Design of a Simulation Package for Automated Guided Vehicle Systems

The lack of analytical techniques in designing optimal network configurations and control policies in Automated Guided Vehicle Systems (AGVS) leaves simulation as the designer's primary tool. ASP is a general purpose AGVS Simulation Package developed in SIMAN and FORTRAN. This interactive package is designed to relieve the user of programming the simulation model and allow the user to input different design configurations quickly. The package consists of an interactive user interface, a model file which contains the generic portion of the system model and an experiment file which contains user defined parameters which are problem specific. The user enters the network topology, vehicle operating characteristics and selects system and simulation control policies. Waiting time at each intersection and station and total system time are the general output of the package and may be further analyzed using the SIMAN Output Processor.     

A planar graph drawing program

This paper describes a program, written in FORTRAN, for a 64K I.C.L. 4130 which will accept data describing the ordering of nodes and branches within the regions of a planar graph, and generate a two-dimensional representation, without crossovers, from these data. The program was written to provide one of the basic ‘tools’ required in the development of a printed wiring board layout program for the electronics industry The program generates display code which is sent to a satellite PDP-7 computer driving a 340 display. On completion of the automatic drawing phase an interactive phase is entered in which the user can ‘tidy’ and label the drawing, by means of keyboard and light-pen commands Brief notes are included on the hardware, the data structures package (MINIJASP, derived from ASP) and the graphics package, employed.     

Parking lot design by interactive computer graphics

An Interactive Computer Graphics Parking (ICG-PARK) Program which provides an efficient way to design parking lots is described. Using ICG-PARK program, composite pictures of the system can be generated by computer graphics quickly and accurately. The modification or redesign of such pictures can be done easily through interactive display systems.

The area under study is initially drawn with fixed objects. The user can then proceed to any desired subroutine by using the interactive capabilities of the system. The length, direction of row(s) of parking spaces and the dimension of the parking stalls are given by the user each time through the interactive device when a parking stall drawing subroutine is called. Row(s) of parking stalls are drawn on a subpicture. When attached to the cross cursor, it can be moved to the desired location. The approximation of a curve can be drawn by calling the curve drawing subroutine recurrently. The design vehicle minimum turning path curve is provided, and can be used to check the adequacy of the aisle, entrance, and exit layout. The CRT screen can be erased either entirely or partially and redrawn at any time. Finally, a hardcopy of a satisfactory parking lot layout plan can be obtained through the plotter.     

Developing AGVS Petri net control models from flowpath nets

The paper presents a control-based Petri net (PN) modeling method that translates a high-level automated guided vehicle system (AGVS) flowpath net model into a low-level on/off control model systematically. The relation between a high-level AGVS flowpath net model and the equivalent low-level control net model is uniquely defined by introducing certain I/O control functions and station control macros into the net model. To ensure the uniqueness of the translation, the AGVS flowpath layout is first decomposed into constituent basic PN flowpath modules. By employing a modular concept, the wiring layout of each basic flowpath module is established. Proper I/O control functions and station control macros are introduced and incorporated into basic flowpath net modules to generate basic control net modules. The union of constituent basic control net modules systematically leads to a complete AGVS control PN model. A laboratory AGVS is used to verify the effectiveness of the proposed modeling method. The results indicate that the proposed method is capable of generating a control model directly from a given flowpath layout. Many by-products are generated by the method: wiring layout, minimum size and specification of the controller, scanning time of the control program, and so on. These features allow a designer to quickly conduct cost estimation and performance evaluation on any given flowpath layout.     

CAE system in mechanical engineering

Two interactive CAE systems in mechanical engineering were developed. One is a general purpose system for structural design. All stages of design from the beninning of structural analysis to the last stage of strength evaluation can be treated so that optimal structures can be obtained by using this system with changing shapes and dimensions of the structures.

The other one is limited for turbomachinery design. But this includes not only analysis and simulation programs but also design programs and accumulated data for the products, etc.

This paper explains these systems and some element programs which support the system.     

