Piezoelectric Active Semi-active Hybrid Vibration Control Study

The methods of vibration control adopting piezoelectricity component are mostly active control,semi-active control and passive control at present. Passive vibration control does not need external energies, but it's difficult to meet high demand of variable vibration forms. Active vibration control technique is effective in low frequency control, but it needs too much external energy; so it is often restricted by the environment. The advantages of semi-active control is that it has good adaptability to the change of external conditions, and does not need external energy;but semi-active control method can not get distinct effect. In this dissertation, a new method named mixed active and semi-active control method is introduced. The new method learns from the strong points of both active and semi-active meanwhile offset their weakness, it will have an excellent effect in practical.The focus of this dissertation is to study the mixed active and semi-active control method from theory modeling, simulation, experiment, etc., offering the technological means for vibration control of the flexible part in the engineering structure.Taking the piezoelectric cantilever beam with mixed active and semi-active control for example, using R-L branch circuit, a serial of differential equation has been set up, based on these equations the finite element models has been set up using discrete element method, and the finite element models has been solved with precise time step integration method. Through the simulation, we conclude that mixed active and semi-active control method has better effect with both sinusoidal steady state excitation and instantaneous excitation than single active control or single semi-active control method; meanwhile we can get from the simulation that the R and L value in the circuit has a optimal value in the new mixed active and semi-active control method.A lot of experiments with the mixed active and semi-active control method on piezoelectricity controllable cantilever beam were carried out in this study.The experiments include following works: Firstly, using the new chip PA78 produced in APEX company gives the high voltage that piezoelectric needed.Secondly, real inductance was instead by Analogue inductance to solve the problem of the high inductance in the branch circuit..Thirdly, to realize the real-time control mechanical potentiometers were replaced by digital potentiometers.Fourthly, experiment platform was built on LabVIEW dummy device and ARM7-board. The real-time control of vibration system was realized.The data got in the experiment verified that the mixed control method indeed has better effect than the single active or the single semi-active control method with sinusoidal steady state excitation examined.The study is supported by the natural science fund of Fujian Province (serial number of project: E0510020).