This paper is designed to propose a possible evolution of CAD/CAM in relation to the current technology. The context evolves round Web-based technology covering web based design and manufacturing respectively. The paper also suggest interventions to tackle the identified challenges and obstacles. Web-based systems in design and manufacturing , with machining intelligence built into the program, there is increase in efficiency and consistency. CAD/CAM technology is moving in the direction of
CAD is defined as Computer Aided Design -The use of computers to assist Engineering Design in developing, producing, and evaluating design data and drawings.
CAM is Computer Aided Manufacturing - The use of computers and computer data in the development and production of a part (product) including fabrications, assembly, and installation. (AviBank 2008)
Since the invention of CAD/CAM 50 years ago, the computer industry has witnessed a drastic change, in today's fast paced world, CAD/CAM systems have become an essential element in manufacturing companies throughout the world. Technology and communication are changing rapidly, driving business methods for organizations and requiring capitalization in order to maintain competitiveness. Knowledge prior to investing into a system is crucial in order to maximize the benefits received from changing CAD/CAM systems. This Field has contributed immensely to the development of the Global Engineering industry. Designs before the invention of CAD/CAM were done by Engineering drawings drawn with pen and paper which consumed much time and was difficult or impossible to adjust, manufacturing on the other hand was always cumbersome. However with the introduction of CAD/CAM, designs have been much faster to produce, more detailed, more accurate and flexible, this also applied to manufacturing.
The internet has rapidly grown to be the most popular information service; so many things can now be done online, from paying bills, to schooling and to dating. CAD/CAM has also benefited tremendously from this technology - the web has provided tools that have made design and manufacturing much faster and easier. With these web based technologies, designers who live thousands of miles apart can work on different parts of an assembly drawing and send these parts by email to be assembled. Databases of supplier certified parts are hosted on websites, this means that a designer doesn't need to redesign a part that is already in the market, he simply goes to this website, selects his preferred manufacturer and takes the specific part he requires for his design, this makes design faster, promotes standardization and reduces cost of manufacturing - a classic example is www.3Dcontentcentral.com which is a free service for locating, configuring, downloading, and requesting 3D parts and assemblies, 2D blocks, library features, and macro, (3d content central, 2010) also, manufacturing isn't left out, CAD drawings are sent to manufacturers across seas and boarders, virtual simulation over the internet is practiced by some manufacturers and some manufacturers presently allow customers to customise their orders.
A developing web based technology in CAD/CAM is the Web-based collaborative Visualisation (WCV) which allows for visualising, annotating and controlling 3D models in a regular browser. (chu, cheng and Wu, 2006). This technology allows for end users of the product to be able to Customise CAD assembly drawing in a regular web browser, similar to this development is the Web based Collaborative software, examples are Alibre and CollabCAD which enables dynamic sharing of the designs across the network. Multiple designers can work concurrently accessing the same design for viewing and modification. It also offers links to Audio and Video Conferencing (NCIT-MICTI, 2010)
The Web-based technology is also greatly influencing the Computer aided Manufacturing (CAM). One major development is the research on Virtual machine simulations. Web based virtual simulations can produce realistic 2D and 3D machine simulation results and they are used to evaluate and optimise machine processes. (Jonsson, Wall, and Broman 2005)
WEB BASED COLLABORATIVE DESIGN
This argument is based on web-based collaborative design focusing on integrated system for co-design and concurrent engineering. In other to facilitate web-based design, an internet enabled system has been packaged to support collaborative and concurrent engineering design by integrating 3 functional modules on co-design, web-based visualization and manufacturing analysis.
In co-design module, designers are trained with co-modelling and co-modification facilities to carry out a design task collaboratively.
Web-based visualization module provides a portal for users who deal directly with co-modelling process, who view and analyse a design part conveniently. Manufacturing analysis on the other hand can be used to evaluate and optimized the manufacturing cost and the feasibility of a design part so as to implement the concurrent engineering methodology during a co-design process.
The futuristic approach to this intervention is to become more product oriented, aiming at decrease lead time from design to manufacturing, generating minimal work in process, timely flow of materials, high efficiency and flexibility of manufacturing capacity utilization.
