基于柔度比优化设计杠杆式柔性铰链放大机构

分析与研究了柔性铰链的柔度特性,用于柔性放大机构的优化设计。提出了一个通用的柔度比参数λ,探讨了具有不同柔度比λ的柔性铰链主要输出位移形式的灵敏度,分析了它对常用柔性铰链的柔度特性的影响规律。然后,以柔性铰链的柔度比λ为基本参数,在考虑柔性铰链转动中心偏移量的基础上,推导了二级杠杆式柔性铰链放大机构放大率的理论计算方法,并依据柔性铰链的柔度比特性提出了柔性放大机构的优化设计方法。开展了有限元仿真和实验研究。结果显示,优化后的柔性放大机构的放大率比优化前的放大率分别提高了0.234和0.23。实验表明,依据柔性铰链的柔度比λ对柔性放大机构进行优化设计能够有效地提高柔性放大机构的位移放大率与工作行程,进而提高放大机构的末端运动及定位精度。

Optimization design of amplification mechanism for level flexure hinge based on compliance ratio

The compliance features of flexure hinges were analyzed to design and optimize the flexible amplification mechanisms. A new general structural parameter called compliance ratio λ was proposed. The sensitivities of main type of output displacement of the flexure hinges with different compliance ratios λ were analyzed, and the effect laws of compliance features on the commonly used flexure hinges were also discussed in detail. Then, by taking the compliance ratio λ as the basic parameter, the theoretical calculation method of the amplification ratio of a two-stage lever-type flexure hinge mechanism was proposed in considering the offset of the flexure hinge's rotation. The optimization design of the flexible amplification mechanism was studied on the basis of the characteristics of the compliance ratio λ. The finite element simulation and the experiment were performed. The results show that the amplification ratio of the optimized flexible amplification mechanism is larger than that of the flexible mechanism before optimization, and the increases of the simulation and the experiment are 0.234 and 0.23, respectively. These results demonstrate that to optimize the flexible amplification mechanism based on the compliance ratio λ of flexure hinges improves the amplification ratio and the working range significantly, and enhances the accuracy of movement and positioning of the amplification mechanism.