Fixed-time tracking control of MASs with fast time-varying delay under switching topology

This paper investigates the fixed-time tracking control problem for non-strict-feedback nonlinear multi-agent systems subject to fast time-varying delays, unknown disturbances, and switching topologies. By modeling the system under a switched-system framework, a novel control strategy is developed that integrates the adding power integration technique (APIT) with adaptive neural networks to simultaneously address singularity avoidance, system uncertainties, and Lipschitz condition relaxation. The proposed design incorporates an improved Lyapunov–Krasovskii functional to achieve delay compensation without requiring traditional bounds on delay derivatives. Fixed-time stability is guaranteed for each modal subsystem through the Lyapunov analysis. The interplay between subsystem fixed-time convergence and average dwell-time constraints is rigorously characterized, establishing global exponential stability for the overall switched system. Simulation results demonstrate the controller’s effectiveness in achieving fixed-time tracking under the considered challenges.