Ames, IA--Desktop CAD has dramatically transformed engineering, but we're still awaiting what could well be CAD's next great revolution: widespread use of virtual reality (VR) tools in design.
Iowa State University's Center for Emerging Manufacturing Technology is one of the nation's leaders in trying to accelerate this process. In its "C2'' virtual environment facility, the engineering school tackles real-world design problems for big name manufacturers like John Deere. The school's engineering graduates also are transferring the latest VR techniques to their new manufacturing employers.
"Virtual reality is a fresh way to interact with the computer model that goes beyond 3D graphics," says Professor Judy Vance, a mechanical engineering professor who has been with the center since 1992. "With VR, you become immersed in the design and gain a more intuitive feel for problems you must solve."
While 3D solids modeling packages on the desktop have brought enormous productivity benefits to engineers, Vance cites shortcomings that VR can help solve.
Take the issue of line-of-sight in vehicles. When an engineer views a small-scale model of a bulldozer's design on a CAD screen, it can be very difficult to spot features that could obstruct an operator's vision once that design is scaled up to real-world size. Such problems are more readily apparent when the engineer is surrounded by a full-scale VR model.
Fluid Dynamics in manufacturing is another example. Envision the advantages of being able to view a full-scale virtual mockup of a series of chutes needed to mix precise quantities of chemicals or materials as they move down toward a receptacle. If your job was to design the shape and size of those chutes, consider how much faster you could find the optimum solution if you could manipulate full-scale models in a VR room.
In Iowa State's virtual environment, engineers can view computer images on the front, left, and right walls and on the floor using BARCO 1208s projectors. Users don shutter glasses synchronized to the computer graphics refresh rate by an infrared signal. A magnetic tracker detects a user's head and hand movements and conveys that information to the computer, so that images are displayed based on where the user is standing and looking in the room. Input devices consist of gloves and wands.
The center recently used its VR environment, combined with Pro/ENGINEER 3D solids modeling and MSC/NASTRAN finite-element analysis, to redesign a tractor lift arm for John Deere. Not only did these tools succeed in reducing stresses in the lift arm but they also dramatically reduced the number of design iterations required to eliminate potential collisions between the lift arm and a lift cylinder rod.
Despite such productivity benefits, Vance admits that VR is still in its infancy. An estimated 25 universities, 15 federal agencies and some 100 companies are experimenting with VR.
Chief roadblocks to wider use, says Vance, are the lack of VR experts and commercial VR software modules. "This new tool won't be much good in helping solve time-to-market pressures if it takes you three years to set up your VR environment."
Still, she notes that interest in VR has grown enormously over the last five years. "New companies tour our facilities every week," says Vance, "and firms like Ford, Deere, and Case are hiring our students."
Vance also believes more companies, especially such giants as Chrysler and Boeing, are moving ahead aggressively with proprietary VR systems to gain a competitive edge.