Designing with Digits

Gary S. Vasilash

Wayne K.

Wayne K. Cherry is the vice president of GM's North American Operations Design Center. He's the fifth person to head up GM Design.

Cherry has been with GM Design since 1962, which, obviously, means that he's seen a lot in that period of time. As so far as he's concerned, the single biggest change that he's encountered—in fact he describes it as "single biggest change in the way we develop vehicles in the history of the auto industry"—is the use of math, or digital tools for designing, engineering, and producing vehicles.

According to Cherry, there is a solid commitment at GM to move its design capabilities to math. But he points out that this isn't something that just happens—voilà!—but takes time to learn, not only from the standpoint of the designers working with the computer-aided design (CAD) tools, but for the people who are involved in program approval to learn how to judge a vehicle that is being exhibited in virtual reality (VR).


And they are rapidly moving up that curve at GM: he notes that the Chevy SSR concept car that was introduced at the 2000 North American International Auto Show—sort of the El Camino for the 21st century—went from sketch to concept vehicle entirely in math: "There wasn't a clay model made." He points out, however, that a clay model was produced for final approval for the production version of the SSR (the SSR will go into production in 2002 at the Lansing Craft Center).

(Cherry says that people have asked why they didn't design an up-to-date version of the '55 Chevy—perhaps à la what their cross-town rivals did with one of their classic cars of the '50s. He points out that one of the benefits of designing in math is that it is possible to overlay the design of one vehicle on top of another and see how they compare. Someone had created a math model of the '55 Chevy. When they did an overlay with the SSR, they discovered that there were several striking similarities, such as wheelbase, overall height, chair height...)

Cherry observes, "It won't be long before designers and engineers are developing vehicles simultaneously." This simultaneity will have a profound effect on the speed of development. However, there are some skeptics. But so far as Cherry is concerned, "People who don't think that's going to happen pretty soon must be living on another planet." The terrain that GM is going to be on is exceedingly digital in nature.

According to Cherry, "To a large extent, we are going to eliminate developing the design in clay." But although they are doing complete electronically based designs in the GM Corporate Brand Center, although they have people working in the North Los Angeles Design Center who have animation skills that are being applied to provide realistic settings for vehicles-in-becoming-that-have-yet-to-take-physical-form, Cherry believes that it will still be some time before all physical models are gone, that there continues to be a need for a hard model for purposes of prove out, certification, or final approval. It will take some time before there is a sufficient comfort level and perceptual capability to do without it. Still, he also points out that because a design is in math, it is a whole lot easier to mill out a model, using post-processed CAD data to run the machine tool.


The GMC Terracross The GMC Terracross. Although a 2001 concept vehicle, it is the shape of things to come. As there are multi-functional units like this, there is the opportunity for designers to create uni-functional vehicles: real driver's cars, perhaps.



One of the benefits of designing in math and using the math data for purposes of engineering and manufacturing is that there is greater speed all around, which could facilitate the development of more models, as well as faster modifications to existing products.

One of the benefits that Cherry sees from the point of view of a designer of the increasing number of multi-functional cross-over vehicles that are appearing is that it may allow the owners of those vehicles to have a second vehicle that is "less compromised." This can be something of an exotic vehicle. So it would be multi-functional on one end and forward-fashion on the other.

"Forget the one in the middle," Cherry remarks.


The Chevy SSR

The Chevy SSR. Between the first sketch and the physical concept car, there was no clay model—it was all done using digital design tools.