Research On Two-photon Polymerization Processing Control System Based On Sliding Mode Control

Femtosecond laser processing has many advantages,such as high accuracy,no pollution,and small heat affected area,while the three-dimensional micro-nano structures produced by femtosecond laser two-photon polymerization processing technology can achieve micro-nanometer resolution.It not only occupies an important position in advanced manufacturing,ultra-precision machining and other research fields,but also has shown important application prospects in microelectronics,micro-optics,micro-electromechanical systems and biomedical fields.However,currently Not only at home but also abroad,the processing efficiency of the workpieces processed by the femtosecond laser two-photon polymerization processing system and the processing capability of the three-dimensional structures are not very perfect,and there are great restrictions.At the same time,most of the domestic processing systems are still undergoing experimental research,so in order to solve the above problems and defects,the laboratory has set up a set of femtosecond laser two-photon polymerization processing system.In order to improved processing accuracy,processing efficiency and ensure the processing quality processing of the femtosecond laser two-photon polymerization processing system,We must constantly experiment and research,improve and optimize continuously.At the same time,make the processing system has the ability to process complex three-dimensional micro-structures,so that it can has a good processing effect,the processing picture is more clear and complete.The main research contents of the paper are as follows:(1)The overall structure layout of the built-up femtosecond laser two-photon polymerization processing system is introduced.Not only briefly introduce the optical system of the processing system(laser transmitter,power attenuator,beam expander,shutter,mirror,4F system,bidirectional mirror and optical lens),but also introduce a real-time monitoring system composed of a CCD high-speed camera and an optical microscope;Finally,the detection feedback device of the positioning system,The macro-micro positioning system which consists of a three-dimensional macro motion platform driven by an air bearing linear motor and a three-dimensional micro motion platform driven by a piezoelectric ceramic,two-dimensional XY galvo system,laser shutter are introduce.(2)Firstly,the dynamics modeling of the macro-positioning platform driven by the air bearing linear motor and the micro-positioning platform driven by the piezoelectric ceramics is performed.Through analysis,the Kalman filter-based sliding mode control is used to suppress system vibration and various noise disturbances and improve the control system positioning accuracy.Simultaneously with MATLAB simulation,the results show that the Kalman filter-based sliding mode control scheme can not only suppress the corresponding vibration of the output of the macro-motion platform,but also can solve the noise interference problem.At the same time,it can also improve the displacement control accuracy of the system and illustrate the feasibility of this control scheme;Aiming at the low hysteresis nonlinearity and other factors of piezoelectric ceramics in two-photon polymerization processing system,this paper analyzes the problems of low positioning accuracy and jitter which generate in processing,and a robust adaptive sliding mode control scheme for RBF neural networks with uncertainties and interference estimation was adopted.The identified model was simulated using Matlab's Simulink module.the simulation results confirmed the superiority of the proposed control scheme and verify the validity of the model.(3)The laboratory uses the A3200 control system based on Aerotech as the controller,and carries out secondary development in the Labview module of the system.Through graphical programming,collaborative linkage control between important moving parts in the experimental system can be realized.(4)Through a series of three-dimensional structure processing experiments not only verify the femtosecond laser two-photon polymerization processing system has a good processing quality and processing results,but also verified that the processing system has the ability to process complex three-dimensional micro-structure,And it has a good processing effect,the picture is more clear and perfect.