中文摘要：

以一种1T2R,3自由度并联动力头——A3头为对象,研究其静柔度半解析精细建模与预估方法。该方法在建立系统静柔度模型的基础上,将支链体分解为若干子部件,建立这些子部件在各自局部坐标系中定义的柔度系数与界面柔度系数的映射模型,提出一种采用分层递阶格式精确计算出各零部件柔度系数的策略,进而有效地提高了整机全域静柔度预估的效率与精度。在试验验证该方法正确性的基础上,采用灵敏度分析揭示出各部件弹性对动平台参考点柔度的影响。结果表明,移动副沿约束方向的抗弯刚度及球铰链沿驱动（约束）的抗拉压（弯曲）刚度是影响整机刚度的主要薄弱环节,进而为该类装备的改进与优化设计提供了依据。

英文摘要：

A semi-analytical approach for compliance modeling and evaluation of a 3-DOF spindle head having one translational and two rotational movement capabilities is presented.The method can be implemented into two steps,such as the expression of the compliance matrix of the end-effect in terms of the compliance matrix at the interfaces located at centers of the spherical joint,and the expression of the compliance coefficients at the interfaces in terms of those of the subparts within a limb,which are defined in their own local body-fixed frames.A hierarchical strategy is proposed for computing the compliance coefficients of the sub-parts,allowing the compliance of the system as a whole to be effectively and accurately evaluated.Based upon the verification by experiment,the sensitivity analysis is carried out to find the weak links within a limb.The results show that the bending stiffness of prismatic joint in the direction of constraint and the tension/compression（bending） stiffness in the direction of actuation（constraint） of spherical joint are the weak links affecting the rigidity of the system,providing an informative guidance for the improvement of the current design.