Next-generation humanoid robot can do the moonwalk

KAIST research team’s independently developed humanoid robot boasts world-class driving performance, reaching speeds of 12km/h, along with excellent stability, maintaining balance even with its eyes closed or on rough terrain. Furthermore, it can perform complex human-specific movements such as the duckwalk and moonwalk, drawing attention as a next-generation robot platform that can be utilized in actual industrial settings.

Professor Park Hae-won’s research team at the Humanoid Robot Research Center (HuboLab) of KAIST’s Department of Mechanical Engineering developed the lower body platform for a next-generation humanoid robot. The developed humanoid is characterized by its design tailored for human-centric environments, targeting a height (165cm) and weight (75kg) similar to that of a human.

The significance of the newly developed lower body platform is immense as the research team directly designed and manufactured all core components, including motors, reducers, and motor drivers. By securing key components that determine the performance of humanoid robots with their own technology, they have achieved technological independence in terms of hardware.

In addition, the research team trained an AI controller through a self-developed reinforcement learning algorithm in a virtual environment, successfully applied it to real-world environments by overcoming the Sim-to-Real Gap, thereby securing technological independence in terms of algorithms as well.

Currently, the developed humanoid can run at a maximum speed of 3.25m/s (approximately 12km/h) on flat ground and has a step-climbing capability of over 30cm (a performance indicator showing how high a curb, stairs, or obstacle can be overcome). The team plans to further enhance its performance, aiming for a driving speed of 4.0m/s (approximately 14km/h), ladder climbing, and over 40cm step-climbing capability.

Professor Hae-Won Park’s team is collaborating with Professor Jae-min Hwangbo’s team (arms) from KAIST’s Department of Mechanical Engineering, Professor Sangbae Kim’s team (hands) from MIT, Professor Hyun Myung’s team (localization and navigation) from KAIST’s Department of Electrical Engineering, and Professor Jae-hwan Lim’s team (vision-based manipulation intelligence) from KAIST’s Kim Jaechul AI Graduate School to implement a complete humanoid hardware with an upper body and AI.

Through this, they are developing technology to enable the robot to perform complex tasks such as carrying heavy objects, operating valves, cranks, and door handles, and simultaneously walking and manipulating when pushing carts or climbing ladders. The ultimate goal is to secure versatile physical abilities to respond to the complex demands of actual industrial sites.

During this process, the research team also developed a single-leg “hopping” robot. This robot demonstrated high-level movements, maintaining balance on one leg and repeatedly hopping, and even exhibited extreme athletic abilities such as a 360-degree somersault.

Especially in a situation where imitation learning was impossible due to the absence of a biological reference model, the research team achieved significant results by implementing an AI controller through reinforcement learning that optimizes the center of mass velocity while reducing landing impact.

Professor Park Hae-won stated, “This achievement is an important milestone that has achieved independence in both hardware and software aspects of humanoid research by securing core components and AI controllers with our own technology.

“We will further develop it into a complete humanoid, including an upper body to solve the complex demands of actual industrial sites and furthermore, foster it as a next-generation robot that can work alongside humans.”

The results of this research will be presented by JongHun Choe, a Ph.D. candidate in Mechanical Engineering, as the first author, on hardware development at Humanoids 2025, an international humanoid robot specialized conference held on October 1st.

Additionally, Ph.D. candidates Dongyun Kang, Gijeong Kim, and JongHun Choe from Mechanical Engineering will present the AI algorithm achievements as co-first authors at CoRL 2025, the top conference in robot intelligence, held on September 29th.

The presentation papers are available on the arXiv preprint server.