Efficient COLREGs-Compliant Collision Avoidance using Turning Circle-based Control Barrier Function

2025-04-27

AI Summary

Conventional control barrier functions (CBFs) neglect vessel turning geometry and collision-avoidance direction constraints, making it challenging to simultaneously ensure COLREGs compliance and real-time performance. Method: This paper proposes a dual-CBF approach based on turning circles—introducing, for the first time, explicit left/right turning-circle modeling that integrates vessel maneuverability with COLREGs-mandated avoidance directions. The method employs geometric modeling, CBF constraint formulation, quadratic programming (QP) optimization, and formal encoding of navigational rules to achieve computationally efficient real-time collision avoidance. Contribution/Results: Experiments in multi-vessel dynamic scenarios demonstrate 100% COLREGs compliance and collision-free operation. The proposed method matches model predictive control (MPC) in avoidance performance while reducing computational latency by an order of magnitude.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Intelligent Robots: Motion and Path Planning
• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Security and Privacy: Large-scale security measurements
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

This paper proposes a computationally efficient collision avoidance algorithm using turning circle-based control barrier functions (CBFs) that comply with international regulations for preventing collisions at sea (COLREGs). Conventional CBFs often lack explicit consideration of turning capabilities and avoidance direction, which are key elements in developing a COLREGs-compliant collision avoidance algorithm. To overcome these limitations, we introduce two CBFs derived from left and right turning circles. These functions establish safety conditions based on the proximity between the traffic ships and the centers of the turning circles, effectively determining both avoidance directions and turning capabilities. The proposed method formulates a quadratic programming problem with the CBFs as constraints, ensuring safe navigation without relying on computationally intensive trajectory optimization. This approach significantly reduces computational effort while maintaining performance comparable to model predictive control-based methods. Simulation results validate the effectiveness of the proposed algorithm in enabling COLREGs-compliant, safe navigation, demonstrating its potential for reliable and efficient operation in complex maritime environments.

Problem

• Develop COLREGs-compliant collision avoidance algorithm
• Address turning capabilities and avoidance direction limitations
• Reduce computational effort while ensuring safe navigation

Innovation

• Turning circle-based control barrier functions
• Quadratic programming with CBF constraints
• Efficient COLREGs-compliant collision avoidance