Active Vibration Control Of Space Intelligent Truss Structure By H_∞Controllers

Large space structure is an essential part of the large space vehicles. At this stage, it is the basic conditions to build a large space station and implement the future space missions. Uncertainty of the structural dynamics parameter is the main features of the large space truss vibration. The unstructured uncertainty can be precisely dealt by H∞control. In this paper, a bandpass controller for the active vibration control of space intelligent truss is considered based on a bandpass H∞controller design method. The controller is based on a collocated actuators/sensors pair strategy, considering the uncertainty of the parameters of structural dynamics. By resorting to the properties of the flexible structure and setting a suitable disturbance matrix, the proposed technique derived analytical solution of the Riccati equation, thus avoiding the need to solve any Riccati equation. Not only can it achieve fast computation, but also can solve the ill-conditioned problem in the case of very high-order, poorly damped flexible systems. The authority is effective in a chosen band of frequency, resulting in a selective broadband control action.1. In this paper, modal simulation analysis by FEM is introduced. FEM models of the space intelligent truss are created by use of the finite software NASTRAN/PATRAN. The dynamic equations of the space intelligent truss are established in the modal space. Let modal displacement and velocity as the state variables. The generalized state-space model is established.2. Based on the explanation of H∞control theory concisely, this dissertation focuses on an analytical solution of the Riccati equation. The explicit closed-form solution of the H∞controller is obtained based on the analytical solution.3. In order to test the proposed control strategy, the simulation was made on the basis of finite element modeling and analysis.The final simulation results show the bandpass property of the controller. The controller can effectively deal with the flexible structures of high modal density. The results also show the strong robustness of the controller. So it can effectively deal with the problem of high modal density. The vibration is reduced rapidly. It is feasible and valid to apply the H∞controller to the active vibration control of the space intelligent truss.