Impact Angle Constrained Three-Dimensional Integrated Guidance and Control Based on Fractional Integral Terminal Sliding Mode Control

In this paper, considering a class of skid-to-turn (STT) missile with impact angle constraint to intercept the maneuvering target, a three-dimensional integrated guidance and control law based on the fractional integral terminal sliding mode control (FITSMC) scheme is proposed. Firstly, a three-dimensional integrated guidance and control model is established for missile-target relative motion and nonlinear missile dynamics with multiple system uncertainties and unknown disturbances. Secondly, in order to achieve the desired impact angle in finite-time without singularity, a novel nonsingular FITSMC scheme is employed to construct the sliding surface, and a modified filter is applied to dynamic surface control design. Also, an extended state observer is introduced to estimate and compensate the system uncertainties and unknown disturbances. Then, a robust integrated guidance and control scheme with impact angle constraint is developed using aforementioned techniques. Furthermore, the finite-time stability of the closed-loop system is proven based on Lyapunov theory. Finally, the effectiveness and robustness of the proposed integrated guidance and control algorithm are verified through numerical simulations.