光电层合柔性板壳结构的智能主动振动控制研究

发布时间：2019-05-26 18:51

【摘要】：在航空航天领域,板壳结构有着广泛的应用背景,其形状控制和振动控制一直是系统设计和工程应用中的重点和难点。当前,利用智能材料对板壳结构实施有效的主动激励来抑制振动的方法是一种有效的方法。但传统的由电、磁信号激发的智能材料,需要附加复杂的电磁激发装置,不利于系统的轻质小型化,同时其与激发装置之间需要导线连接,易引起电磁噪音干扰,而影响控制信号的传送准确性和实时性。而新型的镧改性锆钛酸铅(PLZT)陶瓷,可直接将光能转化为机械能,不受电磁干扰的影响,适于在太空环境下实施非接触激励及远程控制,有着广阔的应用前景。本文以层合光致伸缩PLZT驱动器的板和壳结构为对象,研究其智能振动主动控制技术,对与其相关的驱动器构型、动力学建模、驱动器位置优化以及单模态和多模态智能主动控制方法等几个方面的问题进行了相应的理论研究。论文的主要工作和创新性成果如下:(1)基于PLZT驱动器的光-热-力-电多场耦合本构模型,采用数值仿真方法分析了影响PLZT驱动器性能的主要因素;对当前常用的驱动器构型进行了分析比较,分析指出现有的驱动器构型在外部光源作用下“只能伸长不能缩短”,因而只能产生单向膜控制力。进一步,提出了两种能够产生正负膜控制力的多片组合驱动器构型,成功地克服了现有驱动器构型的缺陷,这种构型在曲壳结构的主动控制中具有明显的优势,能够显著的提高驱动器的作动效率;(2)基于板壳结构振动理论,建立了可适用于不同结构类型、不同几何参数的光电层合板壳结构的通用动力学模型,利用此模型可以进一步推导出层合有光致驱动器的不同类型板壳结构,如矩形板、圆柱壳、球壳,锥壳等结构的系统动力学方程;基于所建立的动力学模型,利用模态展开技术建立了光电层合板壳结构的模态控制方程。(3)结合PLZT驱动器切换致动和非线性驱动的特性,提出了独立模态变结构模糊控制器,与现有的常规李亚普洛夫控制(常光强控制)和速度反馈控制(变光强控制)相比,该控制器具有两方面的优势:一方面对光照方向的切换函数进行了优化设计,得到了最优光照方向切换函数;另一方面对光强的控制采用量化因子自调节模糊控制器,充分考虑了驱动器的驱动特性。所提出的控制器综合了模糊控制与变结构控制的优点,是一种不依赖于系统精确模型的智能控制器,能够克服驱动器的非线性驱动特性,其控制效果明显优于速度反馈控制。(4)结合算例给出了相应受控模态在驱动器位置变化时其模态控制因子的变化规律;分析得出了:对于确定的模态,存在一个或多个极值区域;在该区域,驱动器产生的模态控制因子幅值明显大于其他贴片区域;而且,随着模态半波数的变化,极值区域的分布会发生变化。进一步,为了实现对多个受控模态的振动同时进行抑制,需要将驱动器粘贴在能够对所有受控模态都产生尽可能大的模态因子的位置,为此,提出了以受控模态控制力因子的绝对值之和为优化函数及以驱动器的位置坐标为优化变量的板壳结构的多模态振动驱动器位置遗传优化算法,并结合本文提出的多片组合驱动器构型对板壳结构的驱动器位置进行了优化设计,计算得到了板壳结构在相应驱动器构型下的驱动器优化布片位置。(5)针对光电层合板壳结构的多模态主动控制问题,提出了最优模糊主动控制算法,该算法是由当前成熟的LQR控制与模糊控制组合而成,在算法设计过程中将结构系统控制和驱动器控制分开考虑,设计步骤分为两步:首先基于简化的线性系统模型设计LQR控制律,然后通过模糊控制器调节光电驱动器的输入光强使其输出的光致应变逼近最优控制量。该方法解决了当前光电层合系统不能直接应用线性系统控制方法的矛盾,通过将一个复杂的问题进行分解简化了控制器的设计,实现了光电层合板壳结构的多模态主动控制。结合该算法,通过仿真对比,对本文提出的多模态驱动器位置优化准则函数的合理性进行了验证。(6)将驱动器和结构系统作为整体考虑,提出了模糊神经网络控制(FNNC)和自组织模糊滑模控制(SOFSMC)等两种多模态主动控制算法。提出的FNNC主动控制算法综合了模糊控制和神经网络控制的优点,为了简化系统,所提出的模糊神经网络基于RBF网络,并采用两输入单输出结构。然而,在多模态振动问题中,控制变量的个数要多于控制器的输入个数,为了解决这一问题,参考欠驱动控制理论中所采用的二级滑模面思想,首先以各受控模态的位移和它们的速度信号线性组合构成各模态的一级滑模函数,然后将所有一级滑模函数进行线性组合构成二级滑模函数;最后将二级滑模函数和它的导数作为FNNC的输入变量。所提出的FNNC主动控制器不依赖于系统的数学模型,具有模糊规则和隶属度函数在线学习能力。(7)提出的SOFSMC主动振动控制算法通过引入二级滑模函数,降低了系统的控制阶数,简化了模糊控制系统的结构;通过引入自组织学习算法实现了控制器规则的在线学习,克服了常规模糊滑模控制器依赖系统规则的缺点;系统控制中模糊滑模的使用柔化了控制信号,避免了一般滑模控制的抖振现象;采用了单值模糊规则参数,这种单值模糊规则参数可以通过自组织学习算法进行自动调节;所使用的自组织学习算法与当前公开报道的文献是不相同的,其是依据光电层合结构多模态振动系统线性自回归平滑模型推导得到的新的自组织学习算法。为了验证所提出的智能主动控制算法的有效性,结合板壳结构的多模态主动控制算例进行了仿真。
[Abstract]:In the field of aeronautics and astronautics, the shell structure has a wide application background, and its shape control and vibration control have been the key and difficult point in the system design and engineering application. At present, the method for suppressing the vibration by using the intelligent material to implement effective active excitation to the plate shell structure is an effective method. But the traditional intelligent material excited by the electric and magnetic signals needs to be added with a complex electromagnetic excitation device, which is not beneficial to the light miniaturization of the system, and meanwhile, a wire connection is required between the intelligent material and the excitation device, so that the electromagnetic noise interference can be easily caused, and the transmission accuracy and the real-time property of the control signal are influenced. The new type of modified lead titanate (PLZT) ceramic can directly convert light energy into mechanical energy, and is not affected by electromagnetic interference. It is suitable for non-contact excitation and remote control in space environment, and has wide application prospect. In this paper, based on the plate and shell structure of the layer-based telescopic PLZT driver, the intelligent vibration active control technology is studied, and its related drive configuration and dynamic modeling are studied. The problems of drive position optimization, single mode and multi-mode intelligent active control method are studied in this paper. The main work and