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首页> 外文学位 >Structural dynamic modeling, dynamic stiffness, and active vibration control of parallel kinematic mechanisms with flexible linkages.
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Structural dynamic modeling, dynamic stiffness, and active vibration control of parallel kinematic mechanisms with flexible linkages.

机译：具有柔性连杆的并联运动机构的结构动力学建模，动态刚度和主动振动控制。

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摘要

This thesis is concerned with modeling of structural dynamics, dynamic stiffness, and active control of unwanted vibrations in Parallel Kinematic Mechanisms (PKMs) as a result of flexibility of the PKM linkages.;Using energy-based approaches, the structural dynamics of the PKMs with flexible links is derived. Subsequently, a new set of admissible shape functions is proposed for the flexible links that incorporate the dynamic effects of the adjacent structural components. The resulting mode frequencies obtained from the proposed shape functions are compared with the resonance frequencies of the entire PKM obtained via Finite Element (FE) analysis for a set of moving platform/payload masses. Next, an FE-based methodology is presented for the estimation of the configuration-dependent dynamic stiffness of the redundant 6-dof PKMs utilized as 5-axis CNC machine tools at the Tool Center Point (TCP). The proposed FE model is validated via experimental modal tests conducted on two PKM-based meso-Milling Machine Tool (mMT) prototypes built in the CIMLab.;For active vibration control of the PKM linkages, a set of PZT transducers are designed, and bonded to the flexible linkage of the PKM to form a "smart link". An electromechanical model is developed that takes into account the effects of the added mass and stiffness of the PZT transducers to those of the PKM links. The electromechanical model is subsequently utilized in a controllability analysis where it is shown that the desired controllability of PKMs can be simply achieved by adjusting the mass of the moving platform. Finally, a new vibration controller based on a modified Integral Resonant Control (IRC) scheme is designed and synthesized with the "smart link" model. Knowing that the structural dynamics of the PKM link undergoes configuration-dependent variations within the workspace, the controller must be robust with respect to the plant uncertainties. To this end, the modified IRC approach is shown via a Quantitative Feedback Theory (QFT) methodology to have improved robustness against plant variations while maintaining its vibration attenuation capability. Using LabVIEW Real-Time module, the active vibration control system is experimentally implemented on the smart link of the PKM to verify the proposed vibration control methodology.
机译：本文的研究涉及结构动力学，动力学刚度的建模以及由于PKM连杆机构的灵活性而导致的并联运动机构（PKMs）中的有害振动的主动控制。派生出灵活的链接。随后，提出了一组新的可允许的形状函数用于包含相邻结构部件的动态效果的柔性链节。从提议的形状函数获得的结果模式频率与通过有限元素（FE）分析获得的整个PKM的共振频率进行比较，用于一组移动平台/有效载荷质量。接下来，提出了一种基于有限元的方法，用于估计在工具中心点（TCP）用作5轴CNC机床的冗余6 dof PKM的与配置有关的动态刚度。通过在CIMLab中构建的两个基于PKM的中铣机床（mMT）原型上进行的实验模态测试对所提出的有限元模型进行了验证;为了对PKM连杆进行主动振动控制，设计了一组PZT传感器并进行了粘结与PKM的灵活链接形成“智能链接”。开发了一种机电模型，该模型考虑了PZT传感器相对于PKM链路的质量和刚度增加的影响。机电模型随后用于可控性分析中，结果表明，通过调整移动平台的质量，可以简单地实现所需的PKM可控性。最后，设计了一种基于改进的整体共振控制（IRC）方案的新型振动控制器，并与“智能链接”模型进行了综合。知道PKM链接的结构动力学在工作空间内会发生与配置有关的变化，因此控制器必须具有针对工厂不确定性的鲁棒性。为此，通过定量反馈理论（QFT）方法显示了改进的IRC方法具有改进的抵抗植物变化的鲁棒性，同时保持了其振动衰减能力。使用LabVIEW Real-Time模块，主动振动控制系统通过实验在PKM的智能链接上实现，以验证所提出的振动控制方法。

著录项

  • 作者

    Mahmoodi, Masih.;

  • 作者单位

    University of Toronto (Canada).;

  • 授予单位 University of Toronto (Canada).;
  • 学科 Mechanical engineering.;Robotics.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 166 p.
  • 总页数 166
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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