cs.ROMar 3, 2026

COLREGs Compliant Collision Avoidance and Grounding Prevention for Autonomous Marine Navigation

Authors: Mayur S. Patil, Nataraj Sudharsan, Veneela Ammula, Jude Tomdio, Jin Wang, Michael Kei, Sivakumar Rathinam, Prabhakar R. Pagilla

Organizations: Department of Mechanical Engineering, Texas A&M University, College Station, USA · American Bureau of Shipping, Spring, TX, USA

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Abstract

Maritime Autonomous Surface Ships (MASS) are increasingly regarded as a promising solution to address crew shortages, improve navigational safety, and improve operational efficiency in the maritime industry. Nevertheless, the reliable deployment of MASS in real-world environments remains a significant challenge, particularly in congested waters where the majority of maritime accidents occur. This emphasizes the need for safe and regulation-aware motion planning strategies for MASS that are capable of operating under dynamic maritime conditions. This paper presents a unified motion planning method for MASS that achieves real time collision avoidance, compliance with International Regulations for Preventing Collisions at Sea (COLREGs), and grounding prevention. The proposed work introduces a convex optimization method that integrates velocity obstacle-based (VO) collision constraints, COLREGs-based directional constraints, and bathymetry-based grounding constraints to generate computationally efficient, rule-compliant optimal velocity selection. To enhance robustness, the classical VO method is extended to consider uncertainty in the position and velocity estimates of the target vessel. Unnavigable shallow water regions obtained from bathymetric data, which are inherently nonconvex, are approximated via convex geometries using a integer linear programming (ILP), allowing grounding constraints to be incorporated into the motion planning. The resulting optimization generates optimal and dynamically feasible input velocities that meet collision avoidance, regulatory compliance, kinodynamic limits, and grounding prevention requirements. Simulation results involving multi-vessel encounters demonstrate the effectiveness of the proposed method in producing safe and regulation-compliant maneuvers, highlighting the suitability of the proposed approach for real time autonomous maritime navigation.

Figures & tables

Figure 1: Geometric interpretation of QP-based safe velocity selection in velocity space.
Figure 2: Geometric representation of collision cones. (a) Standard collision cone derived under perfect state information, (b) Expanded collision cone accounting for bounded position uncertainty of agent BB , (c) Robust collision cone reflecting the combined effects of bounded position and velocity uncertainties.
Figure 3: ILP results for convexification of nonconvex geometries
CaseVesselsStart (N,E) [m,m]Heading [ ∘ ]Speed [m/s]
(a)V1(6000, 0)18018010
(b)V1(3500, 2500)27027010
V2(6000, 0)18018010
Table 1: Initial conditions of target vessels for four encounter scenarios.
Figure 4: Simulation results for representative encounter scenarios.
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