Essential concepts and ingredients • virtual reality (VR) or virtual environment (VE), computer-generated environment with and within which people can interact. The advantage of VR is that it can immerse people in an environment that would normally be unavailable due to cost, safety, or perception restrictions. A successful VR environment offers users immersion, navigation, and manipulation. VR encompasses a range of interactive computer environments, from text-oriented on-line forums and multiplayer games to complex simulations that combine audio; video, animation, or threedimensional graphics; and scent. Some of the more realistic effects are achieved using a helmet like apparatus with tiny computer screens, one in front of each eye and each giving a slightly different view so as to mimic stereoscopic vision. Sensors attached to the participant (e.g., gloves, bodysuit, footwear) pass on his or her movements to the computer, which changes the graphics accordingly to give the participant the feeling of movement through the scene. Computer-generated physical feedback adds a "feel" to the visual illusion, and computer-controlled sounds and odors reinforce the virtual environment. Other VR systems, such as flight simulators, use larger displays and enclosed environments to create an illusion. Less-complicated systems for personal computers manipulate an image of three-dimensional space on a computer screen. In a virtual network many users can be immersed in the same simulation, each perceiving it from a personal point of view. VR is used in some electronic games, in amusement-park attractions, in military exercises, and to simulate construction designs. Experimental and envisioned uses include education, industrial design, surgical training, and art. An artificial reality that projects the user into a 3D space generated by the computer. A virtual reality system uses stereoscopic goggles that provide the 3D imagery and some sort of tracking device, which may be the goggles themselves for tracking head and body movement, or a "data glove" that tracks hand movements. The glove lets you point to and manipulate computer-generated objects displayed on tiny monitors inside the goggles. • Virtual manufacturing (VM) may play a significant role in distributed manufacturing, since it may improve design critiquing and process planning. These improvements will result in better designs and more informed partner selection. Furthermore, VM is expected to support distributed design if it provides protocols and computer aids for negotiation. • Evaluating the manufacturability of a proposed design involves determining whether or not it is manufacturable with a given set of manufacturing operations---and if so, finding the associated manufacturing efficiency. • Distributed manufacturing is performed by virtual enterprises. A virtual enterprise is a partnership of companies that forms in response to a certain market opportunity. The partners, who may geographically distributed and of various sizes and technical sophistication, contribute their core competence to the enterprise, enhancing its ability to deliver high quality, cost effective products to the market in a timely fashion. Distributed design is performed by multiple designers who may be distributed geographically and who employ heterogeneous design support systems. • Design-Centered • Production-Centered • Control-Centered Addition of simulations to control models and actual processes, allowing for seamless simulation for optimization during the actual production cycle. • • • • • new product development (NPD) advanced planning and scheduling (APS), computer-aided manufacturing (CAM), computer-aided production engineering (CAPE), computer-aided production planning (CAP/CAPP), • manufacturing execution systems (MES), and • manufacturing process management (MPM) • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training • • • • • • a) Styling b) Concept Design c) Ergonomics d) Design Review e) Virtual Maintenance f) Virtual Manufacturing • g) Virtual Training In VM the engineer studies the real process a priori No empirical study is necessary anymore. MV allows for in expensive, fast evaluation of many processing alternatives before committing the process to the shop floor. Manufacturing process is optimized, potentially down to the physical level. Scope pf VM “Soft” design prototypes can be virtually manufactured to optimize the design of the product for a specific goal. Applications V. R. can be applied in a variety of ways. In scientific and engineering research, V. E. are used to visually explore whatever physical world phenomenon is under study. Training personnel for work in dangerous environments or with expensive equipment is best done through simulation. Airplane pilots, for example, train in flight simulators. Virtual reality can enable medical personnel to practice new surgical procedures on simulated individuals. As a form of entertainment, virtual reality is a highly engaging way to experience imaginary worlds and to play games. Virtual reality also provides a way to experiment with prototype designs for new products. VM Constitution Essentials of DM VR is a collection of technologies. Is VM an application of VR? VR is only a tool for visualizaion in VM GUI serves this purpose. • Collaborative computing is an emerging networking strategy that links every department -- even every employee -- throughout a company. The idea itself has floated around since at least the early 1990s, but has finally come into its own thanks to expanded networking capabilities presented by the ubiquitous nature of the World Wide Web and corporate intranets. • Concurrent engineering has become one of the latest technology buzzwords for industrial users. It allows different groups to create individual parts of a mechanical design at different locations, and at different stages of the design process. • For instance, one user might be designing an electrical component while another person is testing it for installation or maintainability, while a third person is performing training on that same component (see ISR, May 1996). Virtual reality developers are adding another dimension to the collaborative effort, and making VR technology accessible throughout an enterprise during a product's entire lifecycle. • For more information go to Appendix1. • A VR-based methodology for design of holonic-agile manufacturing systems has been presented. The methodology uses VR for modeling, simulation and monitoring holonic manufacturing control systems and their operations. VR technology allows the users to interact intuitively with the manufacturing environments and its objects, as if they were real, by immersing them in a highly realistic 3-D environment. • Two major components are proposed and developed as building environments of the methodology. These are namely; holonic control and VR operations environments. • MASs