Hybrid Time-delay Effects In Multi-objective Optimization Of Structural Vibration Control

The high-rise building structure is easy to vibrate under the earthquake and strong wind,which will reduce its comfort and safety.At first,people used passive control to suppress the vibration of the building structure.However,the control efficiency of passive control is low and the adaptability is poor,which can not meet the needs of production practice.The active control has many advantages,such as good control effect and strong adaptability.In recent years,the active control has been widely used in structural vibration control.In active control,the time-delay is inevitable because of the time-consuming of collecting signals,generating control signals and exerting control force by actuator.The research shows that the time-delay has an important influence on the control effect of active control.In this paper,the influence of multiple time delays(mixed time delays)on different control performance indexes(multi-objective)in structural vibration control is studied,and the mixed time delay effect in multi-objective optimization of structural vibration control is described.Acceleration feedback control and PD(proportional differential)feedback control are widely used in practical engineering.In this paper,the vibration control effect of the building structure with active mass damper under the two kinds of feedback control is investigated,and the influence of the mixed time delay on the stabilization time and the maximum peak value is mainly studied,and the mixed time delay effect in the multi-objective optimization is described.Firstly,Lagrange equation is used to establish the dynamic model of the system.Secondly,the stabilization time and maximum peak value of the controlled system are regarded as two control performance objectives,and then a multi-objective optimization model is established.Thirdly,the multi-objective optimization problem is solved based on genetic algorithm,and the Pareto solution set and Pareto frontier are obtained.Finally,by comparing the answers of multi-objective optimization problems with and without time delay,it is found that the appropriate mixed time delay can reduce the stabilization time and the maximum peak value at the same time,thus to improve the control effect.In practical engineering,people usually think that the time delay is an unfavorable factor and will reduce the control effect of active control However,the result shows that the appropriate mixed time delay can improve the control effect of active vibration control and becomes a favorable factor.The research results enrich the research content of active control of structural vibration,provide theoretical reference for practical engineering application,and have potential application value.