Abstract: This paper presents the derivation of a centrally computational formula for robot dynamic equation. Using the quantities describing the mass feature of generalized-links, this formula calculates centrally the effects of concerned links on the coefficients of dynamic equation. The mass feature quantities of generalized-links, which have explicit mechanical meanings, can be calculated recursively from the end-effector to the base of the robot. Compared with other modelling formulas cited in references, this formula requires the minimum amount of computation and is much more concise in structure. The relationships between the coefficients of dynamic equation and the quantities describing the mass and geometry feature of robot links are clearly demonstrated. So the derived formula for robot dynamic equation is more efficient in modelling computation than other ones.

Key words: Dynamics, Modelling, Robot