基于超磁致伸缩驱动微振动主动隔振平台的设计研究

发布时间：2018-12-17 10:17

【摘要】：随着超精密工程的迅猛发展，精密仪器对其工作环境的稳定性提出了越来越高的要求。精密仪器在工作环境中经常受到外界微振动的干扰，其中高频微幅的振动干扰可以通过被动隔振方式将其隔离，而低频多自由度微幅的振动干扰则需要通过多自由度主动隔振平台将其隔离。超磁致伸缩材料在超精密驱动工程中有着广泛的应用，它有响应快速，应变大，，输出应力大，控制精度高等优点，同时也具有非线性、滞回等缺点，使得材料的理论建模和控制具有一定困难。现有的超精密驱动器，无法兼备大行程、大负载、高效率、高稳定性的需求。面向这一需求，在原有的对于超磁致伸缩驱动器研究的基础上，针对驱动位移大、负载能力强、驱动效率高、驱动稳定性高的三自由度微振动主动隔振平台设计方面进行了探索。本文对超磁致伸缩驱动平台进行了静力学结构设计、结构尺寸优化和动力学仿真分析，并最终设计实现了三自由度微振动主动隔振平台原型样机。在平台的静力学结构设计部分，阐述了隔振平台的整体结构、工作原理；设计超磁致伸缩驱动器的各部分结构，包括超磁致伸缩材料棒、电磁线圈、磁路；对放大机构进行了静力学方面的初步设计和强度校核；确定了平台、驱动器和位移传递机构的结构形式。基于驱动器的效率最高即能量损耗率最小的系统优化设计原则，本论文对驱动器和放大机构的结构尺寸进行优化设计。首先对驱动器从能量输入到能量输出整个过程的能量传递流程进行分析，将此流程分为电磁耦合、磁机耦合、机械能传递三个部分，针对每部分的能量转换机理以驱动器的结构参数为自变量推导出相应的能量损耗计算方法，以此建立平台全系统的能量损耗率函数，从而推导出能量损耗率最小时的最优化结构尺寸参数，最终完成基于多参数优化全系统的平台集成设计。在平台的动力学仿真分析方面，建立单个驱动器及放大机构的动力学模型，将其整合到全系统的动力学模型，将结构参数的优化结果带入动力学模型，对优化前后的动力学响应进行对比，包括不同输入电流、不同负载情况下的位移响应、瞬时加速度响应，分析平台的动力学性能，并依此判断优化方法的有效性。利用有限元仿真软件对整个平台进行模态分析，提取平台的前八阶的共振频率和振型。按照以上方法最后确定平台的部件和总体结构设计，绘制设计图纸，并加工和装配实现了原型样机和完成了平台功能实验验证。对每个驱动器进行性能测试，包括碟形弹簧的刚度确定、最佳预紧力调节、装配可靠性的测试；组装平台整机，对其进行输出响应测试，与动力学分析结果进行对比。本文的最后对全文研究内容进行总结，对其中的缺点和不足深入挖掘，提出未来的改进方法和展望。
[Abstract]:With the rapid development of ultra-precision engineering, precision instruments put forward higher and higher requirements for the stability of their working environment. Precision instruments are often disturbed by external micro-vibration in the working environment, in which high-frequency micro-amplitude vibration interference can be isolated by passive vibration isolation. The vibration disturbance of low frequency multi-degree-of-freedom microamplitude needs to be isolated by multi-degree-of-freedom active vibration isolation platform. Giant magnetostrictive material has been widely used in ultra-precision drive engineering. It has the advantages of fast response, large strain, large output stress, high control precision and so on. It is difficult to model and control the material theoretically. The existing ultra-precision drive can not meet the needs of long stroke, large load, high efficiency and high stability. In order to meet this demand, on the basis of the original research on giant magnetostrictive actuator, aiming at the large displacement, strong load capacity and high driving efficiency, The design of 3-DOF micro vibration active vibration isolation platform with high driving stability is explored. In this paper, the static structure design, structural size optimization and dynamic simulation analysis of the giant magnetostrictive drive platform are carried out, and the prototype of the three-degree-of-freedom active vibration isolation platform is designed and implemented. In the statics design part of the platform, the whole structure and working principle of the platform are described, and the structure of the giant magnetostrictive actuator is designed, including the giant magnetostrictive material rod, the electromagnetic coil and the magnetic circuit. The preliminary design and strength check of the amplifying mechanism are carried out, and the structural forms of the platform, the actuator and the displacement transfer mechanism are determined. Based on the principle of optimal design of the system with the highest efficiency, that is, the minimum energy loss rate, the structural dimensions of the actuator and the amplifying mechanism are optimized in this paper. Firstly, the energy transfer process from energy input to energy output is analyzed, which is divided into three parts: electromagnetic coupling, magneto-mechanical coupling and mechanical energy transfer. According to the energy conversion mechanism of each part, the corresponding energy loss calculation method is derived with the structural parameters of the driver as the independent variable, and the energy loss rate function of the whole platform system is established. Thus, the optimal structural dimension parameters are derived when the energy loss rate is minimum, and the platform integration design based on multi-parameter optimization is finally completed. In the aspect of dynamic simulation analysis of the platform, the dynamic model of single driver and amplifying mechanism is established, which is integrated into the dynamic model of the whole system, and the optimization results of structural parameters are brought into the dynamic model. The dynamic response before and after optimization is compared, including displacement response under different input current, displacement response under different load and instantaneous acceleration response. The dynamic performance of the platform is analyzed, and the effectiveness of the optimization method is judged. The modal analysis of the whole platform is carried out by using finite element simulation software, and the first eight resonance frequencies and modes of the platform are extracted. According to the above methods, the design of the components and the overall structure of the platform is determined, the design drawings are drawn, the prototype is machined and assembled, and the experimental verification of the platform function is completed. The performance of each actuator is tested, including the stiffness determination of the disc spring, the optimal pretightening force adjustment, the assembly reliability test, and the output response test of the whole assembly platform, which is compared with the dynamic analysis results. At the end of this paper, the research contents are summarized, the shortcomings and shortcomings are deeply excavated, and the improvement methods and prospects in the future are put forward.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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