ACTIVE CONTROL OF ULTRALIGHT-WEIGHT AND FLEXIBLE SPACE STRUCTURES

在本研究项目中，提出了将智能结构系统用于空间结构，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中，用于精确控制，形状确定和振动抑制。该项目还包括开发用于故障检测和识别的软件算法，因为需要为这种智能结构的在轨应用开发高度可靠的控制系统。(1)柔性空间结构的控制器设计研究1-1高度柔性结构的形状和振动控制的控制器设计方法已经发展。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。提出了一种基于压电作动器的柔性结构振动控制方法。本文将滑模控制应用于具有参数误差的悬臂梁模型。所设计的控制器对模型误差具有良好的鲁棒性。解决了1-3同时优化设计问题，找到最优的结构参数集和输出控制器。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。该方法适用于自由度较低的简单结构体系。对于更复杂的结构，结构/控制系统的同时优化设计需要进一步的研究。(2)智能结构控制系统的故障检测与识别研究基于模型的智能结构故障检测与隔离（FDI）系统在考虑模型不确定性时的鲁棒性。提出了一种新的鲁棒故障检测方法，该方法对未知建模误差引起的干扰不敏感，而对部件故障高度敏感。对柔性智能波束控制系统中传感器故障的鲁棒检测能力进行了检验。该方法抑制了模型误差引起的干扰，显著提高了检测性能。少

In this research project, the use of smart structural systems has been proposed for 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 vibration suppression. The project also includes the development of software algorithms for fault detection and identification because there exists the need for developing highly reliable control systems for on-orbit application of such smart structures.(1) Studies on Controller Design for Flexible Space Structures1-1 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.1-2 A method of vibration control for flexible structures with piezoelectric actuators has been developed. Sliding mode control has been applied t … More o the model of a cantilever beam with parameter errors. The designed controller shows high performance of robustness against the model errors.1-3 Simultaneous optimal design problem has been solved to find the best set of structural parameters and output controller. The proposed design method is based on Bilinear Matrix Inequality (BMI) and presents an improved branch and bound method for BMI by using graph theory. The method is useful for simple structural systems with low degrees of freedom. Further studies are needed for the simultaneous optimal design of structural/control systems in the case of more complex structures.(2) Fault Detection and Identification for Smart Structure Control SystemsModel-based FDI (Failure Detection and Isolation (FDI) systems for smart structures have been studied with careful considerations about robustness with respect to model uncertainties. A new method of robust fault detection has been proposed that is insensitive to the disturbances caused by unknown modeling errors while it is highly sensitive to the component failures. The capability of the robust detection algorithm is examined for the sensor failure of a flexible smart beam control system. The proposed method suppresses the disturbances due to model errors and remarkably markedly improves the detection performance. Less