An Experiment Based reach model for fighter cockpit design

Reach envelope is one of the design tools to ensure industrial workspace accommodates users. As for fighter pilots, their reach capability must be considered during the design of cockpit. Normally fighter seat back rest angle is between 13 degrees and 30 degrees, and due to the fact that postural change affects the reach capability of the pilot, the reach envelope can be different under different seat backrest angle, which is normally ill considered and thus limits the cockpit design. This research employed a reach envelope transformation model based on the anthropometric measurement approach to transform experiment based reach envelope at 0 degrees of back rest angle to that at other seat back rest angles. 12 male subjects' Reach data under 4 different seat angles and other anthropometric data were collected using motion capture system with a sample rate of 120Hz. A simplified model of human body was introduced and modified using the captured data from 4 subjects, with which other subject's reach points at 0 degrees seat backrest angle were transformed to reach points at other seat backrest angles. Comparison between the transformed envelope and measured reach envelope indicated that the average of difference, SD of difference was -5.5 and 42.76(mm) respectively.