Theory And Application Method Study Of Fuzzy Control On Long-span Space Structure

With the progress of scientific and technological and development of society, long-span structures have been widely applied at home and abroad. But large vibrations tend to happen when long-span structures are in outside dynamic loads. If these vibrations are not controlled, the whole building will be affected or damaged. Because of complex structure, it is difficult to form precise modeling for long-span structures. Thus, traditional control methods relying on accurate model are not suitable. From this point of view, the dynamics of long-span spatial structures are studied in this thesis.The fuzzy control is a kind of control method relying on rules and do not need precise structure model. Based on fuzzy control method and GMM actuator made of Giant Magnetostrictive Giant Magnetostrictive Material (GMM), vibration of long-span structures is controlled.(1) Characteristic and feature performance of giant magnetostrictive material (GMM) are analyzed. A new kind of actuator is designed with GMM and its output performance is tested through experiments. Relationship of the input current, incentive magnetic field and output force is analyzed and a transformation equation between electricity and force is deduced. These work lay foundation for long-span spatial structures vibration control.(2) The working principle of the active control system is analyzed and a control system of state equation is established. In view of a space truss, methods of integrating the quality matrix, the stiffness matrix and the position matrix are expounded. These work provide theoretical basis for building long-span space structure model.(3) The working principle of fuzzy control theory and the structure of fuzzy control system are introduced. A standard fuzzy logic controller is designed. This controller is used in long-span spatial structures by selecting appropriate scaling factors and the entire fuzzy vibration-control system is build finally. (4) On base of the optimization of the actuator, fuzzy control routine established by the Matlab software is used to carry on the initiative control simulation analysis to long-span spatial structures. The simulation results indicate that the active control effect is obvious.