REACT: Real-Time Entanglement-Aware Coverage Path Planning for Tethered Underwater Vehicles
Abdelhakim Amer, Mohit Mehndiratta, Yury Brodskiy, Bilal Wehbe, Erdal Kayacan
AI summary
Problem
Existing coverage path planners for underwater vehicles ignore tether constraints, leading to frequent entanglement with underwater structures, reduced operational range, and time-consuming post-mission disentanglement.
Approach
REACT decouples offline coverage planning from online tether management by using a computationally efficient SDF-based tether model and a dual-mode replanner that enforces maximum tether length constraints to dynamically avoid entanglement.
Key results
- Computationally efficient SDF-based tether model for real-time simulation
- Online dual-mode replanner enforcing maximum tether length constraints
- 20% faster mission completion in simulation versus conventional planners
- Successful real-world pipe inspection with full coverage and zero entanglement
Why it matters
It enables reliable, efficient, and safe inspection of complex underwater infrastructure by eliminating tether entanglement risks that currently limit tethered ROV operations.
Abstract
Inspection of underwater structures with tethered underwater vehicles is often hindered by the risk of tether entanglement. We propose REACT (real-time entanglement- aware coverage path planning for tethered underwater vehicles), a framework designed to overcome this limitation. REACT comprises a computationally efficient geometry-based tether model using the signed distance field (SDF) map for accurate, real-time simulation of taut tether configurations around arbi- trary structures in 3D. This model enables an efficient online replanning strategy by enforcing a maximum tether length constraint, thereby actively preventing entanglement. By inte- grating REACT into a coverage path planning framework, we achieve safe and entanglement-free inspection paths, previously challenging due to tether constraints. The complete REACT frameworkâs efficacy is validated in a pipe inspection scenario, demonstrating safe navigation and full-coverage inspection. Simulation results show that REACT achieves complete cov- erage while maintaining tether constraints and completing the total mission 20% faster than conventional planners, despite a longer inspection time due to proactive avoidance of entan- glement that eliminates extensive post-mission disentanglement. Real-world experiments confirm these benefits, where REACT completes the full mission, while the baseline planner fails due to physical tether entanglement.