Research On Transfer Alignment Of The Missile Onboard The Aircraft

Transfer alignment, which uses the information of the calibrated aircraft INS to calibrate another INS onboard the missile, is a very important technology for the weapons. The duration of the transfer alignment will decide the preparation period to launch the missile, and the misalignment will determine the navigation precision which the missile can reach in flight. The main work of this paper is:1. The concept, process and the already done work of transfer alignment are briefly introduced. The coordinate systems, error models and initial alignment of the inertial system which will be used in building the transfer alignment model later are discussed. Discrete kalman filter equations are introduced, status equations of continuous system are discreted, and the stability of the filter is discussed.2. This paper discusses the theoretical principle of dimension effect, and the dimension effect error formula is deduced. At the same time, an online compensation method based on kalman filter is proposed. The results of simulation show that this method is simple, effective and has widely practical value.3. The velocity matching, angular rate matching and attitude change matching transfer alignment are researched. Line-maneuver, wing-rock and acceleration-maneuver, s-maneuver, circle-maneuver are designed for velocity matching transfer alignment procedures, and the states to be included in the velocity matching transfer alignment kalman filter are chosen, simulations of the transfer alignment on four maneuver are performed, and then the simulation results are analyzed. Simulations of angular rate matching and attitude change matching transfer alignment on wing-rock maneuver are performed, and then the simulation results are analyzed.4. Single matching method has its disadvantages, so velocity plus angular rate matching, velocity plus attitude matching and specific force plus angular rate transfer alignment approaches are compared by simulations.5. The observability analysis theory and method of PWCS (piece-wise constant systems) is introduced. In allusion to velocity matching and velocity plus attitude matching method, the degree of observability of the main states during transfer alignment of SINS on various moving bases is quantitatively analyzed using method of singular value decomposition (SVD). The result provides a theoretical basis for devising the best maneuver during the transfer alignment. The validity of the SVD method is proved by the simulation results.