integrated to IEC 61499 function blocks have been used for design of holonic control environments, involving autonomous, cooperative holons, providing quick response to the perturbations in the system. • For more information go to Appendix2. • The VR operations environment consists of an interactive VR container platform with a GUI for receiving the user requests upon several manufacturing operations, editing parameters of production processes and viewing the HMS operations in virtual environment. • The objects of VR environment communicate with the holonic control function blocks through ‘sockets’ which are modular and re-configurable interfaces for data transfer between software platforms based. • The function blocks designed for control of the virtual manufacturing system is directly connected to the VR objects in order to trigger the events of operations in VR environment. • Each holon is autonomous and has the responsibility of maintaining its local knowledge and keeping its neighbor holons informed once something changed. None of the individual holons has the knowledge about the whole system. • For more information go to Appendix3. • The overall objective of the solutions are to provide a virtualinteractive environment which supports the entire life cycle of a factory. This includes the usage of VR as a command and control tool for factory design and factory operation. The virtual world can act as the integration platform for different simulation models (e.g. OEM supplier models developed in different simulation tools) .In the design phase of the factory the processes of the planned factory can be tested and optimized within the VR world. This very world can be enhanced by didactical knowledge to qualify workers for assembly procedures. In the operation phase of the factory the VR world can act as the virtual representation of the real factory. Based on on-line simulation concepts [8] and a connection to the shop-floor systems the state of the VR world (and the connected simulations) can reflect the state of the real factory. In case of emergencies (e.g. machine failure) the factory operator can plan and test different plans of action (fast-forward simulation) and select the best option. In summary, the issue of combining simulation and virtual reality into truly interactive and immersive environments is the next logical step in the development of visual 3D simulations and is a logical consequence derived from the requirements of the digital factory. The wide application areas include the virtualinteractive planning and design of new factories, the support for operating a factory, the worker qualification and many more. supplier1 Company 1 supplier2 supplier3 Customer 1 Customer 2 Company 2 Customer 3 Multi Enterprise Layer Factory1 Sales 1 Factory 2 Sales 2 Enterprise Layer Work Area 3 Work Area 1 Work Area 2 Shop Floor Cell Layer VR is applicable at these 3 layers • Detail planning and building of the production system (Delmia example) Factory1 Sales 1 Factory 2 Sales 2 Enterprise Layer Previous planning results are detailed 3D Process Verification Detailed time analyses Ergonomic analyses Results of detailed planning: • 6 manual work stations are realized. • The cycle time is reduced to 105 seconds. • Estimated costs for engine are not exceeded. Detailed layout planning Simulation Work Area 3 Work Area 1 Work Area 2 Shop Floor The purposed design and processes can be simulated directly in the virtual environment in order to verify applicability of the proposal Cell Layer VR can also directly simulate the cells which are the machines for example a CNC machine can be programmed and tested virtually prior the real action for verification. • Manufacturing paradigm, addresses rapid and efficient product development by equipment sharing technique Efficient utilization of the equipment sharing, distributed in different enterprises Provides: Low-cost Secure and fast analysis tool which can be reached with small and medium sized enterprises. Economical advantage Contribution to the total manufacturing output and employment opportunities global competition demands high manufacturing efficiency which dramatically impacts SMEs Shared using the internet technology that could provide a shared usage of the latest integrated manufacturing facilities. Conceptualization Design Development } networked virtual Environment platform For supporting Equipment sharing real-time Real time collaboration Same virtual environment Open Architecture Client server technology • Open Architecture • Client server technology The major benefit of client-server technology Processing load be shared between client and the server Due to inherent complexity, it is convenient to decompose the proposed platform into simpler components: Server Side Client Side Based upon distributed information management systems in internet-based manufacturing multi-agent technology exploitation of equipment sharing systems effectively Based on their functionalities, identified agents are classified as follows: Web-based interface Define a project manage a task sending and receiving message Communication services one-to-one (TCP/IP) (LAN/WAN) exchange of data A client can be any program, such as GUI applications that requests services from a server application A system that is used directly by the users to accomplish the communication between the front-end and platform’s database. Complies with the browser user interface which allows the exploitation of all net-place capabilities by using any demanded web browser. Clients are connected to servers via the Internet. This connection may be via leased line, dial-up, wireless or etc. A computer system is used to perform a workstation for each client. user interface comprehensive networked virtual environment in support of equipment sharing systems to improve the utilization factor and lower the cost of the enterprises group. The developed platform is based on standard technologies applied to J2EE language. Such technologies consist of Java Server Page (JSP) for visualization data by creation of HTML pages for data handling and user communication. The Viscape is used as basis for the visualization and development of the virtual environments. This system has been integrated into the web platform so as to be directly accessed by users through the graphical user interface. The communication between the equipment sharing platform and other application is handled through the Extensible Markup Language protocol. Network manufacturing technology combining the advanced net technology and virtual manufacturing technology, is an effective approach to reduce geographical distances and allowed products to be manufactured on a regional or global basis. The platform’s integration into virtual environment enables the interaction of users with the virtual equipments that efficient evaluation the manufacturing where the user intervention is crucial