组合柔性机械臂抑振性能的仿真及实验研究

Experimental Research and FEA Simulation on Restraining Vibration of Assembled Flexible Link

为抑制柔性机械臂的低频固有振动,该文提出利用组合结构滞迟阻尼效应来提高柔性机械臂的抑振性能。以单根叠层组合柔性机械臂为对象,通过有限元仿真和实验,对组合柔性机械臂的减振性、结构参数和预压力对其减振性能的影响进行了研究,并由仿真实验确定了组合柔性机械臂的动态恢复力曲线。研究结果表明:与实体柔性机械臂相比,组合柔性机械臂的抑振效果显著;确定合适的预紧力和结构尺寸参数可得到最佳的抑振性能;组合柔性机械臂-质量系统的固有频率不是一常量,其大小随振幅的减小而增大;组合层之间的相对刚度对其抑振性能有影响,减小相对刚度可提高其抑振能力。实验证明,该文采用的有限元仿真方法能较准确地反映组合柔性机械臂的动力学性质,可以代替实物实验确定动态恢复力滞迟回线,为组合柔性机械臂动力学建模、减振性设计及运动控制研究提供了有效方法。

In order to restrain low frequency vibration of flexible manipulator, hysteretic damping of assembled flexible link is used to restrain the vibration of flexible manipulator. Through experiment and FEA simulation, a pre-pressed multi-layer flexible link is researched on the vibration-restraining capability of the flexible link, and the relationship between its vibration-restraining capability and its structure and pre-pressing force. Experimental results indicate that： compared with solid flexible link, the assembled flexible link can effectively restrain low frequency vibration of flexible manipula- tor; a proper pre-pressing force and layer thickness can make assembled flexible link have most damping ; the frequency of natural vibration of assembled flexible link doesn＇ t keep constant but in- creases with the attenuation of amplitude of vibration; the vibration-restraining capability increases with the reduction of relative rigidity between layers. FEA simulation is applied to calculate the vibration response with ANSYS. The dynamic load-deflection graph with hysteretic characteristics is consistent with experiment. This method provides an effective way for research on the dynamics of assembled flexible link.