基于叠加柔性铰链的超磁致伸缩驱动器建模与实验

Model and Experiment of Giant Magnetostrictive Actuator Based on Superimposed Flexible Hinge

为了满足高精度、大行程的需求,设计了一种基于尺蠖运动方式的超磁致伸缩直线驱动器,通过前、后箝位机构和驱动机构的相互配合,实现了驱动器的步进式位移输出。采用叠加式柔性铰链作为弹性元件,有效地改善了柔性铰链的受力情况,采用有限元法进行了强度校核和模态分析。计算了叠加式柔性铰链的等效刚度,建立了直线驱动器的动力学模型,对设计的样机进行了实验测试。实验结果表明,建立的位移模型和实验结果基本一致,最大相对误差为1.86%;设计的驱动器稳定工作电压为1~3 V,最小和最大单步位移分别为4.55、12.01μm,最高工作频率为150 Hz,最快速度为1.34 mm/s;位移输出状态稳定,单步位移最大相对误差为2.69%。

In order to meet the requirement of large stroke and high precision displacement,a giant magnetostrictive linear actuator was designed based on the principle of inchworm cumulative displacement.The front clamp mechanism,the back clamp mechanism and the driving mechanism were given a specific time series of excitation signals,and the step-by-step displacement output of the driver was realized by the cooperation of the three.The superimposed flexure hinge was used as the elastic element to improve the force condition of the flexure hinge effectively.The strength check and modal analysis of flexure hinges were carried out by using finite element method.Simplifying flexible hinges into cantilever beams,the equivalent stiffness of superimposed flexure hinges was calculated.The dynamic model of linear actuator was established based on the voltage law,magnetoresistance theory,linear piezomagnetic model and dynamic theory,and the prototype was tested experimentally.The experimental results and simulative results showed that the calculated model was consistent with the experimental results,and the maximum relative error was 1.86%.The stable working voltage range of the giant magnetostrictive actuator was 1~3 V,the minimum single-step displacement was 4.55μm,and the maximum single-step displacement was 12.01μm.The maximum frequency was 150 Hz,and the maximum speed was 1.34 mm/s.The output state of displacement was stable,and the maximum relative error of single step displacement was 2.69%.