Research On Optical System Design And Algorithms Of The Plane Attitude Measuring Device

In the new airplane flight test experiments, the measurement of attitude parameters is the key. It is of great practical value and significance in practical applications such as aircraft design, test identification and failure analysis and so on. Electro-optical measurement technology has the advantage of non-contact, simple and high accuracy. It is importantly used in aviation and space field, such as UAV autonomous landing, the landing guidance system for a ship-borne helicopter, and the optical guidance system in the spacecraft rendezvous and docking. But these systems have a high requisition on measurement accuracy and real-time, sometimes even very harsh. Therefore, using of electric-optical measuring technology to achieve the plane 3D attitude measuring has important research significance.A new method of ascertaining plane outside attitude by compensation and positioning of the laser spot center was proposed, using cooperative target attitude measurement principle combined with the wander and spreading effects of the laser beam under actual atmospheric turbulence. A polygon can be formed through calculating the centroid of the single frame laser spot and extracting feature point of outline constituted by centroid of the laser spot within unit interval, the gravity center of which was taken as reference, and then adaptive attitude measurement compensation model can be established.3D pose information of the plane can be calculated by using the adaptive compensation model.The optical system of aircraft attitude measuring device was designed. According to the R-C system and the theory of Third-order aberration, the basic structure of the primary baffle and secondary baffle was designed. The R-C system was designed by using the reflex system to eliminate the Spherical aberration and Coma. The dispersion spot of full view was uniform distributed. Field curvature was less than 0.05 mm, and the Full field distortion was less than 0.1%. The MTF closed to the diffraction limit at 1161p/mm.In order to satisfy the requirement of real-time, the optimization function of target 3D attitude was solved based on the perspective projection principle. Through the statistics of the experimental data of spot image, the influence of atmospheric turbulence was considered into target attitude measuring error, which can improve the precision of the laser spot center extraction. Laser flare center was calculated by the method of polygon centroid, which eliminated accident caused by outside environment and improved the accuracy of each link in the measuring process. Numerical results show that the maximum of adaptive error compensation of the attitude angle is 0.221°by using simulated annealing algorithm to iterative solver and adaptive compensation when the target distance is 3km, which indicated that attitude measurement algorithm by using adaptive compensation technology has high accuracy and convergence.