Physics-based ROV navigation simulation with coupled tether dynamics, current, seabed interaction, and active tether management.
Coupled ROV-Tether Dynamics under Current and Seabed Interaction with Active Tether Management
- Category: Robotics / Underwater Robotics
- Authors: Marvin H. Cheng, Hemal Dave, Ezzat Bakhoum
- Focus: ROV dynamics, tether management, marine robotics, control
This project investigates how tether length and environmental interaction affect the operation of a remotely operated vehicle (ROV). A physics-based simulation couples six-degree-of-freedom vehicle dynamics with a dynamic lumped-mass tether, time-varying current, tether-seabed contact and friction, thruster actuation, and variable tether deployment and retraction.
Long fixed, short fixed, and automatically managed tether configurations are compared over a common waypoint mission using PID, sliding-mode, and model-predictive control. The results show a practical tradeoff: excess tether increases seabed interaction and sustained tether loading, while insufficient tether can increase axial tension and constrain vehicle motion. Active tether management preserves reach while reducing unnecessary cable exposure and tether-force coupling.
Research Highlights
The simulation treats the tether as a dynamic subsystem rather than a prescribed external disturbance, allowing vehicle motion, current-induced cable loading, seabed interaction, and tether tension to evolve together.
- Coupled 6-DOF ROV, dynamic tether, ocean-current, and seabed-interaction modeling.
- Automatic tether deployment and retraction based on vehicle reach and seabed contact.
- Comparative evaluation using PID, sliding-mode control, and model predictive control.
- Mission-level testing in a canyon-bridge environment with eight waypoints.
- Active tether management substantially reduces unnecessary seabed contact while maintaining comparable trajectory tracking.