APRIL 28, 2016 — While researchers at the Norwegian University of Science and Technology believe that the future of underwater robotics lies in swimming snakes (see earlier story), their counterparts at Stanford University believe it will have a rather more human face.
OceanOne, a humanoid robotic diver developed by Stanford, is powered by artificial intelligence and haptic feedback systems, allowing human pilots an unprecedented ability to explore the depths of the oceans.
In its first real-life mission the robotic diver recovered treasures from King Louis XIV's wrecked flagship, La Lune, 100 m below the Mediterranean.
The ship sank in 1664, 20 miles off the southern coast of France, and no human had touched the ruins – or the treasures and artifacts the ship once carried – in the centuries since.
Then, with guidance from a team of deep-sea archaeologists who had studied the site, Oussama Khatib , a professor of computer science at Stanford, "swam" through the wreck of La Lune, and hovered precisely over a grapefruit-size vase. He reached out, felt its contours and weight, and stuck a finger inside to get a good grip. He swam over to a recovery basket, gently laid down the vase and shut the lid.
Then he stood up and high-fived the dozen archaeologists and engineers who had been crowded around him. Professor Khatib had even gotten wet, he'd been sitting comfortably in a boat, using a set of joysticks to control OceanOne..
When the vase returned to the boat, Professor Khatib became the first person to touch it in hundreds of years.
The expedition to La Lune was OceanOne's maiden voyage. Based on its success, Professor Khatib hopes that the robot will one day take on highly skilled underwater tasks too dangerous for human divers, as well as open up a whole new realm of ocean exploration.
"OceanOne will be your avatar," he said. "The intent here is to have a human diving virtually, to put the human out of harm's way. Having a machine that has human characteristics that can project the human diver's embodiment at depth is going to be amazing."
Anatomy of a robo-mermaid
Born from the need to study coral reefs deep in the Red Sea, below the comfortable range of human divers, OceanOne was conceived and built from the ground up as a smarriage of robotics, artificial intelligence and haptic feedback systems.
OceanOne looks something like a robo-mermaid. Roughly five feet long from end to end, its torso features a head with stereoscopic vision that shows the pilot exactly what the robot sees, and two fully articulated arms. The "tail" section houses batteries, computers and eight multi-directional thrusters.
It's the hands that really set OceanOne apart. Each fully articulated wrist is fitted with force sensors that relay haptic feedback to the pilot's controls, so the human can feel whether the robot is grasping something firm and heavy, or light and delicate. (Eventually, each finger will be covered with tactile sensors.) The robot's "brain" also reads the data and makes sure that its hands keep a firm grip on objects, but don't damage them by squeezing too tightly. In addition to exploring shipwrecks, this makes it adept at manipulating delicate coral reef research and precisely placing underwater sensors.
"You can feel exactly what the robot is doing," Professor Khatib said. "It's almost like you are there; with the sense of touch you create a new dimension of perception."
The pilot can take control at any moment, but most frequently won't need to lift a finger. Sensors throughout the robot gauge current and turbulence, automatically activating the thrusters to keep the robot in place. And even as the body moves, quick-firing motors adjust the arms to keep its hands steady as it works.
Navigation relies on perception of the environment, from both sensors and cameras, and these data run through smart algorithms that help OceanOne avoid collisions. If it senses that its thrusters won't slow it down quickly enough, it can quickly brace for impact with its arms, an advantage of a humanoid body build.The humanoid form also means that when OceanOne dives alongside actual humans, its pilot can communicate through hand gestures during complex tasks or scientific experiments.
Ultimately, though, Professor Khatib designed OceanOne with an eye toward getting human divers out of harm's way. Every aspect of the robot's design is meant to allow it to take on tasks that are either dangerous – deep-water mining, oil-rig maintenance or underwater disaster situations like the Fukushima Daiichi power plant – or simply beyond the physical limits of human divers.
"We connect the human to the robot in very intuitive and meaningful way. The human can provide intuition and expertise and cognitive abilities to the robot," Professor Khatib said. "The two bring together an amazing synergy. The human and robot can do things in areas too dangerous for a human, while the human is still there."
Professor Khatib was glad of these capabilities while recovering the vase. As OceanOne swam through the wreck, it wedged itself between two cannons. Firing the thrusters in reverse wouldn't extricate it, so Khatib took control of the arms, motioned for the bot to perform a sort of pushup, and OceanOne was free.
The expedition to La Lune was made possible in large part thanks to the efforts of Michel L'Hour, the director of underwater archaeology research in France's Ministry of Culture. Previous remote studies of the shipwreck conducted by L'Hour's team made it possible for OceanOne to navigate the site.
Vincent Creuze of the Universite de Montpellier in France commanded the support underwater vehicle that provided third-person visuals of OceanOne and held its support tether at a safe distance.Several Stanford students played key roles in OceanOne's success, including graduate students Gerald Brantner, Xiyang Yeh, Boyeon Kim and Brian Soe, who joined Professor Khatib in France for the expedition, as well as Shameek Ganguly, Mikael Jorda, and a number of undergraduate and graduate students.The professor also drew on the expertise of Mark Cutkosky, a professor of mechanical engineering, for designing and building the robotic arms.
Next month, OceanOne will return to the Stanford campus, where work on the platform will continue. The prototype robot is a fleet of one, but hopes are to build more units that would work in concert during a dive.In addition to Stanford, the development of the robot was supported by Meka Robotics and the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia.