无驱动冗余的单层纯中心压电旋转平台

MONOLITHIC PURE CENTER PIEZOELECTRIC ROTARY PLATFORM WITHOUT ACTUATOR REDUNDANCY

为了实现微纳操作任务中所需的高精度、纯中心旋转运动,采用单个压电驱动器致动二级柔顺放大机构,设计了一款单层、纯中心柔顺旋转平台。与传统压电旋转平台相比,所设计的旋转平台具有无驱动冗余、固有频率高、旋转角度大和结构紧凑优点。结合伪刚体法和有限元法,建立了旋转平台的静力学与动力学模型,并利用Ansys软件对输出转角、输入刚度、输出刚度和固有频率进行仿真。最后搭建实验测试系统,通过多组实验测试平台性能,并利用前馈控制补偿压电迟滞现象。实验结果表明,平台旋转角度为16.8 mrad,固有频率为527.3 Hz,分辨率为0.3μrad,前馈控制能有效补偿迟滞非线性,实现高精度纯中心旋转操作。

In order to achieve high⁃precision and pure⁃center rotation motion in micro/nanomanipulation tasks,a monolithic pure⁃center rotation platform was designed using two⁃stage compliant amplification mechanisms and a single piezoelectric actuator.Compared with other platforms,the designed rotation platform exhibited the merits of no actuator redundancy,high natural frequency,large rotation angle,and compact structure.The static and dynamic models were established by combining the pseudo⁃rigid body and finite element methods.Also,the output angle,input stiffness,output stiffness,and natural frequency of the rotation platform were simulated by Ansys software.Finally,an experimental test system was built,and the performance of the platform was tested through several experiments.Also,the feedforward control was used to compensate for the piezoelectric hysteresis.The experimental results show that the rotation angle is 16.8 mrad,the natural frequency is 527.3 Hz,and the resolution is 0.3μrad.Meanwhile,the hysteresis nonlinearity is compensated effectively using feedforward control.Thus,the platform is capable the high precision center rotation operation.