虚拟仪器软件Labview和数据采集

Labview系统是著名的虚拟仪器开发平台。和传统的编程语言C,Fortran等用于虚拟仪器的开发平台相比,Lab view开发平台程序编写简单、灵活,易于掌握,用户不必花费大量的时间用于程序编写,可以将更多的精力投入到数据的分析、处理中。Labview开发平台使用图形语言,界面友好、直观,非常适合试验数据采集。文中阐述了Labview的开发环境,结合USB9100ms数据采集卡介绍了Labview如何进行数据采集。     

GCI—A tool for developing interactive cad user interfaces

GCI is a Unix-based tool for developing interactive CAD programs. By separating command/ menu definitions from the progam, GCI makes it easier to change and extend the user interface. The language provided by GCI is used to define the syntax of commands, menus, messages, and help text. Generally, GCI supports a static hierarchical structure of commands and menus. However, through a program interface, an application program has the freedom to change environments, commands and menus. This flexibility of run-time control of the user interface is essential for developing highly responsive interfaces in a CAD environment. This paper presents the main concepts and definition language of GCI. It then discusses architectural and implementation issues, and finally presents a typical application's view of using the tool.     

虚拟拆卸中多方式交互技术的应用

通过分析虚拟环境下不同人-机交互方式的特点，结合对产品装配体进行人工拆卸的操作活动，提出面向虚拟拆卸的人-机-零件间的多方式交互操作方法，在虚拟环境下研究和利用手抓取操作、手势操作、语音命令和3D虚拟菜单等多种交互方式对产品零部件进行自然、直观的人工拆卸，人机结合进行产品的装配／拆卸序列规划。     

The future of interactive systems and the emergence of direct manipulation

This paper suggests three motivations for the strong interest in human factors' aspects of user interfaces and reviews five design issues: command language versus menu selection, response time and display rates, wording of system messages, on-line tutorials, explanations and help messages and hardware devices. Five methods and tools for system development are considered: participatory design, specification methods, software implementation tools, pilot studies and acceptance tests and evolutionary refinement based on user feedback.

The final portion of the paper presents direct manipulation, an approach which promises to become widely used in interactive systems. Direct manipulation involves representation of the object of interest, rapid incremental reversible actions and physical action instead of complex syntax.     

Egocentric Object Manipulation in Virtual Environments: Empirical Evaluation of Interaction Techniques

The acceptance of virtual environment (VE) technology requires scrupulous optimization of the most basic interactions in order to maximize user performance and provide efficient and enjoyable virtual interfaces. Motivated by insufficient understanding of the human factors design implications of interaction techniques and tools for virtual interfaces, this paper presents results of a formal study that compared two basic interaction metaphors for egocentric direct manipulation in VEs, virtual hand and virtual pointer, in object selection and positioning experiments. The goals of the study were to explore immersive direct manipulation interfaces, compare performance characteristics of interaction techniques based on the metaphors of interest, understand their relative strengths and weaknesses, and derive design guidelines for practical development of VE applications.     

A theory of personalisation of appearance: quantitative evaluation of qualitatively derived data

Abstract

This paper suggests three motivations for the strong interest in human factors' aspects of user interfaces and reviews five design issues: command language versus menu selection, response time and display rates, wording of system messages, on-line tutorials, explanations and help messages and hardware devices. Five methods and tools for system development are considered: participatory design, specification methods, software implementation tools, pilot studies and acceptance tests and evolutionary refinement based on user feedback.

The final portion of the paper presents direct manipulation, an approach which promises to become widely used in interactive systems. Direct manipulation involves representation of the object of interest, rapid incremental reversible actions and physical action instead of complex syntax.     

Visualizing and animating the winged-edge data structure

The winged- and half-edge data structures are commonly used representations for polyhedron models. Due to the complexity, students in an introductory course to computer graphics usually have difficulty in handling these data structures and developing applications. This paper describes the authors’ effort in the development of a visualization and animation tool for teaching and learning these data structures. This tool also includes a simple pseudo-code-like language for algorithm design. Instructors may employ this tool for presentation and demonstration purposes. Students may use the simple language to develop and experiment with new algorithms before their actual implementation. The visualization and animation system may be used to explore and understand the relationship among mesh elements and algorithm execution.     

