Design And Implementation Of Fast Laser Scanner For Elrctromagnetic Drive

Fast laser scanner has been widely used in airborne laser system,space laser communication,precision tracking system and laser processing because of its advantages of compact structure,fast response speed and high pointing precision.In addition,to increase its spatial scanning range,it is often combined with a large inertia mirror to form a composite axis scanning system to achieve the pointing function with wide range and highprecision.In this paper,a novel electromagnetic drive fast laser scanner system is designed and the performance of the system is tested.Besides,different control algorithm was analyzed and applied in the control system.The main contents of the paper are as follows(1)Mechanical structure designExisting faster laser scanners driven by intelligent materials,as piezoelectric,magnetostrictive,exist limitations,such as small swing angle,high hysteresis loss and high requirements for the power supply.This paper designed a novel fast laser scanner,which utilizes magnetic field provided by coil and permanent magnets,to achieve high bandwidth and pointing precision.The whole mechanical system consists of base,flexible support,scanning mirror and electromagnetic driver.To improve the response frequency of the scanning system,the flexible support is analyzed in detail,especially the influence of different parameters on its rotational stiffness.(2)Electromagnetic actuators design and analysisSince electromagnetic actuators are the heart of the whole system,the design and modeling of the flux-steering electromagnetic actuators which are fundamental to attain the specified performance is crucial.Normally,finite element analysis and equivalent circuit analysis are two main methods applied in electromagnetic machine design.In this paper,the equivalent circuit method is used to establish the equivalent circuit model of the designed electromagnetic actuator.Moreover,the theoretical calculation formula of its output force is deduced according to Kirchhoff's law and Maxwell stress tensor method.(3)Hardware circuit designThe hardware circuit means the programmable high-power drive circuit.Considering the complexity of using the discrete components to build the high-power amplifier circuit,this paper employs the integrated high-power operational amplifier combined with discrete components to build the programmable high-power drive circuit,providing adjustable current for coil.Besides,the performance of the drive circuit was tested.(4)Control algorithm researchThis paper introduces the characteristics and application of traditional PID control algorithm and adaptive control algorithm.An adaptive inverse control algorithm based on FIR filter model is applied in the fast laser scanner control system.The experimental test platform was setup by using Compact-RIO controller and Labview graphical programming language from NI.The control effect of the two algorithms is compared in the fast laser scanner control system.At last,the performance of the scanner in the two directions around the X,Y axis is tested.