Optimal design of a spatial four cable driven parallel manipulator

Abstract

This paper presents simulation and optimization of a spatial four-cable robot. For various points on the paths, tension in the cables and stiffness of the robot are determined before optimization. By selecting a function related to the stiffness matrix as the objective function of genetic algorithm, vertical positions of the connection points on the base platform as the optimization variables for each point on the paths can be determined in a way that the related function is optimized and a tension reduction in all the cables can be observed. Finally, the results of using different objective functions are presented for three different criteria: workspace volume, kinematic performance indices and actuating energy of the robot. The results indicate which function has the largest workspace volume with tension reduction property in all the four cables, which has the highest values for the kinematic performance indices and which has the lowest actuating energy.