"Design in Virtual Space," Feature Article, August 2007

design in virtual space

The vantage point of the computer is giving designers ever-deeper insights into their craft.

by Harry Hutchinson, Executive Editor

We rarely hear the word "cyberspace" anymore. Remember? It took the world by storm for a while several years ago and then, like a hurricane, blew out to sea. Maybe as a society we wore it out.

It was truly evocative, though. The term was coined in the early 1980s by a science fiction writer, William Gibson, who defined it as "a consensual hallucination." It caught on in the early days of the World Wide Web, and came to have a slightly different meaning. It evoked the sense of the computer as an opening to an environment. The computer could provide access to worlds in which ideas moved and people, who might not otherwise connect, could communicate.

Today, with online billing, 3-D CAD, video games, and electronic mail, our minds spend a lot of time walking around in cyberspace, although these days we are more likely to call it by a term that includes "virtual" or "digital" or the simple prefix "e."

Engineering, too, is a kind of cyberspace. It expresses the reality of the physical world in the abstract terms of mathematics, and that has conferred a mastery over the environment that has resulted in everything from airplanes to satellite TV and medical technologies that perhaps are keeping us or our loved ones alive.

And whatever you call it, the world that used to be cyberspace has grown into an environment where an astonishing quantity of work is accomplished.

It is the environment where minds meet to hammer out engineering decisions, and to plot how to build parts and assemble entire systems. What's more, the means of getting there are rapidly changing, too. New interfaces promise to bring new methods of communication among thinkers over networks, and between each thinker and the computer.

From virtual to real is the track that aircraft follow. Here, the Boeing 787 Dreamliner takes shape. Its fuselage, made of composites, consists of four cylindrical sections.

It is the vast workplace where a system as complex as an airplane, for instance, takes shape and definition, where the concept for a plane can be probed, tried, discussed, and tested, long before it is introduced as an object in the physical world. The Virtual Reality Center at Wichita State University is a case in point.

Wichita, Kan., may have a greater concentration of aircraft manufacturers than any other place in the world. It's not surprising, then, that the VR Center is part of Wichita State's National Institute for Aviation Research.

According to the VR Center's manager, Fernando Toledo, the center provides a number of services for aircraft manufacturers, including virtual assemblies.

VR has been around for decades, but because of its costs, the technology has been not been widely applied. In recent years, though, the cost has fallen. "Now you can buy a PC, clusterize it, and use high-speed graphics cards." Toledo said. The result approximates the graphic representation that only a few years ago would have required a major investment in hardware. The technology, he said, is increasingly accessible.

Virtual mockups, especially at full scale, let manufacturers study ergonomics and other human factors of interiors and cockpits before they run the expense of building anything, Toledo said. Virtual reality can be used early in development to guide design decisions.

According to Toledo, "VR enables non-technical guys to understand." What's more, the information can be communicated around the world in real time.

Visualization of data in virtual reality is also useful for digital manufacturing, to aid in process planning and the design of work cells; for representation of large data sets resulting from CAE analysis, and for real-time product customization for potential clients.

The center has also used software called EnSight from CEI in Apex, N.C., to animate a crash scenario for Amelia Earhart's Lockheed Electra for a National Geographic documentary.

Composing Parts

Then there is the Dema Group, a company of 300 employees based in Naples, Italy, that provides industrial engineering services to manufacturers of airplanes and helicopters. According to engineers there, virtual tools are giving them greater control over the development of composite parts.

Composites, because of their light weight and strength, are gaining favor as a material for aircraft. The Boeing Co.'s 787 Dreamliner, officially unveiled on July 8, has become the poster child for composites in aircraft design because the design uses the materials extensively. According to Boeing, composite materials constitute about 50 percent of the aircraft by weight.

The entire fuselage is made of composite materials, a distinction from the airframes of other Boeing planes, which are made of aluminum panels. Instead of panels, the 787 fuselage is assembled from four barrels of composite materials, an assembly method that would be impractical with aluminum. Boeing has received more than 650 advance orders for the plane.

