Synthesis of spherical four-bar linkage for open path generation using wavelet feature parameters

A wavelet feature parameters method is proposed for the non-periodic design requirements in the path synthesis of a spherical four-bar linkage mechanism. A mathematical model for the coupler curve of the spherical four-bar linkage is established using a spherical coordinate system. The geometrical characteristics of the open path are described using wavelet feature parameters. Then, a database of wavelet feature parameters is established. Based on the positional relationship of the prescribed curve with the coupler curve generated by the basic dimensional types, the installation positions of the desired linkage can be calculated. Moreover, the open path generation of spherical four-bar linkages can also be performed. Four examples are given. The design results show that the proposed method is effective for the open path generation of spherical four-bar linkages.