Research On 2-DOFs Precision Micro Positioning Stage Based On Giant Magnetostrictive Actuator And Its Driven Control System

Precision positioning technology is an important symbol of national manufacturing level and the main pillar of a country's advanced manufacturing technology,but also is one of key technologies in fields of precision drive,precision measurement and precision machining.It is of great significance to study precision positioning system to promote the development of high performance precision machining equioment,to achieve the development goals of hign grade CNC machine tools and basic manufacturing equipment,and to implement the strategy of "made in China 2025".For the precision positioning stage based on piezoelectric ceramic actuator being short stroke,small load,high voltage,a micro positioning system with high performance is developed,its driving system is designed with giant magnetostrictive materials,and a flexible hinge platform with two degree of freedom is designed,and a control system is developed in this paper.The developed precision positioning system is in-depth studied by combination methods of theoretical modeling,electromagnetic simulation,static and dynamic finite element analysis,numerical analysis and experimental research.The extreme free energy mathematical model of single domain of GMM is established based on the principle of minimum free energy of the Stoner-Wohlfarth model,the change rules of magnetic domain deflection angle under applied stress and electric magnetic field are obtained,and the magnetostrictive mechanism of GMM is revealed.A new structure of high thrust actuator based on GMM and a new mechanism of precision transmission based on flexure hinge are proposed,and their specific design sizes are determined.The output model of the precision positioning stage is established,and a hybrid parameter identification algorithm of particle swarm optimization and artificial fish swarm is introduced.The hardware and software platform of the control system is constructed,and the control strategy of DRNN feedforward fuzzy PID feedback is adopted.The results show that the magnetic field structure of double coils,the pre-stress mechanism of disc spring combined with screws and water cooling system of pipe winding for structure design of GMA,the optimum parameters of magnetic field,pre bias pressure and working temperature are obtained,and the maximum displacement of GMA is 80?m,the maximum output force of GMA is 292.3N;the hysteresis characteristic of this system is described by Jiles-Atherton model,the hysteresis model parameter identification is identified by a hybrid optimization algorithm of particle swarm optimization and artificial fish swarm,the hysteresis inverse model of this system is obtained by DRNN,the feedback control for the output displacement of this system is using fuzzy PID,so that the positioning accuracy of this system reaches 0.75?m,the positioning resolution is 10nm,the positioning stroke of X and Y directions are 30.8?m and 40.5?m respectively,the maximum repeatability error is 0.6?m.The contents of each chapter are as follows:In chapter 1,subject source,research background and research significance are introduced.The overall performance of precision positioning system can be improved from three aspects:the improvement of acturtor performance,the design of precision transmission mechanism and the improvement of reliability of control system by analyzing the present situation of the precision positioning system,and the research status of these three aspects at home and abroad are summarized,and the research contents of this paper are determined.In chapter 2,the extreme free energy mathematical model of single domain of GMM is established based on the principle of minimum free energy of the Stoner-Wohlfarth model,the change rules of magnetic domain deflection angle under applied stress and electric magnetic field are studied,and the magnetostrictive mechanism of GMM is revealed.And on this basis,the four aspects of this actuator are optimized design from the GMM bar selection and structural design of magnetic field,prestressing force and temperature control mechanism,and a new structure of thrust actuator based on GMM is proposed to ensure the performance of actuator of precision positioning stage.In chapter 3,the electromagnetic field model,hysteresis model and magnetostrictive model of giant magnetostrictive actuator are established respectively,and the electromagnetic properties are optimized analysis.The influences of bias magnetic field and pre-stress on the magnetostrictive strain are obtained through the numerical simulation analysis of hysteresis model.The control equations of weak solutions of mechanical stress field and magnetostrictive constitutive equation are established,and simulation analysis is carried out by finite element method.Finally,the optimal driving parameters are obtained,which can provide theoretical basis for improving the hysteresis nonlinearity and improving the control precision of giant magnetostrictive actuator.In chapter 4,a new structure of flexible hinge platform having two degrees of freedom is proposed.Based on the flexible hinge design theory,the static and dynamic models between output displacement and input force are established and the optimal design parameters and geometric dimensions of flexible hinge are obtained by numerical simulation method.The natural frequency of the flexible hinge platform is obtained through the analysis of the vibration characteristics of flexible hinge platform on the basis of the dynamic equation.Finally,the static and dynamic models of flexible hinge platform are verified by using ANSYS Workbench and MTALAB software,and the transmission characteristics of flexible hinge platform are obtained.In chapter 5,a hybrid parameters identification algorithm of particle swarm and artificial fish swarm is proposed,and a DRNN-PID fuzzy feedforward feedback control strategy is introduced,which is simulated based on MATLAB/SIMULINK module.The simulation results show that the proposed parameters identification algorithm has high identification precision and that the introduced control strategy is is effective.In chapter 6,the experimental platform of GMA is established,and the magnetic field intensity of double coils,the output force and the output displacement of GMA under different bias magnetic field and different pre-stress are tested,and the magnetic field strength model is verified and the optimal driving parameters are obtained.The experimental device of flexible hinge platform is built,and the established static and dynamic models are verified by experiments.The hardware structure of control system is established,and the software platform of control system is developed,and the effectiveness of the proposed control strategy is verified by experiments.Finally,positioning stroke,repeatability,positioning accuracy,resolution and response time of the precision positioning stage are tested.In chapter 7,the research contents and innovations of this paper are summarized,and the future research contents are prospected.