리아프노프 안정성 정리를 이용한 종말시간 구속조건을 갖는 유도법칙 설계

학위논문(박사) - 한국과학기술원 : 항공우주공학전공, 2014.2, [ vi, 77 p. ]This paper proposes the nonlinear guidance laws satisfying terminal time constraint for two- and three-dimensional problems. A salvo attack problem of missiles and a formation flight problem of UAVs are considered for two- and three-dimensional cases, respectively. In two-dimensional problem, each missile should simultaneously impact the target at a designated impact time to enhance the survivability of the anti-ship missile group against CIWS. In three-dimensional problem, also, UAVs have to precisely complete the desired formation shape at a specified formation time and maintain the formation shape. To derive the guidance law, appropriate Lyapunov function candidates, i.e., positive definite function consisting of an expected terminal collision error and the zero-effort-miss, are selected for each problem. The guidance commands are finally determined to ensure the negative definiteness of the time derivative of the proposed Laypunov function. The previous guidance laws to control impact time in two-dimensional case are mostly derived by solving the optimal control problem based on the linearized governing equation under the small angle assumption. Hence, the time-to-go estimation process is basically required for real application and the guidance performance depends on the accuracy of the time-to-go estimation. However, this main drawback is eliminated in the guidance law proposed in this paper because it is obtained by using Lyapunov stability theorem and directly applied the full nonlinear governing equation. Furthermore, the proposed guidance law for salvo attack to impact a stationary target at the designated impact time is also extended to a slowly moving target. The guidance law for three-dimensional problem, i.e, formation flight of UAVs, is determined in the similar manner as two-dimensional problem and its final guidance command is a velocity vector. The velocity vector command can be easily transformed into the typical autopilot commands of an UAV...한국과학기술원 : 항공우주공학전공

Analysis on Flight Test Results of Reconfiguration Flight Control System

This paper presents the analysis results obtained by the flight test of reconfiguration flight control system for an aircraft. The reconfiguration flight control system was designed by using control allocation scheme that automatically distributes the demanded control moments determined by control law to each actual control surface. In this paper, some control allocation algorithms for reconfiguration control of general aircraft with redundant control surfaces are summarized and their performance evaluation results through nonlinear simulation and Hardware-In-the-Loop-Simulation (HILS) test are shown. Also, Unmanned Aerial Vehicle (UAV) system adopted as a platform for the flight test of reconfiguration flight controller and the implementation procedure of reconfiguration flight controller into real-time UAV system were introduced. Finally, flight test results were analyzed