Safe cooperative interception must coordinate arrival, terminal geometry, closing speed, and internal spacing at the same time. This study formulates a spatial cooperative guidance scheme that couples range synchronization, terminal relative-speed regulation, adaptive transverse convergence, and active separation among interceptors. Along the line of sight (LOS), finite-time agreement of range-related states is superposed with a shared closing-speed servo, thereby separating the difference dynamics inside the multi-vehicle system from the mean radial-speed mode. In the two angular channels, the constant reaching gain is replaced with a time-, range-, and error-dependent gain that moderates the initial command peak while preserving terminal LOS-angle convergence. Collision risk is handled in two phases. During the early trajectory-reshaping phase, a smoothed neighbor-repulsion command is projected onto the transverse plane so that the radial speed loop is not perturbed. After the LOS-angle errors enter the assigned band, separated terminal approach directions are used to avoid late trajectory aggregation. Numerical tests show that the scheme removes early overload saturation and increases the minimum spacing while keeping the terminal constraints. In three deterministic cases, the terminal angle errors are on the order of ${10}^{-6}$, the relative impact-speed errors are on the order of ${10}^{-3}$, and the miss distances are approximately $0.8\mathrm{m}$. Two 200-run Monte Carlo tests with launch-condition perturbations and measurement noise give terminal angle errors on the order of ${10}^{-3}$, relative impact-speed errors around $0.5\mathrm{m}/\mathrm{s}$, and miss distances concentrated near $0.5\mathrm{m}$. These results indicate that the proposed design improves command smoothness and spacing performance without sacrificing cooperative terminal accuracy under the tested engagement conditions.

Three-dimensional skip-reentry trajectory tracking is challenging for hypersonic glide vehicles because of strong nonlinearity, pronounced state oscillations, model parameter uncertainty, and bank-angle constraints. This paper develops a trajectory-tracking control method based on the drag-acceleration profile and piecewise nonsingular practical prescribed-time control. A three-dimensional point-mass model that accounts for the Earth’s curvature and rotation is first used with predictor–corrector guidance to generate a reference skip trajectory considering process constraints and terminal requirements. The longitudinal bank-angle magnitude and the lateral bank-angle sign are then obtained separately. Taking the cosine of the bank angle as the control input, the drag-tracking error is formulated as a second-order control-affine system. The proposed controller uses an odd cubic polynomial extension to remove the derivative singularity of low-order fractional powers near the origin, and combines a dual-power reaching law in the prescribed-time phase with a linear hyperbolic-tangent holding law after that phase. Using Dini derivatives, a cited predefined-time Lyapunov criterion, and an explicit target-entry-time estimate, it is shown that the sliding variable and the drag-tracking error enter prescribed neighborhoods within an upper time bound independent of the initial condition; positive invariance of the neighborhoods, ultimate boundedness of the second-order error, and the discretization-error correction condition are also obtained. Simulations show that the proposed method improves drag-acceleration tracking accuracy under nominal conditions and constant parameter perturbations, while keeping the closed-loop states bounded and satisfying the bank-angle constraint under random parameter perturbations and initial measurement errors. The method provides a feasible route to configurable-time tracking control for constrained skip trajectories of hypersonic glide vehicles.

For a class of second-order nonlinear systems subject to matched disturbances, this paper investigates preset-time establishment and subsequent high-precision maintenance, and proposes a time-varying sliding mode control method based on prescribed error evolution. First, a quintic prescribed error-evolution function satisfying smooth endpoint constraints is constructed to explicitly shape the error establishment process, thereby avoiding excessive transient control demand caused by directly injecting a large initial error into the closed loop. Then, a time-varying sliding variable is constructed around the error-evolution deviation, and a continuous control law is designed by combining a bounded nonlinear mapping with a distance-dependent scheduling gain, achieving coordination between preset-time establishment and input smoothness. The theoretical analysis proves that, under nominal conditions, the closed-loop system can complete the establishment exactly at the preset instant; in the presence of bounded matched disturbances, the system satisfies an explicit small-neighborhood estimate at the preset instant and maintains high precision thereafter. The simulation results show that the proposed method achieves timing-consistent state establishment under different preset establishment scenarios, and significantly reduces the control peak and total input variation, thereby effectively alleviating the risk of actuator saturation.