Abstract: A new approach is developed to model dynamic behaviors of robot system. The process is realized through equivalent elements and the equivalent system of forces. Firstly, the concept of element pseudo-mass matrix is proposed based on the equivalent principle of elements—— the generalized inertia matrix is equal to that of real components, then establishes pseudo-mass matrix of the equivalent system through assem-bling units normatively, based on finite element thought. Sec-ondly, produces dynamical modeling equations based on the generalized dynamical equation and concepts of the equivalent system and vector of force. The expression is concise, standard and convenient for using with computer normatively. At last, the approach is used to generate the dynamical equations of 2-DOF planar parallel robot mechanism, the results are the same as those of ADAMS simulation.

Key words: Equivalent vector of force, Finite elementEquivalent element, Robotic dynamics