Elliptical Walking Motion- US Army Picatinny Arsenal
Elliptical Walking Motion capability now available for Newton manikins.
For a specialized US Army research project that required a more natural manikin walking motion technology, Thermetrics engineers designed and built a 20-zone Newton thermal manikin system that included an all-new Elliptical Walking Motion Device.
CAD modeling was used to determine the necessary range of motion and identify the correct geometry for the actuation levers, to ensure a smooth elliptical walking motion. As with Newton’s standard EN 342 walking motion systems, walking speed is variable from 0-55 double steps per minute (about 70 meters/minute). The new elliptical walking system can also accomodate shoes of varying heel/sole heights.
But there was more to the project than that, explained Sheela Nagaraj, from the US Army’s Picatinny Arsenal test facility.
“A novel modification that Measurement Technology NW [now Thermetrics] made to the new elliptical walking system was in its ability to automatically generate a series of manikin events consisting of 1) standing still, 2) walking at various speeds, and 3) sitting. Automating this motion sequence through the walking stand and associated ThermDAC software reduced the amount of human interaction with the testing apparatus and reduced the chances for human-related error.”
Sheela also noted, “Due to our group’s test requirements it was also necessary for all motors and components to be made explosion-proof with intrinsically safe electrical components and with circuits designed not to spark. The walking stand had to be an encapsulated system that would be easy to clean and decontaminate.
This 20-zone Newton thermal manikin system was outfitted with our new ManikinPC2 (Manikin Physiology Control and Predictive Comfort) software. ManikinPC2 operates under ThermDAC as a closed-loop feedback control package that accurately simulates the human thermoregulatory system and provides metrics for thermal comfort and thermal sensation. The software permits variable activity levels that simulate the human metabolism while sleeping, resting, working, or exercising. Any level of activity can be input and appropriate metabolic wattages will be imposed onto the manikin.
The complete Newton thermal manikin system was installed at the Army’s Picatinny Arsenal research laboratory. Project funding was coordinated through SOSSEC.
“As with any unique and innovative system we encountered a few issues and glitches with the new equipment” reported Sheela, “but it has been a pleasure working with MTNW [Thermetrics] and their support has been extremely helpful in familiarizing ourselves with the Newton manikin and its operation.
For over 25 years, Thermetrics has manufactured a wide range of precision instruments for measuring and evaluating the thermal comfort of textiles, garments, and environments such as automobile, truck, and aircraft interiors. Thermetrics systems support all major ASTM, ISO, and ENV textile testing standards.