An integrated modelling approach for the representation and embodiment of engineering systems with standard components

In todays global markets the commercial success of a product, however defined, is highly dependent upon the rapid and efficient transformation of an engineering system from a design schema to a fully embodied optimal solution. The ability of the designer to achieve this is severely frustrated by the analytically intensive and time-consuming aspects of embodying a concept. This is particularly the case where standard components have to be considered. This paper presents a new modelling approach that supports the designer during the transformation of a concept to an embodied solution. This modelling approach provides for the representation of conceptual schemas and their subsequent embodiment with standard components from third-party electronic representations. The modelling strategies and associated software issues for representing a mechanical system, handling the interactions between components and incorporating the governing representations for the design and selection of individual components are discussed. The process of constructing a system model, specifying the desired performance characteristics and the process of system resolution are also described. The paper concludes with an industrial case study which is used to demonstrate the capabilities and potential of the new approach for supporting the embodiment of systems and the important task of design synthesis.     

An Expert System Realization for Conceptual Design of Mechanical Products

Through the practice of developing an expert system FBCDES(Feed Box Conceptual De-sign Expert System)for the planomillingmachine in CIMS ERC(CIMS Engineering Research Center)in China,the paper intends to introduce a common problem-solving strategy for the mechanical productconceptual design expert system.Meanwhile some problems such as system architecture,knowledgerepresentations and inference engine sets are also described.A yet more detailed discussion is given tothe technical problems for realizing two key modules,that is concept design module and layout module.     

Container spaces and functional features for top-down 3D layout design

Although there have been many advances in computer-aided modelling techniques and representations of mechanical parts, there are areas where exact modelling is a handicap. One of these is 3D layout design. Here, simpler models are useful for initial design sketches to verify kinematic behaviour and organise product structure before the detailed component design phase begins. A commitment to exact, or close approximational geometry too early can imply a commitment to form before functionality has been finalised. This paper describes a system for top-down 3D layout design based on simple conceptual elements which can be used as a basis for visualisation, discussion, definition of product structure and kinematic functionality in the conceptual design phase before the embodiment or detailing begins. This tool forms a bridge between the abstract nature of the conceptual design phase and the geometric nature of the embodiment phase. The 3D layout module uses design spaces with simple geometry and kinematic connections to represent a product. The design spaces act as containers or envelopes within which the final component design is to be realised. The kinematic connections allow the behaviour of the product to be simulated to gain more information (such as overall component dimensions and areas of potential collisions) for the detailed design phase. In addition the paper describes the design process based on the proposed 3D layout design system and contrasts this with the traditional design process. An industrial case study is presented to illustrate the following advantages of the proposed approach: (i) the design process proceeds faster because unnecessary layout parameter and constraint modifications are avoided since kinematic functionality verification precedes the detail design, (ii) the design process can produce better designs since alternative solution principles can be explored early in the design process. Theoretical issues are discussed concerning kinematic constraint inheritance during design space decomposition and concerning computer support for non-rigid design spaces.     

Multidisciplinary interface model for design of mechatronic systems

The design of mechatronic systems is based on the integration of several disciplines, such as mechanical, electrical and software engineering. How to achieve an integrated multidisciplinary design during the development process of mechatronic systems has attracted the attention of both academia and industry. However, solutions which can fully solve this problem have not been proposed by now. The concept of multidisciplinary interface represents the logical or physical relationship integrating the components of the mechatronic system or the components with their environment. As the design of mechatronic systems is a multidisciplinary work, the multidisciplinary interface model can be considered as one of the most effective supports to aid designers for achieving the integrated multidisciplinary design during the development process. The paper presents a multidisciplinary interface model for design of mechatronic systems in order to enable the multidisciplinary integration among design team members from different disciplines. On the one hand, the proposed model ensures the consistency of interface defined by the designers. On the other hand, it helps the designers to guarantee the different components integrate correctly. The interface model including three concepts: classification, data model and compatibility rules. The multidisciplinary interface model is implemented by a case study based on a 3D measurement system.     

A framework for virtual disassembly analysis

Product reuse or recyclability is enhanced by designing the product for inexpensive and efficient disassembly. However, accomplishing enhanced product design requires design for disassembly (DFD) tools. This paper presents a disassembly framework that consists of design modules; both of these are embodied in the geometric DFD tool. These modules consist of different tasks including: selection of the appropriate disassembly method; producing an optimized disassembly sequence; evaluating a disassembly sequence for cost; producing design change recommendations. These considerations make a product easier to disassemble and therefore have potential benefit to the environment.     

