为了实现柔性精密操作系统的高频控制,提出一种新型空间柔性并联精密定位工作台系统,该工作台采用多个压电陶瓷驱动方式,通过半圆形凹槽单自由度柔性铰链的弹性变形实现末端执行件3平动自由度的主动调整。根据机构伪刚体模型,采用矢量闭环方法建立其位置、速度以及加速度方程,并结合柔性铰链弹性应变能,采用虚功原理方法进行动力学分析,推导出机构的动力学逆解模型,利用其中的质量矩阵和刚度矩阵确定了系统固有频率的求解表达式。在此基础上,讨论柔性铰链刚度与构件质量对支链驱动力矩的影响规律,采用有限元分析方式对定位工作台进行模态分析并对工作台的模态频率进行试验测试,试验测试、有限元仿真与理论结果的比较验证了所建理论模型的正确性和数值分析的有效性。
For the realization of high frequency control of the flexure-based micromanipulator,a novel spatial compliant precision positioning stage driven by PZT is designed,and flexure hinge with circular notches and one rotational degree of freedom is utilized to realize the passive adjustment of the three translations of the platform.The position,velocity and acceleration equations are established on the basis of the Pseudo-Rigid-Body model.After calculating the potential energy of the flexure hinges,the inverse dynamic is developed on the principle of virtue work.By the mass matrix and the stiffness matrix,the expression of the natural frequency is derived.Then,the influence of the stiffness of the flexure hinges and the mass on the drive torques are analytically discussed.The model analysis of the stage is carried out by means of ANSYS,a finite element method code.Experiments are conducted to measure the modal frequencies of the stage.The results obtained from experiment,finite element method and formulation are compared to prove the correctness of the established theoretical model and the validity of the numerical analyses.