The Case for a General Method of Kinematic Analysis of Plane Mechanisms Based on Equations of Constraint

Abstract

All but the simplest of single degree of freedom mechanisms have a relatively large number of component parts. To analyse the motion of such systems, therefore, one parameter is rarely sufficient. For an adequate description of the motion characteristics of all components, a number of additional coordinates are needed. This paper introduces a clear and logical notation which facilitates the setting up of the required number of constraint equations by simple inspection of clear line diagrams of the mechanism to be analysed. These constraint equations are eminently suitable for the calculation of velocities and accelerations by direct differentiation. The resulting equations are linear in the velocities and accelerations of all component parts. A method based on this approach is presented and applied to a selection of widely different examples.