Dynamic Modeling And H_∞Control Of Space Intelligent Truss Structures

In recent years, more and more space truss structures have been widely applied to the spacecraft,such as solar panels, support structures of detection equipment, truss antenna and so on. However, it cancause vibration problems such as low natural frequencies and intensive modes because of its large span,light weight and small cross-sectional area. Therefore it is necessary to vibration control, otherwise itwould lead to instability and even damage the structure. Piezoelectric material is a kind of functionalMaterials with electromechanical coupling characteristics. Based on the forward and inversepiezoelectric effect, the piezoelectric material will be added to the truss structure as active lever (withactuator function). Finally, a control method based on H theory will be so designed to supress thevibration of the space truss structure caused by impact.The work of this dissertation can be divided into the following four aspects.1） To get the finite element model of active lever through Lagrange equation with considering theelectromechanical coupling characteristics of piezoelectric materials.2） To propose an improved encoding genetic algorithm, then optimize the allocation of piezoelectricactive position in the truss stucture, and get the optimized finite element model of intelligent trussstructure, based on an optimization criterion of maximum modal force per unit voltage.3） To design a H controller having a bandpass characteristic, by defining weightmatrix interference wisely, based on state-space model of the intelligent truss structure.4） To simulate open-loop system and closed-loop system, based on the precise integrationmethod.Finally, the simulation examples show that the design of robust controller can suppressthe vibration of the truss structure quickly. Therefore, it has a good damping effect.