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Venkateshwaran, Akash

University of British Columbia

Underwater radiated noise from ships threatens marine mammals, which rely on sound for navigation, foraging, and communication. Noise levels depend on vessel-specific characteristics and operational parameters. While research on voyage optimization of operational parameters prioritizes fuel efficiency, emissions, and safety, acoustic impact is often overlooked. This thesis introduces a novel decision support system for voyage planning to minimize a vessel’s acoustic footprint. The first contribution is a multi-objective optimization framework for fixed-path voyage scheduling, integrating two competing objectives: minimizing noise levels and fuel consumption. The problem, constrained by voyage parameters, is solved using a non-dominated sorting genetic algorithm. A two-dimensional ocean acoustic environment, incorporating marine mammals from diverse audiogram groups and realistic oceanographic conditions, is simulated. Effectiveness is demonstrated through real-world case studies of a large container vessel. The second contribution extends the framework to dynamic route planning and speed optimization, allowing ships to adapt trajectories while minimizing their acoustic footprint. This approach comprises three components: • Modeling: Near-field noise levels are estimated using a regression-based reference spectrum model (JOMOPANS-ECHO), while far-field propagation losses are computed with a Gaussian radial basis function model for real-time 3D underwater noise modeling. A data-informed density distribution of Southern Resident killer whales models environmental interaction. • Optimization: Route planning is performed using the Batch Informed Trees algorithm, integrating graph-based and sample-based methods. Speed optimization uses genetic algorithms to ensure noise-aware navigation under voyage constraints. • Simulation: A ROS-based simulation models adaptive ship-mammal interactions in a realistic oceanic setting with 3D visualization. To evaluate the proposed system, real-world case studies are simulated using AIS data from vessels operating between the Strait of Georgia and the Strait of Juan de Fuca. A comparative analysis of noise exposure levels under optimized and unoptimized voyage conditions is conducted, demonstrating the practical applicability and effectiveness of the proposed system in mitigating noise impact on marine ecosystems.

Text

2025-03-27

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/90544

Mechanical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/