Design And Analyze Of The Sensor Unit Of The Active Vibration Isolation

With the continual improvement of the ultraprecision processing equipments, it has moredemanding requirements of the processing environment, requirements of vibration is a veryimportant one. Compared to traditional passive vibration, active vibration isolation would becapable of achieving wider frequency band, overcoming disadvantage of passive vibrationwhich cannot simultaneously settle good isolation both ground vibration and load vibration.Besides, sensor unit is an important part of the active vibration isolation system for achievingits function, making an in-depth study has important theoretical and practical significance.Firstly, this thesis starts from the operating principle of the active vibration control system,and proposes functional requirements to the sensor unit. On the above base, this thesis designsand analyzes overall implementation of the sensor unit. According to the model comparisonboth non-contact displacement sensors and absolute speed sensors, this thesis selects thesensors to be used and determines the sensors’ type and performance indicators. Therefore,the design of the overall implementation of the sensor unit is finished.Secondly, this thesis establishes the dynamic model of the absolute velocity sensor, andanalyzes the limit factors of low frequency detection from the aspects such as the mechanicalstructure and exterior noise. And then it elaborates the low frequency compensation principleof the absolute velocity sensor by software method, and designs the compensator in differentways, then compares the time domain simulation results of these methods, two possiblemethods among them are described in detail. According to the comparison of compensationeffects of the results in time domain and frequency domain, this thesis provides the theoreticalbasis of selecting the appropriate software compensation method for the absolute velocitysensor in the practical application.At last, the thesis analyzes the calibration principle of the displacement sensor, andcompletes calibration both the displacement sensor and temperature sensor through themethod of least square fitting. Then, this thesis explains the experiment principle of thetransfer function parameters of the absolute velocity sensor, and that experimental data isobtained by sine sweep test. So this thesis completes curve fitting and gets appropriate parameters in the Matlab curve fitting toolbox. The work above offers reliable experimentbase for the sensor unit of the active vibration control system in practical application.