Integrated Optimal Design Of Delta Robot Using Dynamic Performance Indeices

This dissertation presents a comprehensive package for integrated parameter design of a 3-DOF translational parallel manipulator, including dimensional synthesis using dynamic performance indices, dynamic formulation and design of multiple flexible-body systems, motion law selections, and experimental verification on a prototype machine. The following contributions have been made.A hierarchical structure for integrated parameter design in terms of dynamic dimensional synthesis, dynamic design and selection of servomotor specifications is proposed in the first place for achieving desirable performances of kinematics, rigid-body dynamics and elastic dynamics.On the basis of kinematic and rigid dynamic modeling, dimensional synthesis using dynamic performance indices and kinematic performance constraints is carried out .the major merits can be summarized in brief.(1) Dynamic performance indices. Two novel global dynamic performance indices associated respectively with the inertial and centrifuge/Coriolis components of the driving torque are proposed for minimization. The singular configurations of the robot can fully be investigated by those new indices.(2) Kinematic performance constraints. Based on the Jacobian matrix and its inverse, two types of pressure/transmission angles are defined, with which the direct and indirect singularities can be identified in a straightforward manner. Consequently, the algebraic characteristics can be closely related to the geometry of the system through the transmission angles. These angles can be used to describe the motion/force transmission behaviors in a visible manner.The flexible dynamic model of the robot is formulated using substructure displacement method. With this model, two the performance indices are proposed in terms of energy consumption and dynamic accuracy. The effects of structural parameters on the performance indices and the constraint are investigated in depth via an example, enabling a set of optimized structural parameters to be obtained for achieving good dynamic performance throughout the entire workspace.An approach for evaluating and optimization of the motion laws is proposed in order to reduce the residual vibration. It is easy to select an optimal motion law for minimizing the residual vibration through the analysis of residual vibration envelope of different motion laws.The experimental investigation of the load capacity and the dynamic characteristics is carried out on the prototype machine. It has been shown that the results of the load capacity and the dynamic performance have a good match with those obtained by the theoretical analysis.The outcomes of this dissertation have been applied to the design of a 3-DOF high-speed parallel manipulator for implementing the pick-and-place operations.