Development of Look Angle Guidance Law for Loitering Munition Under Velocity Change

Abstract

Loitering munitions have several advantages in terms of operational flexibility and versatility. However, due to characteristics of fixed wing shape, control surface effects of longitudinal axis to lateral axis are asymmetric and amount of velocity change during terminal guidance phase is large. Since typical guidance laws do not take into account velocity change, a distinguished guidance law is needed. In this paper, look angle guidance law for loitering munition that is able to tune impact angle and consider velocity change is proposed. In the proposed guidance law, longitudinal axis of loitering munition is controlled by utilizing sliding mode control to generate angular rate and thrust commands that follow look angle and velocity command profile. Lateral axis of loitering munition is controlled by utilizing nonlinear dynamic inversion method for generating angular rate commands that control heading angle. The stability and accuracy of proposed guidance law are shown through Monte-Carlo simulation that added disturbance to 6 degree of freedom model.