Optimal Design Of A Novel 4-DOF Hybrid Mechanism

This thesis investigates into some issues on conceptual design, kinematic analysis, dynamics analysis, servomotor parameters estimation and dimensional synthesis of a novel reconfigurable 4-DOF hybrid mechanism. The following work has been accomplished.1. A novel 4-DOF hybrid mechanism named Licept is proposed, which is composed of a 2-PRR&RP parallel mechanism and a 2-DOF rotating head attached to the moving platform. By connecting a 1-DOF mechanism serially, several configurations of a 5-DOF hybrid manipulator with a larger workspace are proposed.2. Using analytical methods, both forward and inverse kinematic analysis of the 2-PRR&RP parallel mechanism are carried out.3. On the basis of the kinematic analysis, the inverse dynamic model of the 2-PRR&RP parallel mechanism is formulated using virtual work principle.4. A servomotor parameters estimating model is formulated based on the inverse dynamic analysis. The effectiveness of this model has been verified by making the mechanism move along a typical path with a typical moving rule.5. On the basis of the work-space and inverse dynamic analysis, a dynamic performance index is presented to satisfy the mechanical and kinematic constraints. The effect of the dimensional parameters on the performance of the 2-PRR&RP parallel mechanism is then investigated by means of monotonic analysis. Consequently, the dimensional synthesis of the 2-PRR&RP parallel mechanism is implemented by solving a set of nonlinear algebraic equations.