Research On Key Technology Of Control Strategy Of Intelligent Isolator Based On Magnetorheological Elastomer And Piezoelectric Stack

Along with the development of precision fabrication, precision measurement and assembling technology, it has been a difficult and hot problem of desiderate to solve that how to effectively reduce the vibration of the adverse effects. The existing micro vibration control methods mainly include passive and active vibration isolation methods. However the two methods have some disadvantages. The passive one has poor low frequency suppression effects, and could not meet the requirements of vibration isolation when the excitation is complicated. The active one has large energy consumption, poor stability and high frequency suppression effects. The semi-active one based on the Magnetorheogical elastomer(MRE) has the characteristics of passive control, and can adjust the parameters in real time according to the excitations. It has been a hotspot in the research field of vibration control. As mentioned above, using the hybrid control method which is combined with active and semi-active control method can make the isolation system has the advantage of suppressing low frequency vibration and good stability. So it can reach better micro vibration suppression effects. Aiming at the key problems of the hybrid control method, the main work are listed as follows:① Dynamic characteristics of the piezoelectric stack actuator(PSA) and MRE isolator have been studied, respectively. Experimental setup has been established to test the output displacement without mechanical load and the force with mechanical load of the PSA, which is to study the relationship between the displacement, force and control voltage. And effective stiffness, damping coefficient, the gain efficient of displacement and force have been computed according to the testing results.② Then experimental setup for testing the dynamic characteristics of the MRE isolator has been established. Transmissibility in different currents have been tested, and the effective stiffness and damping coefficient have been obtained.③ Modal analysis has been conducted by using Ansys Workbench and experiment, and the modal frequency and modal shape of the flexible beam have been obtained. Fuzzy controller of the active vibration control system based on the PSA has been designed, and experimental setup based on the d SPACE system has been established to verify the effectiveness of the control method.④ Then fuzzy controller of MRE isolator based system has been designed, and the semi-active control laws have been derived according to the sky-hook control method. Using Matlab/Simulink platform, the simulation model has been established. In order to validate the superiority of fuzzy control, comparisons among fuzzy control and ON-OFF control have been made under sinusoidal excitation, random excitation and pulse excitation.⑤ The two degree of freedom model of the hybrid isolation system which is based on the PSA and MRE isolator has been established, and the transfer function of the load relative to the ground excitation has been derived. With numerical simulation, the influence of the model parameters such control current, intermediate mass and control voltage have been investigated. Then hybrid vibration control simulation model has been established in Matlab/Simulink, and the vibration control performance under low and high frequency excitation has been investigated by fuzzy control. Meanwhile, the result of switch control between active and semi-active control has been investigated.