静电悬浮式天基超静平台的微振动检测与控制方法研究

With the developing of the missions such as high resolution reconnaissance satellites, laser communication between satellites from an ultra-far distance and telescopes used in deep space, payloads on satellites are more and more precise. The effect of the micro vibration in the satellite can’t be ignored any longer. Using suspension mode to realize the isolation between the payload platform and satellite body-self can improve the performance of vibration control by 1~2 orders of magnitude, creating a possible way in constructing the future spaceborne ultra-quiet environment. At the background of a novel platform for spaceborne vibration isolation and vibration attenuation based on the electrostatic levitation and double drag-free, this project will study the theory and method of 3 key technologies for the platform. The main research contents are as follow: First, the mechanism of multi path coupling between the high-frequency high-magnitude driving voltage and high precision displacement measurement at the condition of capacitance multiplexing will be explored. The method of decoupling and noise reduction will be established, realizing the precise detection of vibration. Second, the method of real time identification and compensation of dynamic factor of the electrostatic negative stiffness will be researched, realizing the vibration isolation with zero stiffness. Third, the double drag-free control method, which bases on the fusion of drag free control and coordinated control will be studied, which makes the electrostatic force and the micro thruster reverse propulsive force collaborative work and breaks through constraints of the micro thruster performance of the traditional drag-free satellite. The micro vibration of payload platform can be realized by active vibration control in the entire frequency band.

随着高分辨率卫星、超远距离星间激光通信和深空望远镜等空间计划的不断深化，卫星上所携带的有效载荷越来越精密，星上微振动效应成为制约载荷性能不可再忽略的因素。采用悬浮方式实现载荷平台与卫星母体的动静隔离，可比传统减振方式性能要高1~2个量级，开创一条构建未来天基超静环境的可能途径。本项目以一种新型的基于静电悬浮和双级无拖曳的天基隔振减振平台为背景，对平台中的三项关键技术所涉及的理论和方法开展深入研究。主要研究内容包括：1、电容复用式高频高压驱动对高精度位移检测的多路径耦合作用机制及解耦降噪方法研究，实现对振动的精密检测；2、基于动态因子实时辨识与补偿的静电负刚度消除方法研究，实现零刚度隔振；3、基于无拖曳控制与协同控制相融合的双级无拖曳协同控制方法研究，使静电力与微推进器反推力协同工作，突破传统无拖曳卫星受微推进器性能的限制，实现在全频带上对载荷平台微振动的主动减振。

随着高分辨率卫星、超远距离星间激光通信和深空望远镜等空间计划的不断深化，卫星上所携带的有效载荷越来越精密，星上微振动效应成为制约载荷性能不可再忽略的因素。本项目旨在探索新型静电悬浮式天基减振平台的检测、驱动原理特性及隔振减振控制方法，以实现对微振动的有效抑制。主要包括：.1、从频域和时域提出两种解耦降噪方法，解决了电容检测和静电驱动在高频高压反馈条件下的解耦问题，实现了精密位移检测、高频高压驱动一体化兼容电路。实验结果表明，所提方法可使主频为1 kHz、幅值为1 kV的驱动造成的耦合影响低于76.3 μV。.2、提出一种基于迭代调节的多自由度静电悬浮系统几何对称性逼近方法，克服了多自由度耦合所引起的对称性调节误差，算法可以在有限步迭代下将悬浮体调节至电极笼的中心位置，误差小于标称间隙的0.001。此方法可普适于以静电悬浮技术为基础的高精度传感、超精密减振控制等领域，让系统保持在最佳工作点。.3、提出一种基于静电悬浮的零刚度隔振减振控制方法，通过反馈电调制构造全频段的绝对零刚度，实现双级无拖曳，同时也实现了对全频段、较大幅度振动的高品质隔振减振。在系统参数误差达10%的条件下，所提方法仍可获得比无刚度补偿系统优1~2个量级的隔振性能。.4、 探索研究了含多正弦扰动的航天器无拖曳控制系统性能极限问题，推导了闭环控制回路的最小灵敏度函数表达式，导出了扰动抑制性能极限的表达式，对无拖曳控制系统下的传感器、执行器的噪声进行指标分解，可对无拖曳控制系统的构建及性能极限评估提供理论判据。