Optimization of Kinematically Redundant Manipulators Force Capabilities Using Improved Harmony Search

The Harmony Search (HS) algorithm is a new evolutionary metaheuristic algorithm based on natural musical performance processes that occur when a musician searches for a better state of harmony, such as during jazz improvisation. In the HS algorithm, the solution vector is analogous to the harmony in music, and the local and global search schemes are analogous to musician’s improvisations.The HS algorithm uses a random search, which is based on random selection, memory consideration, and pitch adjusting. In this paper, an Improved HS (IHS) approach based on truncated Cauchy distribution is proposed and evaluated. The proposed IHS presents an efficient strategy to improve the search performance in preventing premature convergence to local minima when compared with the classical HS algorithm. The efficiency and feasibility of the proposed IHS approach is demonstrated on a force optimization problem, where the force capabilities of a serial PRRR manipulator are evaluated considering actuation limits and different configurations.