Nonsmooth Control Algorithm For Base Smart Isolated Structure With Roller Bearings And Experimental Research

In this paper,the base isolated structure with roller bearings is taken as controlled structure.The active control or semi active control devices are added in the isolation layer of the isolated structure,which is to form the smart isolated structure.And the smart isolated structure combines the advantages of passive control and active control.Thus,structural vibration response can be suppressed.Base on the smart isolated structure,the main work of this paper is as follow:(1)Nonsmooth control algorithm is used in the smart isolated structure.According to Lyapunov stability theory,the global finite time stability of intelligent control closed-loop system under nonsmooth control is demonstrated.The application of nonsmooth control algorithm in the area of civil engineering is of practical significance.(2)According to the characteristics of nonlinear structure,the state-space equation is modelled.And the state-space equation is decouple to subsystems.In the subsystem,nonsmooth controller is deduced.The major objective of nonsmooth controller is to guarantee the finite time and global stability of closed-loop system.With homogeneous and Lyapunov theories,the negative homogeneous degree of closed-loop system is demonstrated.In other words,it is globally finite time stability.(3)According to the design of nonsmooth controller,working interface of Simulink from MATLAB is used to establish nonsmooth active control simulation system and LQG active control simulation system under the control of ideal controllers.After selecting reasonable system parameters,the simulation of structural seismic response control under two control algorithm is analyzed.It is to verify that nonsmooth control needs fewer feedback variable and can suppress structural response greatly.Base on active control simulation systems of two control algorithm,the mechanical model of MR Damper and its semi active algorithm are introduced.Then nonsmooth and LQG semi active control simulation systems are modelled.The simulation results verify that compared with LQG control,nonsmooth semi-active smart control system can achieve feedback control by using less feedback variable.Under the equivalent control force of two control algorithm,nonsmooth semi-acive smart control can suppress controlled structural response and its control effect can approach active smart control effect.(4)In order to study the control effect of MR smart isolated structure under nonsmooth control,shake table tests of base isolated structure with roller bearings and MR smart isolated structure are conducted.The results show that MR smart isolated system has better control for structural vibration response than the isolated structure with roller bearings.And for control of MR smart isolated structure,the effect of nonsmooth control is better than the effect LQG control and isolation.By comparing simulation analysis and experimental results,the correctness and rationality of nonsmooth control method are verified.Nonsmooth control algorithm is a simple and effective method and is studied in the area of space flight,military and machinery.In this paper,nonsmooth control algorithm is studied firstly and then base on civil engineering structure,nonsmooth algorithm of using fewer feedback variables is designed.By analyzing simulation modeling and shaking table test,the effectiveness and correctness of the designed control algorithm are verified.