Sliding Mode Guidance for UAV Rendezvous with a Maneuvering Target in Three-Dimensional Space

In unmanned aerial vehicle (UAV) operations, achieving precise rendezvous with maneuvering targets is final requirement for critical missions. Most of the rendezvous techniques existing in the current literature face significant limitations in simultaneously achieving position and velocity synchronization, often requiring separate control loops and restrictive assumptions about target motion patterns. To this end, this paper introduces a novel sliding mode-based guidance strategy for precise UAV rendezvous with maneuvering targets in three-dimensional environments, where the target is modeled as a generic continuous-time trajectory—representing a realistic and practical scenario. The proposed approach employs a nonlinear sliding vector that couples position and velocity tracking errors. Rigorous stability analysis using Lyapunov theory demonstrates finite-time convergence of both position and velocity errors to predefined tolerances, even in the presence of unknown but bounded sensing uncertainties. Extensive numerical simulations validate the performance of the developed guidance algorithm under different maneuvering target scenarios.