Design Of Microscanning Control System Based On Piezoelectric Actuator

Micro scanning imaging technology is a new technology for improving the resolution of the imaging system.It uses multiple images to reconstruct the high resolution image with the low resolution image of the sub pixel displacement.Micro scanning technology can increase spatial sampling frequency of the imaging system,reduce the of the frequency aliasing phenomenon,significantly improve the resolution of the imaging system,but no need to increase the size of the detector pixel size.Because of basing on existing detectors,the micro scanning imaging system is cost-effective.Micro scanning technology has been successfully applied in many fields,such as satellite remote sensing,digital aerial camera,digital microscope and infrared thermal imaging system.In recent years,there is no report on the actual forming of micro scanning imaging system interiorly.This work has important significance for promoting the development of piezoelectric actuator.It can improve our micro scanning imaging technology.In this paper,the characteristics of the micro scanning imaging system are described.Based on piezoelectric stack actuator,a micro displacement amplification driving platform and control system for micro scanning imaging is designed.Then,the characteristics of the flexible hinge and the principle of triangle amplification mechanism are introduced.Based on the triangle flexure hinge principle,the micro displacement amplification mechanism is designed.The whole micro displacement driving platform is composed of micro displacement amplification mechanism.Finite element method is used to analyse the characteristics of micro displacement driving platform such as natural frequency,displacement magnification and nonlinear error.Piezoelectric stack has the characteristics of hysteresis nonlinearity.Hysteresis nonlinearity can lead to the decrease of the driving accuracy of the piezoelectric stack actuator,which can produce the system oscillation.The system's hysteresis nonlinearity must be reduced.In this paper,the inverse model of the Prandtl-Ishlinskii model is used as the compensator.Inverse compensation model algorithm is designed,the model parameters are obtained by the experimental data.Micro scanning imaging control system is compensated.In this paper,a micro displacement driving control system for micro scanning imaging is designed.The system is composed of the micro displacement driving platform and the displacement control system.The micro displacement driving platform has the characteristics of micro displacement amplification and two-dimensional precise positioning.The hysteresis compensation control system can significantly reduce hysteresis nonlinearity.The micro scanning driving control system can achieve accurate two-dimensional positioning,the system range is ±18?m,the maximum nonlinear error is 0.4?m.