Pasadena, California / Abu Dhabi, UAE – October 2025 — In a groundbreaking demonstration that could redefine the future of autonomous systems, researchers from Caltech’s Center for Autonomous Systems and Technologies (CAST) and the Technology Innovation Institute (TII) in Abu Dhabi have unveiled X1, the world’s first multi-robot system integrating a humanoid robot and a transforming drone.
The X1 system merges two robotic platforms—a humanoid robot capable of navigating complex terrain and M4, a multimodal robot that can fly, drive, and deploy from the humanoid’s back. This marks a major milestone in multimodal robotics, showcasing a seamless fusion of walking, driving, and flying capabilities in one coordinated system.
A Vision for Unified Mobility
“Right now, robots can fly, robots can drive, and robots can walk. Those are all great in certain scenarios,” said Dr. Aaron Ames, Director of CAST at Caltech. “But how do we take those different locomotion modalities and put them together into a single package, so we can excel from the benefits of all these while mitigating their individual downfalls? X1 is that answer.”
In a live demonstration on Caltech’s campus, a modified Unitree G1 humanoid carried the M4 robot like a backpack, walking autonomously through hallways and open spaces before deploying M4 from its back. Once released, M4 transformed into flight mode, soared across obstacles, and later shifted to ground-driving mode to complete its mission — illustrating real-world adaptability in complex, unpredictable environments.
Engineering Collaboration Across Continents
The X1 project is the product of a three-year international collaboration between Caltech, TII, and Northeastern University, combining expertise in AI, control systems, morphing robotics, and autonomy.
“This collaboration was a perfect match,” said Professor Mory Gharib, Founding Director of CAST. “The challenge was to make different robots work together as one integrated system—each bringing unique capabilities to create something far beyond their individual potential.”
TII contributed advanced autonomy, sensing, and secure flight systems, including Saluki, a flight controller and onboard computing platform that powers M4. “We bring the capability of robots to move around with autonomy,” said Claudio Tortorici, Director at TII. “By combining data from lidar, cameras, and range finders, the robot understands where it is and how to reach its destination safely.”
Next-Generation Autonomy
Unlike most humanoid robots that rely on pre-recorded human movement data, Ames’ team employs physics-based modeling fused with machine learning to allow X1 to learn to walk and balance dynamically. “The robot learns to walk as the physics dictate,” Ames explained. “So X1 can walk on varied terrain, climb stairs, and even carry the M4 drone on its back—all autonomously.”
The future of X1 lies in even deeper autonomy — integrating real-time perception, adaptive control, and machine learning-driven decision-making to allow robots to navigate and collaborate safely in real-world human environments.
Toward Safe and Reliable Autonomy
For the Caltech–TII–Northeastern team, X1 represents more than a technical achievement — it’s a vision of trusted, reliable autonomous systems ready for deployment in real-world settings.
“We’re thinking about safety-critical control, ensuring systems are secure and reliable,” Ames noted. “These challenges are large, but through collaboration, we’re moving autonomy forward in a meaningful and concerted way.”
Tortorici added, “People are starting to accept robots around them. For this to continue, we must ensure they are safe, dependable, and capable — and X1 is a step in that direction.”
A Glimpse Into the Future
The X1 project exemplifies what’s possible when global collaboration meets multimodal innovation. By uniting walking, flying, and driving into one cooperative system, Caltech and TII have taken a pivotal step toward the next generation of autonomous robotics — systems that can think, move, and adapt like never before.
Source: Bots & Drones UK