3-PRR柔性微动平台的运动建模与工作空间分析

发布时间：2019-04-12 06:56

【摘要】：基于3-PRR型柔性并联微动平台较3-RRR型更适合直线驱动,提出了一种含不同类型柔铰的3-PRR柔性微动平台最简型式,整体结构形式由3组呈120°对称均布的柔性运动支链构成。针对伪刚体模型法的不足,运用卡氏第二定理,根据不同柔铰的刚度模型和力传递关系建立柔性支链的刚度模型,基于刚度叠加原理得到以柔铰刚度为自变量的系统刚度模型,建立了微动平台封闭型整体运动模型。通过分析结构参数对雅克比矩阵的影响,选取了最佳结构参数。通过建立约束条件,将原平台的工作空间与最佳结构参数时的工作空间进行对比,验证了最佳结构参数选取的正确性。通过有限元法与理论模型计算结果之间的分析比较,模型的运动误差在可控范围之内,说明了该模型的正确性。
[Abstract]:Based on the fact that the flexible parallel fretting platform of 3-PRR is more suitable for linear drive than that of 3-RRR, a simplified type of 3-PRR flexible fretting platform with different types of flexible hinges is proposed. The whole structure is composed of three groups of flexible motion branches with 120 掳symmetrical distribution. In view of the deficiency of pseudo rigid body model method, the stiffness model of flexible support chain is established according to the stiffness model of different flexible hinges and the relation of force transfer by using the second theorem of Cartesian theory, and based on the principle of stiffness superposition, the stiffness model of the system with flexible hinge stiffness as its independent variable is obtained. A closed global motion model of fretting platform is established. By analyzing the influence of structural parameters on Jacobian matrix, the optimum structural parameters are selected. By establishing the constraint conditions, the workspace of the original platform is compared with the workspace of the optimal structural parameters, and the correctness of the selection of the optimal structural parameters is verified. Through the analysis and comparison between the results of the finite element method and the theoretical model, the motion error of the model is within the controllable range, and the correctness of the model is proved.
【作者单位】：山东理工大学机械工程学院;
【基金】：山东省高等学校科研计划项目资助(J13LB07)
【分类号】：TH112

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