This paper studies a structural–parametric synthesis of the four-bar and Stephenson II, Stephenson III A, and Stephenson III B six-bar function generators. A four-bar function generator is formed by connecting two coordinate systems with given angles of rotation using a negative closing kinematic chain (CKC) of the RR type. Six-bar function generators are formed by connecting two coordinate systems using two CKCs: a passive CKC of the RRR type and a negative CKC of the RR type. The negative CKC of the RR type imposes one geometrical constraint to the relative motion of the links, and its geometric parameters are defined by least-squares approximation. Passive CKC of the RRR type does not impose a geometrical constraint, and the geometric parameters of its links are varied to satisfy the geometrical constraint of the negative CKC. Numerical results of the four-bar and six-bar function generators parametric synthesis are presented.

To justify the choice of Clavel's delta robot as a compensating manipulator, its forward and inverse kinematics problems were solved and a virtual experiment was conducted using dynamic modeling in an OpenModelica simulation environment.