Missile guidance law design with impact angle constraint based on SDRE scheme

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This thesis studies the homing missile guidance problem of intercepting constant velocity moving targets, with different terminal impact angles in a three dimensional engagement scenario. According to the literature, there is a one to one correspondence between the Line of Sight (LOS) angle and the impact angle on the collision, thus the guidance problem with impact angle constraint can be converted to the control of the terminal LOS angle [1]. This mission can be treated as a nonlinear optimal control problem. The State-Dependent Riccati Equation (SDRE) method, as a systematic nonlinear optimal control approach, has gained great popularity in solving guidance and control problems. In this research, a three-dimensional missile guidance law is designed based on the SDRE scheme with three different impact angle constraints. Additionally, to meet the practical requirement, a state-varying weighting matrix is proposed to reduce the control magnitude. The simulation shows the good guidance performance. Moreover, the autopilot lag and the measurement noise are considered to test the robust capability of the SDRE controller.