Hysteresis Modeling And Control System Of Micro Displacement Platform Driven By Piezoelectric Actuator

Precision positioning technology has become one of the core technologies in the field of high technology,which plays an important role in the industrial production(such as the production of micro nano CPU,MEMS manufacturing,etc.)and scientific research(such as cell injection,the improvement of the precision of AFM).Therefore,the research of precision positioning technology has become a hot spot for scientists and scholars.The accuracy of the precision positioning technology to improve,accuracy enhancement,improvement of the resolution and improvement of the positioning speed are the difficult points in the research.So,in this paper,a piezoelectric micro displacement worktable is taken as the research object,and control program is written and the hysteresis characteristics of the integrated displacement platform are modeled.By means of the compound control method based on voltage compensation feed-forward control and PID feed-back control,and hysteresis is compensated to achieve the purpose of linear control.The main research contents are as follows:1.For the type of XP-611 Piezoelectrically microPositioning stage,we set up the experimental system of it.Experiment system is composed of the following working module:displacement sensing module,driving power supply module,Piezoelectrically microPositioning stage,computer control system.2.A precise positioning experiment system based on integrated piezoelectric micro displacement platform XP-611,the data acquisition program based on Lab VIEW is used to collect the data of the worktable and use MATLAB based test program to test the characteristics of the micro displacement.3.The hysteresis characteristics of the piezoelectric micro displacement platform are studied,the mechanism of hysteresis nonlinearity is analyzed and the Bouc-Wen model is used to model the hysteresis characteristics.By analyzing the advantages and disadvantages of the model,found that the model is inaccurate in quick positioning of the displacement platform.So,proposing composite modeling method,which conbine with the Bouc-Wen model and the model of inherent characteristic of the platform.The accuracy is greatly improved in the quick positioning of the worktable and verified the superiority of composite model.At the same time,a class Bouc-Wen hysteresis model based on the classical Bouc-Wen hysteresis model is established,which can be applied to the fast positioning of the piezoelectric micro displacement platform with the requirement of timeliness.4.According to the established mathematical model,the corresponding control algorithm is written in order to eliminate the hysteresis characteristics of piezoelectric micro displacement platform and achieve the purpose of linear control,is concrete is:In order to achieve the purpose of linear output,analyzing the characteristics of Bouc-Wen model and using voltage compensation as feed-forward link,PID control as feedback link,and compared with the single PID control method and the single Bouc-Wen model voltage compensation control method,the compound control is better.