Design And Performance Analysis Of Rigid-Flexible Planar Parallel Mechanism

Due to the existence of the mechanism clearance,mechanism vibration and shock is unavoidable in the traditional rigid parallel mechanism.Because of the limitation of parallel mechanism structure,there are many kinds of singularity positions in parallel mechanism movement.Compared to the traditional rigid parallel mechanism,flexible mechanism has its own advantages.For example,flexible mechanism does not have friction,lubrication and clearance of motion pair.In this paper,the flexible mechanism was added into the traditional rigid parallel mechanism as motion pairs,which can solve the problems of vibration and shock in traditional rigid mechanism and the problem of avoiding singularity difficulties in parallel mechanism.The obtained rigid-flexible mechanism possesses ability of avoiding singularity.Due to the existence of flexible joints,the mechanism can reduce the pair clearance,vibration and shock.Simultaneously,the rigid-flexible mechanism can use the advantages of energy storage and energy release to avoid singularity and improve the overall performance of the mechanism.Firstly,design criteria of the mechanism was determined based on strict requirements of precision electronic components.According to the requirements of the mechanism tasks,the traditional rigid parallel mechanism was designed as the main body.By using limb construction method,19 configurations were synthesized.The design method of distributed flexible rotation added into parallel mechanism was determined.A series of rigid-flexible parallel mechanisms were designed and the corresponding 3D diagrams are drawn.Secondly,the flexible joints were analyzed and modified by using the pseudo-rigid body model method.The forward and inverse kinematics was solved.Then,workspace,singularity and dynamics have been analyzed.The performances of the mechanism include avoiding singularity,static stiffness and errors were analyzed.The method of avoiding singularity was proposed.Finally,the virtual prototype was established and simulated.By using 3D printer technology,the flexible joint was made.It can satisfy the requirements of the tasks.The mechanism physical prototype and corresponding control system were established.The avoiding singularity ability has been checked.The results demonstrate feasibility of proposed method and validity of theoretical calculation.