Computer vision techniques applied to ejection seat trials instrumentation

摘要

The effective development of ejection seats for military aircraft depends on accurate measurement of seat trajectories during trials. While trajectory measurement systems have existed for some time the extraction of the trajectory from raw measurements has been laborious and the accuracy has been questionable. Further, development programmes have become more exacting in their requirements and as a result the existing systems have had to be replaced. This paper describes a number of alternative approaches which have been considered recently and discarded in favour of a computer vision solution based on high-speed digital cameras (initially digitised cine film) and manually supervised computer vision processing implemented on a standard PC. The computer vision software package integrates camera calibration, feature extraction, tracking and stereo processing to provide a 3D trajectory for each of the objects of interest. After a manual initialisation stage, the system runs automatically, but allows the operator the ability to intervene if necessary. Initial experiences with this new system indicate that it is providing notable timesavings and providing superior trajectory data compared with the earlier methods.