Structural-Parametric Synthesis of Planar Motion Generating Mechanisms and Manipulators

This paper studies a structural parametric synthesis of the four-bar and Stephenson I, Stephenson II, Stephenson III A, Stephenson III B six-bar motion generating mechanisms. Four-bar motion generating mechanism is formed by connecting the output body and base by two negative closing kinematic chains (CKCs) of the type RR. The six-bar Stephenson I, Stephenson II, Stephenson III A, Stephenson III B motion generating mechanisms are formed by connecting the output body and base by active CKC of the type RRR and two negative CKCs of the type RR. Active and negative CKCs impose geometric constraints on the movement of the output body and they work at certain values of the geometric parameters of their links, which are determined by least- square approximation.