Design engineers throughout the aviation industry are making use of composites. Boeing's rival, Airbus, certainly is, and composites are a key material in many planes in an emerging class of small aircraft called very light jets.

Three Dema engineers—Giuseppe Ombra, who acted as translator for two colleagues, Mariangela Marra and Assia Bassolino—said the company uses a software application called FiberSIM when it designs composite parts. FiberSIM works with CAD systems to include non-geometric data in models.

Dema produces composites at a factory near Naples, where it builds parts in layers of fabric impregnated with resin. The layers are applied over a form that gives the part its shape. If the plies do not fit the form correctly, they can wrinkle and ruin the piece.

The software, from Vistagy Inc. in Waltham, Mass., models composite parts down to the level of each ply. Each layer is composed of several strips cut from the composite raw material. The orientation of the strips in a layer, relative to the ones above and below, is critical to the performance of a part.

Suppliers to Boeing have added software to aid in the development and production of composite parts for the new 787.

Initially, a designer develops a 3-D CAD model to define the shape and dimensions (including total thickness) of the structural component. Then, he feeds the FiberSIM program the parameters necessary to define each part of a layer. The program verifies the details of the part, even to including small cuts in the ply necessary to prevent wrinkles. The program completes all the part parameters needed by a laser machine, which helps the production specialist locate the part location and ply orientation in the stratification process.

According to Ombra, "You must be sure the ply can adapt to the shape, or you can get wrinkling. FiberSIM helps you understand that you are orienting the ply correctly and checks the surface to avoid any wrinkles."

A description of the process may sound something like papier maché, but it is much more serious. Not only because lives often depend on it, but also because trial and error are much costlier than in a crafts project.

According to the Dema engineers, the company's designers in the past had used 2-D drawings for each ply. It would take several tentative designs before they could arrive at a final product. More recently, however, they used the Vistagy software in the design of an engine cowl. Ombra said the software was able to verify the correct displacement of plies and the design worked on the first try.

Although FiberSIM was not created specifically for aircraft engineering, the increased use of composites in flight has given the product a higher profile in that line. Last June, Vistagy issued two separate announcements about FiberSIM in the aircraft field. A Chinese aerospace supplier, Chengdu Aircraft Industrial (Group) Co. Ltd., adopted FiberSIM as its exclusive application for conceptual and detailed design of composite parts, as well as for manufacturing design.

Also in June, Vistagy said an Italian aerospace company, Alenia Aeronautica, is using FiberSIM to develop composite parts for the Boeing 787.

Taking advantage of its presence in the aircraft business, Vistagy has developed another suite of products that it calls the Airframe Design Environment, which works with three major CAD systems—Catia from Dassault Systèmes, NX from UGS, and Pro/Engineer from PTC. It is tailored to the complexities of building airframe structures.

Like FiberSIM, ADE software contains more than the geometry of the CAD model. As described by the company in its promotional literature, the software "captures all non-geometric information related to parts, assemblies, joints, and fasteners."

Just as FiberSIM contains specifications for composite design and manufacture, the Airframe Design Environment has rules specifically for aircraft design and manufacture.

Software from Vistagy adds manufacturing information to models of composite parts and guides the laying of plies in the Dema Group factory.

According to John O'Connor, Vistagy's director of product and market strategy, the Airframe Design Environment, for instance, automatically calculates optimal spacing of fasteners. In an airframe, the hole for a fastener must be drilled a minimum distance from the edge. That distance varies with the diameter of the hole. The software calculates whether a design is in spec or out. It alerts the designer if the holes are too close to an edge.

It also automatically recalculates after changes. For example, a part may be made thicker. It may also have 500 fasteners. The software recalculates the length of each fastener affected. Then it reviews the dimensions of the fasteners, which must be within a certain length-to-diameter ratio. If the fastener diameter must change, the software recalculates the fastener holes. The new, larger-diameter holes are checked for proper spacing from the edge of the piece.

Companion software is Vistagy's Airframe Manufacturing Environment. Embedded in each model are the states it will take during manufacture, beginning with the form in which it is received from a supplier, and proceeding through each stage of development toward final assembly.