Integration of CAD and boundary element analysis through subdivision methods

Subdivision methods have been mainly used in computer graphics. This paper extends their applications to mechanical design and boundary element analysis (BEA), and fulfills the seamless integration of CAD and BEA in the model and representation.Traditionally, geometric design and BEA are treated as separate modules requiring different representations and models, which include continuous parametric models and discrete models. Due to the incompatibility of the involved representations and models, the post-processing in geometric design or the pre-processing in BEA is essential. The transition from geometric design to BEA requires substantial effort and errors are inevitably introduced during the transition. In this paper, a framework of realizing the integration of CAD and BEA was first presented based on subdivision methods. A common model or a unified representation for geometric design and BEA was created with subdivision surfaces. For general 3D structures, automatic mesh generation for geometric design and BEA was fulfilled through subdivision methods. The seamless integration improves the accuracy of numerical analysis and shortens the cycle of geometric design and BEA.     

Research on Variable Structure Parametric Design System of Ceramic Tile Mould Based on Modular

To solve the existing problems during the ceramic mold enterprises product design and development process, the variable structure parametric design system based on modular of ceramic mold has been developed. The system uses the object-oriented technology and top-down design concept as a guide, establishes a ceramic mold parametric design process, divides the process of ceramic mold design into modules of different levels and creates a component model library based on the functional analysis. Expanding modular thinking to parts structure design level is an effective solution to the difficulty of changing the structure during the product design process. Examples show that the system can achieve a ceramic mold product design, improve design efficiency.     

A Novel Concept for Building a Hyper-Redundant Chain Robot

This paper puts forward a novel design concept for building a 3-D hyper-redundant chain robot (HRCR) system, consisting of linked, identical modules and one base module. All the joints of this HRCR are passive and state controllable and share common inputs introduced by wire-driven control. The original prototype developed here, named 3D-Trunk, is used as a proof of concept. We will present its whole mechanical design and controller architecture. The key components of 3D-Trunk, its operational principles, and all implementation issues are exhibited and described in detail. Basic robotics analyses, dynamics simulations, and some experiments are also shown. This novel design concept is highly modular and scalable, no matter how many degrees of freedom are implemented and, thus, provides an affordable solution for constructing an HRCR.      

Expert tutoring system for teaching mechanical engineering

This paper describes the work undertaken, at the Higher Technical School of Industrial Engineers of Gijón, for the development of computer aided systems, in the line of expert systems, concentrating research, and development in the field of mechanical design. We are using this software as an integrated tool in our work for teaching machine design. Models to develop the software of several components are defined, and their application methodology is also presented.

An application which tackles the problem of configuration design, applied to mechanical transmission is also described in this article. The failure of machine elements in mechanical design, frequently occurs due to poorly detailed projects.

The developed work is applied to the design of configurations for mechanical systems, by means of an intelligent program which incorporates the process of geometric design, the calculation of mechanical elements, the selection in electronic databases and the output of CAD plans.

Configuration design is a type of design problem where the different elements (which make up the system, mechanism or machine project object), are selected from databases and connected in order to complete the requirements (functionality, specifications, and established restrictions) outlined in the problem.     

基于改进RBPF算法的轮式机器人SLAM导航系统设计

传统的机器人导航系统在复杂的地形环境中常常无法引导机器人躲避突然出现的障碍物,无法精准采集数据。为此提出一种改进RBPF算法的轮式机器人SLAM导航系统,对系统硬件和软件进行设计。系统硬件主要由导航功能模块、底盘驱动模块、控制模块组成,利用RPLIDAR A1型激光测距雷达设计导航功能模块,并设计底盘驱动模块和控制模块。软件设计中,以改进RBPF算法为基础,设计了轮式机器人SLAM导航系统的实现程序,应用算法代入的方式加强了普通轮式机器人导航算法对粒子计算与卡尔曼滤波的敏感程度。实验结果表明,改进RBPF算法在避障和计算误差方面的优势,证明了该系统相比传统避障后的路径选择更便捷,导航错误出现率降低了30%左右。     

基于功能面的产品布局与人机工程协同设计的研究

在产品概念设计中,布局设计和人机工程设计是两个相互影响和制约的设计过程,。为了将这种布局设计和人机工程设计协同起来,将功能面作为概念设计发解的依据,并在此基础上提出了基于功能面的协同概念设计过程和方法,以及布局设施 人机工程协同设计模型和形式化描述方法,最后结合摩托车的概念设计实例给出了一个计算机支持的布局和人机工程协同设计系统的实现方案。     

