Autonomous robot tackles seabed trash in Marseille

Imagine an oversized claw machine at an arcade, but instead of trying to grab cheap toys, your prize is the assortment of waste that sinks to the bottom of the sea. That’s essentially what an autonomous robot has been doing at Marseille recently.

Let’s face it, we’re a pretty wasteful species. And much of our trash ends up being dumped “out of sight, out of mind” on land or at sea. Irresponsible disposal can lead to huge environmental problems, with cleanup operations then proving difficult at best and often costing a fortune.

We’ve seen a number of efforts aimed at dealing with floating detritus – such as plastic waste – on rivers and oceans, but what about the stuff that sinks to the bottom? The SEACLEAR project funded by the European Union a while back aimed to tackle such things by developing autonomous robot cleaning crews.

Project members include Fraunhofer CML, TU Delft, the University of Dubrovnik, the Technical University of Cluj-Napoca and the Technical University of Munich. The underwater gripper bot seen recovering trash from the Port of Marseilles in the video below is the work of a team from that last project partner.

Part of the second phase of the SEarch, identificAtion and Collection of marine Litter with Autonomous Robots project, the bot sports four claw-like grippers and can grasp an object with a force of 4,000 newtons, even if it tips the scales at up to 250 kg (550+ lb).

If a less crushing touch is required, onboard sensors “enable it to gauge how much force it can apply without causing damage. This prevents plastic buckets from breaking, for example, or glass bottles from shattering.”

Though it moves under its own steam below the water (courtesy of eight propellers mounted to its frame), you’ll notice that this robo-cleaner is tethered. The cable provides both power and access to a data network, while also allowing heavy trash to be craned out of the water and secured aboard a support vessel for responsible disposal. The team decided against installing a built-in battery due to limits on operational time between charges.

Locating and identifying seabed rubbish that’s prime for removal is undertaken via onboard sonar and a vision camera, plus AI processing, to help the robot recognize trash and determine where best to grab on. There’s little image data available for identifying and classifying underwater debris for AI training – which can include everything from discarded fishing nets to old bicycles to old tires and car seats – so the SEACLEAR partners have contributed more than 7,000 images gathered during various test phases. Identified objects have then been converted to 3D.

The general idea is for the whole cleanup operation to be completely autonomous – with various partners working on different aspects of the project. An unmanned service vessel would be able to use ultrasonic waves to generate a rough map of the seabed, with a dedicated search robot then tasked with more detailed scans of the depths. This data would be sent to the gripper bot, which would then be lowered for object extraction duties. An additional autonomous dinghy could serve as the above water collection point.

SEACLEAR 2 is still ongoing, but the pieces are slowly coming together, which could result in fleets of automated robo-teams taking on the arduous task of clearing up our mess in the near future. TUM’s Dr. Stefan Sosnowski has more detail to share on the gripper-bot in the video below.

Source: TUM