Event-triggered three-dimensional adaptive anti-disturbance IGC method for a class of flight vehicles

This paper presents a novel event-triggered three-dimensional integrated guidance and control (IGC) methodology for flight vehicles, designed to address unmodeled dynamic disturbances and stringent state constraints. A hyperbolic tangent function is used to estimate the bounds of unmodeled disturbances, effectively managing time-varying and multi-source uncertainties. To enforce state constraints, the IGC model is augmented with a defined set of admissible states and incorporates a nonlinear transformation function, thus establishing a state-constrained integrated guidance and control (SCIGC) model. Event-triggered criteria are then developed to reduce the update rate of control commands, and the stability of the proposed event-triggered guidance and control methodology is rigorously analyzed. Additionally, it is demonstrated that the proposed event-triggered method avoids Zeno behavior. To prevent instability and numerical issues arising from the differentiation of virtual controllers, a low-pass filter is introduced. Finally, the efficacy of the proposed method is validated through Lyapunov functions and its capability to intercept tactical ballistic targets is confirmed by numerical simulations.