RanMarine: Precise navigation for autonomous swimming robots

The vehicle can also be used to remove small amounts of oil that may be generated in harbors during boat refueling. Or helps in the fight against invasive plants: The water hyacinth, for example, with its purple flowers, is usually a welcome guest in the garden pond. In the bathing lake or reservoir, on the other hand, it is an uncontrollably proliferating nuisance. The company BERKY from the Emsland, one of the partners of RanMarine, gets to grips with it professionally with special mower collecting boats. However, the ten-meter long and ten-ton heavy watercrafts do not reach all corners. This is where the WasteShark now comes into play as a support, which can be steered by remote control to wherever plant remains or litter are left over.

RanMarine began in 2016 with a model that was radio controlled. Since 2019, the WasteShark – a world’s first funded by the EU's Horizon 2020 program, among others – is also traveling autonomously: equipped with a front camera, a LiDAR (light detection and ranging) sensor, and a GPS receiver, the cleaning drone can independently orient itself in bodies of water and avoid obstacles. Users define the collection route with various waypoints beforehand on a digital map. However, the system also had its weaknesses: The inaccuracy of GPS (Global Positioning System) when determining the position via satellite can be several meters. Sufficient for a hiking tour – insufficient for the operation of an autonomous robot that has to master special tasks.

In the meantime, the WasteShark can also measure the water quality with sensors; the measuring points should be located as precisely as possible. And for the latest version, RanMarine even required positioning with centimeter accuracy: In the future, the floating robot will be able to independently navigate to a docking station to empty its waste container and to recharge the battery.

This is where Deutsche Telekom comes in: The Precise Positioning solution, as the name suggests, enables extremely precise determination of the position of mobile vehicles – to within a few centimeters. An area-wide network of hundreds of Telekom reference stations on several continents measures local disturbances in GNSS satellite navigation (Global Navigation Satellite System; this includes the U.S. service GPS as well as the European Galileo). A cloud-based service from Telekom’s partner Swift Navigation sends the corrected position data via 4G mobile communications to the vehicle – in this case, to the WasteShark.

Precise Positioning provides RanMarine with several decisive advantages. Not only does the drone find its way safely to the loading and unloading station. "Before, it kept stopping because of GPS drift, as if it had to think about where to go next," says founder and CEO Richard Hardiman. "Now, it navigates precisely on the entire course it's staked out and moves fluidly." This allows the WasteShark to collect more trash in the same amount of time – reducing costs and requiring fewer charging cycles. In addition, the location and timing of water quality data measured along the way, such as pH or temperature, can be accurately determined. The aqua-drone can avoid obstacles even more reliably.

"Telekom's system is significantly more reliable than public corrections services and works out-of-the-box," Hardiman says. "Plus, the service is available in almost every area in the world where our WasteShark is deployed." Precise Positioning scales to an unlimited number of vehicles – and RanMarine is already planning a new model: the "MegaShark". This autonomous cleaning robot is about five times larger than the WasteShark and is accordingly designed for larger quantities of waste – or water hyacinth carpets.