Computer-Aided Synthesis of Planar Four-Bar Mechanisms for Coupler Link Positions

Abstract

The positional synthesis of the coupler link of a planar four-bar mechanism is presented as a mathematical programming problem. The computer gives a refined design for a four-bar mechanism whose coupler link is required to pass through a number of desired orientations as closely as possible. Theoretically, there is no limit on the number of positions that can be synthesized. If a solution exists it will be determined by the computer. If not, the values of the errors in tracing the desired positions will be large, indicating that a feasible solution probably does not exist. The developed computer program allows the designer to impose constraints on the design such as: link lengths, frame orientation, crank input angles, type of mechanism, and pivot locations.