The Theoretical Analysis And Algorithms For Building Structure Vibration Decentralized Control

There are more and more high-rise and large-span buildings in the future. For the large scale structures, the vibration load such as earthquake, strong wind and wave loading etc. is a key factor which affects the building serviceability and the ultimate load-carrying capacity. Anti-vibration problems of the building become a major issue in the field of civil engineering.The traditional passive vibration control methods that take advantage of the dissipation capacity of the structure and material have there limitations and they are difficult to ensure a natural disaster to people’s life and property safety and to meet the increasing requirements of the living environment. Based on control theory, the active/ semi-active vibration control method become a new way of building structures to resist earthquake, wind load etc. because of good effect, strong adaptability and other potential advantages.In general, the large-scale structure systems are controlled through a central controller using the necessary sensors, actuators and the central controller. One of the main problems with this kind of so-called centralized control approach is that the operation of the whole control system will be disrupted when the central control unit loses its functionality for any reason during earthquake and wind hazards. With the increases in system dimensionality, computation required by a centralized controller increases faster. To overcome these difficulties, decentralized control strategy was proposed. The systems are divided into a number of smaller subsystems and each subsystem has its own controller. These controllers make control decisions through acquiring data from local and neighboring sensor. Decentralized control approach would lead to an increase in the overall reliability of the control system.Based on large systems theory and the structure decentralized control methods, this paper conduct the theoretical analysis and algorithms for building structure vibration decentralized control. Focus on large-scale building structure, the nonlinear decentralized robust sliding model control methods were investigated and the linear multilevel hierarchical decentralized stability control methods were established. The corresponding control programs were developed and the effectiveness of the proposed method was demonstrated by the numerical simulation of the decentralized control for a 20-story benchmark structure under seismic excitations. The main research work and achievements were summarized as follows:(1) Based on large systems control theory, a decomposition method of large tall building was presented. Higher order structural system was decomposed into some lower substructures. The interaction of subsystems and seismic disturbance were conducted as bounded generalized force acting on the subsystem. Large scale structural vibration control model was equivalent to the decentralized substructure control model with bounded disturbances.(2) Using unit vector method that is a nonlinear method of sliding mode variable structure control, a decentralized robust control method was investigated and developed for large scale building structure. Taking advantage of anti-perturbation conditions of sliding mode theory, an overall stability sliding mode trajectory was designed. The control condition, which satisfies the global stability using local state of substructure system, was derived and every substructure was regulated with a parameter. The decentralized robust control algorithm was formulated and at the same time the pseudo-sliding mode control method was used to overcome the chattering of variable structure sliding mode.(3) For the general case that actuators were not arranged in every floor of substructure, the implementation process of decentralized sliding model control model for building structures was presented. According to shear building structure system matrix characteristics, the actuator arrangement criterion. was discussed. Using the singular value decomposition (SVD) method to the control force matrix, the transform satisfying sliding mode control requirements was derived.(4) A decentralized sliding mode part output information control was presented for the large scale building structure. Using linear matrix inequality (LMI) method, the existent condition of stable sliding mode under the output coordinates was derived. The stable decentralized output information control laws were established. The complex coordinate transformation of the sliding mode design can be avoided by the presented method. Moreover LMI was used to simplify the selection of design parameters in the method.(5) Only using displacement output, an overall stability decentralized sliding mode control was developed. To overcome the difficult that the dimension of the system and the system matrix do not meet the conditions of the sliding mode design, an auxiliary dynamic compensator was introduced and an augment system model was obtained. Through a non-singular transformation the augment system was decomposed into both control action space and sliding model space. The control condition that satisfies the global stability only using local information of substructure system was analyzed and every substructure was regulated with the dynamic parameter.(6) For the general case that anti-perturbation conditions of sliding mode theory is not satisfied, optimization control method based on H-infinity performance was used for the design of stable sliding mode. Using the method of linear matrix inequality, stable sliding mode motion with certain performance index was derived. And sliding mode control design with unmatched condition could be achieved(7) The input decentralized control model for large-scale structure was established. The multilevel control consists of local controllers and global controller ensured the closed-loop substructure system asymptotic stability. Using H-infinite control method the stable local controller of each independent substructure was obtained. The stability properties of these substructure systems were aggregated a scalar Lyapunov function and the global controller was derived according to the condition of global stability of the overall structure. The design method of global controller consist of part states feedback was discussed. Results show that through part states feedback the global control could guarantees the overall stability of the structure. Using linear matrix inequality (LMI) method the proposed decentralized design is more flexible.