Amphibious Robot Dog Tames Ruff Waters

As agile as they may be on the land, quadrupedal robot dogs do not much like the water. Aside from sinking like a rock, they would also let out lots of magic smoke and never trot again. Similarly, robots designed to operate on the surface of water, or underneath it, are about as useful as a rock on dry ground. Some amphibious robots do exist, but they tend to be jacks of all trades, but masters of none. Sure, they get the job done, but just barely.

This differs significantly from the natural world, where a real dog can dart around a field like a cheetah, then hop in a lake and swim across like a fish. Researchers at the South China University of Technology and West Chester University wanted to bring this natural versatility to robots, so they developed a robot dog that is agile on land, and that can also hop in the water and doggy paddle with the best of them.

Making this work took a lot of effort. The team had to perfectly optimize their robot’s weight, balance, and buoyancy so that it could stay above the surface of the water and glide through it efficiently. They also had to perform extensive experiments to arrive at the ideal swimming patterns, which resulted in the development of three effective options. Two of the styles are modeled after the doggy paddle, and are best when speed is required. The other option is more trot-like, and it emphasizes stability in water.

The faster swimming modes were found to reach speeds of about 0.36 miles per hour, which is around half the speed of an average human swimmer. On land, the robot moves at 0.78 miles per hour, so it is no speed demon, but it is a good starting point. Future refinements may be able to improve the speed of the robot under both conditions.

Looking ahead, the team sees potential applications for their technology in environmental research, rescue missions, and beyond.