Composite Nonlinear Feedback Controller Based On Genetic Algorithm And Its Application In MEMS Torsional Micromirror

In recent years,research on MEMS has become more and more popular.In various fields of MEMS,MEMS torsion micromirrors have caused a lot of attention.Applications include optical coherence tomography,off switches,high resolution displays.According to the driving method,the torsion micromirrors can be divided into different types,electrothermal MEMS torsion drive,piezoelectric MEMS torsion drive,electrostatic MEMS torsion drive,and electromagnetic MEMS torsion drive.Note that electromagnetic drive can generate a large deflection angle with a small driving voltage and therefore causes great concern.In this paper,the mathematical model of MEMS torsional micromirror is established.The composite nonlinear feedback controller is designed to improve the performance of the system,and better transient performance and positioning accuracy are achieved.The main contents of the paper are as follows:1.For the operating mechanism and working principle of electromagnetic MEMS.Introduced a variety of closed-loop control algorithms,Using electromagnetic correlation theory and finite element analysis,A mathematical model of input current and output declination was established,and a laser scanning system based on hard magnetic micromirror was built.Including voltage control current amplifier circuit production,FPGA-based data acquisition system,The accuracy of the mathematical model is verified by simulation and experimental results.2.Based on the micro-mirror platform,a variety of closed-loop control algorithms are introduced,including PID control algorithm,improved PID control algorithm,and sliding mode control algorithm.The goal is to improve the transient response of the system,making it stable,fast,and accurate.Simulation and experimental results show that the introduced control algorithm can effectively track the target signal and accurately achieve the required controller performance.3.After understanding the working principle and operation mechanism of genetic algorithm,the genetic algorithm is used to determine the optimal solution in the composite nonlinear feedback controller.The effectiveness of the introduced control algorithm is verified by MATLAB simulation and the experiment of MEMS torsion micromirror.The simulation and experimental results show that compared with the previous several control algorithms,The composite nonlinear feedback controller designed in this paper has better transient performance and positioning accuracy,and has potential application value for optical switches based on electromagnetic MEMS torsional micromirrors.Finally,based on the microelectromechanical optical system platform of the School of Automation Science and Engineering,South China University of Technology,The author verifies the validity of the research work in this paper.The experimental results show that the final design of the control algorithm solves the corresponding problem better.