时滞反馈抑制扭转振动

发布时间：2018-10-09 17:25

【摘要】：时滞反馈作为动力，它实际上是根据相对论的同时性原理作为加在动力学方程上的一项，用来降低原系统的振动能量来抑制目标系统的有害振动。时滞反馈控制能够在振动系统的共振区域实现对主系统振动的有效抑制。在线性振动系统中，它可以实现对简谐外激励频率激励下的主系统振动的完全减振。并且控制系统容易用程序设计，链接进嵌入系统循环被实际应用。本文利用时滞反馈控制扭转系统的振动，主要分析了反馈增益系数和时滞量对扭转振动系统的减振作用。第一，文章研究了采用一个线性时滞动力吸振器来抑制扭转振动系统的振动问题。采用稳定性切换方法对时滞反馈控制系统的稳定性进行了分析，得到了系统的时滞稳定性区域。当反馈增益系数和时滞量都调节到合适的数值时，能够将主系统的振动全部消除。当时滞在某些区域进行调节时，能够部分消除主系统的振动。然而，，当时滞在其它一些区域进行调节时反而会增大主系统的振动，甚至会因为系统的不稳定导致结构破坏。第二，文章对一个两自由度的线性扭转振动系统进行了研究。利用反共振点理论对被动动力吸振器减振系统的优化获得了良好的物理参数导致较好的被动减振稳定性。用直接法算出了在稳定区域内的时滞量。理论和数值仿真结果吻合，结果表明，在反共振点，可以完全减振，在反共振点的邻域也可以获得百分之五十以上的减振效果。第三，在以上被动式动力吸振器减振的基础上，采用时滞反馈控制对系统的振动进行进一步的主动控制。科学地基于遗传算法的理论对反馈增益系数和时滞量两控制参数进行优化设计，得出了：在固定的时滞量（这个时滞量一定是在算出的稳定区域内），算出了反馈增益系数和外激励频率优化数组对减振进行控制。结果表明：算出的最优反馈增益系数和外激励频率数组成数组能够使扭转振动主系统完全减振。并且吸振器的能量也有大的下降。第四，文章对在一个带有非线性时滞动力吸振器的扭转振动系统进行了分析,采用多尺度方法获得了系统的近似解析解。分析了反馈增益系数和时滞量对主系统减振的影响。研究结果表明,对某一固定的反馈增益系数,存在时滞的某段调节区间,可以通过调节时滞来抑制主系统的振动。在时滞的调节区间内存在一个最佳时滞点,在该点主系统的振动被抑制到最小值。可以同时调节反馈增益系数和时滞两参数,当反馈增益系数和时滞都调节到最佳值时,主系统振动的振幅获得了很好的减振效果。本文的研究结果能够为扭转振动系统的振动控制提供一种新的减振方法，具有重要的理论研究价值，为时滞减振技术在扭转振动系统中的应用提供了可靠的理论保障。
[Abstract]:The time-delay feedback is actually a term added to the dynamic equation according to the relativistic simultaneous principle, which is used to reduce the vibration energy of the original system to suppress the harmful vibration of the target system. The time-delay feedback control can effectively suppress the vibration of the main system in the resonance region of the vibration system. In the linear vibration system, it can completely reduce the vibration of the main system excited by the simple harmonic external excitation frequency. And the control system is easy to use program design, link into embedded system cycle is used in practice. In this paper, feedback is used to control the vibration of torsional system, and the damping effect of feedback gain coefficient and time-delay on torsional vibration system is analyzed. First, a linear time-delay dynamic vibration absorber is used to suppress the vibration of torsional vibration system. The stability of the time-delay feedback control system is analyzed by using the stability switching method, and the time-delay stability region of the system is obtained. When the feedback gain coefficient and time delay are adjusted to a suitable value, the vibration of the main system can be eliminated completely. At that time, the vibration of the main system can be partially eliminated when it is regulated in some areas. However, at that time, the vibration of the main system will be increased when the adjustment is carried out in some other areas, and even the structure will be destroyed because of the instability of the system. Secondly, a linear torsional vibration system with two degrees of freedom is studied. The anti-resonance point theory is used to optimize the damping system of passive dynamic vibration absorber. Good physical parameters result in better stability of passive vibration absorption. The time delay in the stable region is calculated by direct method. The theoretical results are in agreement with the numerical simulation results. The results show that at the anti-resonance point, the vibration can be completely reduced, and more than 50% can be obtained in the neighborhood of the anti-common vibration point. Thirdly, on the basis of the passive dynamic vibration absorber, the time-delay feedback control is used to control the vibration of the system. Based on the theory of genetic algorithm, the control parameters of feedback gain coefficient and time-delay are optimized. It is obtained that the feedback gain coefficient and the optimal array of external excitation frequencies are calculated to control the vibration reduction in the fixed time-delay (which must be in the calculated stable region). The results show that the optimal feedback gain coefficient and the number of external excitation frequencies can completely reduce the vibration of the torsional vibration master system. And the energy of the absorber also has a big drop. Fourthly, a torsional vibration system with nonlinear time-delay dynamic absorber is analyzed. The approximate analytical solution of the system is obtained by using the multi-scale method. The effect of feedback gain coefficient and time delay on the vibration reduction of the main system is analyzed. The results show that for a fixed feedback gain coefficient, there is a certain interval with time delay, so the vibration of the main system can be restrained by adjusting the time delay. There exists an optimal time-delay point in the regulating interval with time delay, at which the vibration of the main system is restrained to the minimum. Both the feedback gain coefficient and the time delay can be adjusted simultaneously. When the feedback gain coefficient and the time delay are adjusted to the optimum value, the vibration amplitude of the main system can be reduced very well. The results of this paper can provide a new damping method for the vibration control of torsional vibration system, and have important theoretical research value, and provide a reliable theoretical guarantee for the application of time-delay damping technology in torsional vibration system.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TB535

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