Concurrent engineering is a systematic approach to integrate the design of products with related manufacturing processes using some software packages and computing techniques in a computer environment. (Ranky, 1994).
Co-design is used in modern manufacturing corporations to align a multidisciplinary design team to carry out a complex design through effective collaboration. With the rapid trend for global competition and the advancement of the internet technologies, concurrent engineering and co-design are moving in the direction of supporting distributed applications, subsequently, users, system and resources can be integrated in an internet environment beyond the traditional boundaries of physical and time zones.
In this discussion, an internet based integrated system has been developed to support interrelated activities and share ideas between designers and systems by integrating concurrent engineering and collaborative design functions. The system consists of 3 major modules namely: 1) a co-design module to enable designers to fulfil product design collaboratively. 2) A web-based visualisation module to support product preview and evaluation of design parts. 3) A manufacturing analysis module for designers to conduct concurrent engineering methodology through invoking distributed services.
The specific futuristic importance of this discussion is a convenient and flexible platform has been setup for users to carry out a co-design activity, also a generic and scalable distribution mechanism has been proposed to integrate different functional modules in the system to support concurrent engineering, and web portal based visualisation and co-design.
1) Collaborative design and Concurrent engineering
In co-design, research and development are active, a number of software tools and methodology have been developed, it can be categorised into 2 types namely; 1) visualisation tools to assist co-design, 2) co-modelling tools to implement co-design.
The visualisation tools are primarily used to support visualization, annotation and inspection of design models in a web or a CAD environment. Such software includes Oracle's Autovue (Oracle,2010),conceptWorks (inflow-tech, 2010), eDrawings (Solidworks, 2010) etc. The web-based systems are light, easily deployed and platform independent, they can facilitate an online team to take on high level product review. Java Applet and MS ActiveX technologies are widely used for developing the visualisation clients, while some services written in Java Servlet or MS COM/DCOM technologies are deployed in the server side to provide support and system maintenance ( Huang, 1999; Choi, Kim and Yoo, 2001; Shen, Wang and Wong, 2001). Web based Java technologies (Servlet and Applet) can facilitate the communication in an internet environment are used to establish the infrastructures of the modules of the web-based visualisation and manufacturing analysis services. The figure below further illustrates exchange information between modules.
Figure 1. Classes defined to exchange information between modules
(From. Li, Fuh and Wong, 2004)
Co-design module
A co-design module has been established to support simultaneous co-modelling activities of design parts. It is based on the Java RMI mechanism and consists of a collaborative server and clients, a look up service has been designed to provide a naming mechanism to manage clients and manufacturing analysis services dispersed in the integrated system. A working session is to provide a common working space for designers to participate in a collaborative design community to share and manipulate co-design models. Each session is associated with a feature-based modelling system developed based on a solid modelling i.e. Open CASACADE (Open Cascade, 2010).
Web-based visualisation module
Visualisation of design models over the web is one of the effective means to assist co-design. Web-based visualisation assist design model to be dynamically publish on a web environment and conveniently accessed. It has been developed based on Java Servlet, Applet and Java 3D technologies to provide visualisation based operations. (Gary Beene, 2010) in the Java 3D BASED Applet client, a VRML model generated in the above co-design module can be browsed and manipulated, it provide collaborative function such as chatting and messaging. The main functions and component of this module are shown in figure 2 below.
Figure2. The functions and components in the web-based visualisation module.
(From. Li, Fuh and Wong, 2004)
Manufacturing analysis
THE FUTURE OF MANUFACTURING SYSTEMS
From the review of the current trend in the development of computer aided designs and manufacturing above, it is evident that developers are trying to break borders, make automated systems, and reduce cost of production. This paper proposes different manufacturing system that can be controlled over the internet.
