• 动态微推力测量中地面振动和隔振方法研究

    Ground Vibration Analysis and Isolation Strategy for Dynamic Micro-thrust Measurement Systems

    • 在动态微推力测量领域,地面振动噪声对测量精度构成挑战,尤其在动态场景中干扰显著。论文提出一种基于柔性平行导向机构的负刚度隔振方法,旨在抑制地面横向振动或角振动引起的扭转振动噪声,将推力测量动态分辨率提升至0.1 μN。采用传递矩阵法对多级隔振系统的动态特性开展系统性分析,构建起隔振级间力与位移的输入输出量化关系模型,实现对振动传递特性的精准评估。针对低频漂移问题,引入对称布置扭摆的差分测量方法,以降低重力等因素对系统稳态性能的影响。实验环节,搭建了扭摆与被动隔振装置集成的测试平台,测试结果表明,经隔振处理后,扭摆的本底噪声水平降低,动态分辨能力得到增强。理论建模、仿真分析及初步实验验证,该隔振方法可有效隔离高频动态响应,并在0.01~1 Hz及10 Hz频段实现精确隔振,为动态微推力测量技术的性能突破提供了可行路径。

       

      Abstract: In the rapidly advancing field of dynamic micro-thrust measurement, ground vibration noise persists as a fundamental barrier to achieving sub-microNewton measurement accuracy, particularly in high-bandwidth dynamic testing scenarios where transient interference can introduce errors exceeding 50% of the target signal. To address this technical challenge, this research develops a novel negative stiffness isolation method based on a compliant parallel mechanism, aiming to mitigate torsional vibration noise induced by ground lateral displacements and angular vibrations. This approach enhances the dynamic resolution of thrust measurement to 0.1 µN across a 0.01~10 Hz frequency range. In the theoretical analysis, the transfer matrix method is employed to systematically analyze the dynamic behavior of a multi-stage vibration isolation system, constructing a quantitative input-output relationship model between inter-stage forces and displacements that accounts for both structural stiffness and material damping characteristics. This model enables accurate evaluation of vibration transfer properties, revealing that the negative stiffness mechanism can reduce the system's natural frequency while maintaining stable dynamic response. Aiming at the critical issue of low-frequency drift caused by gravitational and thermal effects, a differential measurement scheme with symmetrically arranged torsional pendulums is introduced, which can offset environmental disturbances and significantly improve the system's long-term stability. In the experimental verification phase, an integrated test platform combining torsional pendulums and passive vibration isolation devices is established. The results demonstrate that after vibration isolation treatment, the background noise level of the torsional pendulums is significantly reduced, and the dynamic resolution capability is substantially enhanced. Through comprehensive theoretical modeling, simulation analysis, and preliminary experimental validation, this vibration isolation method can effectively isolate high-frequency dynamic responses and achieve high-precision vibration isolation in the low frequency band of 0.01 to 1 Hz and the characteristic frequency band of 10 Hz, providing a feasible path for performance breakthroughs in dynamic micro-thrust measurement technology and other high-precision measurement fields.

       

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