Assembly code generation from a feature-based geometric model

Design and implementation of a system for assembly code generation (from a feature-based geometric model) is discussed. Assembly code is further used in design for assembly evaluation procedures for produce assembly analysis. Assembly features are classified into three groups: geometric assembly features, non-geometric assembly features and operational assembly features. The first two groups of features have existed in computer-aided design databases, while the last one has existed in an assembly sequence. Algorithms for identifying the first two groups of features are presented. A tree processor to convert assembly features into assembly code is also developed. Finally, examples are presented.     

Process design data for prok chilling

In 1993 legislation is being enacted throughout the European Community (EC) that will require the maximum temperature of pork carcasses to be below 7°C before cutting or transportation. Results from a survey of UK abattoirs are summarized to highlight the problems and inadequacies of current commercial chilling systems. Design data are presented for conventional pork-chilling systems, which detail the effects of air temperature, air velocity and carcass weight on chilling times. Four novel or modified chilling systems are discussed: ultra-rapid chilling with air at −30°C; immersion chilling in brine at 0°C; ice-bank chilling in humid air at 2°C; and spray chilling in two stages, at 10°C for 2 h followed by 4°C for 21 h. The potential of such systems for the acceleration of chilling rates and for substantial weight savings is identified.     

A mathematical formulation for interface-based modular product design with geometric and weight constraints

Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.     

Understanding big consumer opinion data for market-driven product design

Big consumer data provide new opportunities for business administrators to explore the value to fulfil customer requirements (CRs). Generally, they are presented as purchase records, online behaviour, etc. However, distinctive characteristics of big data, Volume, Variety, Velocity and Value or ‘4Vs’, lead to many conventional methods for customer understanding potentially fail to handle such data. A visible research gap with practical significance is to develop a framework to deal with big consumer data for CRs understanding. Accordingly, a research study is conducted to exploit the value of these data in the perspective of product designers. It starts with the identification of product features and sentiment polarities from big consumer opinion data. A Kalman filter method is then employed to forecast the trends of CRs and a Bayesian method is proposed to compare products. The objective is to help designers to understand the changes of CRs and their competitive advantages. Finally, using opinion data in Amazon.com, a case study is presented to illustrate how the proposed techniques are applied. This research is argued to incorporate an interdisciplinary collaboration between computer science and engineering design. It aims to facilitate designers by exploiting valuable information from big consumer data for market-driven product design.     

产品更改设计中尺寸数据传递流程分析

为了提高产品设计效率,从尺寸更改在零件间和零件内部关键结构间传播两个角度出发,探讨了产品更改设计过程中的尺寸数据传递流程。首先,分析了产品尺寸关联设计的基本逻辑结构,建立了更改传播逻辑元模型。然后,通过分析零件之间的装配关联及尺寸关联,建立了装配体中零件之间的关联路径以及尺寸关联更改传播模型;以变更零件为研究对象,基于零件建模过程,根据零件内部尺寸之间的连接与约束关系,建立了零件内部尺寸的更改传播路径,完成零件内部关键结构的尺寸更改传播;基于上述过程,完成了从更改源到零件直至零件内部特定尺寸的更改传播及其数据传递流程分析,最后,通过卷板机实例验证了所提方法的有效性。结果表明该方法可为产品的尺寸更改传播提供一种新的思路,为提高产品设计效率提供理论依据。     

Analysis of dimension data transfer process in product change design

In order to improve product design efficiency, the dimension data transfer process in the process of change design is discussed from two aspects: the propagation of dimension change between the parts and between the key structures inside the part. Firstly, the basic logic structure of product dimension correlation design was analyzed, and the change propagation logic meta-model was established. Then, by analyzing the assembly correlation and dimension correlation among the parts, the correlation path among the parts in assembly and the propagation model of dimension correlation change were established. Taking the change part as the research object, according to the connection and constraint relationship between the internal dimensions of the part, the change propagation path for the internal dimensions of the part was established based on the part modeling process, and the dimension change propagation of the key structures inside the part was completed. Based on the above process, the whole change propagation and data transfer process analysis from the change source to the part and to the specific dimension inside the part were completed. Finally, the validity of the proposed method was verified by an example of a veneer reeling machine. The results show that this method can provide a new idea for the propagation of product dimension change, and provide a theoretical basis for improving product design efficiency.     

A morphing method for shape generation and image prediction in product design

A shape morphing and image prediction method for product design is proposed in this article, in which a feature-based method is first used to construct 3-D CAD models of a product, then new shapes are generated with a shape morphing method and the images of the morphed shapes are analyzed using modified gray theory with Fourier residual correction. With the aid of this model, the designer can quickly obtain a product form and its corresponding image to help him/her to design the required product. Though LCD monitor design is applied, this method can also be used to develop other products.     

