Manipulation

Peg-in-Hole

Peg-in-hole is the canonical contact-rich assembly task in which a robot inserts a peg into a close-fitting hole, often with clearances below a millimeter. Studied since the 1980s, it motivated the remote center of compliance device and much of the theory of fine motion under uncertainty, and it remains the standard testbed for force control, compliant insertion strategies, and learned assembly policies.

Why it matters for physical AI

Insertion tolerances routinely fall below a robot's positioning accuracy, so success depends on exploiting contact feedback rather than precision alone, making peg-in-hole the benchmark for whether a method truly handles contact-rich manipulation.