Key Technologies Of Marine Satellite Antenna Attitude Stabilization System

The proposition of this paper comes from a particular research project, involved in theproject, micro-gyroscope attitude measurement and stability in the marine satellite antennaattitude stabilization system, signal processing for micro inertial devices, the antenna framestructure, attitude measurement system The combination of filtering and other aspects of workto complete the research of micro inertial measurement unit for detecting the core marinesatellite antenna attitude stabilization system. In the process of research projects, theapplication of four-axis frame structure to solve the problem of global navigation satellitetracking, attitude closed loop mode, and design a framework for control and trackingalgorithm for four-axis antenna; proposed to solve the high noise of the MEMS devicesoutliers wavelet coefficients of linear compression, and virtual outliers are two signalprocessing methods; for identification MEMS gyro scale factor error, the proposed rate of themagnetometer simulation algorithm based on magnetometer measurements and KalmanFiltering observed variables; developed a prototype of the antenna stabilization system andalgorithm validation and test prototype.Based on the marine satellite antenna attitude stabilization system project, carried out theinertial measurement unit (MEMS IMU) to detect the core of the marine satellite antennaattitude stabilization system research and prototype research and development. Attitude closedloop mode using four-axis frame structure and designed a framework for control and trackingalgorithm for four-axis antenna; solve the problem of the MEMS device noise and outliers,the MEMS gyroscope zero and scale factor error compensation calibration; proposed basedmagnetometer for measuring the value of the rate of simulation algorithm; developed aprototype of the antenna stabilization systems, validation and test.This thesis to complete the work and innovation are the following:(1) According to this stage the development of marine satellite antenna stabilizationsystems, and inertial sensing the type of the core, the summary of marine systems the inertialmeasurement unit accuracy to determine the feasibility of the use of micro inertial devices asthe key device; antenna attitude stabilization system technology development, summarize thetype of system architecture at this stage, the overall scheme of this article Marine SatelliteAntenna Attitude Stabilization System.(2) Design a four-axis framework Attitude closed-loop control algorithm. Inertialmeasurement units directly with the antenna body solid and antenna attitude closed-loopcontrol mode, to avoid the framework of the projected antenna attitude error vector coordinate system; designed to meet the needs of global navigation satellite tracking, four-axis antennaframework, combined with the structural characteristics of AE and XY two frameworks, andassurance framework system in the global navigation can be a smooth track, eliminating theAE and the XY frame structure tracking dead zone; according to the movement characteristicsof four-axis frame structure and The inertial measurement unit of the installation, design aframework of control of the axis frame system and antenna tracking algorithm, theclosed-loop control of the antenna attitude.(3) design of the wavelet coefficients of linear compression outliers excluded methodsand virtual outliers in the signal noise reduction method. MEMS gyroscope signal errormodeling, wavelet coefficients of inhibition of MEMS gyroscope deterministic errorextraction, outlier rejection and virtual outliers MEMS gyro signal noise reduction three linearcompression of the wavelet coefficients in wavelet domain signal processing methods. Theenergy of wavelet coefficients of linear compression outliers removed outliers reflected in thewavelet coefficients for linear processing, to avoid oscillation due to the wavelet coefficientsare forced to zero reconstructed signal. High noise of the MEMS device, design a virtualoutliers noise, the noise of the signal wavelet coefficients is understood as a series of outliers,the use of the principle, the design of wavelet denoising threshold function to complete thesignal noise reduction processing, and The system measured MEMS gyroscope data foralgorithm validation, and results and the universal threshold method were compared.(4) The proposed algorithm for three-axis magnetometer analog three-axis angular rate.Lower due to the accuracy of the MEMS gyroscope at this stage, require the use of outsideinformation to complete the initial alignment, so the papers in electronic compass andMEMS-IMU combination constitute the program of the attitude measurement system. In thispaper, three-axis magnetometer structure of the electronic compass elliptical error analysis,combined with the measured data and the complete compensation of the electronic compassdata, and improve the measurement accuracy of the electronic compass. Compensation on thebasis of the idea of simulation of three-axis rate output three-axis magnetometer by measuringthe movement of the space geomagnetic vector magnetometer output value of the model ofthree-axis angular rate, derived magnetometer expression of the relationship between the totaloutput value and the antenna system Rodrigues parameters update rate value output,composite filter for the system provides a new observation.(5) Design and Implementation of a MEMS gyroscope zero errors and scale factor errorof line identification and compensation methods. Considering the posture detection systemusing Rodrigues parameters, the establishment of the Rodrigues parameters to the system attitude error as a gesture description and update algorithm of MEMS gyroscope zero valueand scale factor values as state variables of the system state equations, based on the electroniccompass simulation of three-axis rate of the output and magnetometer attitude of the Kalmanfilter equations. And derive the Kalman filter equations MEMS gyroscope zero error and scalefactor error of the new interest rate expressions, to achieve zero errors and scale factor errorestimate of the MEMS gyroscope.(6) the development of marine satellite antenna attitude stabilization system prototypebased micro inertial measurement unit. Completion of the axis frame structure design and thedesign and manufacture of servo mechanism. Verify the practical effect of the proposedmethod in the paper, and sea trial test of a real ship in the Songhua River in September2010,the system will work to achieve the desired effect.