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

在本研究项目中，智能结构系统已被提出用于超轻和柔性空间结构，如大型柔性空间天线，其中许多有源传感器和执行器设备嵌入到结构上，用于精确控制，形状确定和/或振动抑制。超轻空间结构的概念得到了广泛的研究。对实现虚拟刚度和主动减振的智能结构进行了研究。针对高柔性结构的形状和振动控制，已经发展了控制器设计方法。深入的研究强调了控制系统对溢出不稳定性和不确定结构参数的鲁棒性。研究了基于压电作动器的柔性结构振动控制方法。其中，对具有参数误差的悬臂梁模型进行了滑模控制。所设计的co . More控制器对模型误差具有良好的鲁棒性。同时解决了结构参数和输出控制器的优化设计问题。提出了一种基于双线性矩阵不等式的设计方法，并利用图论提出了一种改进的双线性矩阵不等式分支定界法。第二种方法基于线性矩阵不等式（LMI）。该方法已成功应用于智能结构的同步结构和控制器。研究了一种用于柔性结构降噪和抑制声激励的智能结构。设计合理的由压电致动器激活的智能面板，可以有效地抑制通过面板结构传递的噪声对目标结构的声激励。基于模型的智能结构的FDI（故障检测和隔离系统）已经研究，并仔细考虑了关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识别算法，并成功地应用于智能结构的故障检测。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