TAKEHARA, Hiroshima Prefecture—The Yuki-Hime “smart sea bus” made only one blunder during a test cruise when it needlessly slowed down and made a turn.
“A beacon light could have been mistaken for another vessel,” Kyoji Yokoyama, captain of the 19-ton Yuki-Hime, said.
That day, however, Yokoyama never switched the automated navigation to manual mode, underscoring the advances made in self-driving technologies in the maritime industry.
The eventual goal is fully automated, unmanned vessels that can help deal with expected labor shortages in the industry.
Eight Knot Inc., a business venture based in Sakai, Osaka Prefecture, is testing its autonomous navigation system on the Yuki-Hime, usually late at night on weekends, through the end of March.
It is the first autonomously navigated ship placed on a regular route in Japan, company officials said.
The boat is designed to automatically slow down whenever it is expected to cross the path of another vessel, thereby negating the need to take evasive action, the officials explained.
The Yuki-Hime is equipped with a camera, a device for acquiring location data, a radar to detect movements of nearby ships, and sensors to measure the boat’s inclination.
The vessel is also fitted with a system to integrally process similar information to control its rudder and engine.
The compact boat featuring the distinctive camera at its bow was moored in the pitch dark of night at a pier in Takehara,
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This device in Osaki-Kamijima, Hiroshima Prefecture, on Feb. 21 allows users to designate the destination of a ship. (Tomoyuki Suzuki)
Hiroshima Prefecture, in late February.
It departed at 10:10 p.m., carrying three passengers, including an Asahi Shimbun reporter, for a two-hour trial.
The vessel made three port calls at two islands in the town of Osaki-Kamijima, Hiroshima Prefecture, before returning to Takehara Port.
Yokoyama, 70, allowed the curious passengers to take a look around the wheelhouse.
He operated a device that looked like a tablet computer to select the port of destination and then pressed a button shortly after leaving the pier.
“This ensures our vessel will be navigated autonomously until our next port of call,” he said.
Passenger Yuzuki Inoue, a corporate employee from Fukuyama, Hiroshima Prefecture, seemed surprised by the smoothness of the cruise.
“There is no sudden braking or wobbly movement,” Inoue, 25, said. “And automated navigation remains in place until just before the berthing.”
The captain said he never felt the need to take charge manually due to danger or excessively low speeds.
“This system helps reduce my stress,” Yokoyama said. “That allows me to pay attention to safety under a proper level of tension.”
FOUNDING AMBITION
Eight Knot, which has also developed an autonomously navigated ship based on a pleasure boat, has conducted similar trial operations in Tokyo and Ehime Prefecture.
Yujin Kimura, CEO of Eight Knot, said he founded the company with engineers in 2021 to draw on his professional experience in working on robotics.
“I like marine sports, and I obtained a boat pilot license,” Kimura, 41, said. “But I found it so difficult to pilot a boat in the wind and waves that it was no fun at all.
“So, I had this ambition to robotize a vessel to assist the piloting process and enhance safety.”
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Captain Kyoji Yokoyama operates the Yuki-Hime under an autonomous navigation system on a trial basis in Osaki-Kamijima, Hiroshima Prefecture, on Feb. 21. (Tomoyuki Suzuki)
He said autonomous navigation systems have already been introduced for sea taxis and marine civil engineering work vessels, but they could also be used to transport residents of remote islands, where sea routes are gradually going out of service.
Kimura said Eight Knot’s system, which has automated most of the navigation process, is not without problems.
“Human captains can communicate with each other to take evasive action,” he said. “But doing so remains difficult for automated systems, so I wish to improve on that.”
A Japan Coast Guard white paper says 75 percent of all vessel accidents in 2023 were caused by human factors, such as insufficient watch and inappropriate piloting.
PROJECTS ELSEWHERE
“We are hoping to promote social implementation of automated navigation to address labor shortages, stabilize physical distribution and help reduce accidents,” said Tetsuya Kikyo, 42, who is working on the “Meguri 2040” fully autonomous ship project with the Nippon Foundation.
“Meguri” is Japanese for moving around. The project’s goal is to have fully autonomous, unmanned ships account for 50 percent of all vessels in Japan in 2040.
The Nippon Foundation is working with more than 50 businesses and research institutions to develop and test-operate autonomously navigated ships.
In 2022, the foundation test-operated the technology on the Suzaku domestic container ship, a small passenger boat, a car ferry and an amphibious vessel.
Automated navigation achieved a high utilization rate of 99 percent during the trials, although problems were found with vessels’ movements in heavy traffic and in low-speed ranges during the berthing and unberthing processes.
The Nippon Foundation plans to conduct a new round of test operations over longer periods from around July this year.
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The wheelhouse of the Suzaku domestic container ship used in the “Meguri 2040” fully autonomous ship project (Provided by the Nippon Foundation)
A new container vessel better suited to autonomous navigation will debut in November, foundation officials said.
Takefumi Higaki, an assistant professor of naval architecture and ocean engineering with Osaka Metropolitan University, developed a new system for berthing and unberthing late last year.
Higaki collected trajectory data, including locations and paths, from a car ferry and a vehicle carrier, both of which frequently visit Shin-Moji Port in Kita-Kyushu, Fukuoka Prefecture, and fed the data into an artificial intelligence system.
Using trajectories from departure to berthing by replaying the process backward enabled the AI system to present routes that allow a ship to dock without knocking against the wharf, just like a skilled human captain would do, Higaki explained.
He said he hopes to further improve the accuracy of his system and test it on a real vessel.
“I am hoping that my system will also prove useful as a guide for human pilots,” Higaki said. “The goal of my research is to make sure that vessels equipped with the system will be traveling around the world.”
Etsuro Shimizu, a professor of control engineering at Tokyo University of Marine Science and Technology, said autonomous navigation technologies are indispensable amid the depopulation trend.
“Japan has corporate developers of sensors and radars, and the country has a potential for packaging things up,” he said.
Shimizu, who is well-versed in the current state of automated navigation, said international rules are under discussion toward the goal of practical application of similar technologies.
“Rules have yet to be set on fully automated navigation, including on the qualifications of a remote commander in a similar situation,” he said. “There also remain many technical problems, including with obstacle avoidance, berthing and unberthing. The technologies should be gradually put to practical use, starting from where it is easier to solve similar questions.”