A Study of Video-Based Relative Motion Measurement Method for Rocket Separation

Based on launch vehicle separation video, the relative motion process of the rocket separation process can be studied, and the quantitative evaluation of the rocket separation process can be realized. Firstly, the first and second stage separation images of a certain rocket were extracted frame by frame for three cases of about 2s, and four anisotropic feature points were selected according to the extracted image features and combined with the actual size of the rocket body to obtain the pixel coordinates and the world coordinates corresponding to them. Aiming at the unknown internal parameter of the on-board camera, this paper proposes a method of solving the internal parameter matrix of the camera by using the pinhole imaging model combined with the separation stroke, and finally solves the relative velocities of the first and second stage separations based on the PnP algorithm, and compares them with the nominal values at the time of the design, to validate the measurement error of the algorithm. The experimental results show that the method can deeply explore the information in the image without changing the existing on-board camera device, and the error is up to 10%, so the measurement results have good accuracy.