The Korea Advanced Institute of Science & Technology (KAIST) has developed RAIBO 2, a quadruped robot that completed the 42.195-kilometer Sangju Dried Persimmon Marathon in 4 hours, 19 minutes, and 52 seconds – making it the first four-legged robot to complete a full marathon without needing to recharge its batteries.
The 42-kilogram robot, created by Professor Hwangbo Je-min and his research team at KAIST, outpaced the average mass-participation time at the 2023 London Marathon by seven minutes. RAIBO 2’s performance at the 22nd Sangju Marathon in North Gyeongsang Province, South Korea, included conquering two challenging 50-meter elevation gains at the 14-kilometer and 28-kilometer marks.
The robot’s achievement follows an unsuccessful attempt in September at the Geumsan Ginseng Festival Marathon, where it depleted its battery after 37 kilometers. “Through the marathon project, we demonstrated that RAIBO2 has the walking performance to stably execute services such as delivery and patrol in urban environments with many people and random objects,” said Choongin Lee, a PhD student at KAIST.
The team implemented several technical improvements after the initial setback. RAIBO 2’s enhanced design includes an AI-powered system that stores kinetic energy generated during downhill sections. Professor Hwangbo Je-min stated, “The AI component was crucial, as it would have been impossible for a quadruped robot to store kinetic energy in its battery without AI control.”
The robot features two cameras – one mounted on the front body and another on the tail – to detect terrain features. Joint-mounted sensors minimize power consumption. The integration of motor driver circuitry directly into the robot improved walking efficiency and stability.
Before the marathon, RAIBO 2 underwent extensive training in RaiSim, a simulated environment replicating various terrains including slopes, stairs, and icy surfaces. KAIST collaborated with RAION ROBOTICS Inc. to enhance the robot’s stability, addressing the complex challenges of repeated ground impacts and vibrations.
The improved version of RAIBO 2 can run up to 67 kilometers in a straight line. The battery performance exceeds that of Boston Dynamics’ Spot robot, according to the creators.
As quadruped robots gain traction in surveillance and disaster management, RAIBO 2’s successful marathon run demonstrates practical applications. “In follow-up research, we will add autonomous navigation functions to RAIBO and strive to achieve the world’s best walking performance in mountainous and disaster environments,” Lee added.
The achievement arrives as robots increasingly participate in marathon events. In Beijing, a humanoid robot named Tiangong recently served as a closing pacer in the Yizhuang Half Marathon, joining runners 100 meters from the finish line.
While the marathon completion proves RAIBO 2’s endurance capabilities, questions remain about the cost-effectiveness and practical deployment of such robots in real-world scenarios. The development cycle, including the failed attempt and subsequent improvements, indicates the complexities involved in creating reliable autonomous systems for extended operations.
