Wind tunnel model aircraft attitude and motion analysis

摘要

Abstract: A model-based approach to estimating the position and pitch-roll-yaw of the model aircraft in a vertical wind tunnel used to study the aircraft spin characteristics. The video image sequence of the model during flight is digitally analyzed for detection and tracking of target markers installed on the model. The geometric model of these targets is represented by their coordinates relative to the model reference coordinates. The six degrees of freedom (six DOF), namely, the pitch-roll-yaw and the 3-D position, is estimated using the camera model and iterative minimization of the distance in the image plane between the target points and the projected model points. Using prediction of the six DOF for the next video frame, the estimation procedure is repeated in a six DOF tracking loop that utilizes the dynamic as well as the geometric model of the target. The six DOF estimation and target tracking has been implemented on a real-time image processing workstation based on the Sun SPARC architecture. Interactive graphics and video image processing is used for initial designation of the approximate six DOF by the operator, followed by automatic tracking which dynamically displays the stick figure of the model aircraft on the grey-level video sequence.!