光致伸缩层合结构非接触主动控制研究

发布时间：2018-11-10 09:27

【摘要】：随着科学技术尤其是航空航天事业的高速发展,使得这些领域内结构的复杂性不断增加,同时对系统的结构性能也提出了更高的要求。传统电磁激励智能材料在用于结构振动控制时,需要附加的电磁激发设备和导线连接,这样容易受到外界电磁场的干扰,影响控制信号传输的准确性和实时性,而新型透明铁电陶瓷PLZT在外部高能光束均匀照射下会产生光电热力多能场耦合作用,并沿其极化方向上产生一定的应力和应变,从而实现光能转化为机械能,避免了受到外界电磁场和复杂激励设备的影响,将其制成光致伸缩作动器应用于柔性结构振动主动控制领域内具有良好的发展前景。本文主要的工作内容概括为以下四个方面:(1)介绍了透明铁电陶瓷材料的基本特性和PLZT作动器的工作机理以及在控制应用中常见的分类构型,并建立了光致伸缩作动器的本构方程。(2)建立光致伸缩层合简支板结构的动力学模型,利用遗传算法对简支板结构表面的作动器分布进行优化设计,对比分析了在定常光强条件下不同分布方式对层合简支板结构不同模态的振动控制效果。仿真结果表明优化分布后的作动器对简支板结构的模态振动控制效果更为明显。(3)建立光致伸缩层合悬臂梁结构的动力学模型,运用模态分析方法推导了光电层合悬臂梁的模态振动控制方程,并利用有限元方法优化作动器的分布位置,分析研究了在定常光强和变光强两种光控方式下对层合悬臂梁的前两阶模态振动控制效果。仿真结果表明有限元模型分析的正确性,并且选择合适的光照强度可以有效地提高对悬臂梁振动的抑制作用。(4)设计了基于RBF网络模型的模糊神经网络控制器,并利用滑模控制方法设计了以多受控模态的位移和模态速度为变量的一级滑模函数和二级滑模函数,把系统多受控模态控制问题转化为单模态控制问题,同时使控制系统具备了模糊规则和权值系数学习调整的能力并进行了相关数值仿真。仿真结果表明模糊神经网络控制算法是有效可行的,能够实现对光电层合简支板结构的多模态振动控制。
[Abstract]:With the rapid development of science and technology, especially the aerospace industry, the complexity of the structure in these fields is increasing, and the structural performance of the system has been put forward higher requirements. When the traditional electromagnetic excitation intelligent material is used in the structural vibration control, it needs additional electromagnetic excitation equipment and wire connection, which is easy to be interfered by the external electromagnetic field, which affects the accuracy and real-time of the control signal transmission. However, a new transparent ferroelectric ceramic PLZT can produce optoelectronic thermal multifield coupling under uniform external high energy beam irradiation, and produce certain stress and strain along its polarization direction, thus realizing the conversion of light energy to mechanical energy. The application of photostrictive actuator to active vibration control of flexible structures has a good prospect. The main contents of this paper are summarized as follows: (1) the basic characteristics of transparent ferroelectric ceramics, the working mechanism of PLZT actuators and the common classification configurations in control applications are introduced. The constitutive equation of photostrictive actuator is established. (2) the dynamic model of photostrictive laminated simply supported plate structure is established and the actuator distribution on the surface of simply supported plate structure is optimized by genetic algorithm. The vibration control effects of different distribution modes on laminated simply supported plate structures under the condition of steady light intensity are compared and analyzed. The simulation results show that the optimal distribution of actuators is more effective in controlling the modal vibration of simply supported plate structures. (3) the dynamic model of photostrictive laminated cantilever structures is established. The modal vibration control equation of photoelectric laminated cantilever beam is derived by using modal analysis method, and the distribution position of actuator is optimized by using finite element method. The first two modes vibration control effect of laminated cantilever beam under two light control modes of steady light intensity and variable light intensity is analyzed and studied. The simulation results show that the finite element model analysis is correct, and the appropriate light intensity can effectively improve the vibration suppression effect of cantilever beam. (4) the fuzzy neural network controller based on RBF network model is designed. The first order sliding mode function and the second order sliding mode function are designed by using the sliding mode control method, which takes the displacement and modal velocity of multiple controlled modes as variables, and the multi-controlled mode control problem of the system is transformed into a single mode control problem. At the same time, the control system has the ability of learning and adjusting fuzzy rules and weights. The simulation results show that the fuzzy neural network control algorithm is effective and feasible, and it can realize the multimodal vibration control of the optoelectronic laminated simply supported plate structure.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535

【相似文献】