4-legged Korean robot runs full marathon on single charge
A research team, led by Professor Hwangbo Je-min of KAIST's Department of Mechanical Engineering, celebrates as the quadruped robot RAIBO2 completes the Sangju Dried Persimmon Marathon without recharging or swapping its battery, Nov. 17, 2024. Courtesy of Korea Advanced Institute of Science and Technology
In the world of legged robotics, endurance has long been the ultimate hurdle.
While four-legged machines can backflip, negotiate rubble and scale staircases with uncanny agility, their high-performance motors typically drain battery reserves in less than an hour. But along the rural stretches of North Gyeongsang Province, a dog-like machine spent over four hours trotting past orchards and cheering spectators to rewrite the limits of mechanical stamina.
Engineers at the Korea Advanced Institute of Science and Technology (KAIST) developed RAIBO2, a quadrupedal robot that completed a full 42-kilometer marathon on a single battery charge. The landmark feat, detailed this week in the flagship scientific journal Nature, marks the first time robotics research from Korea has graced the main pages of the prestigious publication, signaling a major leap forward for long-distance autonomous field machines.
The milestone unfolded during the annual Sangju Dried Persimmon Marathon — a local race named after the agricultural region’s famous fruit — where RAIBO2 lined up alongside human runners as an officially registered participant. Navigating asphalt roads, gentle inclines and changing temperatures, the machine finished the run at 4 hours, 19 minutes and 52 seconds, becoming the first quadruped in history to finish a full marathon course without a single recharge or battery swap.
Achieving that level of endurance required researchers to abandon the traditional approach of simply packing on heavier batteries. Instead, a research team led by Hwangbo Je-min, a professor of mechanical engineering at KAIST, treated long-distance mobility as a holistic engineering challenge. By co-designing the robot's physical limbs, internal power distribution systems and gait-control algorithms simultaneously, the team systematically tracked and eliminated microscopic energy leaks across every joint and circuit.
Throughout the race, researchers ran alongside the mechanical marathoner to document its progress and monitor a live telemetry stream tracking internal voltage, motor temperatures and real-time GPS coordinates. By the time RAIBO2 crossed the finish line, it had consumed roughly 1,280 watt-hours of electricity, leaving enough reserve power to theoretically stretch its total range to 65 kilometers.
The breakthrough arrives at a crucial moment for industrial automation, where limited battery life remains the primary bottleneck holding quadrupedal robots back from real-world adoption.
Raion Robotics, a commercial spin-off originating from Hwangbo’s university lab, is already moving to mass-produce the platform for real-world applications in disaster recovery, perimeter security, and hazardous industrial inspections.
"We will turn the world-class performance achieved in the lab into products that anyone can use reliably in industrial settings," Hwangbo said.
This article was published with the assistance of generative AI and edited by The Korea Times.