增长,以及企业间竞争的日趋激烈,传统的产品设计方法已经很难满足企业当前生存和发展的需要。为了能在竞争中处于有利位置,实现产品设计数字化势在必行。产品设计过程本质上是一个对信息进行采集、传递、加工处理的过程,其中包含了两种重要的活动:设计活动和仿真活动。因此产品设计也可以看作是一个设计活动和仿真活动彼此交织相互作用的过程。设计活动推动信息流程向前演进,而仿真则是验证设计结果的重要手段,二者关系如图1所示。随着技术的发展,仿真的重要性正在不断…     

面向并行设计的虚拟原型技术研究

虚拟原型技术是在虚拟的逼真环境下,对产品设计信息进行协同仿真验证的有效手段,它可有效支持并行设计,缩短产品开发周期,在分析了虚拟原型与并行的关系后,提出了基于域对象的虚拟原型建模与仿真方法,并阐述了支持虚拟原型的集成框架的关键技术。     

基于核心软件的虚拟样机技术

一、虚拟样机技术的基本概念 虚拟样机技术(Virtual Prototyping,VP)是指在产品设计开发过程中,将分散的零部件设计和分析技术(指在某一系统中零部件的CAD和FEA技术)糅合在一起,在计算机上建造出产品的整体模型,并针对该产品在投入使用后的各种工况进行仿真分析,预测产品的整体性能,进而改进产品设计,提高产品性能的一种新技术.     

MSC SimDesigner在产品设计中的作用

MSC SimDesigner是面向设计工程师开发的仿真平台,借助它可以使产品设计流程中的结构设计和工程分析更紧密地结合在一起,从而减少设计失误. 本文通过示例展示基于该仿真平台的创新流程所蕴含的巨大优势.     

基于系列化配置原理的产品设计技术研究

在分析零件事物特性表的基础上,提出了基于系列化配置原理的产品设计技术.分析了使用该技术的产品开发的一般流程.研究了将产品配置和工艺配置在同一配置表中的存储技术;从三维CAD产品模型中进行特征提取的算法;零件工序简图的自动生成技术等关键技术和算法.以发动机气门产品为研究对象,使用UML的包图设计了发动机气门产品设计系统的组件模型,基于该组件模型和SolidWorks 三维CAD平台,使用Visual C 6.0实现了原型系统.     

Interaction between process design and process control: economic analysis of process dynamics

A method is presented to assess the impact of disturbances on plant economic performance. The method is suitable for use during process design, and can be used to help evaluate alternative process structures or alternative control schemes for a given process. Non-linear steady-state optimization is performed to determine the best operating point in the absence of disturbances. Frequency response analysis of a linearized plant dynamic model is used to estimate the effects of plant disturbances on this ideal performance under a variety of control strategies. The method is illustrated on a case study involving minerals flotation circuit design.     

基于层次分析法的道路照明设计评价方法

道路照明系统设计是一项复杂系统的工程,评价指标繁多,针对此问题建立了一种基于层次分析法的道路照明设计方案评价方法,通过对各影响因素的深入分析,建立评价指标的组合权重,再利用各归一化的评价参数值,可计算出道路照明设计方案的综合评判值用作决策.通过对LED路灯和高压钠灯道路照明设计方案的实例分析比较,得出在同等路况与布灯条...     

A methodology for brand feature establishment based on the decomposition and reconstruction of a feature curve

For creative products, maintaining original brand elements and features in a new product is an important issue in the design process as brand features are conceived and generated for longevity. However, current methods rely on designers’ abilities, and the size of forms is easily affected when shape morphing is applied, causing limitations in computer-aided design. In order to focus on design while preserving key features, a systematic method for presenting brand features is proposed in this article. In this method, the feature curves of the brand features of a company are decomposed with defined feature parameters, which were then used to reconstruct the feature curve of the designed product in the design stage by using a residual modified gray prediction model. A classic vehicle configuration design is taken as an example to show the implementation procedure of the proposed method. With residual modification, this method can also assimilate other forms from the original form database, and generate new forms based on gray prediction. The results show that brand features can be retained in the newly designed product based on the proposed method. Though vehicle design is taken as the example, this method can also be used to develop designs for many other the brand features. For classic products with historical value, this method can generate new forms that maintain original brand features, thereby satisfying customers’ needs for brand authenticity.     

A Quick Rendering Method Using Basis Functions for Interactive Lighting Design

When designing interior lighting effects, it is desirable to compare a variety of lighting designs involving different lighting devices and directions of light. It is, however, time-consuming to generate images with many different lighting parameters, taking interreflection into account, because all luminances must be calculated and recalculated. This makes it difficult to design lighting effects interactively. To address this problem, this paper proposes a method of quickly generating images of a given scene illustrating an interreflective environment illuminated by sources with arbitrary luminous intensity distributions. In the proposed method, the luminous intensity ditribution is expressed with basis functions. The proposed method uses a series of spherical harmonic functions as basis functions, and calculates in advance each intensity on surfaces lit by the light sources whose luminous intensity distribution are the same as the spherical harmonic functions. The proposed method makes it possible to generate images so quickly that we can change the luminous intensity distribution interactively. Combining the proposed method with an interactive walk-through that employs intensity mapping, an interactive system for lighting design is implemented. The usefulness of the proposed method is demonstrated by its application to interactive lighting design, where many images are generated by altering lighting devices and/or direction of light.     