2) METHODOLOGY FOR AN INTERNET CONTROLLED MANUFACTURING SYSTEM
Three different options of implementing a web controlled manufacturing system are proposed in this paper
2.1) Virtual Software
Virtual reality can be defined as a false or synthetic environment which gives a sense of reality of the actual environment. Virtual Reality (VR) as a term was coined by Jaron Lanier in the 1980s. VR initially referred to an immersive system that allowed the user to use natural head and hand movements to interact with the computer-generated environment (Jayaram et al. 1997). However, this technology has evolved over time and has therefore broadened the definition of VR to include semi-immersive systems like large screen projections as well as non-immersive system like viewing of three-dimensional objects on computer monitors (Beier, 2000)
A lot of research has been carried out on web-based virtual operation. Hanwu and Yueming (2009) proposed a web based virtual operation of CNC milling machine tools. This system is based on Virtual Reality Modelling Language (VRML) and browser/server structure and the package can be run normally in a regular browser with a plug-in installed. Their communication approach was VRML, JavaApplet and HTML. Wang et al (2004) researched on the real time monitoring and the remote controlling of CNC machines. A framework named Wise-ShopFloor (Web-based-integrated sensor-driven e-ShopFloor) was designed. A Virtual rapid prototyping system was proposed by Choi and Chan (2004), the virtual prototypes of this system can be transmitted, via the Internet to customers to facilitate global manufacturing. Kan et al. (2001) developed an Internet-based virtual reality collaborative environment (VRCE) using VNet, Java, and VRML. As it is a platform independent, VRCE can be run using inexpensive computer hardware and software and is composed of a set of comprehensive functionality with customizability which makes VRCE more attractive than many existing VCS systems.
This paper proposes software that will be a virtual environment of the actual manufacturing system. Every Manufacturing system will have a unique Mac address which will be alphanumeric, once the software is launched, you enter the Mac address of the particular manufacturing system you want to use. As soon as this is done, you are logged into this system and the software brings on a virtual environment of the actual manufacturing system. This virtual environment is a real time representation of the real manufacturing system, whatever control is activated in the virtual environment is transmitted over the internet to the manufacturing system. The whole manufacturing process will be controlled by this method. This method can be adapted to have more than one person logged on to the same manufacturing system at the same time, this proposition will be very useful for collaborative manufacturing.
2.2) Email
At present, quite a lot of development has been done on Text remote controlled devices. An example is TweetMyPC which is a little software-application for Windows, written in VB.Net using the .Net-Framework v3.0, which allows you to control and access your computer from anywhere by simply sending a twitter-message with a special command as its content http://tweetmypc.codeplex.com
Similar to this technologyThis paper proposes the addition of an intelligent system to the manufacturing system. The manufacturing system has its email address, when a manufacturing process is to occur, the operator simply sends an email containing instructions on the job to be done. The intelligent system then translates these commands to machine readable commands and starts execution of the commands. The machine also sends the operator emails to email detailing every action that is to be carried out and requires confirmation.
2.3) Teleconferencing
This is a system in which the whole manufacturing process is controlled and monitored by an audio - visual system. This system is an interactive one and gives you real time options, controlling is made possible by the use of Dual Tone Multi Frequency (DTMF) Technology, the DTMF technology involves sending two tones simultaneously from a set of tones and will be similar to what is obtainable in some complex answering machines.
DISCUSSION
During the research of writing this paper, we found out that most web based technological development were focused on either CAD only or CAM only, with very little work on integrating the two. Bouzakis K. Et al (2008) proposed a web-based framework - independent from any specific CAD/CAM software for employing electronic interaction between designers and manufacturers. The machined parts data is exchanged by the use of Simple Object Access Protocol (SOAP). The methodologies of UDDI (Universal Description Discovery and Integration) and WSDL (Web Services Description Language) were introduced for providing directories and descriptions information. The figure below gives a description of the system.
Figure3. Main parts and operations of the web based environment. (From Bouzakis et al, 2009)
Integrating the web-based collaborative design and the Virtual manufacturing as one system will greatly improve the communication between designers and manufacturers thus leading to a faster and more qualitative planning process. It will also help bridge the competitiveness that could arise from operating differently.
CONCLUSION
Conclusively, CAD/CAM on web-based system will continue to add to the depth and breadth of both the designing and manufacturing of models and part, thus give rise to better and effective product.
As the wave of the future, KBM capabilities will become commonplace in CAM systems and provide increasingly more powerful automation solutions. KBM is an important piece in the big picture of gaining a competitive advantage, allowing moldmakers to automate redundant tasks and eliminate wasted effort.
REFERENCES