innovative achievements of the paper are as follows: (1) Based on the light-thermal-force-electric multi-field coupling constitutive model of the PLZT driver, the main factors that influence the performance of the PLZT driver are analyzed by the numerical simulation method; and compared with the current common driver configuration, The analysis indicates that the current driver configuration is "can only be stretched and cannot be shortened" under the action of an external light source, and thus the one-way film control force can only be generated. Furthermore, two kinds of combined drive configurations which can produce positive and negative film control force are put forward, and the defects of the existing drive configuration are successfully overcome, and the configuration has obvious advantages in the active control of the curved shell structure, and can obviously improve the operation efficiency of the driver; (2) Based on the vibration theory of the plate-shell structure, a general-purpose dynamic model of the shell structure of the photovoltaic laminated plate which can be applied to the types of different structures and different geometric parameters is established, and different types of plate-shell structures such as rectangular plates, The system dynamics equation of the structure of the cylindrical shell, the spherical shell, the cone shell and the like is solved, and the mode control equation of the shell structure of the photoelectric laminated plate is established by means of the mode expansion technology based on the established kinetic model. (3) In combination with the characteristics of the PLZT driver switching and non-linear driving, the independent mode variable structure fuzzy controller is proposed. Compared with the conventional conventional Lyapunov control (constant light intensity control) and speed feedback control (variable light intensity control), the controller has two advantages: On the one hand, the optimal design of the switching function of the light direction is optimized, and the optimal illumination direction switching function is obtained; on the other hand, the self-adjusting fuzzy controller of the quantization factor is adopted for controlling the light intensity, and the driving characteristics of the driver are fully taken into account. The proposed controller has the advantages of fuzzy control and variable structure control. It is a kind of intelligent controller which does not depend on the precise model of the system, can overcome the nonlinear drive characteristic of the driver, and the control effect is obviously superior to the speed feedback control. (4) The variation law of the mode control factors of the corresponding controlled modes in the drive position is given in the paper. The results are as follows: for the determined mode, there are one or more extreme regions; in this region, And the amplitude of the mode control factor generated by the driver is obviously larger than that of the other patch areas, and the distribution of the extreme region can change as the mode half-wave number is changed. Further, in order to achieve the simultaneous suppression of the vibrations of the plurality of controlled modalities, it is necessary to attach the drive to a position capable of generating as large a modal factor as possible for all of the controlled modalities, for this purpose, The invention provides a multi-modal vibration driver position genetic optimization algorithm based on the sum of the absolute value of the controlled mode control force factor as an optimization function and the plate shell structure with the position coordinate of the driver as an optimization variable, And the drive position of the plate shell structure is optimized and designed in combination with the