Four-bar mechanisms are one of the most common and effective components in the industry. As an example of their applications, they are designed to generate the desired output motion. In this paper, the nonlinear problem of optimal defect-free synthesis of four-bar mechanisms is analyzed by using a constrained version of the newly developed adaptive particularly tunable fuzzy particle swarm optimization (APT-FPSO) algorithm. The analyzed case study is designing a four-bar mechanism to generate a path that included three loops and 90 precision points. The results obtained support the superior performance of APT-FPSO compared to the standard PSO in solving the path generation problem. تفاصيل المقالة