Study On Hysteresis Nonlinear Modeling And Control Methods Of MSMA Actuators

Precision positioning is one of the key technology in precision engineering areas,Highprecision and high-resolution is the important symbol of precision positioning technology.With thedevelopment of science technology,the accuracy and resolution of Precision positioning technologyexperienced by millimeter,micron,submicron,increased to today’s nanoscale.In precision machining,the accuracy and resolution of system are required to achievenanometer,which demand higher requirements to the driving element and control methed ofmicro-displacement positioning system.Magnetic shape memory alloy as a new type of smartmaterials has shape memory,large deformation rate, response speed,high energy conversionefficiency and high power density,easy to control and other advantages.At present,the magneticshape memory alloys formation mechanism and the drive application and sensors and so a lot ofwork was made by many domestic and foreign scholars.However,there is a strong hysteresisbetween the input and output of MSMA actuators due to the magnetic shape memory alloys andother components of the magnetic circuit, the positioning accuracy and more wide range ofapplications of the actuators and materials was limited seriously.In this paper,measurement and control platform based on MSMA drive system are estalishedwith the virtual instrument LABVIEW and MATLAB, hysteresis nonlinearity of MSMA actuator isanalyzed; hysteresis nonlinear modeling of MSMA actuator is established, and the parameter ofmolding is optimized through genetic algorithm; in this paper,compound control and fuzzy PIDcontrol is studied to eliminate the hysteresis nonlinearity.the main research contents is as follows:(1) The MSMA and its driver characteristics,current research and application prospects aredescribed. the concept of hysteresis characteristics and several commonly used hysteresis model athome and abroad and control methods and the latest research progress are outlined. Presentsresearch purpose and contents and significance of this paper are raised.(2) MSMA drive virtual experiment platform is established based on LABVIEW, dataacquisition and Hysteresis characteristics analysis of MSMA actuators are achieved.(3) The hysteresis neural network model of MSMA actuators is established,and parameter ofhysteresis neural network model is optimized through the genetic algorithm, the accuracy of themodel is further improve.(4) A real-time intelligent control combined with LABVIEW and MATLAB is proposed inorder to eliminate hysteresis nonlinearity and improve the positioning accuracy of MSMAactuators,and two control systems performance are compared.Through hybrid genetic algorithm the neural network model parameters of MSMA drive is optimized in this paper. The error of hysteresis hysteresis model is reduced to5nm, and theaccuracy of hysteresis model improved;The large number of experiments on MSMA controlplatform showed that MSMA actuators positioning accuracy is controled within0.8%range usedcomposite control method.Experimental results showed that the effects of hysteresis nonlinearity on MSMA actuatorspositioning accuracy is reduced,and the positioning accuracy of MSMA actuators is improved. Theresearch results of this paper has great significance for the applied research on Magnetic shapememory alloys and the research of precision positioning technology.