Research On Control System Of Giant Magnetostrictive Actuator

With the development of micron and nanometer technology, the demand foraccurate driver and its control technology becomes higher and higher．New types offunctional material and the working principle are unceasingly used to improveaccurate driver and its control technology．Giant Magnetostrictive Actuator(GMA)is akind of micro-displacement actuator whose actuation component is a novel functionalmaterial—Giant Magnetostrictive Material(GMM)．With the advantages of largedisplacement, high force，rapid response, it is applied in lots of fields，such asullra-precise machining, liquid control mechanics, ere．It is expected that GMM has agreat potentiality in future．First, this paper analyzed the magnetostrictive phenomenon and the mechanism,and then it studied the giant magnetostrictive materials and some basic characteristics,then analysised the giant magnetostrictive actuator structure and working principlein-depth, and the giant magnetostrictive actuator device in the mechanical dimensionswere calculated, and obtained a series of related parameters. Then on the basis of this,according to the knowledge of electromagnetism of magnetostrictive actuator devicein the magnetic circuit is studied, identified in giant magnetostrictive actuator biasmagnetic field and permanent magnet as well as the selection of giantmagnetostrictive actuator during normal operation the prestressed value, at the sametime established a reflection of giant magnetostrictive telescopic actuator hysteresisand eddy current loss of the mathematical model.Next, based on giant magnetostrictive actuator control object characteristics,proposed closed-loop control scheme based on displacement. Then with this system,the integral separation PID algorithm applied to the control system to achieve itsdigital and procedures for the implementation of closed-loop control to lay thefoundation.According to control theory and combined with the hysteresis ofmagnetostrictive materials．the GMA micro-displacement closed-loop control systemfor the actuator which based on MCU as the core was founded．Several parts of thesystem were founded, including the channel of micro-displacement detection andtransducer,the channel of analog signals input, the channel of analog signals output, MCU—based digital control unit,etc．The hardware circuit of the system wasdesigned，which mainly includes A/D converter, D/A converter, keyboardand displaycircuit and the interface circuit of constant current source. With C language, andaccording to the modular programming, developed the control system software,including system main program module, sampling and control output modules, thekeyboard display module and PID control module, and other related functionalmodules. So that achieve the functions of data acquisition, processing and controloutput. And on the design of software and hardware, we used a series of measures toprevent the impact of interference for the system.