Math & Kinematics

Denavit-Hartenberg Parameters

Denavit-Hartenberg Parameters are a minimal convention, introduced by Jacques Denavit and Richard Hartenberg in 1955, for describing the geometry of a serial kinematic chain. Each joint-link pair is characterized by four quantities, link length, link twist, link offset, and joint angle, defining the homogeneous transform between consecutive frames. Chaining these transforms yields the manipulator's forward kinematics; modified DH variants fix ambiguities in the original formulation.

Why it matters for physical AI

DH parameters remain the lingua franca for specifying arm geometry in datasheets, calibration routines, and kinematics libraries. Accurate kinematic models built on them underpin the pose accuracy that learned controllers and calibration pipelines assume.