环境一号卫星A/B星数据自动几何精校正设计研究

环境一号卫星A/B星是我国自主研制的小卫星星座,其在轨稳定运行近5年,并稳定获取了大量高质量的观测数据,实现对这些观测数据的几何精校正处理,对发挥环境星宏观、动态的生态环境监测有着重要意义。本文首先分析了环境一号卫星参数特点以及环境一号卫星2级数据(系统几何校正后的数据)的几何特点。基于此,设计了环境一号卫星各载荷总体几何精校正方法流程以及charge-coupled device(CCD)相机自动几何精校正方法。实际运行数据表明,该方法可以较好地实现环境一号卫星各载荷数据的自动几何精校正,环境一号卫星CCD相机自动几何精校正图像精度可达到2个像素以内,同星不同载荷图像之间自动匹配方法可以获取小于1个像素的图像匹配精度。     

Investigating the influence of product perception and geometric features

Research in emotional design and Kansei Engineering has shown that aesthetics play a significant role in the appeal of a product. This paper contributes to establishing a methodology to identify the relationships between perceptions, aesthetic features, desire to own and background of consumers. Surveys were conducted with 71 participants to gather their perceptions of 11 vase concepts. Advanced statistical analyses, including mixed models, were applied to allow generalisation of the results beyond the data sample. Significant relations between the desire to own a product and how the product is perceived were found (the desire to own was found to be related to beautiful, expensive, elegant, exciting, feminine, common and dynamic vases), as well as between the perceptions and the parameters describing the form of the vases (a vase was perceived as beautiful if it had many curved lines and was simple and tall). An automated mixed model analysis was conducted and revealed that general rules can be found between aesthetic features, perceptions and ownership, which can apply across gender and culture. The findings include design rules that link aesthetic features with perceptions. These contribute to research as guidelines for design synthesis and can either be implemented via shape grammars or parametric modelling approaches. These rules are also interesting for 3D printing applications, especially important when the consumer is the designer. Some of these design rules are linked to the desire to own a product, they have implications for industry, and they offer guidelines to creating attractive products that people want to own.     

Process capability: a criterion for optimizing multiple response product and process design

In this research, we consider the maximization of process capability as the criterion in product/process design that is used for selecting preferred design factor levels and propose several approaches for single and multiple response performance measure designs. All of these approaches assume that the relationship between a process performance measure and a set of design factors is represented via an estimate of a response surface function. In particular, we develop; (i) criteria for selecting an optimal design, which we call MCpk and MCpm; (h) mathematical programming formulations for maximizing MCpk and MCpm, including formulations for maximizing the desirability index (Harrington, 1965) and for maximizing the standardized performance criteria (Barton and Tsui, 1991) as special cases of the formulation for maximizing MCpk, (iii) formulations for considering cost when maximizing MCpk and MCpm, (iv) a means for assessing propagation of error; (v) a robust design method for assessing design factor effects on residual variance; (vi) a means for assessing the optimality of a proposed solution: and (vii) an original application in the screening of printed circuit board panels.     

攻心产品设计方法

根据人的潜意识能影响人的意识和行为的原理,进行产品设计时充分考虑消费者和设计者的心理,通过产品的外形、色彩、包装、广告词等影响消费者的潜意识,使消费者在潜意识中产生拥有该产品的欲望,从而做出购买的行为,达到产品设计的目的.依据该方法,提出3个自动冲水的产品设计方案.     

同异反产品设计方法

 在产品设计中，领域专家的经验知识和人类创新思维的信息交合对于最终产品设计的成功与否至关重要．面向产品设计的各个过程，利用集对论的系统分析方法从联系的角度实现了设计信息的整体处理．并在此基础上，提出一种新的产品设计方法—— 同异反设计法． 该方法在设计过程中较好地利用了领域专家的经验知识，体现了“以人为本”的设计思想，实现了知识的重用．最后，针对面向市场的产品设计的3个阶段初步说明其在产品设计中的应用．     

由太极图看中国产品设计风格之形成

"太极图"的辩证法则,是中国人最根本的思维方式,渗透到中国人的各种活动中.在产品设计过程中,要把最核心最传统的文化思想沉淀在产品中,使产品在外形、色彩、人机、内涵上,具有浓郁的中国底蕴.久而久之,水到渠成,形成我国的产品设计风格,既符合中国人的文化及哲学思想,又在时代发展和对外来文化的过滤吸收的基础上得到不断完善.     

