Using metaheuristics for optimum design of 3R orthogonal manipulators considering their topology

Several studies have investigated the properties of the workspace of opened chain robotics with the purpose of emphasizing their geometric and kinematic characteristics to devise analytical algorithms and procedures for their design. The workspace of a manipulator robot is considered of great interest from a theoretical and practical viewpoint. In this paper, the workspace topology is defined by the number of kinematic solutions, the number of cusps and nodes that appear on the workspace boundary. In this work, a multiobjective optimization problem is formulated with the aim of obtaining the optimal geometric parameters of robot, which must obey the topology specified by the designer. The maximum workspace volume, the maximum system stiffness and the optimum dexterity are considered as multiobjective functions. In addition, the optimization problem is subject to penalties that control the topology, forcing it to occupy a certain portion of the workspace. In this study, a computational tool, called Improved Differential Evolution with parallel processing, is developed using the concept of evolution shuffled sets. Moreover, three different metaheuristics are applied to obtain the problem solution. Five robotic applications are presented to show the efficiency of the proposed methodology.