As O'Connor explained it, a piece may come from a supplier with two pilot holes drilled in it. That form is retrievable from the CAD model and can be sent to the supplier. Other retrievable forms of the model may include versions of the piece as new holes or other features are added. The model represents not only a finished part, but also the sequence of assembly states.

The software captures other manufacturing details, including information on fasteners and joints. Automatically generated quality information is made available to the quality control department.

Command of Language

Communication through digital media is the focus of
a great deal of work at the Center for Advanced Engineering Environments at Old Dominion University in Norfolk, Va. The center is exploring ways that users can communicate commands to their computers, as well as technology to communicate ideas across networks.

According to Ahmed Noor, the center's director, his group is "working to advance the user's access to computer tools." He describes the technology of interest as "intelligent, adaptive tools and intercommunication devices." It makes a computer adaptable to user preferences.

The Center for Advanced Engineering Environments has operated for the past seven years at Old Dominion. For 10 years before that, it was associated with the University of Virginia as the Center for Advanced Computational Technology. For most of its history, the center has received the major portion of its funding from NASA. And although it has begun to branch out into other areas, its primary connections are to aerospace applications.

The center is working with commercial partners, including EON Reality Inc., an Irvine, Calif., company that describes itself as an interactive 3-D software provider.

There is a practical aim to its collaborations. "We are building on what's available—the latest technology," Noor said. "We do not want to reinvent the wheel."

A tour of the center uncovers demonstrations of computer-based tools intended to stretch the imagination and address the subtleties of the relationship between a user and a machine.

Noor talks about two kinds of computer users—digital natives and digital immigrants. The natives are those people who have grown up in contact with virtual realities of video games and the like. The immigrants moved to the computer from typewriters and drawing boards. For the natives, the tools available may not be engaging enough, Noor said. On the other hand, the immigrant can be intimidated by new technology.

According to EON Reality's president, Mats Johansson, the keyboard and mouse are a legacy of the typewriter. EON and Noor's center are trying to take the computer beyond that legacy.

Research at Old Dominion would link various interfaces and platforms into collaborative engineering networks.

One technology demonstrated at the center is an interface using avatars, human-like animated figures, each with a distinct appearance and voice. The computer responds to verbal commands, and if the command is not understood, the animated figure of the avatar indicates confusion with a frown. The avatars can also smile and use other facial expressions. The intention is to make the interaction of user and computer closer to an exchange between people.

The center is also exploring technology that Noor calls "intelligent comprehensive information retrieval." One possibility is to have simultaneous visualization of results by different search engines. Using the avatar interface, a user can tell the computer to tile the pages or compose them on pages like a book. According to Noor, the technology is still being refined and is not available outside his lab.

Using the EON Touchlight screen, the operator can flip through the pages or point to the desired sheet. The Touchlight, according to information on EON Reality's Web site, uses a semi-transparent screen with three cameras behind it to detect the motion of the user's hands. It is available as a commercial product.

In a similar vein is an interactive 3-D HDTV-quality system for virtual meetings. It mounts a camera behind a semi-transparent screen. This setup also conveys a psychological benefit.

As the viewers look at the screen, they are also looking into the camera. It avoids what Johansson called a "gaze-avoidance effect" that one encounters with the common practice of mounting the camera above or next to a monitor. The system runs in real time with a T1 connection and allows direct eye contact between people who could be half a world apart.

There are other interfaces, as well—3-D stereo without glasses, and virtual reality screens in which you can manipulate a spacecraft by using a device reminiscent of a Nintendo Wii controller.

EON Reality has developed products for use in retail settings for the virtual design of apartment interiors and the customization of Suzuki motorcycles. It also does factories. In a video demonstration, the user's hands give the commands that configure walls, place machinery, and define traffic flows. The company demonstrates this and other products in video clips on its Web site, eonreality.com.

Noor bills the work of his center as cutting edge. As with anything that future-focused, its final application is yet to be determined. Will the technology advance the practice of engineering? Noor believes that it can.