A Study on Vibration Test with Noncontact Based on Magnetic Levitation

众所周知，结构振动测试方法主要有两种。一种是正弦法和随机激励法。另一种是脉冲激振法。在这些情况下，执行器随时与测试结构接触。因此，对于高速旋转的旋转机械或高速行驶的车辆，运动结构物在运行和工作中的动态特性很难测量，本研究工作提出了一种测量此类运动结构物动态特性的新概念和新策略。也就是说，我们验证了基于磁悬浮的三维非接触式激振器对于测量运动结构的动力学是非常有用的。本论文主要做了以下几方面的研究工作：(1)研制新型的永磁体和电磁铁混合作动器以节约能源；(2)实现被控对象与作动器之间的高刚度；(3)如何用高稳定性的作动器进行激振；(4)三个方向同时激振的研究工作。通过理论工作和实验证明，这种新型的非接触式激励器是有可能实现的。此外，我们还将继续这项研究工作，以实现实际的测试激励器。

It is well known that there are major two vibration test method for structures. One is the sinsoidal and the random excitation method. The other is impulse excitation method. In these cases, actuators contac with test structures anytime. Therefore, it is difficult to measure the dynamic characteristics for moving structures in running and working like a rotating machinery in high speed rotations or a moving vehicle in high speed.This research work proposes a new concept and new strategy to measure dynamic characteristics for such moving structures. Namely, we verified that it is very useful for a three dimensional excitor with noncontact based on magnetic levitation to measure the dynamics of moving structures. This method will be also applied to rotating shaft in high speed rotation.We tried the following research works ; (1)The research work to develop the new hybrid actuators using permanent magnets and the electromagnets to save a energy, (2)The research work to realize the high stiffness between the controlled objects and the actuators, (3)The research works how to excite using actuators with high stability, (4)The research work to excite the three directions simultaneously.We have carried out the research work concerning above mentiond items. We concluded that it is possible to realize this new excitor with noncontact through the theoretical work and the experiments. Also, we will continue this research work to realize the actual test excitor.