The Lowest Contour Line Algorithm: A vehicles’ layout method for enhancing sortie mission reliability

The vehicles’ layout is critical for amphibious landing operations, maritime emergency rescue, and roll-on/roll-off vessel loading. Conventional layout algorithms in Cartesian coordinates focus primarily on maximizing space utilization, yet they overlook congestion that may arise from equipment failures during actual layout, leading to a sharp decline in mission reliability. To address this issue, this paper proposes the Lowest Contour Line Algorithm based on polar-coordinate. Unlike traditional heuristic methods, it explicitly incorporates reliability metrics into the layout process, thereby producing layout schemes with higher sortie mission reliability. By arranging vehicles’ radially and deriving the initial contour from turning radii, the algorithm raises the lower bound of mission reliability. In addition, a scan-point placement strategy, a contour update mechanism, and a circuit breaker mechanism are proposed to balance space utilization and mission reliability. Comparative experiments with three baseline methods demonstrate that the proposed algorithm significantly improves sortie mission reliability while maintaining a number of layout units comparable to that of conventional approaches. The algorithm provides a novel technical solution for layout scenarios with stringent reliability requirements.