RHOMBUS THINKING METHOD AND ITS APPLICATION IN SCHEME DESIGN

Rhombus thinking, a new creative thinking method,is the combination of divergent thinking process and convergent thinking process,in which qualitative analysis is carried out before quantitative analysis This method tries to solve the bottle neck problem in intelligent CAD based on the extension theory The rhombus thinking method to the scheme design of new products is applied In this process, firstly, the matter element expression for the know information are set up, and then a set of matter elements are opened up by matter elements extension method; Finally,the useful information are got by appraisal method of dependent degree It has been successfully applied to the scheme design for the cutter store of machining center Theoretical and experimental results demonstrated fhat the method is much more accurate,objective and efficient than the traditional one

Design strategy of intelligent CAD for welding positioner scheme design

Traditional CAD technique does not support the design processes such as function definition, conceptual design and preliminary design, which are most creative and play significant roles on the design quality. Because scheme design has close relationship with product structure, performance and technology cost, it is important for applying the intelligent CAD of scheme design to improve the quality and competitive level of the product. The definition and function of welding positioner are discussed in this paper. The new definition of welding positioner extends the research scope of welding positioner to welding fixture and welding positioning motion mechanism. The design process of welding fixture and positioning motion system is described, and the cased based and knowledge based design strategy of welding positioner scheme design intelligent CAD is then put forward, which lays foundation for developing proto type system of welding positioner scheme design.

An Approach to Representation for Principle Scheme Design

One of the open issues in principle scheme design of mechanical systems is principle representation, which not only outlines the physical principles, but also facilitates the design synthesis. An energy-based approach to represent principle scheme design is proposed. Firstly, an energy interaction model of mechanical systems is established and an intermediate model is derived, in which principle scheme design is transformed into solving the energy functions of system. Then the energy functions are modeled with the language of bond graphs, and principle representation for components is presented. Finally, characteristics of the developed representation approach are analyzed and a design example of gate drive system is given to demonstrate this approach.

Gust response modeling and alleviation scheme design for an elastic aircraft

Time-domain approaches are presented for analysis of the dynamic response of aeroservoelastic systems to atmospheric gust excitations. The continuous and discrete gust inputs are defined in the time domain. The time-domain approach to continuous gust response uses a state-space formulation that requires the frequency-dependent aerodynamic coefficients to be approximated with the rational function of a Laplace variable. A hybrid method which combines the Fourier transform and time-domain approaches is used to calculate discrete gust response. The purpose of this approach is to obtain a time-domain state-space model without using rational function approximation of the gust columns. Three control schemes are designed for gust alleviation on an elastic aircraft, and three control surfaces are used: aileron, elevator and spoiler. The signals from the rate of pitch angle gyroscope or angle of attack sensor are sent to the elevator while the signals from accelerometers at the wing tip and center of gravity of the aircraft are sent to the aileron and spoiler, respectively. All the control laws are based on classical control theory. The results show that acceleration at the center of gravity of the aircraft and bending-moment at the wing-root section are mainly excited by rigid modes of the aircraft and the accelerations at the wing-tip are mainly excited by elastic modes of the aircraft. All the three control schemes can be used to alleviate the wing-root moments and the accelerations. The gust response can be alleviated using control scheme 3, in which the spoiler is used as a control surface, but the effects are not as good as those of control schemes 1 and 2.

Evaluation of Scheme Design of Blast Furnace Based on Artificial Neural Network

Blast furnace scheme design is very important, since it directly affects the performance, cost and configuration of the blast furnace. An evaluation approach to furnace scheme design was brought forward based on artificial neural network. Ten independent parameters which determined a scheme design were proposed. The improved threelayer BP network algorithm was used to build the evaluation model in which the 10 independent parameters were taken as input evaluation indexes and the degree to which the scheme design satisfies the requirements of the blast furnace as output. It was trained by the existing samples of the scheme design and the experts＇ experience, and then tested by the other samples so as to develop the evaluation model. As an example, it is found that a good scheme design of blast furnace can be chosen by using the evaluation model proposed.

