Optimal design for a 2-dof high dynamic manipulator based on parallelogram mechanism

In this paper, a design and optimization approach for a 2-dof manipulator based on parallelogram mechanism for high dynamic application is proposed. After the kinematic and dynamic analysis, several advantages of the mechanism are illustrated which make it possible to reach good dynamic performance through mechanism optimization. Based on the idea of design for control (DFC), a novel kind of multi-objective optimization method is presented. Several index considering both kinematic and dynamic performances are chosen as objective functions and design constraints. The cross-section area and length of the linkages are chosen as the design variables. NSGA-II algorithm is introduced to solve this complex multi-objective optimization problem. And a new expression for the measuring of dynamic coupling degree with clear physical meaning is proposed, it shows that the optimized mechanism has an approximate decoupled dynamics structure, and each active joint could be regarded as a linear SISO system. The final optimized mechanism could be used in high speed pick-plate applications only using simple linear controller.