Research On Method Of Active Vibration Control Of Flexible Intelligent Frame Structures

The vibration control of engineering structure is a fore field of latter-day structure engineering,meanwhile,it also is a important means of structure anti-vibration;Frame structures are the most essential simplified shape of buildings,and its study on vibration control has importantly theory significance and applied value. In the dissertation,the engineering structures are used as studying background,the frame structures are given as researching object,the key to the dissertation emphasized on the method research of active vibration control of intelligent frame structures. The technology of active vibration control is one of the presently studying hotspots. The study on active vibration control of frame structures possesses a bigger difficulty because bend and torsion are existed as well as self-contained measure can not been realized, meanwhile, it also is a very absorbed task. In the dissertation, frame structures are given as researching object, the related problems are also studied during the method research of active vibration control of intelligent frame structures, including the design of active member system,control model,the design control strategy,the optimal disposition of actuators and sensors,mix design,the emulation experiment of real-time computer vibration control, etc. the chief contents are listed as follows: 1. Aimed at the characteristic of higher order in active vibration control model of frame structures, the multi-step energy method which can be used to determine the main degree of freedom of system is presented. With the help of it, the energy difference between original system and reduced system can be cut down and main freedom degree can be determined. 2. Aimed at the characteristic of bigger error existed in active vibration control model of frame structures, experimental modes data are usually used to modify calculating model. In the dissertation,a new corrected method, straightened algorithm, is presented, with the help of the algorithm, not only the characteristic of sparsely strip matrix be can assured, but also the complicated extent of calculation be can greatly reduced because the variables that locate only in the strip matrix are optimized. The algorithm possess high precision and stability along with the increase if iteration times. 3. As a problem of combined optimization,the calculated times of optimal disposition of actuators/sensors of active vibration control of frame structures is enormous. Meanwhile, two restrictions are existed in the course of optimization,one of the restriction is that partial placement is only allowed to dispose actuators/sensors;another restriction is that the given number of actuators/sensors must be a constant. In the dissertation,Based on modal degree of controllability and least cost function. The genetic algorithm is adapted to solve the optimal disposition in active vibration control. Conventional genetic algorithm is improved to fit into the solution of frame structures. At the same time, the calculated times is also reduced greatly. 4. Aimed at the characteristic of imprecise model as well as measurement error and outer disturbance are existed in active vibration control of frame structures, in this dissertation, the generalized predictive control strategy is introduced and improved to suit for the active vibration control of frame structures; Meanwhile, the generalized predictive control of independent modal which based on modal degree of controllability is developed 5. In order to improve dynamic characteristic of frame system (including stability and response), in this dissertation, a inverted strategy of pole assignment of multi-step is proposed. By using it , we can purposely assign the poles through restriction assigned poles, 6. In order to reduce to the best of our abilities the control energy needed for active vibration control of frame structures,a mix design idea which combine structural design with active control is presented, original structures are designed again to diminish control energy under the premise of basic performance and control effect of frame structures can be assured. 7. Based on generalized predictive control, a real-time control strategy is programmed in VC++ and MASM. A testing and controlling system , which include piezo-sensors/ actuators,signal adjustor,A/D,D/A data collection card ,filter,computer and voltage amplifier, is composed to fulfill emulation control experiment. Emulation results show that control model, actuators/sensors placement ,control scheme in thedissertation are correct and effective.