The scheme design for the earth pressure balance shield cutterhead structure

The earth pressure balance(EPB) shield cutterhead structure, which features an opening ratio and opening distribution as a core, seriously affects tunneling stability and tunneling efficiency. This paper presents a new model for the soil using visco-plastic fluid theory, and then introduces the model into the computational-fluiddynamics model to comprehensively analyze the cutterhead structure, which consists of the soil, the cutterhead,the working chamber, and the screw conveyor. Based on this model, the stability situation and tunneling performance of multiple schemes of the cutting head structure are analyzed by changing the opening ratio and the opening distribution on the cutterhead. In this study, a new method for design and analysis of the EPB-shield cutterhead structure is proposed that fits changes in geologic conditions. The results will be helpful for engineers and manufacturers of more efficient machines and for carrying out tunneling projects with more stable EPB-shield cutterheads, and it will reduce the influences of changing geologic conditions during all stages of tunnel construction.

Design scheme for fast charging station for electric vehicles with distributed photovoltaic power generation

The demand for fast charging is increasing owing to the rapid expansion of the market for electric vehicles. In addition, the power generation technology for distributed photovoltaic has matured. This paper presents a design scheme for a fast charging station for electric vehicles equipped with distributed photovoltaic power generation system taking the area with certain conditions in Beijing as an example construction site. The technical indexes and equipment lectotype covering the general framework and subsystems of the charging station are determined by analyzing the charging service demand of fast charging stations. In this study, the layout of the station is developed and the operation benefits of the station is analyzed. The design scheme realizes the design objective of "rationalization, modularization and intelligentization" of the fast charging station and can be used as reference for the construction of a fast charging network in urban area.

Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis

Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures, the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done, feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.

Tight Relative 6-designs on Binary Hamming Association Schemes

The concept of relative t-designs for Q-polynomial association schemes is due to Delsarte(Philips Res Rep 32: 373C411, 1997). In this paper, we discuss the Fisher type lower bounds of tight relative 6-designs very explicitly for binary Hamming association schemes H(n, 2).

Scheme design of the CHANG＇E-5T1 extended mission

Flight schemes for the CHANG＇E-5T1 extended mission are investigated in this paper.In the flight scheme and trajectory design, the remaining propellant of the CHANG＇E-5T1 mission is utilized. The CHANG＇E-5T1 mission is firstly introduced with feasible flight goals derived based on the terminal trajectory and satellite status. The flight schemes are designed to include a lunar return and the libration points in the Sun-Earth/Moon and Earth-Moon systems, with an emphasis on the Earth-Moon triangle libration point thus far unexplored. Secondly, three schemes are proposed for the CHANG＇E-5T1 extended mission with different flight goals. The direct libration point orbit transfer and injection method is adopted to solve the issue in the transfer trajectory design.Furthermore, an innovative concept is proposed to transfer from the Earth-Moon collinear libration point to the triangle point using the Sun-Earth/Moon libration point. Finally, the merits and drawbacks of the three schemes are discussed in terms of flight time, control energy and frequency, flight distance, and goal value. As a result, the scheme including a lunar return and the Earth-Moon L2 libration point is selected for the CHANG＇E-5T1 extended mission. A flight to the Earth-Moon libration point is achieved, replicating the achievement of the ARTEMIS mission.

A New D-optimal Design Scheme for the Identification of Cubic Polynomials

In this paper, the limitations of the single cube D-optimal design scheme is studied, and a double cube D-optimal design scheme is suggested in order to overcome the limitations. For a sort of incomplete cubic polynomials, the test design of the identification is developed with this new scheme, and the comparation with the single cube scheme is also given. This scheme is shown to be perfectly suitable for the optimal identification of the complete cubic polynomials.

基于NAPA Designer的钻台结构参数化设计

钻台作为钻井船或钻井平台中钻井模块的载体,既要满足作业功能的需求,又受到主船体尺度和重量控制等因素的制约,故在初步设计阶段需快速制定不同设计方案供比较选择。在此背景下,该文基于NAPA Designer软件提供的二次开发功能,编写了钻台结构参数化设计模块,通过用户自定义界面数据交互驱动钻台参数化模型的创建和更新,可实现快速提供多种设计方案进行比选,并导出三维有限元模型用于结构强度的分析校核,从而得到钻台结构的优化设计方案。经过实船项目测试表明,基于NAPA Designer软件的钻台结构参数化设计方法可有效降低使用者门槛并显著提高设计效率。

Victory Ceremony Hosts/Hostess Costume Design Scheme for Beijing Olympics Sought

The Beijing Organizing Committee for the Games of the 29th Olympiad(BOCOG)announced on May 22 that it is organizing a bid across the nation for the design scheme of the victory ceremony hosts/hostess costumes for the Beijing 2008 Olympic Games from May 23 to June 25,2007.

