Research On Active Vibration Control Of Piezoelectric Cantilever System

Saving energy and raw materials and improving efficiency are the key issues faced by the current world economy,military,and science and technology development.A large number of aerospace structures have also brought a series of problems with the use of lightweight materials: structural modal damping is reduced,and flexibility is increased.The large amplitude of the vibration response and other issues seriously affect the accuracy and service life of the system.On the other hand,in recent years,a new type of smart material,a piezoelectric material,has been frequently used in structural vibration control due to its excellent electrical and mechanical properties and electromechanical coupling characteristics.Based on the above situation,in order to effectively suppress the vibration of the flexible structure,the cantilever beam structure with the classic and simple structure in the flexible structure is used as the controlled object,its dynamic characteristics are analyzed,and the positive and inverse piezoelectric effects of the piezoelectric material are utilized.The electromechanical coupling characteristics obtained the differential equations and state space equations of the piezoelectric cantilever beam.Then piezoelectric ceramic actuators were used to design an experimental system for active vibration control of piezoelectric cantilever structures.For sinusoidal signal interference,by using a frequency extraction algorithm based on time-frequency analysis technology,not only can the unknown frequency of the vibration signal be accurately and quickly identified,but also the frequency effect of random interference can be eliminated.In other words,this paper proposes a new type of application-oriented adaptive feed forward control algorithm.This method makes the control input continue to converge to the interference signal,and finally it can perform perfect vibration control on sinusoidal interference with unknown frequency.And through the corresponding experiment to verify the effectiveness and superiority of the method.Considering the advantages of PID control,it is difficult to apply to complex controlled objects.The idea of inverse model control is proposed.The purpose is to suppress or eliminate the effects of high-order modal vibrations of the control object.Only the low-order modes are preserved as much as possible,and then the PID controller can be designed more easily.The characteristics of the PID controller areused to perfectly suppress the vibration in the low frequency range.It is very important that the sensitivity of the parameters in the inverse model transfer function is not high in this method.Even if the model is unknown or the parameter error caused by the random factors in the actual situation,it will not greatly affect the output of the closed-loop system.The comparison of the simulation with the LQG control and controller also verifies the excellent control effect of this method.And this method is extended to the automobile suspension model,and the simulation results also verify the superiority of the method.