Research On The Active Vibration Control Of Piezoelectric Plate Based On Piezoelectric Material

Traditional control methods and structures are very difficult to meet therequirements for vibration control in actual project. Research on the active vibrationcontrol of piezoelectric plate based on piezoelectric materials has been an issue ofgreat concern. With the emergence of smart structures based on piezoelectricmaterials and its application recently, research of smart structures is becoming a veryactive area in research and application of the structure vibration control. As a newtype of smart materials, the piezoelectric materials have been widely used in the fieldof structural active vibration control because of their excellent mechanical-electricalcoupling characteristics. Due to people’s ride comfort requirements of the carimproving, it is necessary to control vibration of body panels. What’s more, bodyvibration has a great influence on car’s performance of NVH. In this paper, asimplified plate as an alternative, active vibration control of piezoelectric plate basedon piezoelectric materials has been performed.LQR algorithm has been proved to be one of the most effective control methods.At present, in the research of active vibration control of structures, the method is in awide use. However, as for how to define the weighting coefficient matrices Q and R,which are vital in the objective function, there are not enough theoretic basis andanalysis in any research report. This paper is utilizing Genetic Algorithms to optimize,linear quadratic regulator controller and solve the bottleneck problem oftransformation from quantitative to qualitative in human-imitating intelligent controlautomatically and releasing people from the time-consuming trial and error exercises.Following is the main contents of this thesis:(1) Based on the large number of references both at home and abroad, the thesisbegins with the review of the previous related studies. Current situation about theapplication of active vibration control technology of piezoelectric intelligent structures and research of active vibration control method of structures aresummarized.(2) By the analysis of basic performance and characteristics of piezoelectricmaterials and piezoelectric equations, the principle of the piezoelectric sensor and apiezoelectric actuator are deduced, which lays the theoretical foundation forsubsequent analysis of the simulation and finite element.(3) Based on the theory of the state space, the problem of state space equationsfor piezoelectric system composed of the simplified rectangular flat plate structureand piezoelectric element is solved in the MATLAB. The observability andcontrollability of the system are analysed.Vibration responses in time domain andfrequency domain for piezoelectric plate with different forms of external excitationsignal effect are analysed by using MATLAB/simulink software. On the basis of theLQR optimal control theory for piezoelectric plate LQR control law is designed.(4) This paper introduces the principle of linear quadratic regulator. Thevibration of the piezoelectric plate are studied by LQR numberical simulationresearch, the obvious effects are obtained in the control effect and control cost. Theweighting matrices Q and R have an influence on the effect of control system. Inconclusion, the control effect of the system is better with the increase of elements inweighting matrix Q, but it needs more input control energy. The requirement for inputcontrol energy is reduced with the increase of elements in weightinng matrix R at theexpense of control performance of the system. Finally, based on the genetic algorithmtoolbox of MATLAB, the optimal state weighting matrices are obtained. It can beseen that the genetic algorithm in the optimization of the weighting matrix isconvenient, feasible and effective.