【作者】 陈德金；

【导师】 郑世杰；

【作者基本信息】 南京航空航天大学 ， 工程力学， 2010， 硕士

【摘要】 传统驱动器需要硬线连接来传输控制信号,当外界环境存在附加的电磁场时,传统驱动器往往受外界电磁场影响,光致伸缩驱动器由于不需要硬线连接从而能完美解决受外界电磁场影响的问题。光致伸缩驱动器可直接将光能转化为机械能,在柔性结构的振动主动控制方面具有可观的发展前景。目前,柔性结构板直接使用光致伸缩驱动器进行振动控制还处于研究阶段。本文采用光电材料作为结构的驱动器,采用遗传算法优化单对及双对驱动器尺寸及位置,并着重对不同模态的振动控制方法进行了深入研究,同时还考虑了不同边界条件梁的振动控制。引入模态控制力的概念,它受模态阶数,驱动器布置,以及驱动器极化方向的影响。本采用二进制编码优化模态控制力最大,在此基础上考虑新的光强算法。进一步考虑板结构的振动主动控制,同样采用优化单片和双片驱动器的结果比较结果。在此基础上,探讨了双片驱动器多阶振动主动控制的可行性。为了改善结构振动控制的效果,选用结构振动能量和控制信号能量作为控制目标函数的LQR控制算法作了初步研究。引入二进制编码的GA和LQR算法相结合,在限制驱动器的电场强度不超过饱和电场强度情况下最大化闭环阻尼系数。仿真算例表明了使用优化的驱动器布置能有效的控制结构的前几阶模态,同时也可以看出驱动器优化布置能有效降低系统振动。更多还原

【Abstract】 The traditional actuators require hard-wired connections to transmit the control signals. When the operating environments contain external electromagnetic field, often there is electromagnetic interference using the traditional electromechanical transducers. The optically driven distributed opto-electromechanical actuators were born to remedy this problem. Photostrictive actuator, which can directly turn light energy into mechanical energy, is a new promising photoactuation technique for active vibration control of flexible structures. Photonic control of flexible plates using discrete Photostrictive actuators is investigated.In this paper, Photostrictive elements are employed as structural actuators. This paper used the method of genetic algorithms to optimize the location and size of one and two pairs of actuators. We also have a deep research on the vibration control of different modes. Beam with different boundary condition is considered. The modal force index function, which has taken into account the mode number, the spatial distribution, and the dimension of the Photostrictive actuator, is established. A binary-coded GA was used to maximize the modal force index. Based on these results, a new definition of the light intensity is developed. The analytical solution shows the new control method can be more effective. On the other hand, the active vibration control of plate is considered. In this part we also use GA to optimize the location and size of one and two patches of actuators. Base on the responses from analysis of plate, we consider the method of using two patches of photostrictive actuators to control multiple vibration modes of the plate. Velocity feedback control and acceleration feedback are used in the active vibration control of plate. In order to improve the effectiveness of the vibration control for plate structure, this paper made some analysis of the linear quadratic regulator (LQR) control method, which chooses the vibration energy of the structure and the control signal energy for the object function. A binary-coded GA based improved LQR control scheme has been incorporated, which maximizes the closed loop damping while keeping the actuator electric field within limit. Analytical solutions and numerical results demonstrate that the use of strategically positioned actuator patches can effectively control the fundamental modes that dominate the structural vibration. It also shows that by properly positioned the actuators the system performance can be improved.更多还原