Issue link: https://digital.copcomm.com/i/83694
■ ■ ■ ■ Simulation remove a cap? Is it ergonomically safe for the technician to execute such a maneuver? On the Virtual Soldier Research project, Malek once received directives from a colonel in the US Army. "He said, 'I want to be able to fi nd out how long and what distance I can have [a virtual squadron] walk before I allow them to sit down, chew on caff einated gum, and have a drink of water.' Th ese are the type of questions they want answered," Malek says. Th at meant Malek and his programmers had to embed in their digital human, Santos, certain biomechanical intelligence, including his energy expenditure, the rate at which his fatigue increases, and the impact of the armor's weight on his mobility over time. For valida- tion, programmers review motion-captured data of real humans performing similar tasks to make sure Santos' simulated behaviors and bio- mechanical feedback refl ect the same outcome. If you ask Santos to perform something that's not humanly possible, Malek explains, "Santos will come back and say, 'You're asking me to carry something that's too much for my elbow joints and muscles—the load is much higher than what I'll ever be able to carry.' " Issuing Directives In games and movies, all the behaviors and movements of a character, from its facial ex- pression to its distinct walk, are governed by a skilled animator's script. In simulation, The CG Santos digital human is versatile; here "astro" Santos provides vital information to real-life researchers and technologists. however, DHMs must come with a software interface accessible to those with little or no animation skills. It's safe to assume that most DHM users will not know how to set up char- acter rigs and defi ne paths. For these users, commanding the DHMs has to be as straight- forward as selecting a manikin and choosing a standard action (Walk, Go Here, Reach, and so forth) from a menu. To perform these tasks, digital humans must rely on the built-in ki- nematics, with little or no intervention from software users. "One of the advancements made in the DHM technology is to move away from the keyframe-based animation used by [movie and video game] animators," says Sie- mens PLM Software's Hoff man. what we're doing is instructing "Here, the digital human to perform a task. If we say, Reach for this object,' it can fi gure out on its own how to move there." Dassault's Charland points out that 10 years ago, that was much more diffi cult. "Now, it's much easier. Th ings that took about 10 clicks now take about three clicks, because when you tell the manikin to grab something, it knows exactly how to reach for it and grab it," she says. Most of the experts hired by Malek came with biomechanical and simulation expertise. But two years ago, Malek hired two senior programmers with experience in video game interface design. Th eir task was to revamp Santos' interface so it would be more acces- sible to non-technical users. "Our mandate is that after three days of training, people should be able to use the [Santos] software," he says. Use-Case Scenarios According to Dassault's Charland, some pro- gressive airplane manufacturers are begin- ning to consider end-of-life disassembly pro- cedures: How should a plane be dismantled when it has reached its retirement? "In these cases, they use [DHMs] to simulate the pro- cess because they want to know how people might get to diff erent parts of the plane and remove them," she explains. DHMs prove to be particularly useful in simulation exercises where a certain stress- ful or dangerous action must be performed repetitively in order to understand its impact on human anatomy. "If you use real people to simulate [an assembly operation], you cannot possibly run tests on an entire cross section capt Sophia is the female counterpart of Santos. Both are virtual models created by Karim Malek at the University of Iowa. 26 August/September 2012 Images courtesy SantosHuman, Inc.