Study On Active And Semi-active Control Of The Piezoelectric Vibration Isolation System

In order to meet the high precision isolation requirements of the precise instrument, the technology of active vibration control which combines intelligent material, has become one of the most active research fields. As an important intelligent material, piezoelectric material has the advantage of wide frequency response, high sensitivity, high load carrying capacity, quick response etc, which shows a good prospect of application in the field of active vibration isolation.In this thesis, three new types of active and semi-active control of the piezoelectric vibration isolation system are proposed based on the piezoelectric effect and negative stiffness vibration isolation principle. The vibration characteristics of these three structures are studied. Firstly, the laminated piezoelectric active vibration isolation structure is proposed by applying the negative stiffness vibration principle, the vibration of this structure is analyzed according to the control method and control parameters of the system; Secondly, the structure of the laminated piezoelectric curved beam with simply supported at both ends is established by using the PVDF film, the multi-layer structure of the piezoelectric curved beam is seen as a single-layer structure, the vibration control equations of the piezoelectric curved beam are gained by applying the related elastic theory, then the control voltage and the dynamic vibration characteristics are analyzed according to the feedback parameters; Finally, the symmetrical semi-active piezoelectric beam structure is put forward based on the traditional negative stiffness structure, the beam model with axial force at both ends is gained by simplifying the structure, the vibration control equations are derived according to the simplified model, further more, the vibration characteristics and the relationship among parameters are analyzed.In summary, the vibration characteristics of these three vibration isolation system are studied by the theoretical derivation and numerical simulation, the vibration isolation effect is analyzed according to their vibration control equations. This study has a certain significance for the research and application of piezoelectric vibration isolation system.