Trajectory and attitude measuring scheme for launching projectiles of inflight aircraft

In this paper, a novel non-contact scheme, based on stereo vision technology and close range photogrammetry, is presented to measure the trajectory and attitude of launching projectiles of inflight aircraft with high accuracy. A conjugated camera group, which is rigidly connected and calibrated to an ensemble, is designed to archive the whole measurement. First, a camera position self-correction method is proposed to eliminate the measurement error caused by aircraft vibration. Then, two trajectory and attitude measurement methods are proposed and used in different stages of the projection process. The single-camera method based on the theory of space resection is applied in the beginning of projection with short measurement distance and small intersection area. The multiple-camera method based on the means of point cloud registration is applied in the following stage with small effective measuring area. Furthermore, a point tracking method is developed to improve the robustness and speed of the algorithm by predicting the position of non-coded target. A novel system is developed and the accuracy test in laboratory confirms that the trajectory and attitude measurement errors of the system are 0.02 mm/m and 0.02°/m respective. A simulation experiment is carried out and the well measured result by the system proves the feasibility and the efficiency of this scheme.