Safe Mobility Score – Establishing a performance metric for the safe operation of H-USVs

Hydrogen complexity and operational downtime

Human errors are believed to be responsible for up to 95% of marine accidents. The leading cause of such failures is in many instances either a lack of relevant and accurate real-time data or an increase in operator burden through information overload.

As the use of uncrewed surface vessels moves towards swarm operations with operators overseeing the control of multiple vessels, it will be critical to decrease the operator burden of monitoring and controlling the power systems, allowing them to focus on the more critical navigational activities.

This need is further accelerated due to the necessary safe operation standards of novel fuels such as hydrogen. Although these fuels will offer a multitude of environmental and operational benefits, they will not be able to scale if remote operator oversight is reliant upon costly systems engineers overseeing systems 24/7.

This begs an important question, What is the minimum critical information required by the operator to ensure the safe remote operation of hydrogen-powered USVs?

The complexity of hydrogen propulsion requires smart automation and optimisation of operational and safety systems and minimising both operator burden and input.

Information overload and loss of connectivity

Increased monitoring and automation of the vessels' hydrogen l.will play a huge role in increasing systems safety, maintaining operations continuity, and reducing vessel downtime by minimising operator burden and identifying vessel performance anomalies in near real-time. However, this will require the development of smart algorithms and predictive maintenance solutions to enable the move away from a human-in-the-loop model to a human-on-the-loop mode

The requirement for increased systems automation applies further in the case of loss of connectivity to the vessel when operating over the horizon. It is critical in incidents or fields of denied communications that essential systems (such as the hydrogen power and safety systems) of the H-USVs can operate autonomously and safely without any interaction or instruction from the communication system and operator.

A risk-based certification (RBC) approach

In February 2022, as part of the project design methodology, ACUA Ocean undertook a hazard identification (HAZID) exercise to cover the use of hydrogen fuel and hydrogen systems. This is in line with the requirements of Lloyd’s Register’s Risk-Based Certification (RBC) process which is being applied to enable design appraisal due to the novel nature of the systems, which are not covered by existing rules and regulations.

The outcome of the regulatory and engineering workshops and industry engagement was a series of recommendations to help mitigate risks relating to hydrogen storage and propulsion. These workshops allowed the team to take an innovative approach to create a vessel data aggregation framework that can combine modern AI algorithms with robust data workflows.

TRIG 2021 Department for Transport (DfT) Award

Building on our discovery sessions, in March 2022, ACUA was awarded the Transport Research and Innovation Grant (TRIG 2021) backed by the Department for Transport, in partnership with Connected Places Catapult. The TRIG 2021 funding has enabled ACUA to spend six months developing a monitoring and reporting solution for hydrogen-powered USVs.

The project takes the next step in maintenance automation and remote vessel monitoring by capturing vessel data and distributing it securely to a ROC.

We introduced a data aggregation and analytics pipeline that ingest vessel data records, models, and identifies asset failures, and raises alarms, e.g., hydrogen-related alarms from the fuel cell and fuel tank. These are based on trends in one or more parameters and provide a “digital” supervisor which works 24/7. The team is now working on a decision engine that will ingest the vessel data records (historical and current), and environmental conditions (wind, sea state) and computes a safe mobility score, deviation from such a score is notified via alarms to the operator.

ACUA’s CTO Dr. Puneet Chhabra on the completion of the project:

ACUA's approach to uncrewed monitoring and autonomy is slightly different. Our predictive maintenance work aims to collect vessel data over time and expand the operator's awareness of the vessel’s state at any given point in time. Once operator-predefined mission parameters, e.g., geofencing, speed, etc. are fixed, onboard algorithms compute a ‘safe mobility score’ by solving a complex optimisation problem – a performance metric for the safe operation of hydrogen-powered USVs.