Dynamics Analysis And Optimization Design Of6-PUS Parallel Mechanism

With the development of modern machinery towards the direction of the highspeed, high precision, heavy load and high controllability, etc., parallel mechanismattracts attention of lots of scholars at home and abroad for its superior structuralperformance. Compared with serial mechanism, parallel mechanism has manyadvantages, such as good carrying capacity, high mechanical stiffness, high precision,good dynamic performance, easy to feedback control, etc. At present, parallelmechanism has wide and important applications in the field of sports simulators,industrial robots, parallel machine tool, medical robots and micro-robots.Although the theoretical study and practical application of parallel mechanismhave been made a lot of achievements, but there are still some challenging problems inmechanism, kinematics, dynamics and motion control. In order to exert parallelmechanism’s merits better and extend its application area, the author researches a kindof6-PUS parallel mechanism used for test, including its dynamics, performance indexand structural optimization based on performance index analysis.Firstly, the structural characteristics of6-PUS parallel mechanism is introduced，the DOF is calculated using screw theory，then，inverse kinematics equation andkinematics equation are given using the space vector method and quasi-Newtoniteration method respectively. Secondly, dynamics is analyzed, which includes solvingthe first and the second order influence coefficient matrixes, establishing kinetic modelbased on influence coefficient matrixes, simulating with ADAMS software, whichverify the correctness of the kinetic model. Thirdly, mechanical performances forkinematics and dynamics such as angular velocity, linear velocity, angular acceleration,linear acceleration, force and torque, inertia force are analyzed. Correspondingperformance atlas providing basis for the choice of structure sizes are drew. Finally, themodel of6-PUS parallel mechanism is parameterized and its velocity and accelerationare optimized using ADAMS software, the optimized structure sizes are obtained.The design method of combining theoretical analysis with virtual prototypingtechnology about6-PUS parallel mechanism reduces the design period, decreases thecost of product and provides reference to the research of similar mechanism.