Research On Precise Tracking Of Two-dimensional Steering Mirror Driven By Rotating Voice Coil Motor

Two-dimensional steering mirror tracking control system used in the field of space,the control accuracy and system response speed have higher requirements.In this thesis,a set of two-dimensional steering mirror system driven by a rotating voice coil motor was designed and implemented.The selection of the motor and the experimental data analysis are described in detail.Rotating voice coil motor has good dynamic performance and control characteristics,especially for the two-dimensional swing mirror unique limited rotation mode of operation,and rotary voice coil motor torque output mode was consistent.As a result two-dimensional steering mirror control system actuator rotary voice coil motor has become the first choice.First of all,the dissertation makes a detailed investigation of the communication ATP terminal in the field of space communication,and then gets to know the various indexes of photoelectric tracking equipment in various countries as well as the control methods and control structures adopted.The advantages and disadvantages of implementing motors of space communication terminals in various countries are analyzed.The rotary voice coil motor was selected as the actuator of the control system based on the working characteristics of two-dimensional steering mirrors.Through the analysis of the principle of the selected rotary voice coil motor to establish its perfect mathematical model,in order to further establish the mechanism model of the control system.The closed-loop control structure can improve the stiffness of the system and the system's disturbance rejection ability.Its multi-closed-loop structure was determined based on the established system mechanism model.At the same time,the influence of encoder differential velocity measurement on system bandwidth was analyzed when the closed-loop speed was established.From theoretical deduction to experimental analysis,the relationship between encoder sampling frequency and system bandwidth was analyzed from these two aspects.Experiments show that the influence of sampling frequency of the encoder on the system bandwidth was first and foremost.The improvement of the sampling frequency will increase the bandwidth to a certain extent.This contribution was limited.When more than one frequency was exceeded,the precision of the speed loop will be affected.The overall two-dimensional steering mirror control system was established.The system hardware core DSP+FPGA,DSP as the computing core,FPGA assisted DSP computing timing and communication processing,the completion of the control algorithm in the hardware platform,including the PI control loop speed adjustment Implementations,error-loop control regulators with position loop.Finally,the two-dimensional steering mirror tracking control system driven by a rotating voice coil motor was established.Two-axis sinusoidal tracking experiment and optical loop closed-loop tracking error experiment are carried out.When tracking the sine curve 1.5~?sin(2??0.5)t,the maximum error of E tracking error was 0.023 degrees,and the maximum tracking error of A axis was 0.0331 degrees.Meanwhile,when tracking the sinusoidal curve 0.15~?sin(2??0.5)t,the tracking error of E axis was<14",and the error of A axis was<25".In the closed loop experiment of target optical path with CCD as a TV sensor,the angle of target maneuver is±2 degrees,and the CCD miss distance was within 1.5 pixels.