Computer-generated pictures that delighted filmgoers in movies like “The Matrix” and “Gladiator” may one day help you buy a truck. The same software used in these cutting edge films, producing characters and scenery that appear as though they were in three dimensions, is helping truck makers produce vehicles on a screen that seem as real as life.
“The future for us is to have the customer spec their truck on a laptop at the dealership and have the truck change before their eyes,” says Mark Stassel, vp-product development at International Truck and Engine Corp. He notes that software used to produce many of today's movies is finding its way into truck makers' computers, making trucks appear three dimensional onscreen. “We want to make the truck package look real on the computer screen at the point of sale. That's our goal.”
Truck makers also envision a “virtual reality” showroom where buyers don special helmets and “walk” around a prototype model, viewing it from different angles, taking in the changing reflections of sun and moonlight on the body. Sensory gloves would allow potential buyers to “touch”' the grille and cab interior to feel its texture. They could also sit in the seat and handle the steering wheel. If you didn't like the play in the wheel you could tighten it and try again, until it suited your tastes.
We're not quite there, but we're getting close, say truck makers.
To say that computer aided design (CAD) has revolutionized the truck making and truck buying business is a gross understatement; the pace at which it has moved is miraculous. “For the last six or nine months, we've gone to 100% CAD,” says Eric Hjelt, chief engineer at Volvo Trucks North America. “We don't make any mock-ups until the end.”
For the truck buyer, CAD means that lead times can be cut as much as one-third; new-model cycles, which used to be about ten years, have dropped to three to five years.
Because of the latest CAD innovations, the truck consumer gets a vehicle that is better engineered and safer. “We can work our suppliers into the design process earlier,” says Mike Kalkoske, who as assistant chief engineer of operations oversees CAD activities at Kenworth Truck Co. “We can get their input earlier than ever before and find out how difficult it may be to manufacture a certain part. This means fewer surprises for us and for them.”
This flexibility also allows truck makers to try new designs — which may be tricky or radical — without incurring excessive costs. They're able to show buyers possible designs without going to the expense of a full-scale clay model.
CAD allows OEMs to have more confidence in their designs and that parts will actually fit together and work in concert as expected. Another benefit to the end user is that truck makers usually don't have to wait for parts because suppliers are brought into the design process early.
CAD also means more customization is possible than ever before. For example, manufacturers can produce a digital mock-up of a specific combination of options to see how it looks and acts and check for conflicts. “For us, CAD means that we can do so much more customization for the customer,” says Mark Albertson, vp-vehicle development for Mack Trucks. “CAD helps us solve interference problems for custom jobs.”
Working out “what if” scenarios is where CAD really shines. With so many different variables and elements, many modern designs would be impossible without CAD. The state of the art in CAD is adding as many variables as possible so prototypes can be tested for real-life conditions.
For example, a process called finite element analysis enables truck makers to test varying loads on a frame to see how the truck responds. On the computer, they can simulate bumps, different weather conditions and varying speeds. By changing as many variables as possible, designers hope to test almost every scenario the truck driver will experience.
But this leads to a major roadblock for CAD: How do you get the data to feed into the computer so the software knows how to react and change the design? Unfortunately, the answer is as old as designing trucks with pencil and paper.
The data comes from testing similar design elements on a test track — using real trucks — and collecting the data. The more measurements a truck designer has, the better CAD will work. “You can never have enough real-life data points,” says Craig Brewster, chief engineer at Peterbilt Motors.
Like others, Brewster believes that the computer analysis is relatively straightforward — a certain input will yield a certain output — but that the data used to make the computations is the limiting factor in truck design. “One of our missions is to get enough data points to feel 100% sure of our analysis. I don't know that anyone will ever get to that point.” Peterbilt's Model 387, introduced last year, was the OEM's first vehicle fully designed using CAD.
The overwhelming number of design choices, combined with a lack of data points, puts limitations on CAD, which tends to work better for some design elements than others. By understanding these shortcomings, truck buyers can better arm themselves when they go shopping.
Truck makers agree that CAD works best in the design and engineering of chassis, frames, crossmembers, driveshafts and other rigid components. It's less able to handle flexible components like wiring harnesses and ductwork, where there are many opportunities for bending and curving around other parts.
In these situations, there are simply too many choices for the computer to handle. A flexible wiring harness that is moved at one end may not move to the same degree at the other end. In a more rigid component like a transmission, the rest of the shaft moves with it if its position is changed by an inch. As trucks become even more dependent upon electronics and their wiring systems, better handling by CAD will become even more crucial.
Because of its importance to driver comfort and safety, OEMs have stretched the limits of CAD to tackle in-cab design and engineering. They have used real people and test dummies to collect huge amounts of data. They have even begun using virtual reality to test cab design for fatigue and comfort. By simulating different size drivers, truck makers use these parameters to test placement of gauges, seat positions, shift placement and hundreds of other in-cab components. “Over the course of the day, how tired will the driver become after reaching for a specific component? That's what we want to find out,” says International's Stassel.
So precise is CAD that designers can check exactly how air conditioning blows on a driver's face to determine whether it will feel refreshing or too cold. Stassel says they've had great success testing drivers wearing the “virtual glove” to reach for controls and check their proper placement.
Another important element of driver comfort and fatigue is noise. “We have used CAD to predict in-cab noise using acoustic modeling. We can look at precise noise transmission paths. CAD cuts down on all the trial and error of placing noise insulation,” he says.
CAD is also effective in aerodynamic design, checking wind and drag patterns around truck bodies without having to build a mock-up and place it in a wind tunnel.
Where does CAD go from here?
Clearly, software is becoming more adept at handling more combinations, permutations and “what if” scenarios. The move to designing by virtual reality is only a few years away.
One key is to make sure that everyone is using the same software, or at least software that's compatible. Currently, truck makers may use several software packages because they have different strengths and weaknesses. Some are better for styling; others for wiring. The problem is integrating these packages so they can “talk” to each other.
Buyers can expect to become more involved in the end product as virtual reality takes hold and they have the opportunity to choose components and configurations in real time. In the virtual world, buyers might step into a holographic room and walk around the models they're interested in to see the lines and styling. Using a virtual glove connected to a computer, they might remove one component and replace it with another one to see how it looks and works.
“Looking is the easy part; making changes is the hard part,” says Sankar Jayaram, a professor at Washington State University's School of Mechanical and Materials Engineering. Jayaram has been working with Paccar for several years, tackling virtual reality issues. “In the laboratory you can put on the virtual helmet and drive. You can reach for the gauges or the pedal and see how it feels,” he says. The challenge is to translate the change you made with your hand into a change in the computer design. “The tools are almost there,” says Jayaram.
According to Rishi Madabusi, business development manager, Product Lifecycle Management at IBM, the latest frontiers for CAD and virtual reality include putting more knowledge into the software system, capturing more data points, and then turning these data into rules that cannot be violated by the computer-generated design. “For example, we need to have sophisticated rules about bending ducts or routing wires.” By codifying rules, truck makers will not need to collect any more data points.
Madabusi is also excited about the possibility of collecting diagnostic data from trucks on the road that will be fed back to central computers and used to design components that will last longer or perform more efficiently.
But as high tech as we have become, OEMs say that today's buyers still insist on seeing the actual physical mock-up before buying. “Buyers still have trouble visualizing the full-size truck,” says Kalkoske. “People still want to touch and feel it and walk around it. But it won't always be that way.”
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