Nonlinear Robust Generalized Dynamic Inversion based Homing Guidance and Control of Aerial Interceptors

Abstract

Abstract This paper presents the design of Robust Generalized Dynamic Inversion based Homing Guidance and Control (RGDI-HGC) methodology for highly maneuvering targets interceptors. In two-loops structured RGDI-HGC system, the outer RGDI based homing guidance loop generates the desired normal acceleration command to minimize the relative distance between the interceptor and the target. In the inner loop, RGDI based control law is engaged to follow the desired normal acceleration command while stabilizing the interceptor pitching rate dynamics. The proposed RGDI-HGC system is composed of the equivalent part and the robust part. The equivalent part is formulated by prescribing the dynamical constraints that encapsulate the interception kinematic and dynamic objectives, and the guidance and control variables are solved by inverting the constraint dynamics using dynamically scaled Moore-Penrose Generalized Inverse (MPGI). The robust part of the RGDI-HGC system is established by employing the discontinues term based on the theory of the sliding mode that will provide robustness against system nonlinearities, parametric variations, and external disturbances such that semi-global practically stable tracking performance is guaranteed. Numerical simulations are executed to illustrate the performance of the RGDI-HGC system for different interception scenarios. Additionally, the performance of RGDI-HGC system is compared with a guidance/control system that is made by replacing the outer guidance law by a conventional Augmented Proportional Navigation (APN) law. The test results illustrated that the proposed RGDI-HGC system supersedes the other by strongly accomplishing the hit-to-kill guidance interception requirements against agile target maneuvers in the presence of parametric uncertainties and measurement noise.