DYNAMIC MODELLING OF PLANAR LINKAGES USING PARTICLE DYNAMICS AND VELOCITY TRANSFORMATION

摘要

In this paper the dynamic analysis of some planar linkages is presented. The equations of motion are formulated using a two step transformation. Initially, a dynamically equivalent system of particles that replaces the rigid bodies is constructed and then Newton's second law is applied to derive their equations of motion. The equations of motion are then transformed to a reduced set in terms of the relative joint variables using a velocity transformation matrix. For the open loop case, this process automatically eliminates all of the non-working constraint forces and leads to an efficient solution and integration of the equations of motion. For the closed loop case, suitable joints should be cut and few cut joints constraint equations should be included for each closed loop. The suggested planar mechanisms incorporate open and/or closed loops with the common types of kinematic joints. The results of the simulations indicate the simplicity and generality of the dynamic formulation.