This paper develops a position-domain guidance optimization framework that adopts along-track position as the independent variable, enabling spatially indexed enforcement of geometric constraints and decoupling trajectory shaping from time parameterization. Building on this framework, a position-domain generalized spectral model predictive convex programming (PGSMPCP) method is proposed to remove reliance on a prespecified terminal time or fixed time window, thereby mitigating time-window-induced infeasibility in multi-constraint missions involving detours, altitude corridors, and no-fly-zone avoidance. The method is validated on a representative sea-skimming precision-strike planning problem with waypoint and terminal impact-angle constraints. Numerical results demonstrate that PGS–MPCP provides substantial improvements over representative MPSP variants in terms of terminal/waypoint accuracy and feasibility preservation. Relative to convex-optimization and pseudospectral methods, it achieves a favorable balance among computational efficiency, constraint satisfaction, and terminal performance, which makes it promising for online planning and real-time guidance. Additional Monte Carlo studies under both initial-condition perturbations and waypoint-geometry uncertainty further verify stable convergence and robust feasibility preservation.
Zhang et al. (2026) studied this question.