Kinematic synthesis of adjustable moving pivot four-bar mechanisms for multi-phase motion generation

A four-bar linkage can satisfy up to five prescribed positions for the motion generation problem. The adjustable four-bar linkage, on the other hand, can satisfy more than five given positions by making some of the parameters adjustable. Limited work had been done in the area of motion generation problems of kinematic synthesis of adjustable four-bar linkages. This paper considers for the first time, the adjustment of a moving pivot. Equations are developed for the most complicated cases, which are two phase adjustable moving pivot problems with three positions in each of the two phases. Solutions are developed for two and three phase adjustable moving pivot problems. The numerical method developed for solving adjustable fixed pivot problems are extended to solve adjustable moving pivot problems. Synthesis examples are presented. Several Turbo Pascal programs are developed for solving the synthesis problems. Many user-defined AutoLISP functions and commands are specially designed for this work.