Synthesis of adjustable spherical four-link mechanisms for approximate multi-path generation

An optimization based method is presented for the synthesis of adjustable spherical four-link crank–rocker mechanisms for approximate multi-path generation. The synthesis is done in two stages, first the driving dyad of the spherical mechanism is determined and then the remaining parameters are determined. The method uses a least squares based plane fitting procedure and this results in a lesser number of design variables for optimization than existing approaches. Two numerical examples, including one dealing with generating two different trajectories of a flapping wing micro air vehicle, are presented to demonstrate the effectiveness of the proposed synthesis method.