Research On A Frictional Micropositioning Stage Based On Piezoelectric Driving

The precision manufacturing, precision measurement and micromanipulation techniques have gradually become an important support technology, while the precision positioning technology is one of the key technologies, and has played an important role in modern advanced industrial production and scientific research. Micropositioning control system is the basic stage in the study of precise positioning technology, so it has a significant impact to promote the wider use of precise positioning technology that we need to constantly develop some new and reliable micropositioning stages to meet kinds of application requirements. In this paper, we designed a frictional micropositioning stage based on the piezoelectric driving, which not only can provide the high precision and fast response micro-displacement, but also has a larger travel range (unlimited travel range in the theory) and larger bearing capacity.Firstly, the micropositioning stage designed in this study relies mainly on the guiding devices to bear the capacity, and generate the displacement by the friction driving. There are four parts in this system:micropositioning stage, piezoelectric actuator driving power, computer and laser interferometer, and they form a closed loop system which can satisfy the high precision positioning requirements. We analyzed the driving mechanism of the stage using the structural mechanics theory and finite element method, so we got the transmission chain's equivalent stiffness and response frequency of the driving mechanics, providing static characteristics of the micropositioning stage.Secondly, we establish the dynamics model and equation of the driving system according to its characters. We also establish the frictional simulation model according to the friction phenomena in the driving process, and analyze the changing laws of the main factors to affect the system precision, and get the reasonable range of the main parameters in the system control.Thirdly, the experimental micropositioning system has been made based on the above static and dynamic mechanics analysis results. The experiment results are also compared with the simulation results. It shows the simulation method is correct, so the research method about the micropositioning stage is valuable and useful.Finally, the factors to generated system errors are analyzed except the driving mechanics, and it includes piezoelectric actuators'output displacement characteristics, guiding device's precision and measure Abbey errors etc, while the corresponding methods to reduce the errors are proposed to improve the micropositioning system precision.