In January, Professor Stefan Williams and Dr Oscar Pizarro from the Australian Centre for Field Robotics at University of Sydney and the IMOS AUV Facility, joined a group of engineers, roboticists and oceanographers from Woods Hole Oceanographic Institution, Massachusetts Institute of Technology, University of Rhode Island, and University of Michigan on board the Schmidt Ocean Institute RV Falkor in the ocean off Maui, Hawaii.
The various groups on the Coordinated Robotics voyage worked on developing a new cost-effective and efficient underwater robotics program. The ultimate goal of the research is the development of autonomous ocean mapping systems capable of scaling up in a cost-effective manner. The 21-day voyage was dedicated to the goal of characterizing the distribution of reefs by deploying a fleet of autonomous vehicles using automated planning and scheduling tools.
For the Coordinated Robotics voyage, the Australian group brought several different robots: including the AUV Sirius which is the vehicle that has done all of the IMOS benthic monitoring so far; the newest vehicle NextGen; and the mini-vehicle Iver.
Autonomous Underwater Vehicle (AUV) Sirius is the largest vehicle. It was purchased from Woods Hole Oceanographic Institution twelve years ago, and it has been used to perform benthic monitoring at selected locations on Australia’s continental shelf.
Sirius can hover and navigate relatively rough terrain, operate for up to 8 hours, and collect high resolution stereo imaging data. While flying, it measures temperature, salinity, and water quality (by detecting dissolved organic matter, turbidity, and fluorescence). Sirius also has a multibeam sonar and a ADCP current profiler.
However, one of limitations is its size: It weighs 250 kg, which demands a big ship for its deployment. This limitation gave the team enough reason to begin working on their newest creation, temporarily called NextGen.
“We have a brand new AUV which has capabilities that are somewhere in between Sirius and the Iver, which is capable of hovering and sitting and working over rough terrain,” Professor Williams explains.
“The new AUV is smaller than Sirius and easier to deploy, but it is brand new, so we have to make sure that all the subsystems are working, including checking what the data quality is like.”
The new vehicle has all of those capabilities, yet at about 100 kg, it has no need of a ship as large as Falkor to be deployed.
Finally, there is the simplest vehicle, the Iver. “The Iver is smaller. It weighs about 35 kg, so it can be deployed from a small boat. One or two people can lift it in and put it in the water. It is torpedo shaped with fins.”
One of the Iver’s limitations is that it can’t hover, only move forward. “Because of this, it is not well suited for very rough terrain with cliffs or obstacles,” Professor Williams explains. “It is faster, it has better resolution cameras than Sirius, it can cover more ground, so if it’s relatively flat, we can cover a lot more ground with it.”
Over the course of the three-week voyage, several different robots were deployed constantly, pushing their autonomy and capacities. The researchers left the Coordinated Robotics voyage with all the experience and exchanges they were able to share on board, as well as results from experiments taking technology a step further at the service of science.
“All these techniques we are developing and demonstrating will help build our ability to understand the oceans. Having more observations is critical to having good science,” says Dr Pizarro.
“Having more observations is critical to have good science. If the observations are done in ways that are cheaper and that don’t require so many experts and manpower in the field, we will have a more comprehensive view of what is happening – how things are changing in the oceans. Hopefully, that will empower us to make wiser decisions and policies in the future.”
This story was originally published on the Schmidt Ocean Institute cruise log (https://schmidtocean.org/cruise-log-post/a-happy-marriage/ and https://schmidtocean.org/cruise-log-post/tech-and-science/), and was written by Mónika Naranjo González.