无刷双馈电机研究综述与展望

无刷双馈电机具有结构可靠、变频器容量小等优势,非常适合灵活运行于防爆、易燃等特殊或极端工况,近年来受到广泛关注。该文根据无刷双馈电机的基本工作原理,明确了该类电机的命名原则与规范名称;总结了现有定转子方案的结构及性能特点,综合考虑性能指标与结构工艺,提出了转子双套绕组的发展方向;梳理了无刷双馈电机的稳态等效电路模型及基于各类数学模型的优化设计方法,针对现存难以完整考虑不同转速工况性能的不足,阐明了利用新型同步-异步相串联等效电路进行优化设计的思路;对比分析了经典及新近出现的无刷双馈电机控制系统拓扑和控制策略特点,面向典型电动、发电工况建立了完整的电机及控制系统。最后,对无刷双馈电机的上述理论研究问题及工业应用的发展方向进行了总结阐述,为该类电机的深入研究及加快推广应用提供参考和指导。

乙二胺四乙酸铁钠补铁剂制备实验改进

本项目将乙二胺四乙酸铁钠(NaFeEDTA)补铁剂制备实验项目进行了改进,将理论知识与实际生产紧密衔接,依据药物制备工艺流程,设置集方案设计、药物制备、结构鉴定、纯度分析等模块于一体的全链条实验内容,将实验项目由验证性实验转变为综合性、设计性实验,引导学生结合制药工艺流程中所涉及到的质量控制、安全生产、环境保护等因素设计实验方案。本实验项目可结合多条专利路线,能激发学生探究兴趣,促进学生自主探究,培养学生方案设计和创新思辨能力,提升学生解决实际问题能力和科学素养,增强专业自信。

基于预补偿的缸孔型线优化设计及其密封特性研究

以某非道路高压共轨柴油机为研究对象,建立了螺栓–缸盖–缸垫–缸套–机体装配耦合模型,采用仿真分析与测试相结合的方式研究了工作状态下的缸套热机耦合失圆变形。基于缸套变形结果设计了锥形、瓶颈形、纺锤形、椭圆形、椭圆纺锤复合形5种具有不同型线特征的异形缸套预补偿方案,研究了不同异形缸套的热机耦合变形量、傅里叶变形幅值及其密封与摩擦性能。研究结果表明,在第三缸的101.8 mm截面处,椭圆形方案的最大径向变形量比原机缸套减小了15.42%;椭圆形缸套的窜气量与原机缸套相比减小了1.34%,其他方案的窜气量均比原机缸套大;与原机缸套相比,纺锤形缸套和椭圆纺锤复合形缸套的机油消耗量减小了21.36%。

建筑智能化方案精准设计方法探索

以智能建筑的顶层设计为基础,在比较不同智能化系统优劣的基础上,提出基于约束条件的智能化设计方案的整体比较方法,为业主智能化设计的投资优化方案提供指导。同时,构建MATLAB模型以简化计算过程,实现设计方案的便捷比较和直观展示,助力精准控制方法在实际应用中的优化。

建筑智能化系统顶层设计方法探讨

通过自上而下地展开,吸收质量功能配置的思想,对建设过程中影响智能化系统的因素进行统筹考量。通过逐层迭代的方式,直观展示不同技术方案对业主满意度的影响,为建筑设计提供可比较的方案效益评价,也为设计明确后续技术路径。

一种便携式机械设计工具箱的设计

随着社会的发展和智能制造技术的进步,无论是企业还是生产工人,对机械设计工具箱的要求越来越高。机械设计工具箱广泛地应用于机电类、机械类、汽车类、建筑类等专业中。针对目前机械设计工具箱结构简单、功能单一、工具难以找寻、容易发生碰撞导致损伤等缺点,本文将箱体、箱盖、滑轮、折叠支撑柱、拉杆、阻隔板、防水工具袋、电源、固定块、显示屏、缠绕柱、手提把等连接在一起,设计出一种新型的便携式机械设计工具箱,保证了机械设计工具的方便拿取,便于携带,提高了工作效率,极大地满足了企业和员工的需求,适合大批量生产、推广和应用。