An efficient approach to understanding and predicting the effects of multiple task characteristics on performance

Abstract

In ergonomics there is often a need to identify and predict the separate effects of multiple factors on performance. A cost-effective fractional factorial approach to understanding the relationship between task characteristics and task performance is presented. The method has been shown to provide sufficient independent variability to reveal and predict the effects of task characteristics on performance in two domains. The five steps outlined are: selection of performance measure, task characteristic identification, task design for user trials, data collection, regression model development and task characteristic analysis. The approach can be used for furthering knowledge of task performance, theoretical understanding, experimental control and prediction of task performance.

Practitioner Summary: A cost-effective method to identify and predict the separate effects of multiple factors on performance is presented. The five steps allow a better understanding of task factors during the design process.     

面向产品布局设计的组件特征模型

从特征角度看，产品设计可视为一个特征演化过程。然而就目前研究的内容来看，特征的范围基本局限于机械产品的零件级层次，难以支持外形、布局、人机工程占很大比重的通信、家电等电子机械产品的设计过程。针对上述不足，本文立足于特征的广义内涵，提出了基于产品级的组件特征概念及其相应的面向产品布局设计的组件特征模型。     

基于数值模拟技术的产品概念设计方法

为解决传统工业设计流程中,设计方案缺乏相应工程技术的校验,导致设计返工 率高及开发效率低下的问题,借助于数值模拟技术可实现产品性能预评估的优势,提出一种基 于数值测试技术为驱动的产品概念设计方法。首先对产品的工作机理进行数值分析,明确合理 的设计方向,并以此为基础指导产品造型设计,然后再次运用数值测试分析手段对设计方案的 可行性进行验证,最后对通过验证的方案进行细节完善并输出最终设计概念。数值模拟技术与 产品概念设计过程相融合,驱动设计过程的逐步完善,可实现提升设计效率与质量的目的,通 过电热毛巾架的设计实例验证了方法的有效性。     

Glowworm swarm optimization (GSO) for optimization of machining parameters

This study proposes glowworm swarm optimization (GSO) algorithm to estimate an improved value of machining performance measurement. GSO is a recent nature-inspired optimization algorithm that simulates the behavior of the lighting worms. To the best our knowledge, GSO algorithm has not yet been used for optimization practice particularly in machining process. Three cutting parameters of end milling that influence the machining performance measurement, minimum surface roughness, are cutting speed, feed rate and depth of cut. Taguchi method is performed for experimental design. The analysis of variance is applied to investigate effects of cutting speed, feed rate and depth of cut on surface roughness. GSO has improved machining process by estimating a much lower value of minimum surface roughness compared to the results of experimental and particle swarm optimization.     

Extensions of design potential concept for reliability-based design optimization to nonsmooth and extreme cases

The reliability-based design optimization (RBDO) can be described by the design potential concept in a unified system space, where the probabilistic constraint is identified by the design potential surface of the reliability target that is obtained analytically from the first-order reliability method (FORM). This paper extends the design potential concept to treat nonsmooth probabilistic constraints and extreme case design in RBDO. In addition, refinement of the design potential surface, which yields better optimum design, can be obtained using more accurate second-order reliability method (SORM). By integrating performance probability analysis into the iterative design optimization process, the design potential concept leads to a very effective design potential method (DPM) for robust system parameter design. It can also be applied effectively to extreme case design (ECD) by directly representing a probabilistic constraint in terms of the system performance function. Received July 25, 2000     

Space exploration and global optimization for computationally intensive design problems: a rough set based approach

Modern engineering design problems often involve computation-intensive analysis and simulation processes. Design optimization based on such processes is desired to be efficient, informative and transparent. This work proposes a rough set based approach that can identify multiple sub-regions in a design space, within which all of the design points are expected to have a performance value equal to or less than a given level. The rough set method is applied iteratively on a growing sample set. A novel termination criterion is also developed to ensure a modest number of total expensive function evaluations to identify these sub-regions and search for the global optimum. The significance of the proposed method is twofold. First, it provides an intuitive method to establish the mapping from the performance space to the design space, i.e. given a performance level, its corresponding design region(s) can be identified. Such a mapping could be potentially used to explore and visualize the entire design space. Second, it can be naturally extended to a global optimization method. It also bears potential for more broad application to problems such as metamodeling-based design and robust design optimization. The proposed method was tested with a number of test problems and compared with a few well-known global optimization algorithms.