Construction of feature-matching perception in virtual assembly

An important characteristic of virtual assembly is interaction.Traditional direct manipulation in virtual assembly relies on dynamic collision detection,which is very time-consuming and even impossible in desktop virtual assembly environment.Feature-matching is a critical process in harmonious virtual assembly,and is the premise of assembly constraint sensing.This paper puts forward an active object-based feature-matching perception mechanism and a feature-matching interactive computing process,both of which make the direct manipulation in virtual assembly break away from collision detection.They also help to enhance virtual environment understandability of user intention and promote interaction performance.Experimentl results show that this perception mechanism can ensure that users achieve real-time direct manipulation in desktop virtual environment.     

The Personal Interaction Panel – a Two-Handed Interface for Augmented Reality

This paper describes the introduction of a new interaction paradigm to augmented reality applications. The everyday tool handling experience of working with pen and notebooks is extended to create a three dimensional two-handed interface, that supports easy-to-understand manipulation tasks in augmented and virtual environments. In the design step we take advantage from the freedom, given by our very low demands on hardware and augment form and functionality to this device. On the basis of examples from object manipulation, augmented research environments and scientific visualization we show the generality of applicability. Although being in the first stages implementation, we consider the wide spectrum of suitability for different purposes.     

综合传动系统虚拟样机建模与仿真平台研究

液力机械综合传动系统是现代履带装甲车辆的主要传动形式,都为系列化产品.传动系统虚拟样机技术是提高设计质量,缩短研制周期的重要技术之一.通常的方法是采用分块建模,手动组装,效率低,难以满足新型传动系统及部件快速设计性能仿真的需要.采用自顶向下设计方法,基于模块化和参数化思想,以动力学软件ADAMS为开发平台,综合运用ADAMS/Solver语言和cmd命令建立一个以模块为基元、能够自动化搭建车辆传动系统的虚拟样机建模仿真平台.应用表明,该平台满足了传动系统性能仿真平台快速构建的需要,达到缩短传动系统的研制周期的目的.     

虚拟拆卸环境中工具的操作技术

在虚拟拆卸环境中借助工具拆除紧固零件，能够使虚拟环境下的拆卸活动更加真实，有利于获得符合工程实际的拆卸序列．提出工具定位约束的概念，对虚拟拆卸环境中工具的操作技术进行了深入研究．首先分析工具的拆卸操作过程；然后对常用工具的工具定位约束进行研究，并论述了虚拟环境中工具精确定位的实现方式；最后以Bell-roller产品装配体模型为例，在沉浸式虚拟环境中基于工具定位约束、操作螺钉起子和扳手完成紧固零件的拆除。     

Wsh—a new command interpreter for unix

WSH is a window managing command language interpreter (shell) for the UNIX operating system. This interface increases a user's power to communicate with UNIX by providing a process management environment based on an integrated virtual terminal-shell design. Unlike conventional shells, WSH affords its user the ability to monitor and communicate with multiple processes within a single display context. Windows represent virtual terminals in the WSH design, and as such are device-independent abstractions of real terminals. Since the design of the virtual terminal environment is based on UNIX's TERMCAP terminal database facility, WSH is portable across all versions of UNM supporting this feature. WSH requires neither alteration of existing UNIX facilities nor special display devices. The current implementation runs on a Digital VAX 11/780 under Berkeley UNIX 4.1 environment.     

Performance evaluation methodologies for abstract data type implementation techniques

The runtime management system for a programming language must allow the efficient manipulation of complex objects, such as instances of abstract data types (ADTs). We describe an implementation model for ADTs based on coroutine objects (i.e. as an alternative to ad hoc modifications of the runtime stack). We evaluate the performances of variants of our implementation model using two different approaches: a benchmarking technique which monitors actual costs for test programs and a “pseudo-execution” technique which estimates costs based on idealized instruction timings. The results of our comparison indicate that the two forms of evaluation give very similar cost estimates, supporting the use of the (cheaper) pseudo-execution technique. The overall performance results identify applications in which our coroutine implementation model has definite strengths and weaknesses. Finally, our implementation approach is compared with modified stack implementations used in other ADT systems.     

HADT: Hypermedia application development tool for tourist applications

This paper describes an authoring tool prototype design for the development of hypermedia applications. The system is based on a generic object oriented data model suitable for hypermedia, that has been designed and implemented in our department. The model is extensible for integrated multimedia manipulation and provides an enhanced linking system. The design aims at a general purpose hypermedia application development tool which may well be used for the development of tourist applications. It is of special interest in the Greek tourist market since tourism contributes considerably to the national income of Greece. Current technology provides the hardware for manipulation of multimedia information and increases the quantity and quality of information flow between the user and the machine. Thus in a travel agency environment it would be desirable to have an interactive multimedia demonstration helping the user find places of interest in any context (physical beauty, archaeological interest, tourist infrastructure, possible itineraries etc.). Such a tool would be very effective compared with the static presentation of brochures. HADT has the potential to fulfil these needs when it is developed, and in this paper we explore such possibilities. Furthermore, research directions for future work are discussed.     

