Research On Vibration Isolation Control Of Precision Instrument Based On Magnetorheological Elastomers

With the continuous development of society and the progress of science and technology,people need more and more precision instruments and equipment,especially in the optical industry,photographic chemistry,aerospace and semiconductor industry which has entered the era of precision and ultra precision.It is well known that vibration which will lead to the loss of accuracy and shorten the service life has great influence on the stability of vibration sensitive instruments,instruments and equipment.However,the vibrations are everywhere,Therefore,in order to ensure the precision and stability of the precision instrument,the vibration of the surrounding environment should be controlled.In this paper,the precision instrument factory building which through the overall vibration isolation of the plant and the instrument work platform isolation vibration control joint control measures is taken as the research object,and the effect of vibration control under ambient excitation is analyzed and discussed.First of all,this paper analyzes the environmental excitation of the precision instrument factory,and simulates the corresponding artificial excitation(0~500 Hz)and its time history which provide the basis for subsequent calculation and analysis.Then,Based on the finite element software ABAQUS,the vibration isolation effect analysis model of the vibration isolation ditch is established,which to explore the influence rule of vibration isolation groove depth,width,position,filling and quantity and other factors,The results show that the vibration isolation effect is better when the position of the vibration isolation trench is closer to the excitation point and the pick-up point.In a certain range,with the increase of the vibration isolation trench depth,the effect of vibration reduction is gradually enhanced,but the vibration isolation trench width has little effect on the vibration isolation effect;The harder(the shear modulus)of the filler is,the better the damping effect is;With the increase of the number of vibration isolation ditch,the effect of vibration reduction has changed obviously.The vibration reduction effect is determined by the deeper vibration isolation trench for the different depth of the vibration isolation ditch.Secondly,based on the design of the group of MRE vibration isolation device,the magnetic circuit is analyzed.Based on the physical model of magneto rheological elasticity,a mechanical parameter model which can reflect the relationship between the output power and current is presented.The results of theoretical analysis and finite element simulation are compared and analyzed,the results show that the theoretical values are in good agreement with the finite element simulation results.Finally,the parametric modeling of the working platform with the MRE isolation damping device and the high damping isolation bearing is established,and a seven degree of freedom parameter model is established to reflect the main motion attitude of the platform.According to the working characteristics of the control device,the corresponding vibration isolation control strategy is proposed,and the fuzzy control algorithm is used to analyze the dynamic response of the vibration isolation platform.The results show that using the passive control,medium and high frequency(30 Hz~100Hz)control effect is about 70%,in the range of 0~30 Hz,the passive control effect is only about 50%.When the semi-active control is used,the control effect can be reached to 90% and about 75%.