Research On Structural Semi-active Control Method Based On Enhanced Variable-universe Fuzzy PID Control

With the development of large-scale and complicated architectural structures in China,how to effectively avoid structural damage caused by earthquake has become a great challenge for disaster reduction and prevention of modern architectural structures.In recent years,the theory and technology of vibration damping based on structural vibration control have been rapidly developed,especially semi-active control.Due to the advantages of achieving better vibration control effects with less input of external energy,semi-active control has received continuous attention and preliminary application in the field of structural vibration control,and has become a research preface and hot direction in the field of disaster prevention and mitigation in civil engineering.The variable universe fuzzy PID(VUFP)algorithm can achieve better semi-active control effects,but it is difficult to design the parameters of the scaling factor and the parameters of the scaling factor cannot be adjusted adaptively according to the response of the structure.Therefore,based on the fuzzy control theory,this paper proposes two enhanced VUFP control algorithms to provide a new method for solving the vibration control of complex building structures.At the same time,the magnetorheological damper is selected as the control device,two semi-active simulation control systems with improved VUFP control algorithm are established,and the effectiveness of the proposed algorithm is verified by SIMULINK simulation and shaking table test.The specific research content of this paper is as follows:(1)Aiming at the problem for parameter design of functional scaling factor,the system error and error change rate are taken as the input variable and the scaling factor parameter as the output variable.Combined with the traditional VUFP control algorithm,a scaling factor parameter adaptive control algorithm is proposed.The framework structure is selected as the research object,the magnetorheological damper is used as semi-active control device,and the program of structural vibration control simulation system based on the proposed algorithm is programmed by SIMULINK tool.Comparing the vibration control effect of the proposed control algorithm with PID control,fuzzy control,VUFP control and verifying the anti-interference ability of the proposed algorithm.The simulation results show that: the proposed algorithm can obtain better damping effect than other control algorithm and it can achieve 68.62%,68.79% and 52.52%damping rates for the top layer peak displacement,peak velocity and peak acceleration of the three-layer frame model structure,respectively.After adding 10% of white noise to the bottom displacement and velocity of the structure response observations,the proposed algorithm makes the control rate of the top displacement peak and velocity peak of the structure increase by nearly 2%.There is a 3% increase,indicating that the proposed algorithm has strong interference ability.(2)In view of the problem that the adaptive VUFP algorithm for the scaling factor parameter lacks fuzzy control rules and the control performance is not high,the scaling factor parameter is designed as a new function about system error and error rate of change.Combined with the basic theory of traditional scaling factor design,a new scaling factor VUPF control algorithm is proposed.The simulation results of the three-layer frame structure show that: The control rate of the proposed control algorithm can reach 65.88%,70.97% and 52.36% of the top layer peak displacement,peak velocity and peak acceleration of the three-story frame structure,respectively.Considering the influence of noise on the proposed algorithm;applying 10% white noise to the bottom displacement and velocity of the frame structure,the control rate of the top peak displacement,peak velocity and peak acceleration of the structure becomes 66.47%,71.39%,54.67%,indicating the proposed algorithm has good anti-interference ability.(3)Aiming at the VUFP control algorithm with self-adaptive scaling factor parameters,an experimental study on frame structure vibration control is carried out.A three-layer steel frame model was designed and produced,and a magneto-rheological damper was used as the control device.A laboratory semi-active control system based on the adaptive VUFP control algorithm of the scaling factor parameters was built.Through the shaking table experiment,the vibration reduction effect of the uncontrolled,PID control,fuzzy control,VUFP control and the scaling factor adaptive VUFP improved control algorithm is compared.The peak control rate of displacement,velocity and acceleration of the top layer of the structure can reach 55.30%,50.83% and 45.39%respectively;under the action of Taft seismic wave,the peak control rate of displacement,velocity and acceleration of the top layer for the structure are 59.95%,48.12% and49.11%,respectively.Moreover,the VUFP control algorithm with adaptive scaling factor parameters has better damping performance than the PID fuzzy control algorithm and the traditional VUFP control algorithm under the action of different seismic waves.