A Virtual Reality Interface for Space Planning Tasks

Manipulating and assembling elements in a 3D space is a task which interests a huge number of potential applications whether they deal with real or abstract objects. Direct manipulation techniques in traditional interactive systems use 2D devices and do not allow an easy manipulation of 3D objects. To facilitate user interaction, we have studied direct manipulation techniques in a virtual reality environment. A VR interface is naturally object-oriented and allows the definition of real-world metaphors. Operators can thus work in the virtual world in a similar way to the real world: they perceive the position of objects through the depth cue of stereo view, and can grab and push them in any direction by means of avirtual handuntil they reach their destination. They can put an object on top of another and line it up with other objects. We model the virtual world as ajob-orientedworld which is governed by a few simple rules which facilitate object positioning. In this paper, we describe the design and implementation strategies to obtain a real-time performance on a low-level workstation.     

一种适合VRML应用的三角网格简化算法

交互虚拟环境中，VRML作为三维场景描述语言得到广泛应用，场景中的物体常常用三角形网格模型来描述，本文提出了一种适合VRML应用的网格简化算法，该算法不仅可以快速减少模型中的画片数目而且能保持模型良好的视觉效果，算法中给出了一种有效的误差控制方法，能在用户指定的误差范围内通过使原始网格中的边折叠达到大量简化的目的，该算法实现简单且速度快，另外能够有效地支持细节层次模型的表示，最后给出实例证明了该算法的有效性。     

Designing an adaptable heterogeneous abstract machine by means of reflection

The concepts of abstract and virtual machines have been used for many different purposes to obtain diverse benefits such as code portability, compiler simplification, interoperability, distribution and direct support of specific paradigms. Despite of these benefits, the main drawback of virtual machines has always been execution performance. Consequently, there has been considerable research aimed at improving the performance of virtual machine's application execution compared to its native counterparts. Techniques like adaptive Just In Time compilation or efficient and complex garbage collection algorithms have reached such a point that Microsoft and Sun Microsystems identify this kind of platforms as appropriate to implement commercial applications.What we have noticed in our research work is that these platforms have heterogeneity, extensibility, platform porting and adaptability limitations caused by their monolithic designs. Most designs of common abstract machines are focused on supporting a fixed programming language and the computation model they offer is set to the one employed by the specific language. We have identified reflection as a basis for designing an abstract machine, capable of overcoming the previously mentioned limitations. Reflection is a mechanism that gives our platform the capability to adapt the abstract machine to different computation models and heterogeneous computing environments, not needing to modify its implementation. In this paper we present the reflective design of our abstract machine, example code extending the platform, a reference implementation, and a comparison between our implementation and other well-known platforms.     

Manipulating Objects in Virtual Worlds: Categorization and Empirical Evaluation of Interaction Techniques

The acceptance of virtual environment (VE) technology requires scrupulous optimization of the most basic interactions to maximize user performance and provide efficient and enjoyable virtual interfaces. Motivated by insufficient understanding of human factors implications in the design of interaction techniques for object manipulation in virtual worlds, this paper presents results of a formal study that evaluated two basic interaction metaphors for virtual manipulation—virtual pointer and virtual hand—in object selection and positioning tasks. In this work, we survey and categorize current virtual manipulation techniques according to their basic design metaphors, conduct experimental studies of the most basic techniques, and derive guidelines to aid designers in the practical development of VE applications.     

机器人图形化编程与三维仿真环境

介绍一种采用JAVA开发、基于RTLinux平台的适合多机器人多任务的图形化编程与三维仿真环境．采用图标和连线方式快速建立具备流程图特点的控制程序．运行管理内核实现程序图结构的信息流向跟踪,对程序运行采用边解释边执行机制．机器人运动学指令由底层RTLab执行,结果返回上层;由Java3D实现的三维仿真环境可动态显示机器人的运动过程．该环境支持离线编程和在线调试．目前支持日本安川公司研制的Motoman UPJ和SmartPal类人轮式移动服务机器人．