A diving robot can pick up people who have sunk below the surface and bring them back up.
According to the DLRG, around 400 to 600 people drown every year in Germany. Researchers from the Fraunhofer Institute for Optronics, System Technology and Image Evaluation (IOSB) in Ilmenau are now working with the Halle Water Rescue Service to develop a rescue robot that is supposed to detect and rescue drowning people. In December it was tested in the Hufeisensee near Halle an der Saale with an 80 kilogram dummy.
For the underwater vehicle, the researchers were able to fall back on an in-house development – a remote-controlled diving robot that hangs on an 800-meter-long cable. Among other things, it has already been used to inspect offshore systems, dam walls, ship hulls and aquacultures. The energy comes from on-board batteries; only data and control commands are transmitted via the cable.
For his new job as a rescue diver, the robot was equipped with a sonar sensor and cameras. The sonar has a large opening angle and is used to track down people within a larger radius. “Modern sonars are so good that you can even recognize individual fingers,” says project manager Helge Renkewitz.
15 to 20 kilos of buoyancy
If the person you are looking for is in sight, camera images provide further orientation. The images are transmitted to a small monitor on board a boat. The pilot uses a joystick to maneuver the robot among the drowning people. Bodies that have completely sunk to the ground cannot be salvaged in this way. But that is not even necessary, says Renkewitz: “When an emergency is recognized, people are still floating in the water – it takes a while before they sink down.”
Then the central innovation of the system comes into play: side folding wings that fix lifeless people on a stretcher without injuring them. To bring them to the surface of the water, balloons are inflated with a total of 15 to 20 kilos of buoyancy. These floats also set up the side flaps so that a body can no longer slip out – servomotors or hydraulics are not necessary. “We wanted as little electronics as possible,” says Renkewitz. “The system should always be foolproof.”
Because of Corona, the researchers could not try their rescue robot in the swimming pool, but had to test it “under real conditions” in a quarry pond. A rescue diver hid the dummy within a radius of 50 meters. “The robot is able to find a person in an area of 1000 square meters, almost regardless of the depth, within two minutes and bring them to the surface,” said Sven Thomas, Chairman of the Board of Water Rescue Hall, to the television channel ” TV Hall “.
Don’t replace people
The system should not replace human rescuers, but support. “Across Germany there is a lack of 2,000 rescue workers in the swimming pools,” said Thomas. “In addition, it is almost impossible to rescue people in natural waters once they are under the surface of the water.”
Later versions of the robot will operate autonomously, but the current prototype is still completely remote-controlled. The project was financed by the Federal Ministry of Economics as part of the “coal exit subsidy” until the end of 2020.
“The project financing only ran for nine months,” says Renkewitz. “During this time you don’t develop an autonomous vehicle. That’s why we developed the fixing device first.” It can be attached to any comparable underwater robot. The researchers filed a patent for it last December.
Robots for swimming pools
The researchers have not yet received follow-up funding. But if you find new project partners, you want to develop two variants further: A small and inexpensive rescue boat for swimming pools that looks like a ray and sits like an automatic vacuum cleaner in a loading bay at the edge of the pool; and a more powerful version with sonar and larger batteries for swimming lakes.
A ceiling camera is supposed to monitor people in the swimming pool. The images are to be evaluated by an AI, which uses movement patterns to recognize whether someone has serious problems or is simply diving, and steers the robot accordingly. Something similar, albeit based on an underwater camera and without an associated robot, was presented by the Israeli start-up ” Coral Detection Systems ” in Las Vegas earlier this year.
Drones or zeppelins could provide corresponding images at swimming lakes. The on-board cameras of the underwater vehicle should then allow it to autonomously record a drowning person. It will take at least two years before such a system can be “let loose on humanity”, says Renkewitz.