A Y-Star Robot: Optimal Design for the Specified Workspace

This paper adopts a methodology to determine a set of optimal design parameters of a Y-Star robot whose workspace is as close as possible of being equal to a prescribed cylindrical dexterous workspace (PCDW). Two requirements should be satisfied simultaneously: (i) the local or global performance index; (ii) a regular shape. The kinematic problem is analyzed in brief to determine the design parameters and their relation at first. The optimal design problem with nonlinear constraints is discussed and then translated into two optimal problems without constraints. Then, an optimal design procedure which adopts the generalized pattern search algorithm in the genetic algorithm and direct search toolbox of Matlab is adopted to solve these problems. As an applying example, the results of four cases of PCDW to the robot are presented. And the design results are compared with a concept of the distance between the best state of the robot and the requirement of the operation task. The methodology and result of this paper are very useful for the design and comparison of the Y-Star robot.