According to the principles of piezoelectric smart concrete structure health monitoring , a mathematic model of monitor system for static performances is discussed . then , the virtual waveform generator based on dds is designed using a data acquisition card and a pc to supply multiform excitation signals to piezoelectric elements in experiment . the theoretical analysis and experimental research demonstrate the performances of the waveform generated by the virtual instrument 为了给压电元件提供多种类型的激励信号，根据直接数字合成原理，设计了利用数据采集卡和计算机实现dds波形发生的虚拟仪器，并对生成波形的各方面性能进行了理论分析和实验研究，从理论和实验两个方面分析了这种波形发生方式所能取得的效果。
Firstly , the connected end sets of the relay lines are got using the breadth first search algorithm and the connected relationship of wiring terms is got in the electrical circuit diagram according to different cad block structure of different element type . secondly , the appropriate specification of the relay element is chosen by using the equinoctial graph algorithm , and the panel layout diagram is generated automatically by the combining automatic layout and manual intervention . finally , the optimized path algorithm which passes each vertex in the completed non - directional graph once and only once is put forward , this algorithm and the prim minimum spanning tree algrotithm can generate the inner panel wiring diagram and terminal wiring diagram automatically 首先,采用广度优先搜索算法查找电气原理图中的连通导线端点集,并根据不同类型的继电元件对应的cad图块结构的不同,得到电气原理图中元件接线端子之间的连接关系;其次,根据二分图匹配算法为电气原理图中继电元件选择合适的型号和规格,并采用人工干预和自动布置相结合的方法完成屏面布置图的自动生成;最后,提出了完全无向图中经过每个顶点一次且仅一次的优化路径算法,利用该算法和经过预处理的prim最小生成树算法自动生成屏内安装接线图和端子接线图。
Based on the requirements of high precision pointing / targeting of advanced spacecraft , dynamic modeling of spacecraft with flexible appendages bonded with piezoelectric sensors / actuators , attitude control and active vibration suppression theory are studied deeply in this dissertation , which is funded by the research fund for the doctoral program of higher education of china item ? “ large flexible multi - bodies structure spacecraft active vibration control technology ” ( 20050213010 ) . the main contents of this dissertation are as the follows : an approximate analytical dynamic model of a flexible spacecraft with surface bonded piezoelectric sensors and actuators is derived using hamilton ’ s principle with discretization by the assumed mode method . the model is then converted to state - space form for the purpose of control design 本学位论文结合高等学校博士学科点专项科研基金“挠性多体结构卫星主动振动控制技术研究” ( 20050213010 )课题,从理论上对粘贴有压电智能元件的挠性航天器的建模、姿态控制和主动振动控制理论等展开了深入的研究,其研究内容主要包括以下几个方面:利用hamilton原理推导了挠性航天器的动力学模型、压电元件的作动方程及检测方程,并采用模态分析方法,进一步将挠性航天器的耦合方程规范化,使之适应于姿态控制系统的分析和设计。
Based on the simplified principle , the modal shapes of selected structural modes are converted into modal strains . to minimize the calculation error , curve - fitting technique is used in the process . the modal strains are summed together to determine the global distribution of the structure for selected vibration modes so that the position of piezoelectric elements could be optimally determined according to the simplified optimization principle 通过二阶中心差分运算将模态振型转化为模态应变，采用应变曲线拟合方法降低离散误差，进而将各阶待控模态应变进行叠加，获取系统整体特征应变分布情况；最后根据压电元件位置优化的简化目标函数，将压电片的最优位置确定为柔性板叠加模态应变的极值区域。
Pzt ceramics are bonded on the surface of fiberglass - reinforced composite materials acting as both actuators and sensors to generate and collect lamb wave . characteristic parameters are extracted from the filtered sensors signal by hht method . using these parameters in different methods for damage detection , the location and the degree of damage in the composite material can be determined 综上,本文采用lamb波主动监测技术,选择合适的激励信号,利用粘贴在复合材料结构表面上的压电元件,在复合材料结构中激发出lamb波并接收传感信号,利用hht方法分析经过滤波后的传感信号,提取出表示损伤的特征参数,运用不同的损伤识别方法实现对复合材料结构的损伤定位和损伤程度的识别。
In addition , the principle of component synthesis vibration suppressing ( csvs ) method is also briefly introduced and summarized to several lemmas , which can suppress flexible vibration by utilizing the character of vibration system itself and has the characters of simple , multiform , easy to apply and so on 另外,为了将分力合成方法应用于挠性系统的振动抑制,简要地介绍了分力合成方法的一些基本概念及原理。针对采用推力器作为执行机构的挠性航天器姿态机动的振动抑制问题,提出了将分力合成振动抑制( csvs )方法和基于分布压电元件( pzt )的主动振动抑制技术相结合的一种复合主动控制方法。
In this paper , at the cut - in spot of beam active vibration control and use the pzt material as the drive component , the main research works can be summarized as follows : 1 ) using the finite element theory , a general finite element formulation of piezoelectric media is derived , the direct and converse piezoelectric effects are considered in the formulation 本文从梁的振动主动控制研究为切入点，利用了pzt材料作为驱动元件，作了如下几个方面的研究： 1 )利用有限元理论，考虑压电材料的正、逆压电效应的影响，导出了机电耦合压电元件的有限元方程。
The experimental results showed that the substrate of pyroelectric sensor could significantly affect the detectivity . the porous silicon dioxide and pet plastic film substrate could effectively decrease the thermal conduction and the thermal fluctuation noise of the pyroelectric element , increase the voltage responsivity and the detectivity obviously 结果表明，多孔氧化硅和pet塑料可有效降低热释电元件的对外热传导，明显提高传感器的电压响应率和降低热释电元件的热噪声。
Then , global coordination controller is designed through rule base . thus , a hierarchic controller of the coupled system , which consists of execution level , coordination level and organization level , is finished . in order to improve sensing and actuating performance of pzts , auto configuration of pzts function is presented and corresponding circuit is completed 另外，为了充分地利用压电元件的传感能力和驱动能力，在传感器和执行器的优化配置中，提出了根据外部激励和柔性结构本身的振动状况来对压电元件的功能进行自动配置的思想。
In theoretical analysis , finite element method is firstly used to solve the mechanical - electric coupling problems in a flexible plate with piezoelectric elements and to obtain structural vibration modal shapes . focusing on collocated type of piezoelectric sensors / actuators , the maximum determinant of fisher information matrix criteria is chosen as the optimization function and then simplified to determine an optimal principle for the best location of piezoelectric elements 本文研究柔性板振动控制中压电元件的位置优化设计问题，针对压电传感器和驱动器的同位布置结构型式，将压电元件的有限元分析方法与d优化设计准则相结合，直接利用结构的模态振型确定压电元件在柔性板上的最优位置。
