Date of Award
2026
Degree Type
Thesis
Degree Name
Master of Science in Ocean Engineering
Department
Ocean Engineering
First Advisor
Stephen Licht
Abstract
Fiber optic tether systems are used for real-time data transmission to remotely operated vehicles (ROV) due to their ease of deployment and light weight, but are prone to damage from tension loads. An active heave compensation system applied to a fiber optic tether system can address these challenges by actively managing the tether payout to reduce peak loads. Tether management systems with active heave compensation have been in use for larger systems such as work class vehicles and offshore oil rigs, but few are developed for small maritime systems. This work focuses on the development and incorporation of an active heave compensation system in a lightweight, affordable, and compact manner to an existing tether system. It is a software and electronics addition to the Fiber Optic Reel System (FOReelS) -- a compact fiber optic microtether winch. This addition serves as a development towards a larger system that combines the commercial Blue Robotics BlueBoat with the tether management system in order to autonomously deploy ROVs. This work presents the development of an active heave compensation (AHC) system for an existing fiber optic tether system and targets the sea conditions faced during the tether breakage of a past ROV deployment. The system adapts the active heave compensation approach intended for offshore cranes and implements it onto an affordable off-the-shelf microcontroller with estimation, prediction, and control methods. The estimation system produces attitude estimation from sensor fusion of measured IMU data and uses adaptive filtering to estimate the heave, while the prediction algorithm is used to produce a forecasted heave and velocity from auto-regressive modeling and a Levinson recursive least squares algorithm. This is then successfully used as a pure feedforward command to drive compensator action from the motor to correct for heave. Simulation and bench tests are used to demonstrate the performance of the system.
Recommended Citation
Truong, Frances, "DEVELOPMENT OF AN ACTIVE HEAVE COMPENSATION SYSTEM ON A COST EFFECTIVE MICROCONTROLLER FOR A FIBER OPTIC TETHER MANAGEMENT SYSTEM" (2026). Open Access Master's Theses. Paper 2714.
https://digitalcommons.uri.edu/theses/2714