网络设计符号的表达

网络时代,设计符号被高度提炼,以更高的效率进行传递。网络符号是传达人类内心世界的情感符号。本文重点讨论了网络产品如何提供用户最佳体验效果,这要求网络设计符号具备三要素:①功能丰富,使用便捷;②美观的视觉效果;③良好的互动性。借助计算机技术突飞猛进的发展,伴随网络用户的不断壮大,网络设计符号的表现性不断强化,符号的个性也更加明显。作为一种新的传播媒介,网络设计符号的互动性更是得到了充分的体现。     

A CAE system for micromachines: Its application to electrostatic micro wobble actuator

This paper describes a new computer-aided engineering (CAE) system for micromachines 10⁻⁶−10⁻³ m in size. An automatic finite-element (FE) mesh-generation technique, which is based on the fuzzy knowledge processing and computational geometry techniques, is incorporated into the system, together with a commercial FE analysis code, MARC, and a commercial solid modeler, DESIGNBASE. The system allows a geometry model of interest to be automatically converted to different FE models, depending on the physical phenomena of the micromachines to be analyzed, i.e., electrostatic analysis, stress analysis, modal analysis, and so on. The FE models are then automatically analyzed using the FE analysis code. Out of the whole process of analysis, the definition of a geometry model, the designation of local node patterns and the assignment of material properties and boundary conditions to the geometry model are the only interactive processes to be done by the user. The interactive operations can be processed in a few minutes. The other processes, which are time consuming and labour intensive in conventional CAE systems, are fully automatically performed in a popular engineering workstation environment. With the aid of multilayer neural networks, the present system also allows us to obtain automatically a design window in which a number of satisfactory design solutions exist in a multi-dimensional design parameter space, considering coupled multiple phenomena such as static and dynamic deformation, thermal conduction, electrostatics, and so on. This CAE system is successfully applied to evaluate an electrostatic micro wobble actuator. As a typical CAE evaluation, we identify the quantitative conditions for operating the micro wobble actuator, considering both structural and electrostatic phenomena.     

Exploring large graphs in 3D hyperbolic space

Drawing graphs as nodes connected by links is visually compelling but computationally difficult. Hyperbolic space and spanning trees can reduce visual clutter, speed up layout, and provide fluid interaction. This article briefly describes a software system that explicitly attempts to handle much larger graphs than previous systems and support dynamic exploration rather than final presentation. It then discusses the applicability of this system to goals beyond simple exploration. A software system that supports graph exploration should include both a layout and an interactive drawing component. I have developed new algorithms for both layout and drawing (H3 and H3Viewer). The H3Viewer drawing algorithm remains under development, so this article presents preliminary results. I have implemented a software library that uses these algorithms. It can handle graphs of more than 100,000 edges by using a spanning tree as the backbone for the layout and drawing algorithms     

Designing screens for people to use easily

The use of interactive computer systems is expanding rapidly. In many applications users can communicate directly with computer-based systems through an interactive dialogue at a display terminal. However, this direct form of communication has created problems. Whereas early users of on-line systems were skilled computer professionals, today's users may have little or no training in computer technology. How then does this group communicate effectively with a computer systems?

The answer is that many users communicate only with considerable difficulty. The result is that the effectiveness of many systems is very much less than expected. The reason for this is simple: these systems are not very good at communicating with their users.

The most common communications bridge between a person and a computer system is a display screen. A well-designed screen format can enhance user productivity, eliminate or reduce user input errors, and promote end user satisfaction. A poorly designed screen has the opposite effect: it will decrease human processing speed, provoke user mistakes, and complicate computer operations.

Screen design requires the same care as designing the overall application. It employs the same techniques as planning and preparing good user documents. Screens, like documents, must be easy to understand and easy to use. To achieve these objectives, screen designers must make good choices regarding three ease-of-use parameters: format; screen content and layout; and style. This paper describes how standards may be established for each of these parameters in a proposed application or system. Futher, an interactive tutorial computer program has been developed (using Bricklin's DEMO program) which may be used to illustrate the application of these standards.     

Design of a PCB plant with expert system and simulation approach

This paper presents a case study of using simulation in planning a new Printed Circuit Board (PCB) manufacturing system. The process simulation technique and expert system are proposed to evaluate the design alternatives and logistics management. Simulation results, such as machine utilisation, waiting time, and throughput of system are generated for evaluation. Simulation models were developed using software package SIMPROCESS, which is based on the concept of visual interactive simulation. Besides, the formation of the models is assisted by the expert system package VP-EXPERT. Each approach was found to accurately model the PCB manufacturing plant layout, provide operational and logistics performance in terms of throughput, waiting time, and resource utilisation, and provide a basis for suggesting the best modes of logistics operation.     

Coupling interface of a microcomputer-based intelligent structural design system

An interactive interface has been created to couple a conventional structural analysis and design package to a knowledge-based system so as to form a microcomputer-based intelligent structural design system. Primarily, the interface comprises an automatic data generator and an interactive graphic editor. The data generator has been designed to automatically translate the symbolic output inferred by the knowledge-based system into numerical input for the structural analysis and design package. The interactive graphic editor allows the user to visually verify and/or modify the pre- and post-processed structural model. This paper presents an overview of the proposed intelligent structural design system, ISTRUDS, and describes the coupling interface, GENED.     

