A 42.195-kilometer marathon is a sport that tests the limits of human endurance. Participants endure not only physical pain but also mental fatigue while running the full course. Overcoming these obstacles and finishing the race gives humans a sense of accomplishment. For robots, however, the marathon serves a different purpose. It is a powerful means of demonstrating that a robot can operate reliably despite variables such as time, distance, weather, and road obstacles. A prime example is the quadruped robot from Lion Robotics, which in 2024 became the world's first quadruped robot to complete a full marathon course. Lion Robotics is now focused on developing robots based on the technology it proved in that marathon.
Hwangbo Jemin, CEO of Lion Robotics, recently met with Seoul Economic Daily at the company's office in Gangnam, Seoul, and said, "Our technology in quadruped robots is among the most advanced in the world." He added, "Demand for quadruped robots in the defense market is high, and we are developing products for that sector." Hwangbo will take the stage as a panelist at the Robotics Venture Forum during Seoul Forum 2026 on the 27th and 28th of this month.
Lion Robotics is a startup founded in October 2023 by Hwangbo while he was serving as a professor in the Department of Mechanical Engineering at the Korea Advanced Institute of Science and Technology (KAIST). Hwangbo is an expert who has researched quadruped robots for 15 years. He decided to start the company after winning the grand prize in the pre-startup league at "Challenge! K-Startup 2023," hosted by the Ministry of Science and ICT and the Ministry of SMEs and Startups. "More than 7,000 teams competed, and we won the grand prize thanks to recognition for our artificial intelligence (AI) technology and hardware optimization," he said. "During the competition, we incorporated the company and began running the business in earnest."
Lion Robotics has focused on developing quadruped robots since its founding. A defining feature is that the company develops both hardware and software in-house, including robot design and simulation. What sets it apart from other robotics firms is its physics engine. This software calculates real-world laws and factors such as gravity, friction, speed, and inertia in real time to replicate them in simulation, enabling natural robot movement. "We design everything, including the batteries, and outsource the manufacturing to external partners," Hwangbo said. "This approach allows us to produce everything with domestic components."
This technology was proven at a marathon in the company's second year. Lion Robotics' quadruped robot "Raibo2" completed the full course of the 2024 Sangju Persimmon Marathon on a single battery charge. Raibo2 finished in 4 hours, 19 minutes, and 52 seconds, becoming the first quadruped robot to complete the 42.195-kilometer distance. "The robots that competed in the humanoid robot marathon held in China had short arms and were designed to run only forward, built specifically for marathons," Hwangbo explained. "Raibo2, by contrast, can be used for general purposes, not just marathons."
Raibo2's competitive edge is that it is fast and long-lasting. The quadruped robot can run at up to 22 kilometers per hour. With about an hour and 40 minutes of charging, the robot can operate for up to 8 hours. It can walk or run anywhere, indoors or outdoors. By comparison, Boston Dynamics' quadruped robot "Spot" operates only indoors at a speed of 5.8 kilometers per hour and runs for one hour on a single battery charge. The quadruped robot made by China's Unitree also has a maximum battery life of just four hours. Lion Robotics has also trained its robot in various simulated environments using AI and autonomous driving technology. "Raibo2 walks well even on rough terrain and over uneven obstacles," Hwangbo said. "The robot determines in real time how to control the force in its legs, shift its center of gravity, and place its legs in stable positions."
This durability and endurance have drawn attention from the defense industry. "If a robot is used only indoors, short battery life is not a disadvantage, but it becomes a problem the moment the robot goes outdoors," he said. "To actually deploy quadruped robots on the battlefield, we need to ensure safety against water, dust, sand, and temperature, so we are preparing to obtain the relevant certifications."
Last year, the company sold nine units of Raibo2. It also conducted a proof of concept (PoC) with a unit under the Ministry of National Defense. "In the PoC, while other robots could move only briefly before recharging, Raibo2 could operate all day, which drew a positive response from military officials," Hwangbo said. "With overseas defense companies, we have verified the robot's performance in tests running on uphill and downhill mountain terrain."
Hwangbo sees many ways to deploy quadruped robots on actual battlefields. A prime example is mounting firearms on the robots to fight in place of soldiers. The company is also conducting research on a chemical, biological, and radiological (CBR) detection robot with a domestic defense firm. The idea is to equip quadruped robots with sensors so they can move around and detect CBR threats. Establishing a cooperative system between drones and quadruped robots on the battlefield is also possible. Drones and quadruped robots would communicate with each other, with the drone guiding the path and recharging its battery on the quadruped robot. "Within the next five years, quadruped robots will be commercialized on actual battlefields," Hwangbo predicted. "In the future, robots will fight other robots in the military, and only a small number of control personnel will remain among soldiers." He added, "However, robots firing weapons and attacking on their own is still a distant prospect. Robots attacking humans is currently a violation of the law."
Based on this practicality, Lion Robotics aims to mass-produce 50 quadruped robots this year. To that end, the company plans to pursue a Series B funding round at the end of this year. To date, it has raised a total of 26.2 billion won from investors including SBVA, Company K Partners, and FuturePlay.
The company will also continue to test and verify Raibo2's performance in diverse environments. Earlier this year, Raibo2 climbed Mount Dalma in Haenam, South Jeolla Province. At the time of the climb, strong winds and cold weather made it difficult even for humans to walk. Despite the irregular mountain terrain, slopes, and rough surfaces, Raibo2 stably completed a 1.6-kilometer round trip up and down the mountain. "Physically, it is possible for a quadruped robot to climb all the way to the summit," Hwangbo said. "We plan to test it in various environments, including climbing Mount Gyeryong in Daejeon."
The most pressing need for this is manpower. Lion Robotics currently has about 40 employees, already double the number in early January of this year. The headcount is expected to exceed 100 by the end of this year. "We need many engineers with experience in robot development and design, and securing talent is not easy, but Korea has many excellent manufacturers, creating a favorable environment for collaboration," Hwangbo said. "Our goal is to continue leading the development of quadruped robots for the defense sector."
