Dynamics Analysis Of3-PRRU Parallel Robot

Compared with the general6-DOF (degrees of freedom) parallel robots,lower-mobility parallel robots have advantages of simple structure, low cost inmanufacturing and controlling and so on. As the diversity of industrial demands,the lower-mobility parallel robots have received extensive attention because of havingmore potential applications in industry.In this paper, the inverse dynamics analysis of3-PRRU parallel robot and relateddynamics performance index were presented based on mechanism kinemics analysis.The main works are as follows:Firstly, the geometry constraint relationship of3-PRRU parallel mechanism’s eachlimb was analyzed. The YXZ Euler angles were chosen to describe the movingplatform’s orientation. The mechanism’s kinematics model was obtained Combiningwith the Euler angle rotation matrix.The Jacobian matrixes between moving platform and each part were proposed andinertia moment of rotating components were obtained.The principle of virtual work was used to get the dynamics model with theconsideration of effects of all parts’ gravity and inertial force. And the dynamicperformance of3-PRRU parallel robot was proposed. Then, the figures of dynamicsperformance inertial ellipsoids were depicted.The ADAMS simulation results were consistent with the numerical analysis whichillustrated the correctness of the dynamics model.Based on the inverse dynamics model solutions, peak velocity, peak driving forceand moment of inertia were computed as the main parameters of the servo motor of3-PRRU parallel robot.The inverse dynamics analysis in this paper provides a sound basis to developcontrollers for controlling a3-PRRU parallel robot.