大型柔性构件振动控制的特征结构配置

THE VIBRATION CONTROL OF LARGE FLEXIBLE STRUCTURE BY EIGENSTRUCTURE ASSIGNMENT METHOD

根据大型柔性构件存在着建立运动方程自由度多，整体结构参数不宜测量等特点，文中研究了基于子结构的振动特征结构配置．为克服以往在拼装子结构时由于界面耦合作用，造成振动能量相互传递，破坏原有各子控制器设计性能的缺陷，作者提出了通过在界面上安装控制执行器，以割断子结构间能量传递的分散解耦控制法。

The eigenstructure assignment for large flexible structure is studied in the paper basedon the fact that vibration control of large flexible structure has the characteristics of possessingmuch more degrees of freedom at nodes, being not appropriate to directly measure the globalstructure parameters, taking too much computation time for its feedback and having need to redesigning the global controller if a component is partially modified. In order to reduce the amount ofcalculation, to facilitate modification, and to manufacture in differeds places, the author assumesthat the features of global control system can be obtained by assigning eigenstructure to eachindividual substructure respectively. Starting from eigenstructure and its decomposition features,the impacts of left and right eigenvectors at each stage on controllability and observability of thesystem are analyzed and 'the output features of the mode is decided by both observable matrix andright eigenvector while the controlling features of the mode is determined by the left eigenvector,controlling matrix and also feedback matrix' are pointed out. Furthermore, the assignment ofpartial eigenstructures and the relevant protective algorithm is put forward is accordance withthe feature that only some eigenstructures of the actual substrcture need to be reassigned whileothers remain unchangeable. The algorithm makes those unnecessarily assigned left and righteigenvectors orthogonal with the newly decomposed sub-controller and sub--observer maines, andthus they become uncontrollable and unobservable parts. Moreover, a joint decoupling controlmethod is suggested to avoid disrupting the results of the original assignment of each individualsubstructures in the process of assembling each substructure controller into a global one. Byinstalling controllers at the interface of each individual substructure, the convey of vibration energyamong all substructures is severed. So the global structure features are equal to the characteristicsof each individual substructure. Finally, the proposed method is proved by a two-substructuremass-spring-damper system.