Application of geometric programming to transformer design

This paper considers the transformer design optimization problem. In its most general form, the design problem requires minimizing the total mass (or cost) of the core and wire material while ensuring the satisfaction of the transformer ratings and a number of design constraints. The constraints include appropriate limits on efficiency, voltage regulation, temperature rise, no-load current, and winding fill factor. The design optimization seeks a constrained minimum mass (or cost) solution by optimally setting the transformer geometry parameters and the relevant electrical and magnetic quantities. In cases where the core dimensions are fixed, the optimization problem calls for a constrained maximum volt-ampere or minimum loss solution. This paper shows that the above design problems can be formulated in geometric programming (GP) format. The importance of the GP format stems from two main features. First, GP provides an efficient and reliable solution for the design optimization problem with several variables. Second, it guarantees that the obtained solution is the global optimum. The paper includes a demonstration of the application of the GP technique to transformer design. It also includes a comparative study to emphasize the advantage of including the transformer core dimensions as variables in the design problem.     

Multicriteria decision-aid approach for product end-of-life alternative selection

The selection of the best compromise alternative for treating a product at its end of life (EOL) is presented. Each EOL alternative has its own consequences from an economical, environmental and social point of view. The criteria used to determine these consequences are often contradictory and not equally important. In the presence of multiple conflicting criteria, an optimal EOL alternative rarely exists. Hence, the decision-maker should seek the best compromise EOL alternative. The present paper proposes a multicriteria decision-aid (MCDA) approach to aid the decision-maker in selecting the best compromise EOL alternative on the basis of his/her preferences and the performances of EOL alternatives with respect to the relevant environmental, social and economic criteria. This approach is important because it allows the user to consider various conflicting criteria simultaneously and it takes into account his/her preferences. The paper analyses the most important aspects of this approach such as the constitution of a set of EOL alternatives, the selection of a list of relevant criteria to evaluate the EOL alternatives and the choice of an appropriate multicriteria decision-aid method. A case study is provided to illustrate how the proposed approach can be used for product EOL alternative selection in real-world applications.     

Using product family evaluation graphs in product family design

Product family design and platform-based product development have garnered much attention. They have been used to provide nearly customised products to satisfy individual customer requirements and simultaneously achieve economies of scale during production. The inherent challenge in product family design is to balance the trade-off between product commonality (how well the components and functions can be shared across a product family) and variety (the range of different products in a product family). Quantifying this trade-off at the product family planning stage in a way that supports the engineering design process has yet to be accomplished. In this paper, we introduce a graphical evaluation method, the product family evaluation graph (PFEG), that allows designers to choose the ‘best’ product family design option among sets of alternatives based on their performance with respect to an ideal commonality/variety trade-off determined by a company's particular competitive focus, and guides designers towards a more desirable trade-off between commonality and variety in an existing product family. Two necessary supporting pieces for developing the PFEG are also proposed. One piece is the development of commonality and variety indices to quantitatively capture the degree of commonality and variety in a product family and its functions and components. We introduce two sets of commonality and variety indices–the CDI (commonality versus diversity index) for commonality (CDI_C) and variety (CDI_V), and the CMC (comprehensive metric for commonality) for commonality (CMC_C) and variety (CMC_V)–to achieve this. The other supporting piece is the development of a quantitative representation of the ideal trade-off between commonality and variety in a product family, known as the commonality/variety trade-off angle α, based on the elements that characterise a company's competitive focus and their industry-wide competitors. A linear regression model is used to link the qualitative competitive focus to a quantitative engineering perspective, and then to estimate the ideal trade-off angle. The commonality/variety trade-off angle can then be applied to the PFEG to help designers evaluate a product family or compare product family design alternatives. Most importantly, the PFEG is not just the graph of the two sets of indices; it is the representation of the commonality/variety trade-off relative to the desired competitive focus. Four families of power tools are used to illustrate how the computation of such indices supports product family design evaluation in the PFEG. In this paper, we only use the CDI in the example application, but the CMC can be computed using the same approach.     

现代产品设计中的适当设计理念

论证了在现代产品设计中提出适当设计理念的理由,阐述了适当设计的本质含义.并从消费需求、产品的功能、材料及造型等4个方面,对适当设计的具体运作方法进行了比较详细的分析和研究.同时也指出了,利用适当设计,可使产品能最准确地满足目标群体最真实、最合理的消费需求,以缓解当前因产品的过度设计所带来种种问题.