Terminal Impact-angle-constrained Guidance Law of Miniature Munition Based on High-order Fully Actuated System Approach

Aiming at the terminal impact-angle constraint in the interception of large maneuvering targets by munition, this paper proposes a three-dimensional(3D) maneuvering target interception guidance law combined with the high-order fully-actuated (HOFA) system theory based on biased proportional navigation guidance (BPNG). First, a complete second-order nonlinear model with fully-actuation is built for munition-target relative motion without the small-angle assumption. Second, the nonlinear system of the munition-target relative motion is transformed into a quasi-feedback system, and a HOFA model is developed for the system. A BPNG law with the linear relationship of the line-of-sight angle is introduced to transform the closed-loop system into a linear time-invariant closed-loop system with the expected characteristic structure. Finally, target maneuver information is taken as the model compensation and adopted as the external input of the closed-loop system together with the remainder of the guidance law; thus, the channel coupling of the nonlinear three-dimensional system is eliminated. The effectiveness of the proposed method is verified by simulation results.