正负刚度并联精密主动隔振系统研究

发布时间：2018-04-06 02:38

本文选题：精密隔振系统　切入点：正负刚度并联　出处：《华中科技大学》2014年博士论文

【摘要】：精密主动隔振系统是超精密加工、制造与测量装备纳米级精度生成的必要保障之一。它通过隔离精密设备外部环境的振动,以解决影响超精密装备精度生成的微振动问题。随着超精密装备精度朝着纳米、甚至亚纳米的演进,对隔振系统的性能要求也愈加苛刻,进一步降低系统固有频率以及实现共振峰附近振动的高效隔离成为提升隔振系统性能的关键,同时也是当前精密隔振领域研究的热点与难点。本论文依托国家重大科研项目,面向重大工程的实际需求,针对精密主动隔振系统越来越高的隔振要求,从结构新构型和振动主动控制两方面入手,研究实现超低频隔振关键单元的隔振机理,以及多自由度隔振系统精密定位-高性能隔振复合振动主动控制策略,完成主动隔振系统样机的设计与应用,以进一步提升隔振系统的性能,使其满足超精密加工、制造与测量装备日益苛刻的性能要求。首先,本文分析了影响精密隔振系统性能的关键因素,提出了基于正负刚度并联的精密隔振新构型,解决了隔振系统为保障大承载力而难以实现超低频隔振的问题。研究了基于磁引力的负刚度磁弹簧,分析了其刚度非线性的影响因素,通过参数优化设计降低了刚度非线性度,为其在精密隔振系统中的应用提供了基础。提出了基于磁斥力的负刚度磁弹簧,通过曲线拟合获得了刚度的近似表达式,搭建了单自由度隔振实验装置,对磁斥力负刚度磁弹簧的可行性与有效性进行了验证。建立了正负刚度并联精密隔振系统单元级和系统级的数学模型,为控制策略的研究与制定提供了模型基础。然后,通过对振源特性和精密隔振系统自身隔振特性的分析,研究了正负刚度并联精密隔振系统的主动控制策略。提出了基于天棚阻尼的多自由度独立模态振动主动控制方法,解决了制约传统隔振系统低频振动传递率和高频振动衰减率不可兼得的矛盾。结合精密隔振系统精密定位-高性能隔振复合功能的需求,设计了位置控制器和多自由度模态解耦主动控制器,完成了隔振系统样机控制单元的硬件设计和软件设计。最后,构建隔振系统测试实验台对磁引力负刚度磁弹簧的有效性进行了验证,并对隔振系统性能进行了初步测试。测试结果表明,隔振系统实现了低至约1Hz的固有频率,振动传递率大于2Hz时小于-20dB(振动衰减了90%),大于10Hz时小于-40dB(振动衰减了99%)。在实际工程应用中,将隔振系统样机应用于光刻机隔振机架,对隔振系统的时域和频域性能进行了最终测试,垂向精密定位精度为±4μm,共振峰传递率0dB,隔振系统性能满足使用要求。实验结果表明,以正负刚度并联隔振新构型配合多自由度主动控制策略使得隔振系统具有极低的固有频率,保证隔振系统高频衰减率的同时降低了固有频率附近振动的传递,大大提高了隔振系统的有效隔振带宽。
[Abstract]:Precision active vibration isolation system is one of the necessary guarantees for nano-level precision generation of ultra-precision machining manufacturing and measuring equipment.By isolating the vibration of the external environment of the precision equipment, the problem of micro-vibration which affects the precision of the ultra-precision equipment is solved.As the precision of ultra-precision equipment evolves towards nanometers, even subnanometers, the performance requirements of vibration isolation systems become more and more stringent.Further reducing the natural frequency of the system and effectively isolating the vibration near the resonance peak become the key to improve the performance of the isolation system, and it is also a hot and difficult point in the field of precision vibration isolation.This paper relies on the national important scientific research project, facing the actual demand of the major project, aiming at the higher and higher vibration isolation requirement of the precision active vibration isolation system, starting from the structure new configuration and the vibration active control two aspects.The vibration isolation mechanism of the key unit of ultra-low frequency vibration isolation and the active vibration control strategy of multi-degree-of-freedom vibration isolation system are studied. The design and application of the prototype of the active vibration isolation system are completed.In order to further improve the performance of vibration isolation system, to meet the ultra-precision machining, manufacturing and measuring equipment increasingly demanding performance requirements.Firstly, the key factors affecting the performance of precision vibration isolation system are analyzed, and a new configuration of precision isolation system based on positive and negative stiffness parallel connection is proposed, which solves the problem that the vibration isolation system is difficult to achieve ultra-low frequency vibration isolation in order to ensure the large bearing capacity.The negative stiffness magnetic spring based on magnetic gravity is studied, and the influencing factors of its stiffness nonlinearity are analyzed. The stiffness nonlinearity is reduced by parameter optimization design, which provides the basis for its application in the precision vibration isolation system.A magnetic spring with negative stiffness based on magnetic repulsion force is proposed. The approximate expression of stiffness is obtained by curve fitting. A single degree of freedom vibration isolation experimental device is built, and the feasibility and effectiveness of the magnetic spring with negative stiffness of magnetic repulsion force are verified.The mathematical models of unit level and system level of parallel precision vibration isolation system with positive and negative stiffness are established, which provide the model basis for the research and formulation of control strategy.Then, the active control strategy of the parallel precision vibration isolation system with positive and negative stiffness is studied by analyzing the vibration source characteristics and the vibration isolation characteristics of the precision isolation system.The active control method of multi-degree-of-freedom independent modal vibration based on ceiling damping is proposed, which solves the contradiction that the low frequency vibration transmission rate and the high frequency vibration attenuation rate of the traditional isolation system can not be obtained simultaneously.The position controller and the multi-mode decoupling active controller are designed according to the requirements of precision positioning and high performance vibration isolation system. The hardware design and software design of the control unit of the vibration isolation system prototype are completed.Finally, the effectiveness of the magnetic spring with negative magnetic stiffness is verified by building a test bench for vibration isolation system, and the performance of the isolation system is preliminarily tested.The test results show that the vibration isolation system achieves the natural frequency of about 1Hz, and the vibration transfer rate is less than -20dB when the vibration is larger than 2Hz (the vibration attenuation is 90???In the practical engineering application, the vibration isolation system prototype is applied to the isolation frame of lithography machine, and the performance of the vibration isolation system in time domain and frequency domain is finally tested.The precision of vertical positioning is 卤4 渭 m, the transfer rate of resonance peak is 0 dB, and the performance of vibration isolation system meets the requirement of application.The experimental results show that the new configuration of parallel vibration isolation with positive and negative stiffness and the active control strategy of multiple degrees of freedom make the vibration isolation system have extremely low natural frequency, which ensures the high frequency attenuation rate of the isolation system and reduces the vibration transmission near the natural frequency.The effective vibration isolation bandwidth of the vibration isolation system is greatly improved.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB535.1

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