Based On State Feedback Optimal Control Of The Damping Effect And Stability

The research of control algorithms is an important content for active control and semi- active control. Optimal control is a powerful tool, and has been widely applied in civil engineering. The existing optimal control algorithms include classical optimal control algorithm (COC), instantaneous optimal control algorithm (IOC), and sequential control algorithm (SOC) proposed by the author's research group who synthesizes the advantages of COC and IOC. The paper takes "smart" isolated structure as research objection, aims at the controlled response and stability of optimal control algorithm, and mainly focuses on the following things:1) When a structure comes up against small earthquake, the paper applies elastic model to the structure, derives the variation discipline following time of three optimal control forces based on state feedback, and provides a semi- active algorithm according to the characteristic of MR damper. Based on state feedback, a "smart" isolated structure is controlled under equal energy of three control algorithms. The result shows that the effect of sequential control algorithm is better than classical optimal control algorithm and instantaneous optimal control algorithm.2) Under small earthquake, with equal control energy, based on output feedback, compare the result of output feedback with that of state feedback. The result shows the effect of output feedback exceeds state feedback, which shows the rationality of using output feedback in smart isolated structure.3) When a structure comes up against big earthquake, the structure usually comes to its elastic-plastic deformation, and becomes hysteretic system. The paper expresses the resilience of the hysteretic system with usual Bouc -Wen model. Based on state feedback, a "smart" isolated structure is controlled under equal energy of three control algorithms. The result shows that the effect of sequential optimal control algorithm cutting maximal peak value response of base isolator is close to classical optimal control, and better than optimal control, but classical optimal control algorithm increases response of the substructure greatly.4) Only stable system can work well, so researching the stability of control system is always an important question for control theory. The paper applies Lyapunov's second theory to stability for its wide application. The result indicates that for elastic system three optimal control algorithms are all stable. And for elastic-plastic system, the stability of sequential optimal control algorithm is obviously better than the other two optimal control algorithms, showing good stability.