辐照环境下转速测量系统设计

针对辐照环境中转机设备转速测量的需求,从环境要求、系统设计、传感器选择和前置信号处理模块四方面入手,提出了辐照环境下转速测量系统的设计方法。考虑到辐照对电子元器件的影响,采用分体和冗余等设计手段,设备侧采用对辐照不敏感的机械感应传感器,电子处理部件则安装在和缓环境。机械感应传感器信号输出为非标准信号,需设计信号处理模块将非标准信号转换成工业控制系统可接受的标准电信号。信号处理模块针对不同转速工况进行优化设计,提高了在稳定工况下工作的准确度。核电站主泵转速测量系统的应用验证了该研究成果的可行性。     

Development of an automated flexible fixture for planar objects

A three fingered automated flexible fixturing system has been developed to fixture planar objects in a machining process. The fixturing system consists of two computer numerically controlled (CNC) modules, an auxiliary mechanism and a fixturing algorithm. This fixture is designed on the idea of the minimum number of fingers needed to immobilise an object. The fixturing algorithm is developed on the concept of the maximal inscribed circle in a polygon. It offers the flexibility to reconfigure the fingers of the system to accommodate workpieces of different shapes and sizes. A prototype of the system has been successfully built and tested, showing satisfactory performance in mechanical design and automatic control over the configurations of the fingers. Examples are given of the application of the system with objects of different shapes. The system is shown to be flexible, reconfigurable and automatic, capable of fixturing planar objects of different shapes and sizes in the machining process.     

Object-oriented design support system for machine tools

This paper deals with an object-oriented intelligent design support system which is intended to assist in the basic design of machine tools, in particular machining centres. The machine tools design process is analysed through interviews with experienced designers, and an object-oriented model is established to represent the design process. Software modules named design objects are proposed, which are basic components for the implementation of an intelligent design support system for machine tools. A prototype of the design support system for machining centres is developed based on the design objects, and some case studies are carried out to verify the effectiveness of the methods proposed.     

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。     

Petri net modules in the transformation-based component framework

Component-based software engineering needs to be backed by thorough formal concepts and modeling techniques. This paper combines two concepts introduced independently by the two authors in previous papers. On one hand, the concept of Petri net modules introduced at IDPT 2002 in Padberg [J. Padberg, Petri net modules, Journal on Integrated Design and Process Technology 6 (4) (2002) 105–120], and on the other hand a generic component framework for system modeling introduced at FASE 2002 in Ehrig et al. [H. Ehrig, F. Orejas, B. Braatz, M. Klein, M. Piirainen, A generic component concept for system modeling, in: Proceedings of FASE ’02, Lecture Notes in Computer Science, vol. 2306, Springer, 2002]. First we develop a categorical formalization of the transformation based approach to components that is based on pushouts. This is the frame in which we show that Petri net modules can be considered as an instantiation of the generic component framework. This allows applying the transformation based semantics and compositionality result of the generic framework to Petri net modules. In addition to general Petri net modules we introduce Petri net modules preserving safety properties which can be considered as another instantiation of pushout based formalization of the generic framework.     

Introduction to assembly features: an illustrated synthesis methodology

The article is an introduction to a new concept of assembly features able to support intelligent design and manufacturing of complex products. An assembly feature is defined as a generic solution referring to two groups of parts that need to be related by a relationship so as to solve a design problem. The concept of assembly feature encompasses the notions of design intent, technical function, technological solution and manufacturing process as well as it provides a justification for the use of part features. After a general introduction and a justification of the interest of assembly features, some guidelines are provided to show how assembly features can be characterized in any domain of application concerned with engineering design of assemblies. As an illustration of the proposed methodology, the concept is finally applied to the engineering phase of aeroplane design.     

特征设计的形式化描述

特征设计方法在设计中的成功应用取决于其形式化设计理论的建立。文章从形式化定义和设计过程描述这两个方面研究了特征设计的形式化描述方法。文中提出了特征定义、特征表示的形式化方法,探讨了特征设计过程的操作性和过程性描述,并给出了相应的设计算法。为解决特征设计系统开发和运行缺乏统一方法学这一课题作了有益的尝试。     

基于FPGA的图像融合处理系统方案设计

一种基于FPGA技术的图像处理系统,实现了图像数据的A/D采集、在SRAM以及SDRAM中的存取、在FPGA内部的DSP运算以及图像数据的D/A输出,具备图像融合处理功能。文章在阐述系统结构、总体方案和设计思想基础上,重点论述了系统各模块划分、芯片选型依据以及系统有关模块的接口设计。