Synthesis of a planar four-bar mechanism for position control using the harmony search algorithm

Harmony Search (HS) algorithm, explored in recent literature, is an efficient metaheuristic optimization technique based on the musical improvisation process. Different versions of HS have been developed and used in solving real-world problems; however, most of the applications are oriented to combinatorial optimization. This paper presents a novel application of a modified HS for the synthesis of a four-bar planar mechanism that follows a specific trajectory, in order to demonstrate the capabilities of this algorithm for handling numerical optimization problems. Four-bar mechanisms are a good example of hard optimization problems, since they are used in a wide variety of industrial applications. HS algorithm was modified to handle design constraints by implementing Deb's feasibility rules. Simulation results show a high-precision control of the proposed trajectory for the designed mechanism, thus demonstrating that HS can be applied successfully not only to classical benchmark problems but for solving real engineering cases.