数字产品设计符号互动研究

如今,对于许多数字产品而言,造型符号在回归极简,功能符号却在不断增加和丰富,功能的执行不再是传统的可感知方式。数字产品设计符号与使用者之间存在着更为复杂的沟通,将有越来越多的关于交互的问题出现。本论文从数字产品设计符号的表达、互动的转变、互动的要求和互动的发展四个方面对数字产品设计符号互动进行了研究,以帮助数字产品设计符号更好的构建、理解和互动。     

仿真数据管理平台的需求分析与实施

CAE分析方法在汽车行业得到广泛应用,迫切需要对模拟分析结果和CAE分析方法进行有效管理.模拟分析过程本身比如边界条件、模型设置和结果处理都需要进行标准化,CAE应用阶段的拓展也需要有数据库做基础.在这种背景下,定义和开发基于SimManager的CAE平台.通过这个平台,将CAE任务包标准化后,用CAE模板对CAE分析过程和结果数据进行管理.不同CAE团队之间的模拟数据可以被追踪、重新利用和共享.在某些领域,重要的参数可以和以往数据对比或与试验数据比较.该平台实现发动机进、排气道CFD分析过程的自动化,极大地提高分析效率.     

Developing a Higher-Cycled Product Design CAE Model： The Evolution of Automotive Product Design and CAE

To help corporations survive amidst worldwide quality competition, the authors have focused on the strategic development of a higher-cycled product design CAE model employing a highly reliable CAE analysis technology component model. Their efforts are part of principle-based research aimed at evolving product design and CAE development processes to ensure better quality assurance. To satisfy the requirements of developing and producing high quality products while also reducing costs and shortening development times, the effectiveness of this model was verified by successfully applying it to the technological problems of loosening bolts and other product design bottlenecks at auto manufacturers.     

Parametric graph drawing

A diagram is a drawing on the plane that represents a graph like structure, where nodes are represented by symbols and edges are represented by curves connecting pairs of symbols. An automatic layout facility is a tool that receives as input a graph like structure and is able to produce a diagram that nicely represents such a structure. Many systems use diagrams in the interaction with the users; thus, automatic layout facilities and algorithms for graphs layout have been extensively studied in the last years. We present a new approach in designing an automatic layout facility. Our approach is based on a modular management of a large collection of algorithms and on a strategy that, given the requirements of an application, selects a suitable algorithm for such requirements. The proposed approach has been used for designing the automatic layout facility of Diagram Server, a network server that offers to its clients several facilities for managing diagrams     

Evaluation of a traceability approach for informal freehand sketches

Most engineers and designers prefer to use large drawing boards such as whiteboards or flip charts for the initial collaborative sketching of a system’s models. Large interactive displays have recently begun to replace these physical drawing boards, blurring the line between freehand sketching and toolkit-aided modeling. While digital boards offer more flexibility in drawing and navigating models, they must also provide appropriate cognitive support for frequent shifts of focus and navigation between related artifacts. Furthermore, automated assistance in uncovering potential inconsistencies and contradictions between model sketches would be beneficial so that users do not get lost amid their sketches. In this paper, we discuss an approach to create relationships between the elements of informal hand-drawn sketches on large interactive displays by combining fuzzy search with classic information retrieval techniques. The identification and maintenance of relationships is particularly challenging because we are working with hand-drawn and hand-lettered model sketches rather than the syntactically clean models created with digital modeling toolkits. We evaluated our approach by analyzing 89 model sketches from 16 industry projects and found that it identifies relations between sketched model elements with high precision and recall.     

计算机辅助结构设计与分析的集成框架研究

针对计算机辅助结构设计和分析的集成问题,设计了一种基于统一模型库 方式的组件式CAD/CAE 集成框架,以结构CAD/CAE 集成模型库为框架底层,以几何造型、 可视化交互、第三方CAD、第三方CAE 等组件为中间组件层,以空间结构设计子系统、空 间结构分析子系统为上层应用层,提供空间实体建模、工程模型管理、多种有限元模型分析 与计算等功能,并应用于港口码头的结构设计及有限元分析。     

Interactive design system application

An interactive design system for the drawing office is described that should provide better control and standardization of drafting procedures, electrical and electronic symbology, repeatable designs and manufacturing processes, thus making it possible to produce higher-quality drawing documents in a shorter time and to increase the capacity of the drawing office.