ACTIVE SHAPE AND VIBRATION CONTROL OF FLEXIBLE SPACE STRUCTURES

1.由于柔性空间结构的设计模型含有很大的不确定性，因此所设计的控制器必须对这种模型不确定性具有足够的鲁棒性。此外，空间结构具有丰富的结构设计自由度，使得结构和控制器的同时/集成设计成为可能。针对柔性结构的振动主动抑制问题，提出了一种基于鲁棒极点配置的结构/控制器设计方法。该方法通过设计结构和控制器参数，在目标位置分配闭环系统的特征值，并使闭环系统的模态矩阵的条件数准最小化。条件数是闭环系统鲁棒性的量度，它与闭环系统特征值在系统矩阵摄动下的最大偏差有关。条件数也是控制性能的量度，它给出了FeedBAC…大小的上界更多的k增益矩阵和瞬时响应。因此，减少条件数可以提高所设计闭环系统的鲁棒性和控制性能。该方法通过结构/控制器的设计进一步减少了闭环系统的条件数。目标闭环极点位置也可以重新设计为设计参数。引入了一个新的条件数指标作为代价函数。用该指标代替实际条件数，减少了计算量，提高了问题的可解性。通过数值仿真验证了该方法的可行性。为柔性结构主动形状控制的形状测量、估计和控制方法的发展进行了基础性研究。所提出的估计和控制设计方法已应用于悬臂梁主筋形状控制系统中。数值模拟结果表明，恢复误差的大小很大程度上取决于可用驱动器的数量及其位置。较少

1. Since design models of flexible space structures contain significant uncertainties, the designed controller must have sufficient robustness with respect to such model uncertainties. Besides, space structures have abundant structural design freedom that enables simultaneous/integrated design of structure and controller. In this research project, a method of structure/controller design via robust pole assignment has been developed for active vibration suppression of flexible structures. The proposed method assigns the closed-loop eigenvalues at target locations and quasi-minimizes the condition number of the closed-loop modal matrix by designing structure and controller parameters. The condition number is a measure of the closed-loop system robustness that is related to the maximum deviation of the closed-loop eigenvalues subject to perturbations of the system matrix. The condition number is also a measure of the control performance, which gives the upper bound of magnitude of feedbac … More k gain matrix and transient responses. Therefore reducing the condition number improves tabiliy rebustness and control performance of the designed closed-loop system. The proposed method further reduces the resulting closed-loop condition number via structure/controller design. The target closed-loop pole locations can also be redesigned as the design parameters. A new index of condition number has been introduced as the cost function. Use of this index in place of actual condition number reduces computational effort and improves problem solvability. Feasibility of the proposed method is examined by numerical simulations.2. Fundamental studies have been done for developing methods of shape measurement, estimation and control for active shape control of flexible structures. The proposed estimation and control design methods have been applied to a tendon shape control system for a cantilevered beam. The results of numerical simulation show that the magnitude of the restoration errors largely depends on the number of available actuators and their locations. Less