节点文献
结构局部振动控制理论与算法研究
Research on Theory and Algorithm of Local Vibration Control of Structure
【作者】 高雪飞;
【导师】 姚国凤;
【作者基本信息】 吉林大学 , 固体力学, 2009, 博士
【摘要】 本文所论述的问题主要包括结构局部振动控制的概念、基础理论以及实现方法。在基础理论部分,论文重点给出了重频完备系统和亏损系统可控性的充分条件,此结论可用于指导结构局部振动主动控制中的输入矩阵的选取。本文还详细论述了结构局部振动控制的一种新型实用理论:动柔度理论。在结构局部振动控制的具体实现方面,论文给出了一些有关实现控制系统零极点配置的主被动控制算法的研究成果。其中,在主动控制领域中,给出了同位输出反馈控制的输出反馈增益矩阵的模态计算方法,并用悬臂梁主动控制的算例证实了该方法的有效性;另外,提出了一种结构部分极点配置的方法,并结合特征向量投影方法对可控模态实现了部分极点和特征向量的配置并且同时保证不需要配置的特征值和特征向量不发生改变,而且利用上述方法实现了对重频系统的部分极点配置。在被动控制领域中,主要论述了利用动柔度理论对结构进行局部修改,从而实现对结构的局部振动控制,同时还指出了动柔度理论在主动控制领域内的发展与应用。
【Abstract】 There are two ways for local vibration control of structure: the passive control and active control. Since the passive control is easy for the engineering realization, it gains more attention in engineering field. Now, theory research and engineering practice of the passive control have been well-developed. As for the active control of structure, it has already arrived at the stage of intelligent-structrue control. One of main questions in the active control concerns with pole assignment or modal control.As we know, the one of main objective of system control is modal control. We can control both part of modes and the whole modes. But the condition is the respective modes are controllable. So controllability problem plays a key role in vibration control and suppression of a vibration system. In this dissertation two necessary conditions of completely controllability of a repeated eigenvalues system (regular and defective system) and its proof are given. At same time two sufficient conditions and its proof are also presented. According to above theory, this dissertation gives a method of selecting control force distribution matrix and some numerical example.About pole assignment of system it is still an open question. There is not a sufficient and necessary condition to answer that some poles are assignable, and some others are not to any control system. Poles replacement is one of important goal of system control. Now using feedback control to assign poles is one of main pole assignment method. There are two kinds of feedback control, one is state feedback control and another is output feedback control. In this dissertation, modal computing method of output feedback control gain matrix in pole assignment problem is addressed by using modal coordinates. It is obvious advantage to save computing time and protect some methods from invalidity for high order structure. The numerical example of a cantilever beam is presented. The output feedback gains are computed by using original structural state space equation, four-order, six-order and eight-order state space equation of modal coordinates for first two eigenvalue assignment of original structure, respectively, and then apply those gains obtained under modal coordinates to original structural state space equation. Comparing the control effect of Modal gains with one of original gain, it is verified that modal computing method is available.By combining the orthogonality relations for a symmetric definite quadratic pencil and the open-loop eigenvector orthogonal projection, an effective method is formed to deal with the partial poles assignment. The method can assign some poles and corresponding eigenvectors of a given structure, while leave the other eigenpairs unchanged. Moreover, this orthogonal projection method makes the assigned closed-loop eigenvector as close as possible to the original open-loop eigenvector and this leads the closed-loop system has the similar behavior as the open-loop system. After properly selecting the open-loop eigenvectors which are corresponding to the repeated poles, we can also use the method to assign repeated poles. Finally, two numerical examples are presented to illustrate the validity of the method.This paper also discusses the theory and applications of the receptance method in the local vibration control of structure. Through this method, the vibration control can be realized without acquirement of the approximate mathematical model of the structure.