Optimal Dimensional Synthesis of Six-bar Stephenson I Mechanism for Path Generation

This paper presents optimal dimensional synthesis of a planar, single degree of freedom, sixbar Stephenson mechanism having rotational constraints. The prescribed parameters of the mechanism are displacement vector and coupler link motion. The aim of the present work is to determine the optimized dimensions and orientation of various links of the mechanism that is capable to follow the prescribed path. For this purpose, an objective function in terms of error between actual path followed by the coupler tracing point of the mechanism and the desired path prescribed by the designer is minimized. The optimization task for minimum error is carried out with the help of genetic algorithm. The effectiveness of the optimal dimensional synthesis of mechanism is demonstrated by a numerical example. The global optimal solution of the example is searched using MATLAB optimization toolbox. Finally, based on the minimum error, the link lengths and their orientation angles are calculated and verified.