In this article, computer aided methods and tools for improving the accuracy of a mechanism's dynamic model used in the Matlab/Simulink simulation environment are presented. This is done by a simple but exact method with the support of a high-level CAD system Pro/Engineer that allows the analysis of mass properties and the dynamics of complicated spatial mechanisms. These tools can serve for a synthesis of the control system based on Lagrangian dynamics and following a simulation of the whole mechatronic system behavior. (C) 2004 Published by Elsevier Ltd.