Cadalyst - May 2008 - (Page 42)

plmstrategies By Kenneth Wong The Jack and Jill of Ergonomics How Ford uses human-motion modeling for manufacturingprocess simulation. R emember Jack and Jill from the nursery rhyme, the unwieldy pair that went up the hill to fetch a pail of water? As you might recall, Jack fell down and broke his crown, and Jill came tumbling after. Well, guess what? They’re working for Ford now. Jack and Jill take turns crawling under the newest Ford models. As they lie on their backs, they try to reach for oil filters. On the plant floor, they negotiate rooms in the nooks and crannies of the assembly machineries. Meanwhile, Ford ergonomists carefully note the level of fatigue and injury risk produced by their repetitive motions. Then the automaker incorporates what it has learned from its observations into the design of the next generation of vehicles and the layout of the next factory wing. Jack and Jill can’t feel pain the way humans do. They’re digital models. They can twist their anatomically detailed spines, shoulders, and hands without being subjected to the physical discomfort we would. Instead, they provide numerical feedback about the amount of force they feel in various joints. The workers on the plant floor installing the satellite radio antenna on the Ford Edge or the cargo-management system on the Ford F-Series may never get to meet Jack and Jill face to face. But, for the ease with which they’re able to do their job, they owe a lot to the falls and tumbles that those two have taken on their behalf. Figure 1. Digital prototyping enters a new phase as manufacturers begin to use virtual avatars to verify and eliminate safety and ergonomic issues on the plant floor. Human-Motion Simulation Jack and Jill are part of Tecnomatix, a digital manufacturing suite from Siemens PLM Software. The pair was conceived and brought to life at the Center for Human Modeling and Simulation at the University of Pennsylvania in the 1980s and 1990s. They have gained many new skills since being commercialized in 1996. In their Tecnomatix incarnation, they’re designed to help manufacturers better understand the human-performance factors in their production workflow. (The product is officially marketed under the name JACK, but rest assured, Jill is part of the package.) Here’s how JACK works, according to its creators. First, you build a virtual environment that corresponds National Institute for to your factory Occupational Safety and Health setup. You can do www.cdc.gov/niosh this by importing Siemens PLM Software the geometry of www.plm.automation.siemens.com CAD models in a 42 variety of formats, including VRML or IGES. Ford imports its production machineries as DirectModel JT format, a widely adopted lightweight 3D standard that works with most popular CAD systems. Because detailed CAD geometry can be overkill for real-time simulation (specifically to study movements and collisions), the software allows you to parse the JT data to a manageable level. Next, you define your human avatar’s size and shape to represent your worker population, position him or her in the digital world, assign a task, and let the experiment run (figure 1). By watching the way the avatar interacts with the mechanisms around it, you can better understand the following issues: u What the worker can reach u The strength and time required to perform a specific task u Whether the worker will be exposed to elevated risk of musculoskeletal injury u Whether the task produces fatigue See Them Run Allison Stephens, an ergonomics technical specialist for Ford’s vehicle operations manufacturing engineering, gave Jack and Jill a coming-out party of sorts. In November 2007, she introduced the digital duo at Siemens PLM’s Digital Manufacturing Symposium in Dearborn, Michigan. “Human simulation is part of our virtual manufacturing process,” explained Stephens. In this process, using a mix of virtual vehicle prototypes, virtual machineries, and digital www.cadalyst.com cadalyst May 2008 http://www.cdc.gov/niosh http://www.plm.automation.siemens.com http://www.cadalyst.com

Table of Contents Feed for the Digital Edition of Cadalyst - May 2008

Cadalyst - May 2008 Contents Editor's Window Cad Central A Solid Job in AutoCAD Today’s Power — Quad-Core Workstations Performance — Tomorrow’s Possibilities Reverse Engineering an Antique Italian Treasure Trends in Reverse Engineering NextEngine 3D Scanner — Reverse-Engineering Tool Setting CAD Standards Fight for Your Hardware Rights The Jack and Jill of Ergonomics Technology for Civil Infrastructure Cad Cartoon Issue Indexes Shortcuts and Solutions

Cadalyst - May 2008

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