具有高位移增幅特性的柔顺并联式x-y-θ微动平台

A Parallel Compliant x-y-θ Micro-stage with the Characteristic of High Displacement Magnification

  • 摘要: 考虑到微装配和微操作任务对微动平台高位移增幅比、多自由度和低输出耦合比的要求,结合柔顺放大机构和复合平行四边形机构,设计了一种并联式x-y-θ微动平台.首先根据伪刚体方法得到了微动平台的静、动力学模型,然后采用有限元仿真分析了平台的输出位移、转动角度、共振频率和输出耦合比,最后搭建实验测控系统验证了微动平台的开环性能.实验结果表明:微动平台在x和y轴方向的位移增幅比分别为8.1和8.3;当输入位移为20μm时,平台的行程为162.2μm×165.6μm×2547.1μrad,x、y平动方向的1阶共振频率为224.6 Hz和227.7 Hz,xy轴方向平动时的输出耦合比分别为0.86%和0.91%.位移增幅比和1阶共振频率的实验结果与有限元仿真之间的相对误差分别小于27.2%和6.4%,故而实验测试验证了理论模型和有限元仿真分析的有效性.

     

    Abstract: Microassembly and micromanipulation tasks require micro-stages with high displacement magnification ratios, multiple degrees of freedom and low output coupling ratio. To solve this problem, a parallel x-y-θ micro-stage is designed in combination of compliant amplification mechanisms and composite parallelogram mechanisms. Based on the pseudo-rigid-body method, statics and dynamics models of the micro-stage are firstly derived. Then, the output displacement, the rotation angle, the resonant frequency and the output coupling ratio of the micro-stage are analyzed through finite-element simulations. Finally, an experimental system is established to verify its open-loop performances. Experimental results demonstrate that x- and y-direction displacement magnification ratios of the micro-stage are 8.1 and 8.3, respectively. The workspace range is 162.2 μm×165.6 μm×2547.1 μrad if the input displacement is 20 μm, and the first resonant frequencies in x and y translational motions are 224.6 Hz and 227.7 Hz. Meanwhile, output coupling ratios of x-axis and y-axis translational motions are 0.86% and 0.91%, respectively. Experimental results and finite-element simulations are also compared, and the relative errors of the amplification ratio and the first resonant frequency are lower than 27.2% and 6.4%. Therefore, experimental tests validate the effectiveness of theoretical models and finite-element simulations.

     

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