基于非高斯粗糙表面重构的超精密液体静压导轨微流场分析及微振动主动控制

Hydrostatic guideways are important basic components of precision machine tools. Complex curved surface parts made by difficult-to-machine materials need high precision and high surface quality in areas such as aerospace and weapon equipment, in order to adapt to such requirements, hydrostatic guideways are developing into nanometer accuracy. The vortices of microscale flow and micro-vibration of multi-source disturbance cannot be ignored, which challenges the flow field analysis theory and precision control method. Then ultra-precision hydrostatic guideways are selected as objects to research the internal and external causes of the micro vibration and the active control method. Three key problems are proposed: 1) Non-Gaussian distributed rough surface 3D reconstruction method is proposed to precisely characterize oil film topography, considering the profile error, speed effect and other factors, then hybrid RANS/LES method is used to clarify the microscale flow characteristics and evolution mechanism, and to reveal the intrinsic relationship of micro vortices and micro-vibration. 2) A nonlinear dynamic model of hydrostatic guideway under external disturbance is established, including dynamic cutting force, shafting unbalance, oil source fluctuations, etc., and the global transient behavior is clarified, and the formation mechanism of bearing system's micro vibration is revealed. 3) On the basis of the above researches, a micro-vibration suppression strategy based on the innovation of the orifice structure and the active control of the oil film shape is proposed. Thus, the achievement of this study may solve the micro/nano scale accuracy challenges of hydrostatic guideways, and enhance the core competence of our ultra-precision machine tools and manufacturing equipment.

液体静压导轨是精密机床的重要基础部件。为适应航空航天、武器装备等领域难加工材料复杂曲面零件的高精度和高表面质量制造要求，液体静压导轨向纳米级支承精度发展，其微流场涡胞及多源扰动下微振动不可忽略，对流场分析理论和精度控制方法提出了挑战。本项目以超精密液体静压导轨为研究对象，探究其微振动的内外部成因及主动控制方法：1）提出精确表征油膜形貌的非高斯粗糙表面三维重构方法，综合考虑形状误差、速度效应等因素，采用大涡模拟结合雷诺平均法，阐明微流场特性及其演化机制，揭示微流场涡胞与微振动的内在关联规律；2）建立动态切削力、轴系不平衡量、供油脉动等外部扰动条件下液体静压导轨的非线性动力学模型，阐明其全域场瞬态行为，揭示支承系统微振动形成机制；3）在上述研究基础上，提出基于节流结构创新和油膜形貌主动控制的微振动抑制策略。从而，突破微纳尺度下液体静压导轨支承精度保证难题，提升我国超精密制造装备的核心竞争力。

本项目以超精密液体静压导轨为研究对象，探究其微振动的内外部成因及主动控制方法。首先，开展了基于非高斯粗糙表面三维重构的液体静压导轨瞬态流场特性研究，通过考虑表面形貌的精密液体静压导轨支承特性分析和基于多尺度全流体模型的静压轴承特性分析与优化，阐明了微流场特性及其演化机制。其次，建立多源扰动条件下液体静压导轨的非线性动力学模型，开展考虑油膜可压缩性的液体静压导轨动力学性能分析和基于油垫-导轨结合面的超精密磨床模态与谐响应分析研究，揭示了其纳米级精度生成机制。然后，开展基于可控节流的液体静压支承性能提升方法研究，形成了基于节流结构创新的液体静压导轨微振动抑制机制。最后，开展基于液压传动的液体静压油垫微振动补偿方法研究和基于扰动观测器的静压导轨进给系统微振动抑制方法研究，最终形成了液体静压导轨微振动主动控制策略，突破了微纳尺度下液体静压导轨支承精度保证难题，为超精密机床加工精度的保障奠定基础。