Lagrangian Waverider and Wave Filtering System for use in ROV Control

This paper describes the adaptation of an existing wave filtering method for vessel Dynamic Positioning (DP) Systems for use in a Remotely Operated Vehicle (ROV) control system. The novelty is that the proposed control system will work in tandem with a Lagrangian waverider buoy deployed on a Marine Renewable Energy (MRE) site. The waverider will be tethered to a moored buoy on site, and will have remote release/recovery capability. Once released, the waverider will feed real-time spectral wave data from the microcontroller to a wave filter within the ROV control system. This will enable active filtering of raw heading measurements in real time, during mission execution. Real-time sampling of wave data during the course of the ROV flight will enable adjustment of the estimated peak frequency and direction of the wave spectrum in accordance with the changing dynamics of the ocean. The Lagrangian nature of the device will allow for free flowing, un-damped motion: The buoy will follow the orbital path of the water particles. This will ensure that the device is free from mooring pull forces, which can distort sensor readings, introducing course error.