Redundant actuation refers to the use of more actuators than kinematic degree of freedom of robot manipulator. By utilizing it, manipulators can increase their payload and speed at hand and can get fault tolerance capability. In this study, optimal design procedure of 2 DOF closed-loop type robot with redundant actuation is suggested. First, enhancements of operational performances of manipulators by employing redundant actuation are illustrated. And, sensitivity analysis is performed with respect to kinematic/dynamic parameters of manipulator for the basis of optimal design. Optimal design of kinematic structure is performed based on several objective functions which are constructed by varying weighting factors for each design index, so that the relationship between design indices and design parameters is investigated. In order to improve dynamic characteristics of manipulator, dynamic optimal design is performed based on the objective function reflecting pure inertial effects. Finally, optimal actuator sizes are determined for specified performances, so optimal design of 2 DOF closed-loop type manipulator with actuation redundancy is accomplished.
From simulation results, it is found that kinematic design parameters have more effects on robot performances than dynamic design parameters. And study on the optimal design can help us understand structure of human body.