multi-user interaction and visualization. real-time collaboration on same equipment. learning the implementation of the different equipments (education). intelligent decision making base on fuzzy logic. increase equipment utilization, lower cost, and improve competitiveness of the integrated enterprises alliance. Future works Completion of network platform Adding adequate options in user interface Which are the key barriers prior to VM Hardware and software for VM • • • • Division Inc. (San Mateo, Calif.; http://www.division.com), for instance, has developed the universal virtual product (UVP), a fully functional product simulation that can be used to rapidly study all aspects of a product's form, fit and function. The UVP is a common medium through which all members of the enterprise -- regardless of where they are physically located -- can access, visualize, interact with, and understand the product. It can be used throughout the product lifecycle for conceptual design, marketing, detailed design, manufacturing simulation, training, sales, and other applications that will evolve as companies implement the new concept. Similarly, Deneb Robotics Inc. (Auburn Hills, Mich.; http://www.deneb.com) has developed a virtual collaborative engineering (VCE) environment that links multiple users at multiple locations, allowing them to analyze and review simulations over a wide area network. According to Deneb, users can interactively evaluate trade-off decisions involving design concepts, manufacturing processes, tooling, and factory layouts in the VCE environment. Any VCE user can assume control of a simulation, make changes, or view changes made by others on the VCE network. And a third VR developer -- Engineering Animation Inc. (Ames, Iowa; http://www.eai.com) -has its own collaborative engineering environment, which facilitates real-time peer-to-peer visualization communication throughout a company's product development process. This new communications technology is available as a software module for EAI's 3D visualization and digital prototyping software VisMockUp and VisFly, providing a platformindependent environment in which to view and analyze large product assemblies. EAI's collaborative engineering environment allows for real-time collaboration on product design, analysis, motion and assembly information across an entire corporation. Multiple users in various departments can look at the same data at the same time and interact with real-time collaboration capabilities. • • • • • • • • • • By using a collaborative virtual prototyping environment, conceivably everybody in a manufacturing enterprise, including those at remote locations, can have access to live models, which incorporate real-time visualization, animation and functional simulation features. The idea is to improve communication by helping users better understand the numerous aspects of the design, such as clearances, how parts will move in relation to one another, collision avoidance, how people will interact with the product, and how assemblies will come together and be taken apart. Using a standard Web browser, technical and non-technical users throughout a corporation can participate in product reviews and have a more immediate influence on the product development process. With online design reviews, users can bring together their individual expertise in one collective interactive session to quickly identify and resolve product issues before costly redevelopment efforts are required. Division sees its UVP as being closer in characteristics to a physical prototype than a digital prototype. Some of the UVP's specific functions include: real-time event-based behaviors for functional simulation. a real-time, collaborative engineering environment that simultaneously accommodates multiple users at remote sites. intelligent assembly parts for optimizing designs that respond to user input and to the UVP environment. a scaleable architecture that addresses needs throughout the manufacturing enterprise. real-time animation for assembly/disassembly and maintainability studies. an open architecture to interface with CAD/CAM/CAE tools. When properly integrated with a product data management (PDM) system, Division's dVISE development tool can be automatically updated to ensure that users always have a current view of the UVP. Since dVISE is available as a Net-scape Navigator plug-in, the UVP can be accessed by remote users via a Web browser. • The object oriented modeling and programming techniques are proposed for the development of VR environments and their interaction to the holonic control environments. • A prototype test implementation has been performed in a FMS for demonstrating the various aspects of the holonic system. • As the earlier step of developing and implementing the VRbased holonic design and operations of agile manufacturing systems, the concept and technologies were validated; the original objective was achieved, thus, paving the way for further development and application. • However, this is an on-going work and therefore only preliminary results are presented. • The overall holonic system framework has been also applied to an industrial case study in a die-casting manufacturing factory with another on-going study for solving various production planning, scheduling and process control issues in SMEs. • • • • • The VR operations environment constitutes a human system interface through which human users can feel free to add or delete any type of system entities. Once a system entity is added to the system, a new holonic agent is automatically created and registered to the cooperation domain. The relationship between the new added holon with other holons (i.e. inputs and outputs relations) will be updated into its knowledge base. Through the dynamic information exchange among holonic agents, the transport network of the entire system is stored in each individual holon and any change of the system layout can be detected and captured. The integration of holonic agent control system with the VR simulations forms a design and operations environment for various HMS operations, i.e. material handling, assembly, manufacturing. The human system interface of the platform is used to let user interactively change the system configuration and communicate with other holonic agents to adapt to the changing environment. In addition, the user can simulate several failures of system components and trace the reaction of holonic control for finding delivery routes, repairing workstations and dynamically updating the production schedules. The initial VR, function and control logic models of the virtual factory under study are evaluated, re-generated and instantly implemented into an already running system. The resulting model, which is iteratively upgraded, is verified in VR simulation environment and used to analyze the performance and agility of the desired manufacturing system.