ABSTRACT
In earlier verification and validation studies for digital Human Modeling Systems (HMSs) in an F-16 cockpit application, the initial positioning and posturing of the manikins were found to be the greatest source of error in calculations of manikin reach and clearance (Oudenhuijzen et al. 2002). The goal for this project was to develop a method to reduce these errors based on "training" the HMSs. In essence, this training enables the manikins to assume realistic postures by employing 3D body scans of real people in an actual F-16 ACES II ejection seat. This was the starting point for defining manikin initial position, and posture during reach, as well
as to quantify the effects of the restraint system and the protective equipment in an F-16 cockpit environment. The Safework HMS was chosen as the modeling system to be "trained." Fourteen subjects with a considerable range in body dimensions were selected for the modeling activities in this project. Their scan data were collected under two conditions while seated in the F-16 ACES II ejection seat: 1) wearing stretch shorts (and sports bras for females) to serve as baseline data; and 2) wearing a full pilot cold water immersion ensemble (small subjects only). The resulting subject data were used to produce 15 reach posture libraries for the Safework HMS. These libraries can be considered as a kind of fidelity profile that quantified, and simultaneously accounted for, the effects of the restraint system, protective equipment, and tissue deformation in this seated cockpit environment. The average difference between the small subject reach envelopes and their corresponding manikin envelopes (compared at the radial styloid on the wrist for all 15 reach directions) had an error range of +/ - 7 mm. Hence, the library is considered to be highly accurate and verified for anthropometric accommodation studies on the F-16 when using the HMS Safework and the resulting posture libraries. The positioning accuracy for accommodation tasks was also found to be accurate. Manikin eye location, during positioning in accommodation tasks, lies between +/- 6 mm in the vertical Z direction, and much smaller (+/- 2 to 7 mm) in the horizontal directions.
