Simulation
Bullet Physics (PyBullet)
Bullet is an open-source physics engine providing rigid-body dynamics, articulated multibody simulation via Featherstone's algorithm, and collision detection, with PyBullet exposing it to Python along with URDF loading, synthetic cameras, and reinforcement learning environment utilities. Maintained for years by Erwin Coumans, it became a default for robot learning research in the late 2010s before GPU-parallel simulators like Isaac Gym absorbed much large-scale training.
Why it matters for physical AI
Free, scriptable physics simulation lowered the barrier to policy training and benchmarking for an entire research generation, and PyBullet remains a common choice for lightweight prototyping and reproducible baselines.
Build physical AI
Put these concepts to work on real hardware
Axol is a dual-arm robot built for physical AI — teleoperate it, collect demonstrations, and deploy learned policies out of the box.