An Optical Attitude Measurement Method for Terminal Sensitive Projectile in Vertical Wind Tunnel Test

Abstract

An optical attitude (scanning angle and spin rate) measurement method for terminal sensitive projectile in vertical wind tunnel test is proposed. The principles of measuring scanning angle and spin rate simultaneously depend only on one fixed camera are presented in detail. The measurement processes, which mainly includes preparation, image acquisition, segmentation of projectile, contour extraction, and estimation of attitude, are described accordingly, and the key techniques involved in each step are expanded exactly. Moreover, the measurement errors are analyzed thoroughly. The advantages of the novel method is analyzed as follow: first, the mathematical model for calculating scanning angle of a steady-state terminal sensitive projectile is derived for the first time in literature, which makes it possible to measure scanning angle from images recorded by only a fixed camera; second, the algorithms of estimating scanning angle and spin rate depend only on the line-segments of the perspective cylinders in images are designed, which significantly improve the attitude measurement accuracy. Experiment was also conducted in laboratory to verify the novel method.