multi-piece combination driver configuration set forth herein, and the position of the driver in the corresponding driver configuration of the plate shell structure is calculated. (5) The optimal fuzzy active control algorithm is proposed for the multi-mode active control of the shell structure of the laminated plate. The algorithm is composed of the current mature LQR control and the fuzzy control, and the control of the structure and the control of the driver are taken into account during the design of the algorithm. The design step is divided into two steps: firstly, designing the LQR control law based on the simplified linear system model, and then adjusting the input light intensity of the photoelectric driver by the fuzzy controller to approximate the optimal control amount of the light-induced strain output by the photoelectric driver. The method solves the contradiction that the current photoelectric lamination system cannot directly apply the control method of the linear system, simplifies the design of the controller by decomposing a complex problem, and realizes the multi-mode active control of the shell structure of the photoelectric laminated plate. In this paper, the rationality of the multi-modal drive position optimization criterion function proposed in this paper is verified by simulation and comparison. (6) As a whole, two kinds of multi-mode active control algorithms such as fuzzy neural network control (FNNC) and self-organizing fuzzy sliding mode control (SOFSMC) are put forward. The proposed FNNC active control algorithm has the advantages of fuzzy control and neural network control. In order to simplify the system, the proposed fuzzy neural network is based on the RBF network and adopts two input single-output structures. However, in the multi-modal vibration problem, the number of control variables is more than the number of input of the controller, First, the first-order sliding mode function of each mode is formed by linear combination of the displacement of each controlled mode and their velocity signals, and then all the first-level sliding mode functions are linearly combined to form a two-level sliding mode function; and finally, the second-order sliding mode function and the derivative thereof are used as input variables of the FNNC. The proposed FNNC active controller does not rely on the mathematical model of the system, and has the online learning ability of the fuzzy rule and the membership function. (7) The proposed SOFSMC active vibration control algorithm reduces the control order of the system by introducing the two-stage sliding mode function, simplifies the structure of the fuzzy control system, and realizes on-line learning of the controller rule by introducing the self-organizing learning algorithm, The defect that the conventional fuzzy sliding mode controller relies on the system rule is overcome, the use of the fuzzy sliding mode in the system control is flexible to control the signal, the chattering phenomenon of the general sliding mode control is avoided, and the single-value fuzzy rule parameter is adopted, this single-valued fuzzy rule parameter can be automatically adjusted by the self-organizing learning algorithm; the self-organizing learning algorithm used is not the same as the currently reported document, Which is a new self-organizing learning algorithm based on the linear self-regression smoothing model of the multi-modal vibration system of the photoelectric laminated structure. In order to verify the effectiveness of the proposed intelligent active control algorithm, the multi-modal active control example of the plate-shell structure is simulated.
【学位授予单位】：南京航空航天大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB535.1

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