The new underwater robot can swim underwater using its fins and can walk or crawl along the bottom when necessary. These features can really take it a step further to outperform traditional thruster-driven products.
Underwater remotely operated vehicles (ROVs) are often used for tasks such as searching for sunken ships and inspecting underwater structures.
Like crewed submersibles, the vehicle uses electric propulsion to move through the water. Unfortunately, these thrusters can become blocked by seaweed, dangling cables, discarded fishing lines or other materials. Additionally, the ROV cannot advance against currents flowing faster than the maximum forward speed of the thruster.
This is where HERO-BLUE comes into play.
This experimental device stands for “Biomimetic Multi-Movement-Based Underwater Exploration for Hazardous and Extreme Environments RObot” and was created by Taesik Kim and colleagues at Pohang University of Science and Technology in Korea. This is certainly reminiscent of the AQUA robot from McGill and Dalhousie universities. The robot uses six flippers to swim and perform a type of “flap” across land.
HERO-BLUE's body has four multimode fins (two at the front and two at the back) and two side fins (one at the center of the body).
Each multimode pin consists of several polymer panels connected to each other by elastomeric “tendons.” The pins are constructed in such a way that they remain rigid when force is applied in one direction, but become flexible when force is applied in another direction.
The side fins consist of an elastomeric membrane suspended between two rigid “rays” (basically rods), one at each end of the membrane.
When BLUE swims, its multiple fins flap up and down like the pectoral fins of a fish. The lateral fins can also be operated for finer manipulation, moving in a wavy fashion as needed, like the lower fin of a swordfish.
This means that swimming may not be an option in strong currents. In these cases, BLUE utilizes an integrated buoyancy controller to drop to the bottom and then uses multi-mode fins to walk along gravel, sand, or other underwater terrain. Each fin remains rigid as it pulls the robot's body forward, then becomes flexible as it sweeps forward again to take the next step.
Swimming is also impossible in very shallow water. That's why BLUE's spine is inspired by a salamander. Its spine bends from side to side at the lumbar joint between the front and back parts of the robot body. This layout allows the bot to twist its body back and forth, writhing forward even against relatively strong currents.
In its current proof-of-concept form, BLUE measures 80 cm long, 60 cm wide, and 30 cm high (31.5 x 23.6 x 11.8 inches) and weighs 11.3 kg (24.9 lb). It is currently controlled remotely, but with two camera modules on the front for stereoscopic vision, it may one day be able to operate autonomously.
You can see HERO-BLUE's swimming and floor walking movements in the video below. A paper on the study was recently published in the journal. IEEE Transactions on Robotics.
[HERO BLUE] T-RO: Full video
Source: IEEE Transactions on Robotics