Research On Dynamic Characteristics Analysis And Fuzzy Control Of Micro-vibration Semi-active Vibration Isolation Platform

With the development of precision manufacturing,precision measurement and other technologies,the vibration requirements of working environment become more and more stringent.Because the parameters of the isolator are fixed,the traditional passive vibration isolation method can not meet the requirements of variable vibration suppression.Magnetorheological elastomer(MRE)semi-active isolators have received more and more attention in the field of vibration due to their adjustable parameters under magnetic field,low power consumption and fast response.In this paper,MRE isolators are used to suppress the vibration of micro-vibration precision machining and micro-vibration measurement platform.The accuracy of the vibration isolator model in the control system,the optimization of the controller and the vibration attenuation performance are directly related.Therefore,this paper studies these problems in the application of the micro-active semi-active platform control from the following aspects:(1)For the MRE micro-vibration isolation platform,build a MRE vibration isolator sweep test system,test the parameters of the micro-vibration isolation platform MRE isolator,and determine the consistency of the four isolator parameters.On this basis,the dynamic characteristics of the micro-vibration platform are studied.The mathematical model of the micro-vibration platform is established by ADAMS simulation,and the simulation model is verified by the platform sweep frequency experiment.(2)For the quarter-micro-vibration platform MRE vibration isolation system,a semi-active fuzzy controller is designed,and the fuzzy controller’s scale factor,quantization factor,membership function,fuzzy rules and other parameters are optimized by genetic algorithm.The experiment verifies the effectiveness of the optimal controller.Under the sinusoidal excitation with the excitation amplitude of 0.2g and the frequency of 45-60 Hz,the response acceleration attenuation of the vibration isolation structure is better than the non-optimal fuzzy under the optimal fuzzy controller.Controller,the maximum attenuation of acceleration in the simulation can reach95.6364%.(3)Study the forward and inverse model modeling method of MRE isolator.The mechanical properties of the MRE isolator under alternating current were tested by experiments.The NARX neural network and BP neural network are used to establish the forward and reverse models of the MRE isolators,and the genetic algorithm is used to optimize the network structure.The experimental results show that the NARX neural network can be more accurate than the BP neural network.The positive model of the MRE isolators,while the BP neural network can establish a more accurate inverse model of the isolator.(4)For the quarter-micro-vibration platform MRE vibration isolation system,the optimal fuzzy controller and the neural network inverse model are combined to design the fuzzy-neural network controller to control the vibration isolation system.Experiments verify the effectiveness of the designed controller.The experimental results show that compared with the traditional fuzzy control,the fuzzy-neural network controller can accelerate the acceleration attenuation under the sinusoidal excitation condition with the acceleration amplitude of 0.1-0.3g and the frequency of 30-65 Hz.The acceleration is better than the traditional fuzzy controller.Maximum attenuation60.28%...