Strictly speaking, ‘autonomous navigation’ is when a vessel moves from A to B without any human intervention, regardless of the destination or the waterway traffic that will be encountered. This form of autonomous navigation is not yet a possibility, however.
Autonomous navigation on long-distance voyages is not very challenging because the vessel will nearly always have hundreds of meters or many kilometres of room for any manoeuvre.
The opposite is the case for inland navigation. The traffic levels will be quite heavy and the scope for manoeuvring fairly limited. A 135-metre vessel that has to make a manoeuvre will have little room to deviate from her preferred trajectory. Any software for automating this needs to be very intelligent and should have good tracks available to be able to make constant adjustments when needed.
Tresco’s autonomous navigation software gives you the best of both worlds.
There are always many factors, including depth, other (larger) vessels crossing, or the gradient of the banks, that determine a vessel’s course and can disrupt the preferred trajectory.
That is why it is essential to have enough reference points to check that the vessel is still on her preferred course and, if necessary, to make adjustments quickly. The greater the change to the course, the longer it will take to bring a vessel back on course.
Feedforward and feedback
The most sophisticated solutions for autonomous navigation involve an ingenious combination of ‘feedforward’ and ‘feedback.’ Feedforward is when the software determines the preferred course and gives the initial instructions to the vessel on that basis. Feedback involves continuously comparing this preferred course with the data captured via GPS and sensors and making adjustments if necessary.
The vessel needs to have built-in ‘feedforward’; otherwise, she might set off on the wrong course, and then it will be hard to get her heading in the right direction.
The first ‘live’ tests were completed successfully in early 2020. We consider this to be the official launch of the first generation of autonomously navigating vessels.
We have some exciting applications to look forward to:
- Enabling vessels involved in dredging operations to moor precisely where the dredger wants to discharge. This may seem futuristic, but it is only a matter of making some mathematical calculations.
- A logistics application of autonomous navigation is ‘platooning.’ This means multiple vessels sailing in each other’s wakes so that only the first vessel in line needs to keep a constant course, while the others use the leading vessel as their reference.
- A variant of the above is a fleet of interlinked smaller vessels navigating a larger shipping route together. Each individual vessel can then be diverted to a tributary or canal at the right time.
And what comes after that? Many obstacles still need to be overcome, both technical and legal, before a fully autonomous vessel can travel through our inland waters. The next steps towards autonomous navigation will involve our software supporting the captain, who will still retain the final responsibility.