ACTIVE SHAPE AND VIBRATION CONTROL OF ULTRA LIGHT AND FLEXIBLE SPACE STRUCTURES

在本研究项目中，提出了用于超轻型和柔性空间结构的智能结构系统，例如大型柔性空间天线，在结构上嵌入许多主动传感器和执行器，用于精确控制、形状确定和/或振动抑制。1.深入研究了超轻型空间结构的概念。为开发实现虚拟刚度和主动减振的智能结构进行了研究。2.提出了高度柔性结构形状和振动控制的控制器设计方法。重点研究了控制系统对溢出不稳定和结构参数不确定的鲁棒性。3.提出了含压电作动器的柔性结构振动控制方法。其中，滑模控制被应用于具有参数误差的悬臂梁模型。设计的co…更多的控制器对模型误差表现出很强的鲁棒性。4.同时解决了优化设计问题，找到了最优的结构参数和输出控制器。其中一种设计方法是基于双线性矩阵不等式(BMI)，并利用图论提出了一种改进的BMI分枝定界法。第二种方法是基于线性矩阵不等式(LMI)。该方法已成功地应用于智能结构的同时控制中。5.研究了一种柔性结构的降噪和声激励抑制方法。设计合理的由压电致动器激活的智能面板可以非常有效地抑制由于通过面板结构的噪声传播而引起的目标结构的声激励。6.基于模型的智能结构故障检测和隔离系统的研究仔细考虑了相对于模型不确定性的鲁棒性。提出了一种新的基于子空间的系统辨识算法，并将其成功地应用于智能结构的故障检测。较少

In this research project, the smart structure systems have been proposed for ultra light and flexible space structures such as large flexible space antenna, where many active sensor and actuator devices are imbedded onto the structures for precision control, shape determination, and/or vibration suppression.1.The concept of ultra light space structure has been intensively studied. Researches were made for developing smart structures that realizes virtual rigidity and active vibration suppression.2.Methods of controller design have been developed for shape and vibration control of highly flexible structures. Intensive studies have been carried out emphasizing robustness of the control system against both spillover instability and uncertain structural parameters.3.Methods of vibration control for flexible structures with piezoelectric actuators have been developed. Among them, a sliding mode control has been applied to the model of a cantilever beam with parameter errors. The designed co … More ntroller shows high performance of robustness against the model errors.4.Simultaneous optimal design problem has been solved to find the best set of structural parameters and output controller. One of the proposed design methods is based on Bilinear Matrix Inequality (BMI) and presents an improved branch and bound method for BMI by using graph theory. The second approach is based on Linear Matrix Inequality (LMI). The proposed method has been successfully applied to the simultaneous structure and controller of smart structures.5.A smart structure has been studied for noise reduction and acoustic excitation suppression of flexible structures. The properly designed smart panel activated with piezoelectric actuators is highly effective in suppressing the acoustic excitation of the target structure due to the noise transmitting through the panel structure.6.Model-based FDI (Failure Detection and Isolation systems for smart structures have been studied with careful considerations about robustness with respect to model uncertainties. A new subspace-based system identification algorithm has been developed and successfully applied to the fault detection of a smart structure. Less