Math & Kinematics

Center of Mass

The center of mass (CoM) is the mass-weighted average position of all particles in a body or multibody system, the point at which applied forces produce pure translation without rotation. For an articulated robot the CoM moves with configuration and is computed from link masses and forward kinematics. It is central to balance criteria such as the zero moment point and capture point, and to payload and stability analysis for mobile platforms.

Why it matters for physical AI

Balance controllers for humanoids and mobile manipulators plan CoM trajectories explicitly, and learned locomotion policies implicitly regulate CoM dynamics, making accurate mass models important for sim-to-real transfer.